Enoxaparin in Neurosurgical Patients

The New England Journal of Medicine. Nov, 1998  |  Pubmed ID: 9867528

Severe Pain Confounds Neuropsychological Test Performance

Journal of Clinical and Experimental Neuropsychology. Oct, 2000  |  Pubmed ID: 11094398

There is little information on the effect of pain on neuropsychological test performance. We have undertaken this study to explore which tests are affected by pain, the magnitude of these changes, and other confounders of neuropsychological performance in a population of patients having spine surgery. Twenty-four elderly English speaking Caucasian patients (age > 60 years) were enrolled pre-operatively in this Institutional Review Board approved study. Pain scores using an 11-point Numeric Pain Intensity scale and performance on a neuropsychological battery (Controlled Oral Word Association, Rey Complex Figure, Trails A and B) were assessed at two times, before and one day after surgery. Scores were calculated using the standard algorithms and change scores were calculated by subtracting the baseline from follow-up scores. After surgery, performance on the Rey Complex Figure ( r = -0.577, p = 0.004) and Trails Part A (r = 0.527, p = 0.01) declined with increasing post-operative pain scores. Women reported higher pain scores post-operatively than men (p = 0.046), and performed worse than men for change in performance on Trails Part A (p = 0.027). These data suggest that pain can influence performance on certain cognitive tests, and that some gender differences in these effects may occur. Interpretation of performance measures should take into account possible effects of pain, although our understanding of pain effects and ability to predict them in individual people, currently are quite limited.

Postischemic Cerebrovascular E-selectin Expression Mediates Tissue Injury in Murine Stroke

Stroke; a Journal of Cerebral Circulation. Dec, 2000  |  Pubmed ID: 11108771

Although the deleterious role of several proinflammatory mediators, including P-selectin, in reperfused stroke is well established, the role of E-selectin has not been fully characterized.

A Modified Transorbital Baboon Model of Reperfused Stroke

Stroke; a Journal of Cerebral Circulation. Dec, 2000  |  Pubmed ID: 11108772

Although pathophysiological studies of focal cerebral ischemia in nonhuman primates can provide important information not obtainable in rodent models, primate experimentation is limited by considerations of cost, availability, effort, and ethics. A reproducible and quantitative model that minimizes the number of animals necessary to detect differences between treatment groups is therefore crucial.

Influence of Smoking, Hypertension, and Sex on the Phenotypic Expression of Familial Intracranial Aneurysms in Siblings

Neurosurgery. Jan, 2001  |  Pubmed ID: 11152362

To investigate the effects of smoking, hypertension, and sex on the phenotypic expression of familial intracranial aneurysms (FIAs).

Molecular Analysis of the Prostate-specific Antigen Upstream Gene Enhancer

The Prostate. Jan, 2001  |  Pubmed ID: 11170135

Our objective was to identify factors other than androgen receptor that bind to and regulate the prostate-specific antigen (PSA) upstream gene enhancer (PSE).

Elevation of Soluble Intercellular Adhesion Molecule-1 Levels in Symptomatic and Asymptomatic Carotid Atherosclerosis

Neurosurgery. Apr, 2001  |  Pubmed ID: 11322431

Recent data suggest that the increased expression of intercellular adhesion molecule-1 (ICAM-1) in atherosclerotic plaque taken from the carotid bifurcation correlates with the development of neurological symptoms. As a result, the authors sought to compare the serum levels of soluble forms of ICAM-1 (sICAM-1) in patients who were asymptomatic with those who were symptomatic for carotid artery stenosis as well as in patients who were matched in terms of sex, age, and risk factors who did not have carotid artery disease.

Dehydroascorbic Acid, a Blood-brain Barrier Transportable Form of Vitamin C, Mediates Potent Cerebroprotection in Experimental Stroke

Proceedings of the National Academy of Sciences of the United States of America. Sep, 2001  |  Pubmed ID: 11573006

Neuronal injury in ischemic stroke is partly mediated by cytotoxic reactive oxygen species. Although the antioxidant ascorbic acid (AA) or vitamin C does not penetrate the blood-brain barrier (BBB), its oxidized form, dehydroascorbic acid (DHA), enters the brain by means of facilitative transport. We hypothesized that i.v. DHA would improve outcome after stroke because of its ability to cross the BBB and augment brain antioxidant levels. Reversible or permanent focal cerebral ischemia was created by intraluminal middle cerebral artery occlusion in mice treated with vehicle, AA, or DHA (40, 250, or 500 mg/kg), either before or after ischemia. Given before ischemia, DHA caused dose-dependent increases in postreperfusion cerebral blood flow, with reductions in neurological deficit and mortality. In reperfused cerebral ischemia, mean infarct volume was reduced from 53% and 59% in vehicle- and AA-treated animals, respectively, to 15% in 250 mg/kg DHA-treated animals (P < 0.05). Similar significant reductions occurred in nonreperfused cerebral ischemia. Delayed postischemic DHA administration after 15 min or 3 h also mediated improved outcomes. DHA (250 mg/kg or 500 mg/kg) administered at 3 h postischemia reduced infarct volume by 6- to 9-fold, to only 5% with the highest DHA dose (P < 0.05). In contrast, AA had no effect on infarct volumes, mortality, or neurological deficits. No differences in the incidence of intracerebral hemorrhage occurred. Unlike exogenous AA, DHA confers in vivo, dose-dependent neuroprotection in reperfused and nonreperfused cerebral ischemia at clinically relevant times. As a naturally occurring interconvertible form of AA with BBB permeability, DHA represents a promising pharmacological therapy for stroke based on its effects in this model of cerebral ischemia.

The Baboon (Papio Anubis) Extracranial Carotid Artery: an Anatomical Guide for Endovascular Experimentation

BMC Cardiovascular Disorders. 2001  |  Pubmed ID: 11747471

As novel endovascular strategies are developed for treating neurological disease, there is an increasing need to evaluate these techniques in relevant preclinical models. The use of non-human primates is especially critical given their structural and physiological homology with humans. In order to conduct primate endovascular studies, a comprehensive understanding of the carotid anatomy is necessary. We therefore performed a detailed examination of the vessel lengths, lumen diameters and angles of origin of the baboon extracranial carotid system.

Serum S100B Protein Levels Are Correlated with Subclinical Neurocognitive Declines After Carotid Endarterectomy

Neurosurgery. Nov, 2001  |  Pubmed ID: 11846900

Carotid endarterectomy (CEA) is an effective means of stroke prevention among appropriately selected patients; however, neuropsychometric testing has revealed subtle cognitive injuries in the early postoperative period. The purpose of this study was to establish whether serum levels of two biochemical markers of cerebral injury were correlated with postoperative declines in neuropsychometric test performance after CEA.

Neuroprotection in Cerebral Ischemia by Neutralization of 3-aminopropanal

Proceedings of the National Academy of Sciences of the United States of America. Apr, 2002  |  Pubmed ID: 11943872

Cerebral ischemia stimulates increased activity of polyamine oxidase, a ubiquitous enzyme that catabolizes polyamines to produce 3-aminopropanal. 3-Aminopropanal is a reactive aldehyde that mediates progressive neuronal necrosis and glial apoptosis. Here we report that increased levels of 3-aminopropanal-modified protein levels in humans after aneurysmal subarachnoid hemorrhage correlate with the degree of cerebral injury as measured by admission Hunt/Hess grade. In vitro screening of clinically approved drugs reveals that N-2-mercaptopropionyl glycine (N-2-MPG), an agent clinically approved for prevention of renal stones in patients with cysteinuria, significantly inhibits the cytotoxicity of 3-aminopropanal. N-2-MPG reacts with 3-aminopropanal to yield a nontoxic thioacetal adduct, as confirmed by electrospray ionization mass spectroscopy. Administration of N-2-MPG in clinically relevant doses to rats significantly reduces cerebral 3-aminopropanal-modified protein immunoreactivity and infarct volume in a standardized model of middle cerebral artery occlusion, even when the agent is administered after the onset of ischemia. These results implicate 3-aminopropanal as a therapeutic target for cerebral ischemia.

Rise in Serum Soluble Intercellular Adhesion Molecule-1 Levels with Vasospasm Following Aneurysmal Subarachnoid Hemorrhage

Journal of Neurosurgery. Sep, 2002  |  Pubmed ID: 12296636

Proinflammatory adhesion molecule expression has been demonstrated to be elevated in patients with aneurysmal subarachnoid hemorrhage (SAH). Recent studies have shown that elevations in soluble intercellular adhesion molecule-1 (ICAM-1) may be predictive of poor outcome in patients with good grade (Hunt and Hess Grades 1-2) aneurysmal SAH at delayed time points that correspond with the risk period for cerebral vasospasm. In addition, ICAM-1 is upregulated in experimental models of vasospasm. Unfortunately, the relationship of adhesion molecule expression to human vasospasm remains unclear. The authors hypothesized that the delayed elevation of soluble ICAM-1 in patients with aneurysmal SAH is associated with the development of cerebral vasospasm.

HuEP5C7 As a Humanized Monoclonal Anti-E/P-selectin Neurovascular Protective Strategy in a Blinded Placebo-controlled Trial of Nonhuman Primate Stroke

Circulation Research. Nov, 2002  |  Pubmed ID: 12433835

Although inhibiting interaction of beta(2) integrins with cognate immunoglobulin class adhesion receptor ligands is an effective neuroprotective strategy in small mammal models of stroke, the strategy has failed in human trials. A completely different antiadhesion receptor strategy was therefore rigorously tested in a model that may more closely approximate human reperfused stroke. Early leukoadhesive events in postischemic cerebral microvessels are mediated by upregulated selectin-class adhesion receptors on endothelial cells. Therefore, a blocking antibody prepared against common P- and E-selectin epitopes was humanized to suppress complement activation and tested in a reperfused hemispheric stroke model in Papio anubis (baboon). Histological examination of postischemic cerebral microvessels revealed a strong upregulation of E-and P-selectin expression. Placebo-blinded administration of the humanized anti-human E- and P-selectin monoclonal antibody (HuEP5C7, 20 mg/kg IV, n=9; placebo, n=9) immediately after the onset of 1 hour of temporary ischemia resulted in trends showing reduced polymorphonuclear leukocyte (PMN) infiltration into ischemic cortex, reduced infarct volumes (by 41%), improved neurological score (by 35%), and improved ability to self-care (by 39%). Importantly, there was no evidence of systemic complement activation, immune suppression, or pathological coagulopathy associated with this therapy. These data suggest that a humanized anti-E/P-selectin antibody approach is safe and may be effective as a clinical treatment for human stroke.

Outcome Prediction with Serum Intercellular Adhesion Molecule-1 Levels After Aneurysmal Subarachnoid Hemorrhage

Journal of Neurosurgery. Jan, 2002  |  Pubmed ID: 11794607

Although upregulated adhesion molecule expression has been demonstrated in experimental models of subarachnoid hemorrhage (SAH) and in the cerebrospinal fluid of patients with aneurysmal SAH, the clinical significance of these proinflammatory findings remains unclear. The authors hypothesize that 1) serum levels of soluble intercellular adhesion molecule-l (ICAM-1) are increased in all patients with aneurysmal SAH shortly after the hemorrhagic event, and 2) elevated soluble ICAM-1 values are associated with poor patient outcome, even when controlling for the severity of the initial hemorrhagic insult.

An Improved Functional Neurological Examination for Use in Nonhuman Primate Studies of Focal Reperfused Cerebral Ischemia

Neurological Research. Apr, 2003  |  Pubmed ID: 12739238

There is renewed interest in primate models of acute stroke for the evaluation of potential therapeutic agents prior to clinical trials. The development of more precise functional outcome measures would improve the pre-clinical assessment of neuroprotective strategies. We have constructed a grading scale that utilizes an increased number of goal-oriented tasks to assess both behavior and motor function. The new scoring system is designed to enhance precision and accuracy when compared to existing scales. Twenty-seven male baboons were subjected to 1 h of middle cerebral artery territory occlusion followed by reperfusion. Outcome was evaluated using both a standard neurological function scale and a new task-oriented scale. Each scoring system was assessed for reproducibility (inter-observer reliability) and for association with radiographic infarct volume. The task-oriented grading system was significantly less variable than the standard outcome measure (p < 0.0001). The task-oriented neurological scale demonstrated stronger correlation with radiographic infarct volume (p < 0.0001) than the standard scale (p < 0.01) and more accurately reflected infarct size in animals with small strokes. Compared to the accepted system for grading neurological function, the task-oriented scale demonstrates improved inter-observer variability and a better association with radiographic outcome measures. Incorporating this refined neurological evaluation into a baboon model of stroke may serve to increase the functional predictive value of pre-clinical studies.

Serial Magnetic Resonance Imaging in Experimental Primate Stroke: Validation of MRI for Pre-clinical Cerebroprotective Trials

Neurological Research. Dec, 2003  |  Pubmed ID: 14669528

Precise assessment of stroke outcome is critical for pre-clinical testing of cerebroprotective strategies. Differences in stroke volume measured by various magnetic resonance imaging (MRI) techniques are documented in humans, but not well described in experimental primate stroke. This study characterizes changes in stroke volume using serial MRI scans in a baboon model of reperfused cerebral ischemia. The location/area of hyperintensity on MRI corresponded with the TTC-stained infarct region. T2-weighted fast spin echo (T2W FSE), fluid attenuated inversion recovery (FLAIR), and diffusion weighted imaging (DWI) showed a decrease in infarct volume between 72 h and nine days post-ischemia (p = ns, p = 0.029, and p = 0.006). T2W FSE and FLAIR demonstrated an increase in infarct volume from 24 h to nine days post-ischemia, while DWI displayed a decrease over the same period. While early T2W FSE, FLAIR, and DWI all correlated with late infarct volume (p < 0.001), 72 h T2W FSE was the best direct measure (2.39% +/- 1.40% unity deviation). Serial MRI in a nonhuman primate model of focal cerebral ischemia recapitulates findings in clinical stroke. MRI at 72 h accurately predicts late infarct volume.

Intracranial Pressure Following Aneurysmal Subarachnoid Hemorrhage: Monitoring Practices and Outcome Data

Neurosurgical Focus. Apr, 2003  |  Pubmed ID: 15679302

Elevated intracranial pressure (ICP) is an important consequence of aneurysmal subarachnoid hemorrhage (SAH) that often results in decreased cerebral perfusion and secondary clinical decline. No definitive guidelines exist regarding methods and techniques for ICP management following aneurysm rupture. The authors describe monitoring practices and outcome data in 621 patients with aneurysmal SAH admitted to their neurological intensive care unit during an 8-year period (1996-2003).

The Natural History of Unruptured Intracranial Aneurysms

Neurosurgical Focus. Nov, 2004  |  Pubmed ID: 15633980

Since the publication of preliminary results from the International Study of Unruptured Intracranial Aneurysms in 1998 there has been a great deal of debate concerning the natural history of these lesions and their attendant risk of aneurysmal subarachnoid hemorrhage. Therefore, the authors reviewed a selected number of crucial studies concerning this topic to determine the best evidence-based estimate of a rupture rate for these lesions. Based on this analysis, the yearly risk of bleeding for an unruptured intracranial aneurysm is estimated to be approximately 1% for aneurysms 7 to 10 mm in diameter. This risk of rupture increases with aneurysm size and it likewise diminishes as the size of the lesion decreases. This general rule serves as a reasonable interpretation of the results reported in the current body of literature.

A Modified Transorbital Baboon Model of Reperfused Stroke

Methods in Enzymology. 2004  |  Pubmed ID: 15120246

Pilomyxoid Astrocytoma: a Review

MedGenMed : Medscape General Medicine. 2004  |  Pubmed ID: 15775869

Pilomyxoid astrocytoma (PMA) is a recently described type of brain tumor. PMA shares similar features with pilocytic astrocytoma (PA), the most common central nervous system (CNS) tumor in the pediatric population, yet displays subtle histologic differences. Previous studies have shown PMA to behave more aggressively than PA, with shorter progression-free and overall survival as well as a higher rate of recurrence and CNS dissemination. These findings suggest that PMA may be a unique and distinct neoplasm. This review summarizes the histologic, clinical, and radiographic characteristics of PMA. In addition, the current treatment options and research endeavors involving this disease are described. Increased recognition of PMA within the medical community has the potential to affect the treatment and prognosis of pediatric low-grade astrocytomas.

Hypothalamic Hamartoma in Association with a Suprasellar Arachnoid Cyst: a Case Report

Pediatric Neurosurgery. Mar-Apr, 2005  |  Pubmed ID: 15942283

A 5-year-old female presented with a history of precocious puberty and increased height. MRI of the brain revealed a nonenhancing hypothalamic mass and associated suprasellar arachnoid cyst. The patient underwent a right frontal craniotomy with orbital osteotomy for wide fenestration of the cyst. Intraoperatively, it was clear the mass represented a hamartoma with a very smooth glistening surface. For this reason, no biopsy of the wall was performed. Postoperatively, the patient remains neurologically intact and without any medication dependence. This case highlights the occurrence of a suprasellar arachnoid cyst in association with a hypothalamic hamartoma.

Aggressive Cranial Vault Decompression for Cranial Hyperostosis: Technical Case Report of Two Cases

Neurosurgery. Jul, 2005  |  Pubmed ID: 15987595

Camurati-Engelmann's disease, also known as progressive diaphysial dysplasia, is a disorder of the bone metabolism. Neurological manifestations of progressive diaphysial dysplasia include cranial nerve dysfunction, generalized weakness, cerebellar herniation, and increased intracranial pressure. In the past, surgical intervention has been of limited and temporary benefit. We present two patients with cranial hyperostosis secondary to Camurati-Engelmann's disease who were treated successfully with a single surgery involving a combination of multiple craniotomies for cranial vault decompression.

Internet-based Approach to Multi-institutional Patient Recruitment in the Medico-legal Age

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. Jul, 2005  |  Pubmed ID: 15994166

Toward Objective Quantification of Perfusion-weighted Computed Tomography in Subarachnoid Hemorrhage: Quantification of Symmetry and Automated Delineation of Vascular Territories

Academic Radiology. Jul, 2005  |  Pubmed ID: 16039541

Perfusion-weighted computed tomography (CTP) is a relatively recent innovation that estimates a value for cerebral blood flow (CBF) using a series of axial head CT images tracking the time course of a signal from an intravenous contrast bolus.

Pilomyxoid Astrocytoma: Diagnosis, Prognosis, and Management

Neurosurgical Focus. Jun, 2005  |  Pubmed ID: 16048293

Pilomyxoid astrocytoma (PMA) is a recently defined pediatric brain tumor; PMAs were previously classified within the pilocytic astrocytoma (PA) category. Nevertheless, PMA has different histological features and has been shown to behave more aggressively than PA. These findings indicate that PMA may be a unique entity that is distinct from PA, or it may be an unusual variant. To increase awareness of PMA within the neurosurgical community, the authors review the diagnostic criteria, prognostic implications, and current management of this recently described pediatric low-grade astrocytoma.

Herniation Secondary to Critical Postcraniotomy Cerebrospinal Fluid Hypovolemia

Neurosurgery. Aug, 2005  |  Pubmed ID: 16094157

Cerebrospinal fluid hypovolemia resulting in postural headaches is a well-known clinical entity, but severe forms of cerebrospinal fluid hypovolemia with altered mental status and signs of transtentorial herniation ("brain sag") have rarely been reported. This article describes the clinical features of brain sag after craniotomy in an attempt to increase recognition of this syndrome.

Co-registration of Radiographic and Pathologic Infarct Territory in a Non-human Primate Model of Stroke

Neurological Research. Sep, 2005  |  Pubmed ID: 16157015

Infarct volume correlation using magnetic resonance imaging (MRI) and pathology specimens enables exact tissue localization of cerebral injury following experimental stroke. We describe a protocol that enables co-registration of radiographic signal change and histologic ischemia in a non-human primate model of stroke.

APOE-epsilon4 Predisposes to Cognitive Dysfunction Following Uncomplicated Carotid Endarterectomy

Neurology. Dec, 2005  |  Pubmed ID: 16207841

Between 9% and 23% of patients undergoing otherwise uncomplicated carotid endarterectomy (CEA) develop subtle cognitive decline 1 month postoperatively. The APOE-epsilon4 allele has been associated with worse outcome following stroke.

Decompressive Hemicraniectomy for Poor-grade Aneurysmal Subarachnoid Hemorrhage Patients with Associated Intracerebral Hemorrhage: Clinical Outcome and Quality of Life Assessment

Neurosurgery. 2005  |  Pubmed ID: 15617581

Decompressive hemicraniectomy has been proposed as a potential treatment strategy in patients with poor-grade aneurysmal subarachnoid hemorrhage presenting with focal intracerebral hemorrhage causing significant mass effect. Although hemicraniectomy improves overall survival rates, the long-term quality of life (QoL) for survivors in this patient population has not been reported.

The Natural History of Intracranial Carotid Artery Atherosclerosis

Neurosurgical Focus. Jan, 2005  |  Pubmed ID: 15669798

Intracranial atherosclerosis is the cause of a significant number of strokes. Despite maximal medical therapy, this disease continues to carry a poor prognosis. The authors reviewed studies in which the outcomes after conservative management in patients with intracranial carotid artery atherosclerosis were reported. Analysis of the literature demonstrates that maximal medical therapy frequently fails with this disease, leaving patients at high risk for cerebral infarction and death. A better understanding of the pathophysiological aspects and natural history of this condition may serve to guide clinical decision making and the choice of therapeutic options in this patient population.

Current Endovascular Treatment Options for Intracranial Carotid Artery Atherosclerosis

Neurosurgical Focus. Jan, 2005  |  Pubmed ID: 15669799

A substantial number of strokes are caused by intracranial atherosclerosis, a disease that traditionally has been treated medically. Recent technological advancements, however, have revolutionized the treatment of this condition by enabling the use of endovascular methods. In this paper the authors focus on the internal carotid artery, and review relevant studies concerning angioplasty with stent placement for the management of intracranial atherosclerosis in this vessel. With continued experience and a multidisciplinary approach in the evaluation of these patients, favorable outcomes may be achieved.

An Extramedullary Foramen Magnum Cavernous Malformation Presenting with Acute Subarachnoid Hemorrhage: Case Report and Literature Review

Neurosurgery. Feb, 2005  |  Pubmed ID: 15729780

This case summarizes our experience with the first described intradural extramedullary cavernous malformation at the foramen magnum and reminds the neurosurgical community to consider cavernous malformations in the differential diagnosis for subarachnoid hemorrhage.

Blood Pressure Management in Patients with Intracerebral and Subarachnoid Hemorrhage

Neurosurgery Clinics of North America. Sep, 2006  |  Pubmed ID: 17967691

Galbraith Award: Evaluation of Risk Factors Associated with Neurocognitive Changes After Carotid Endarterectomy

Clinical Neurosurgery. 2006  |  Pubmed ID: 17380766

Elevations in Preoperative Monocyte Count Predispose to Acute Neurocognitive Decline After Carotid Endarterectomy for Asymptomatic Carotid Artery Stenosis

Stroke; a Journal of Cerebral Circulation. Jan, 2006  |  Pubmed ID: 16322501

Although the incidence of major stroke attributable to carotid endarterectomy (CEA) is low (1% to 2%), approximately 25% of patients experience subtle postoperative neurocognitive dysfunction. This study examines whether preoperative leukocyte profiles predict cognitive outcome in asymptomatic CEA patients.

Radiographic Characteristics Fail to Predict Clinical Course After Subdural Electrode Placement

Neurosurgery. Jan, 2006  |  Pubmed ID: 16385336

Subdural arrays of grid and strip electrodes are frequently used in epilepsy patients to localize the seizure focus and determine the location of critical brain functions via stimulation mapping. Postoperatively, the majority of patients with implanted subdural electrodes develop subacute extra-axial collections (EACs). Although conservative management is appropriate in most of these cases, occasionally patients manifest neurological symptoms that may necessitate reoperation for collection evacuation. Currently, there is little information available regarding the range of EAC size and the potential correlation between EAC size and symptom development. To facilitate treatment decision-making in postoperative subdural electrode patients, we reviewed and compared the computed tomographic (CT) features of postelectrode placement EACs in asymptomatic and symptomatic patients.

Temporal Pattern of C1q Deposition After Transient Focal Cerebral Ischemia

Journal of Neuroscience Research. Apr, 2006  |  Pubmed ID: 16447284

Recent studies have focused on elucidating the contribution of individual complement proteins to post-ischemic cellular injury. As the timing of complement activation and deposition after cerebral ischemia is not well understood, our study investigates the temporal pattern of C1q accumulation after experimental murine stroke. Brains were harvested from mice subjected to transient focal cerebral ischemia at 3, 6, 12, and 24 hr post reperfusion. Western blotting and light microscopy were employed to determine the temporal course of C1q protein accumulation and correlate this sequence with infarct evolution observed with TTC staining. Confocal microscopy was utilized to further characterize the cellular localization and characteristics of C1q deposition. Western Blot analysis showed that C1q protein begins to accumulate in the ischemic hemisphere between 3 and 6 hr post-ischemia. Light microscopy confirmed these findings, showing concurrent C1q protein staining of neurons. Confocal microscopy demonstrated co-localization of C1q protein with neuronal cell bodies as well as necrotic cellular debris. These experiments demonstrate the accumulation of C1q protein on neurons during the period of greatest infarct evolution. This data provides information regarding the optimal time window during which a potentially neuroprotective anti-C1q strategy is most likely to achieve therapeutic success.

Racial Differences in Cerebral Vasospasm: a Systematic Review of the Literature

Neurosurgery. Feb, 2006  |  Pubmed ID: 16462484

Despite a significant body of clinical research and the widespread use of early intervention with aggressive postoperative management, cerebral vasospasm (CV) continues to contribute significantly to the morbidity and mortality of aneurysmal subarachnoid hemorrhage (aSAH). Many studies have evaluated predictive factors, although none to date has investigated a possible difference in the incidence of CV between Asian and white patients. We present a review of the modern aSAH literature to examine the incidence of CV in Japan and Europe, two highly researched populations.

An Improved Test of Neurological Dysfunction Following Transient Focal Cerebral Ischemia in Rats

Journal of Neuroscience Methods. Mar, 2006  |  Pubmed ID: 16476486

The Adhesive Removal (sticky-tape) test is a commonly used test of somatosensory dysfunction following cerebral ischemia in rats. This test requires several days of pre-training prior to surgery, which can be time consuming. We present our results with an improved version of the sticky-tape test. Male Wistar rats were subjected to either sham surgery (n = 4) or right middle cerebral artery occlusion (rMCAo) using an intraluminal filament (n = 9), followed by a 10-day survival period. On post-operative days (POD) 1, 3, 7, and 10 animals underwent both the conventional sticky-tape test (CST) with measurement of the time to remove the stimulus (trs), as well as a modified sticky-tape test (MST), in which a non-removable tape sleeve was placed around the animal's paw. Time spent attending to this stimulus (tas) was recorded. Despite 3 days of pre-training, animals undergoing baseline CST still exhibited marked variability in pre-operative baseline test performance (trs range 1-60s). In contrast, animals undergoing MST for the first time demonstrated nearly uniformly excellent performance (% tas range 91.5-98.5% of the 30s testing period). Although, affected (left) limb performance on both CST (6.8-fold increase in trs on POD 1 compared to baseline) and MST (100% decrease in tas on POD 1 compared to baseline) was markedly altered by rMCAo, CST performance declined bilaterally, and no significant differences in the ratio of affected (left) and unaffected (right) limb performance between sham-operated and rMCAo animals were observed at any time point. In contrast, the ratio of left to right performance on the MST was significantly different at all time points (P<0.01). In conclusion, we present a simple modification of the widely used Adhesive Removal test and provide evidence that this test can accurately assess neurological dysfunction in rodents, not only with minimal pre-training, but also with improved localization of the side of injury.

Astrocytoma with Pilomyxoid Features Presenting in an Adult

Neuropathology : Official Journal of the Japanese Society of Neuropathology. Feb, 2006  |  Pubmed ID: 16521485

Pilomyxoid histology is presently considered to occur in pediatric brain tumors. We report an astrocytoma with pilomyxoid features presenting in an adult and discuss its relationship to both the established childhood pilomyxoid astrocytoma (PMA) and recently reported tanycytoma. A 28-year-old man with medically intractable seizures presented for surgical evaluation. MRI revealed a discrete lesion in the right amygdala/uncus region. The patient elected for craniotomy with stereotactic temporal lobe resection and excision of the lesion. Postoperatively, the patient has done well. At 30-month follow up, he is seizure free and without evidence of tumor recurrence. We report an astrocytoma with pilomyxoid features presenting in an adult, illustrating that while this histological pattern is most commonly seen in children, it may also affect older individuals. Recognition of this enigmatic pattern in adult gliomas expands the currently accepted epidemiology for this lesion.

Natural History of Intracranial Atherosclerosis: a Critical Review

Neurosurgery. Apr, 2006  |  Pubmed ID: 16575322

Intracranial atherosclerosis is responsible for a significant number of strokes. Medical therapy for this condition may fail, leaving patients at high risk for cerebral infarction and death. With advances in endovascular techniques on the horizon, understanding the prognosis of conservative treatment is essential for appropriate patient management. Although several small studies have attempted to address this issue, a comprehensive review regarding the natural history of intracranial atherosclerosis in a vessel-specific manner is lacking. Owing to heterogeneity in vascular anatomy and physiology, atherosclerosis in different vessels may represent diseases with fundamentally distinct courses. Therefore, it is important to distinguish vascular territories when studying the natural history of this condition. To this end, we critically review the literature investigating medical management of patients with intracranial atherosclerosis, segregating our findings by vessel. Analysis by this method suggests that middle cerebral artery atherosclerosis carries a lower mortality rate than stenoses involving other intracranial vessels, and that asymptomatic disease follows a more benign course. In addition, plaque progression and transcranial Doppler-detected microemboli seem to predict outcome according to limited data. This comprehensive review may help guide clinical decision-making and therapeutic developments in this patient population.

Predictors of Neurocognitive Decline After Carotid Endarterectomy

Neurosurgery. May, 2006  |  Pubmed ID: 16639318

Although the incidence of stroke after carotid endarterectomy (CEA) is low (1-3%), approximately 25% of patients experience subtle declines in postoperative neuropsychometric function. No studies have investigated the risk factors for this neurocognitive change. We sought to identify predictors of postoperative neurocognitive dysfunction.

Internet-based Neuro-oncology Patient Recruitment

Neurosurgery. May, 2006  |  Pubmed ID: 16639336

THE PRIVACY RULE, as part of the Health Insurance Portability and Accountability Act, was implemented in 2003 as a response to public concern over potential abuses of private health information. Although the Privacy Rule was not intended to place limits on clinical research, its complexity has caused much confusion throughout the academic medicine and research communities. Many clinical and translational researchers have created clinical databases or human tissue banks to facilitate future research. Maintenance of such databases is considered a research activity under the Privacy Rule, and researchers are, therefore, subject to its regulations. We present a novel Internet-based method to generate and maintain a neurooncology patient registry and human tissue bank. Through our web site, we secure both Health Insurance Portability and Accountability Act research authorization and informed consent, enabling us to contact the treating physician for clinical data and pathological specimens. Considering the importance of continued use of clinical databases and tissue banks in the genetic era of medicine, our method offers one way for researchers to adapt to the changing world of clinical research.

Shunt Failure in Idiopathic Intracranial Hypertension Presenting with Spontaneous Cerebrospinal Fluid Leak

Journal of Clinical Neuroscience : Official Journal of the Neurosurgical Society of Australasia. Jun, 2006  |  Pubmed ID: 16678427

A case of spontaneous cerebrospinal (CSF) fluid leak after ventriculoperitoneal shunt (VPS) failure in a patient with idiopathic intracranial hypertension (IIH) is reported. This is the first report of spontaneous CSF leak in an IIH patient without a history of trauma, sinus surgery, or intracranial surgery. The diagnosis was confirmed using thin-sliced post-contrast computed tomography, which revealed a micro-dehiscence of the cribiform plate at the superior aspect of the ethmoid sinus. The patient underwent VPS revision without complication, resulting in complete amelioration of symptoms and cessation of CSF rhinorrhoea at 1 year follow up.

Correlation of Cerebral Metabolites with Functional Outcome in Experimental Primate Stroke Using in Vivo 1H-magnetic Resonance Spectroscopy

AJNR. American Journal of Neuroradiology. May, 2006  |  Pubmed ID: 16687542

Ensuring the translatability of primate stroke models is critical for preclinical testing of cerebroprotective strategies, and such models would benefit from further characterization of the experimental ischemic tissue. Our purpose was to examine the cerebral metabolic response to stroke in baboons with MR spectroscopy and to correlate metabolite levels with functional neurologic outcomes.

Complement Component C3 Mediates Inflammatory Injury Following Focal Cerebral Ischemia

Circulation Research. Jul, 2006  |  Pubmed ID: 16778128

The complement cascade has been implicated in ischemia/reperfusion injury, and recent studies have shown that complement inhibition is a promising treatment option for acute stroke. The development of clinically useful therapies has been hindered, however, by insufficient understanding of which complement subcomponents contribute to post-ischemic injury. To address this issue, we subjected mice deficient in selected complement proteins (C1q, C3, C5) to transient focal cerebral ischemia. Of the strains investigated, only C3-/- mice were protected, as demonstrated by 34% reductions in both infarct volume (P<0.01) and neurological deficit score (P<0.05). C3-deficient mice also manifested decreased granulocyte infiltration (P<0.02) and reduced oxidative stress (P<0.05). Finally, administration of a C3a-receptor antagonist resulted in commensurate neurological improvement and stroke volume reduction (P<0.05). Together, these results establish C3 activation as the key constituent in complement-related inflammatory tissue injury following stroke and suggest a C3a anaphylatoxin-mediated mechanism.

J. Lawrence Pool, M.D.: a Pioneer in Vascular Neurosurgery

Neurosurgical Focus. 2006  |  Pubmed ID: 16819810

The authors detail the life and career of Dr. J. Lawrence Pool, as well as his significant contributions to the field of cerebrovascular neurosurgery. The discipline of cerebrovascular neurosurgery is a young and dynamic field, which underwent rapid and substantial growth during the middle of the twentieth century. As the chairman of the Department of Neurological Surgery at the Neurological Institute of New York, Dr. J. Lawrence Pool was instrumental in the development of new techniques and devices that would ultimately result in decreased mortality rates and improved results from complex cerebrovascular procedures. Passion, ingenuity, and a pioneering spirit fueled Dr. Pool, whose introduction of the operating microscope and use of temporary clip occlusion during aneurysm repair revolutionized the field of cerebrovascular neurosurgery.

Alterations in Plasma Complement Levels After Human Ischemic Stroke

Neurosurgery. Jul, 2006  |  Pubmed ID: 16823297

Stroke is a leading cause of morbidity and mortality in the United States. Recent animal studies have implicated the complement system in cerebral ischemia/reperfusion injury and suggest that complement inhibition may improve stroke outcomes. To assess the applicability of these findings to humans, we evaluated the characteristics and time course of human complement activation after stroke.

Critical Postcraniotomy Cerebrospinal Fluid Hypovolemia: Risk Factors and Outcome Analysis

Neurosurgery. Aug, 2006  |  Pubmed ID: 16883169

Critical cerebrospinal fluid (CSF) hypovolemia may cause acute postoperative clinical deterioration in aneurysmal subarachnoid hemorrhage patients after craniotomy for microsurgical aneurysm clipping. We sought to identify risk factors for critical CSF hypovolemia and determine this syndrome's effect on clinical outcome.

A Cerebroprotective Dose of Intravenous Citrate/sorbitol-stabilized Dehydroascorbic Acid is Correlated with Increased Cerebral Ascorbic Acid and Inhibited Lipid Peroxidation After Murine Reperfused Stroke

Neurosurgery. Aug, 2006  |  Pubmed ID: 16883179

Oxidative damage has been implicated in the pathogenesis of cerebral ischemia. We previously demonstrated that exogenously supplied dehydroascorbic acid (DHA), an oxidized, blood-brain barrier transportable form of the antioxidant ascorbic acid (AA), improves outcome after experimental stroke.

The Complement System: a Potential Target for Stroke Therapy

Advances in Experimental Medicine and Biology. 2006  |  Pubmed ID: 16893073

Preoperative Prediction of Long-term Outcome in Poor-grade Aneurysmal Subarachnoid Hemorrhage

Neurosurgery. Sep, 2006  |  Pubmed ID: 16955034

To evaluate which presentation indices, demographics, and clinical information predict 12-month outcome in poor-grade aneurysmal subarachnoid hemorrhage (SAH), and to provide a preoperative index of prognosis.

Angiographically Occult, Progressively Expanding, Giant Vertebral Artery Aneurysm. Case Report

Journal of Neurosurgery. Sep, 2006  |  Pubmed ID: 16961145

Hunterian ligation is a well-known treatment for complex aneurysms not amenable to direct microsurgical clip application. After proximal parent vessel occlusion, cerebral angiography is typically used to confirm aneurysm thrombosis. The authors report on a vertebral artery (VA) aneurysm that had progressively expanded and caused brainstem compression after hunterian ligation, despite nondiagnostic findings on both conventional and computed tomography (CT) angiography at multiple time points. This 64-year-old woman underwent hunterian ligation of a 1.8-cm VA aneurysm at the origin of the right posterior inferior cerebellar artery. An immediately postoperative conventional angiogram and follow-up CT angiograms obtained 5 and 6 years postligation confirmed complete obliteration of the lesion. Nine years after the initial surgery, however, the patient experienced neurological deterioration. Although CTs showed substantial aneurysm enlargement together with pontine compression, angiograms once again demonstrated complete right VA occlusion with no retrograde filling of the aneurysm. On reexploration, the aneurysm was effectively debulked, clipped, and obliterated. Arterial bleeding was found in the lesion neck, as was evidence of microrecanalization. Hunterian ligation for complex aneurysms carries the risk of microrecanalization and lesion expansion despite nondiagnostic angiography. Although this ligation procedure remains a viable treatment option in carefully selected patients, an extended follow-up evaluation period may be required even when imaging suggests aneurysm obliteration.

A Review of Current and Future Medical Therapies for Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage

Neurosurgical Focus. 2006  |  Pubmed ID: 17029348

In an effort to help clarify the current state of medical therapy for cerebral vasospasm, the authors reviewed the relevant literature on the established medical therapies used for cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH), and they discuss burgeoning areas of investigation. Despite advances in the treatment of aneurysmal SAH, cerebral vasospasm remains a common complication and has been correlated with a 1.5- to threefold increase in death during the first 2 weeks after hemorrhage. A number of medical, pharmacological, and surgical therapies are currently in use or being investigated in an attempt to reverse cerebral vasospasm, but only a few have proven to be useful. Although much has been elucidated regarding its pathophysiology, the treatment of cerebral vasospasm remains a dilemma. Although a poor understanding of SAH-induced cerebral vasospasm pathophysiology has, to date, hampered the development of therapeutic interventions, current research efforts promise the eventual production of new medical therapies.

Ventriculoperitoneal Shunting of Idiopathic Normal Pressure Hydrocephalus Increases Midbrain Size: a Potential Mechanism for Gait Improvement

Neurosurgery. Oct, 2006  |  Pubmed ID: 17038948

Idiopathic normal pressure hydrocephalus (INPH) is characterized by a classic clinical triad of symptoms, including dementia, urinary incontinence, and gait disturbance. Recent work has demonstrated that the maximal midbrain anteroposterior (AP) diameter is significantly smaller in patients with INPH than in healthy, age-matched controls. The current study was undertaken to determine the effect of ventriculoperitoneal shunt placement on midbrain dimensions in INPH patients.

Preclinical Evaluation of the Neuroprotective Effect of Soluble Complement Receptor Type 1 in a Nonhuman Primate Model of Reperfused Stroke

Journal of Neurosurgery. Oct, 2006  |  Pubmed ID: 17044564

Postischemic cerebral inflammatory injury has been extensively investigated in an effort to develop effective neuroprotective agents. The complement cascade has emerged as an important contributor to postischemic neuronal injury. Soluble complement receptor Type 1 (sCR1), a potent inhibitor of complement activation, has been shown to reduce infarct volume and improve functional outcome after murine stroke. Given numerous high-profile failures to translate promising antiinflammatory strategies from the laboratory to the clinic and given the known species-specificity of the complement cascade, the authors sought to evaluate the neuroprotective effect of sCR1 in a nonhuman primate model of stroke.

Long-term Domain-specific Improvement Following Poor Grade Aneurysmal Subarachnoid Hemorrhage

Journal of Neurology. Oct, 2006  |  Pubmed ID: 17063319

While efforts have been made to document short-term outcomes following poor grade aneurysmal subarachnoid hemorrhage (aSAH), no data exist concerning the degree of delayed improvement in neurological function. Here we assess cognitive function, level of independence, and quality of life (QoL) over 12 months following poor grade aSAH.

Surgical Management of Cervical Myelopathy: Indications and Techniques for Laminectomy and Fusion

The Spine Journal : Official Journal of the North American Spine Society. Nov-Dec, 2006  |  Pubmed ID: 17097545

Cervical spondylotic myelopathy (CSM) is a commonly encountered surgical disease that may be approached through a variety of operative techniques. Operative goals in the treatment of CSM include effective neural element decompression and maintaining spinal stability to avoid delayed deformity progression and neurologic compromise. Determining the most appropriate operative approach requires careful consideration of the patient's clinical presentation and radiographic imaging.

Clinicoradiological Review: Bilateral Ethmoidal Artery Dural Arteriovenous Fistulas

Neurosurgery. Jan, 2007  |  Pubmed ID: 17228261

Gangliocytoma of the Spinal Cord

Neurosurgery. May, 2007  |  Pubmed ID: 17460525

Advances in Vasospasm Treatment and Prevention

Journal of the Neurological Sciences. Oct, 2007  |  Pubmed ID: 17570400

Outcome after aSAH depends on several factors, including the severity of the initial event, perioperative medical management, surgical variables, and the incidence of complications. Cerebral vasospasm (CV) is ure to consistently respond to treatment, emphasizing the need for further research into the underlying mechanisms of SAH-induced cerebrovascular dysfunction. To this end, our paper reviews the relevant literature on the main therapies employed for CV after aSAH and discusses possible avenues for future investigations. Current management of this condition consists of maximal medical therapy, including triple H regimen and oral administration of calcium antagonists, followed by endovascular balloon angioplasty and/or injection of vasodilatory agents for refractory cases. As the precise pathophysiology of CV is further elucidated, the development of promising investigational therapies will follow.

External Ventricular Drainage Response in Poor Grade Aneurysmal Subarachnoid Hemorrhage: Effect on Preoperative Grading and Prognosis

Neurocritical Care. 2007  |  Pubmed ID: 17572860

The importance of preoperative response to external ventricular drainage (EVD) for treatment of acute hydrocephalus (HCP) following poor grade (Hunt & Hess grade IV or V) aneurysmal subarachnoid hemorrhage (aSAH) has not been clearly defined. The effect of EVD response on preoperative grade and prognosis is described.

Potential Mechanisms and Clinical Significance of Global Cerebral Edema Following Aneurysmal Subarachnoid Hemorrhage

Neurosurgical Focus. 2007  |  Pubmed ID: 17613238

In an attempt to elucidate the pathophysiology and clinical significance of global cerebral edema (GCE) following aneurysmal subarachnoid hemorrhage (SAH), the authors explored potential mechanisms and reviewed findings associated with this phenomenon. Admission computed tomography (CT) scans show GCE in up to 20% of patients experiencing aneurysmal SAH. This edema is likely to have been initiated by transient global ischemia, as indicated by an association between ictal loss of consciousness and the development of edema. A further cascade of events, including a rise in intracranial pressure and compromise of the blood-brain barrier, are also likely contributors. Clinically, GCE on CT after aneurysmal SAH is predictive of a poor outcome. Further investigation is needed to gain a full understanding of edema development following SAH, with the hope that the knowledge can be used to influence treatment positively and improve outcome.

Selection of a Rigid Internal Fixation Construct for Stabilization at the Craniovertebral Junction in Pediatric Patients

Journal of Neurosurgery. Jul, 2007  |  Pubmed ID: 17644919

Atlantoaxial and occipitocervical instability in children have traditionally been treated with posterior bone and wire fusion and external halo orthoses. Recently, successful outcomes have been achieved using rigid internal fixation, particularly C1-2 transarticular screws. The authors describe flow diagrams created to help clinicians determine which method of internal fixation to use in complex anatomical circumstances when bilateral transarticular screw placement is not possible.

Early Plasma Complement C3a Levels Correlate with Functional Outcome After Aneurysmal Subarachnoid Hemorrhage

Neurosurgery. Aug, 2007  |  Pubmed ID: 17762737

Studies have documented an inflammatory response in the circulating plasma and cerebrospinal fluid of patients with aneurysmal subarachnoid hemorrhage (aSAH). In particular, early upregulation of several complement proteins, including C3a, C4a, and C5b-9, has been demonstrated after the initial hemorrhagic insult. The inflammatory actions of the complement cascade are largely mediated through the anaphylatoxins, C3a and C5a. Recent investigations have established a critical role for C3a in the pathogenesis of cerebral ischemia. We attempt to confirm that plasma C3a and C5a values are elevated in patients with aSAH and to determine whether or not these levels are reliable independent predictors of functional outcome irrespective of clinical presentation.

Herophilus, Erasistratus, Aretaeus, and Galen: Ancient Roots of the Bell-Magendie Law

Neurosurgical Focus. 2007  |  Pubmed ID: 17961062

Since the early 19th century, significant controversy has persisted over the competing claims of two men, Charles Bell and François Magendie, to a pivotal discovery: that the dorsal spinal roots subserve sensation, whereas the ventral spinal roots subserve motion. However, the foundations of neuroanatomy on which Bell and Magendie built their research was formed two millennia in advance. Exploration of the work of four ancient scholars--Herophilus, Erasistratus, Aretaeus, and Galen--reveals a remarkable early appreciation of the separate neural pathways (if not the correct physiology) responsible for sensory and motor control.

Pre-clinical Evaluation of an SLe X-glycosylated Complement Inhibitory Protein in a Non-human Primate Model of Reperfused Stroke

Journal of Medical Primatology. Dec, 2007  |  Pubmed ID: 17976043

Soluble complement receptor-1 (sCR1), a potent complement inhibitor, confers neuroprotection in a murine stroke model. Additional neuroprotective benefit is achieved by sLe x-glycosylation of sCR1. In an effort to translate sCR1-sLe x to clinical trials, we evaluated this agent in a primate stroke model.

O-desulfated Heparin Improves Outcome After Rat Cerebral Ischemia/reperfusion Injury

Neurosurgery. Dec, 2007  |  Pubmed ID: 18162910

Inflammatory cascades play a significant role in progressive neurological injury after transient cerebral ischemia. It has been demonstrated that heparin, a potent anticoagulant, also possesses anti-inflammatory properties that diminish postreperfusion damage after stroke. However, the potential for heparin to induce hemorrhagic transformation of an infarct has deterred its use in cases of focal cerebral ischemia. In this study, we examined whether or not administration of a novel O-desulfated heparin (ODSH), with significantly decreased anticoagulant activity but active anti-inflammatory effects, would ameliorate inflammatory neurological injury without increasing intracerebral hemorrhage in a rat model of transient middle cerebral artery occlusion.

Internal Cranial Expansion Procedure for the Treatment of Symptomatic Intracranial Hypertension

Journal of Neurosurgery. Nov, 2007  |  Pubmed ID: 18459904

The authors describe the internal cranial expansion (ICE) procedure, a surgical technique that was used to treat two chronically shunt-treated children who presented with medically and surgically refractory intracranial hypertension despite the presence of functioning cerebrospinal fluid shunt systems. The ICE procedure was used as a means to increase intracranial volume without sacrificing calvarial rigidity. Intracranial volume was increased by 5% in one case and 10% in the other. Both patients have returned to their neurological and functional baselines, and they are free of symptoms related to intracranial hypertension.

Controversies in the Endovascular Management of Cerebral Vasospasm After Intracranial Aneurysm Rupture and Future Directions for Therapeutic Approaches

Neurosurgery. Apr, 2008  |  Pubmed ID: 18496195

Cerebral vasospasm is one of the leading causes of morbidity and mortality after aneurysmal subarachnoid hemorrhage. Despite maximal medical therapy, however, up to 15% of patients surviving the ictus of subarachnoid hemorrhage experience stroke or death from vasospasm. For those cases of vasospasm that are refractory to medical treatment, endovascular techniques are frequently used, including balloon angioplasty with or without intra-arterial infusion of vasodilators, combined endovascular modalities, and aortic balloon devices. In this article, we review each of these therapies and their expanding role in the management of this condition. Moving forward, rigorous prospective outcome assessments after endovascular treatment of cerebral vasospasm are necessary to clearly delineate the efficacy and indications for these techniques.

Geographical Neurosurgery Workforce Analysis from 1990 to 2005 Improves Our Understanding of the Role of Market Factors

Clinical Neurosurgery. 2008  |  Pubmed ID: 19248681

The Role of Complement in Stroke Therapy

Advances in Experimental Medicine and Biology. 2008  |  Pubmed ID: 19025111

Cerebral ischemia and reperfusion initiate an inflammatory process which results in secondary neuronal damage. Immunomodulatory agents represent a promising means of salavaging viable tissue following stroke. The complement cascade is a potent mediator of inflammation which is activated following cerebral ischemia. Complement is deposited on apoptotic neurons which likely leads to injury in adjacent viable cells. Studies suggest that blocking the complement cascade during the early phases of infarct evolution may result in decreased penumbral tissue infarction and limit the extent of brain injury. Additionally, other elements of the complement cascade may play a critical role in cell survival. In this paper, we review the role of the complement cascade in neuronal damage following ischemic injury and emphasize possible therapeutic targets.

In Vivo Assessment of Rapid Cerebrovascular Morphological Adaptation Following Acute Blood Flow Increase

Journal of Neurosurgery. Dec, 2008  |  Pubmed ID: 19035734

Pathological extremes in cerebrovascular remodeling may contribute to basilar artery (BA) dolichoectasia and fusiform aneurysm development. Factors regulating cerebrovascular remodeling are poorly understood. To better understand hemodynamic influences on cerebrovascular remodeling, we examined BA remodeling following common carotid artery (CCA) ligation in an animal model.

Plasma Levels of Vascular Endothelial Growth Factor After Treatment for Cerebral Arteriovenous Malformations

Stroke; a Journal of Cerebral Circulation. Aug, 2008  |  Pubmed ID: 18535271

The role of abnormal angiogenesis in the formation and progression of cerebral arteriovenous malformations (AVMs) is unclear. Previous studies have demonstrated increased local expression of vascular endothelial growth factor (VEGF) in AVM tissue and increased circulating levels of VEGF in AVM patients. We sought to further investigate the role of VEGF in AVM pathophysiology by examining changes in plasma VEGF levels in patients undergoing treatment for AVMs.

Magnetic Resonance Imaging Characteristics of Pilomyxoid Astrocytoma

Neurological Research. Nov, 2008  |  Pubmed ID: 18662499

Pilomyxoid astrocytoma (PMA) is a recently identified pediatric low-grade neoplasm that was previously classified as pilocytic astrocytoma (PA), yet demonstrates unique histological features and more aggressive behavior. These tumors have been shown to have significantly shorter progression-free and overall survival probability than classical low-grade astrocytomas, as well as a high rate of cerebrospinal fluid (CSF) dissemination. This paper describes the radiographic features of PMA.

Protective Effect of C5a Receptor Inhibition After Murine Reperfused Stroke

Neurosurgery. Jul, 2008  |  Pubmed ID: 18728577

The complement cascade has been implicated in cerebral ischemia/reperfusion injury. To develop clinically useful therapies that successfully manipulate the complement cascade, the individual roles of its components must be clearly defined. Previous studies have shown that C5 inhibition improves outcome after experimental stroke. In this study, we investigated the role of C5a in stroke injury by inhibiting its activity at the receptor level.

Navigability Trumps All: Stenting of Acute Middle Cerebral Artery Occlusions with a New Self-expandable Stent

AJNR. American Journal of Neuroradiology. Nov, 2008  |  Pubmed ID: 18768730

Acute stroke intervention is rapidly evolving. New technologies are improving device deliverability and rates of recanalization. We describe 2 cases of acute middle cerebral artery occlusions wherein Wingspan stents could not be delivered to the occlusive site because of excessive vascular tortuosity. Merci thrombectomy was also unsuccessful. Revascularization was only achieved with deployment of the highly navigable Enterprise stent, resulting in thrombolysis in myocardial infarction 2/3 flow. Thus, all devices should be considered in the armamentarium of stroke therapy.

Morphology Parameters for Intracranial Aneurysm Rupture Risk Assessment

Neurosurgery. Aug, 2008  |  Pubmed ID: 18797347

The aim of this study is to identify image-based morphological parameters that correlate with human intracranial aneurysm (IA) rupture.

A Review of Medical Treatments of Cerebral Vasospasm

Neurological Research. Jun, 2008  |  Pubmed ID: 18953733

We review the literature on the established perioperative therapies for cerebral vasospasm (CV) following aneurysmal subarachnoid hemorrhage (aSAH). Despite aSAH treatment advances, CV continues to be a significant source of post-SAH morbidity and mortality. In fact, CV has been correlated with a 7.5- to three-fold increase in mortality in the first 2 weeks after SAH. As new treatment modalities show promise in animal models and early clinical trials, greater efforts are needed to test these new approaches. Few evidence-based indications for the treatment of vasospasm currently exist. Large-scale randomized clinical trials are needed to determine whether therapies such as magnesium, statins, nitric oxide modulators, endothelin antagonists and others will become standard of care in the prevention and/or treatment of CV.

Cervical Spine Disease May Result in a Negative Lumbar Spinal Drainage Trial in Normal Pressure Hydrocephalus: Case Report

Neurosurgery. Oct, 2008  |  Pubmed ID: 18981823

In this case report, we present a patient with normal pressure hydrocephalus in whom a lumbar drainage trial yielded a false-negative result secondary to cervical spondylosis.

Clinical and Angiographic Outcome After Endovascular Management of Giant Intracranial Aneurysms

Neurosurgery. Oct, 2008  |  Pubmed ID: 18981877

Giant (>or=25 mm) intracranial aneurysms (IA) have an extremely poor natural history and continue to confound modern techniques for management. Currently, there is a dearth of large series examining endovascular treatment of giant IAs only.

C3a Receptor Modulation of Granulocyte Infiltration After Murine Focal Cerebral Ischemia is Reperfusion Dependent

Journal of Cerebral Blood Flow and Metabolism : Official Journal of the International Society of Cerebral Blood Flow and Metabolism. May, 2008  |  Pubmed ID: 18197178

The complement anaphylatoxin C3a contributes to injury after cerebral ischemia in mice. This study assesses the effect of C3a receptor antagonist (C3aRA) on leukocyte infiltration into the ischemic zone. Transient or permanent middle cerebral artery occlusion (MCAO) was induced in wild-type C57Bl/6 mice. Intraperitoneal C3aRA or vehicle was administered 45 mins before or 1 h after occlusion. Twenty-four hours after occlusion, we harvested brain tissue and purified inflammatory cells using flow cytometry. Soluble intercellular adhesion molecule (ICAM)-1 protein levels were assessed using enzyme-linked immunosorbent assays, and ICAM-1 and C3a receptor (C3aR) expression was confirmed via immunohistochemistry. In the transient MCAO model, animals receiving C3aRA showed smaller strokes, less upregulation of C3aR-positive granulocytes, and less ICAM-1 protein on endothelial cells than vehicle-treated animals; no significant differences in other inflammatory cell populations were observed. C3a receptor antagonist-treated and vehicle-treated animals showed no differences in stroke volume or inflammatory cell populations after permanent MCAO. These data suggest that blocking the binding of C3a to C3aR modulates tissue injury in reperfused stroke by inhibiting the recruitment of neutrophils to the ischemic zone. It further establishes antagonism of the C3a anaphylatoxin as a promising strategy for ameliorating injury after ischemia/reperfusion.

The Impact of Microsurgical Fenestration of the Lamina Terminalis on Shunt-dependent Hydrocephalus and Vasospasm After Aneurysmal Subarachnoid Hemorrhage

Neurosurgery. Jan, 2008  |  Pubmed ID: 18300899

Chronic hydrocephalus requiring shunt placement and cerebral vasospasm are common complications after aneurysmal subarachnoid hemorrhage. Recent publications have investigated the possibility that microsurgical fenestration of the lamina terminalis during aneurysm surgery may reduce the incidence of shunt-dependent hydrocephalus and cerebral vasospasm. We reviewed a single-surgeon series to compare postsurgical outcomes of patients who underwent fenestration of the lamina terminalis against those who did not.

Guidelines for the Surgical Treatment of Unruptured Intracranial Aneurysms: the First Annual J. Lawrence Pool Memorial Research Symposium--controversies in the Management of Cerebral Aneurysms

Neurosurgery. Jan, 2008  |  Pubmed ID: 18300906

The management of unruptured cerebral aneurysms remains one of the most controversial topics in neurosurgery. To this end, we discuss the diagnosis and estimated prevalence of these lesions as well as review the literature regarding the rate of rupture for cerebral aneurysms and risks of operative intervention. Our interpretation of the literature concludes that aneurysms are present in approximately 1% of the adult population, varying between less than 1% in young adults to 4% in the elderly. The yearly risk of subarachnoid hemorrhage for an unruptured intracranial aneurysm is approximately 1% for lesions 7 to 10 mm in diameter. Based on these assumptions, we recommend that 1) with rare exceptions, all symptomatic unruptured aneurysms should be treated; 2) small, incidental aneurysms less than 5 mm in diameter should be managed conservatively in virtually all cases; 3) aneurysms larger than 5 mm in patients younger than 60 years of age should be seriously considered for treatment; 4) large, incidental aneurysms larger than 10 mm should be treated in nearly all patients younger than 70 years of age; and 5) microsurgical clipping rather than endovascular coiling should be the first treatment choice in low-risk cases. Critical to our guidelines is collaboration by a highly experienced cerebrovascular team of microneurosurgeons and endovascular neurosurgeons working at a tertiary medical center with a high case volume and using a decision-making paradigm designed to offer only low-risk treatments. In certain patients for whom both treatment and natural history carry high risks, such as those with giant aneurysms, nonoperative management is typically elected.

International Subarachnoid Aneurysm Trial Analysis

Journal of Neurosurgery. Mar, 2008  |  Pubmed ID: 18312087

Optimal Treatment of Carotid Artery Disease

Journal of the American College of Cardiology. Mar, 2008  |  Pubmed ID: 18325435

Extracranial carotid artery disease accounts for approximately 25% of ischemic strokes. Although carotid endarterectomy (CEA) is the established gold standard for carotid revascularization, carotid artery angioplasty and stenting (CAS) is continually developing into a safer and more efficacious method of stroke prevention. Embolic protection, improving stent designs, and ever-increasing surgeon experience are propelling CAS towards equipoise with and possible superiority to CEA. One multicenter randomized trial and several nonrandomized registries have successfully established CAS as an accepted treatment for high-risk patients. Clinicians must strive to perform well-designed clinical trials that will continue to aid understanding and improve application of both endovascular and open techniques for extracranial carotid revascularization. We review the data published to date regarding the indications for and recent developments in the use of CAS.

Chronic Myelopathy Due to a Giant Spinal Arachnoid Cyst: a Complication of the Intrathecal Injection of Phenol. Case Report

Journal of Neurosurgery. Spine. Apr, 2008  |  Pubmed ID: 18377326

Acquired intradural arachnoid cystic lesions of the spine have been associated with trauma, hemorrhage, parasitic infections, and other insults that cause inflammation and subarachnoid adhesions. The authors describe the case of a previously healthy 36-year-old woman who presented with a chronic myelopathy due to the progressive development of a giant spinal arachnoid cyst that resulted after the intrathecal injection of phenol for the management of chronic upper extremity pain. Neurological examination, spinal computed tomography, and magnetic resonance imaging were used for diagnostic and follow-up purposes. Even after the initial excision of the cyst, the patient remained symptomatic with minimal functional recovery.

Controversies in the Surgical Treatment of Ruptured Intracranial Aneurysms: the First Annual J. Lawrence Pool Memorial Research Symposium--controversies in the Management of Cerebral Aneurysms

Neurosurgery. Feb, 2008  |  Pubmed ID: 18382317

The management of aneurysmal subarachnoid hemorrhage has evolved over time, including the use of the microscope for aneurysm clip application, improved imaging modalities, endovascular methods for aneurysm treatment, dedicated neurointensive care units, and more aggressive therapy for cerebral vasospasm. Although these advancements have reduced the morbidity and mortality associated with aneurysmal subarachnoid hemorrhage, outcomes for this patient population continue to leave much room for improvement. This work highlights controversial adjuvant techniques, maneuvers, and therapies surrounding the surgical treatment of ruptured cerebral aneurysms that currently lack a consensus opinion. These treatments include centralized care in high-volume centers, as well as the use of antifibrinolytic therapy, routine cerebrospinal fluid diversion, intraoperative hypothermia, temporary clip application, neuroprotective drugs, intraoperative angiography, and decompressive hemicraniectomy. Although definitive answers will only be possible through future multicenter collaboration, we review the controversy surrounding these adjuncts and report the consensus opinion from a highly experienced audience.

Quantification of the Frontotemporal Orbitozygomatic Approach Using a Three-dimensional Visualization and Modeling Application

Neurosurgery. Mar, 2008  |  Pubmed ID: 18424994

We sought to simulate the frontotemporal orbitozygomatic (FTOZ) craniotomy in a three-dimensional virtual environment on patient-specific data and to quantify the exposure afforded by the FTOZ while simulating controlled amounts of brain retraction.

Asymmetric Vascular Stent: Feasibility Study of a New Low-porosity Patch-containing Stent

Stroke; a Journal of Cerebral Circulation. Jul, 2008  |  Pubmed ID: 18436886

Intracranial aneurysm (IA) treatment through hemodynamic modification with novel stent designs is a burgeoning area of research. We present a feasibility study for a new low-porosity patch-containing stent designed to treat intracranial aneurysms. The device is deployed so the patch covers the aneurysm neck ensuring strong flow diversion away from the aneurysm while keeping a low probability of occlusion of perforating vessels.

Doppler Ultrasonography Screening of Poor-grade Subarachnoid Hemorrhage Patients Increases the Diagnosis of Deep Venous Thrombosis

Neurological Research. Nov, 2008  |  Pubmed ID: 18973729

Prophylactic anticoagulation greatly decreases the prevalence of deep venous thrombosis (DVT) in neurosurgical patients. Using Doppler ultrasonography (USG), recent studies demonstrate a 1% DVT detection rate following microsurgery or endovascular treatment for aneurysmal subarachnoid hemorrhage (aSAH). We hypothesize that reported statistics underestimate the DVT detection rate in this high risk cohort by accounting for only symptomatic thromboses. This study utilizes Doppler USG to examine the prevalence of DVT in a large population of aSAH patients and attempts to identify a high-risk subgroup within this cohort.

Post-carotid Endarterectomy Neurocognitive Decline is Associated with Cerebral Blood Flow Asymmetry on Post-operative Magnetic Resonance Perfusion Brain Scans

Neurological Research. Apr, 2008  |  Pubmed ID: 17803842

Up to 25% of patients experience subtle declines in post-operative neurocognitive function following, otherwise uncomplicated, carotid endarterectomy (CEA). We sought to determine if post-CEA neurocognitive deficits are associated with cerebral blood flow (CBF) abnormalities on post-operative MR perfusion brain scans.

Treatment of Intracranial Aneurysms with the Enterprise Stent: a Multicenter Registry

Journal of Neurosurgery. Jan, 2009  |  Pubmed ID: 18976057

The development of self-expanding stents dedicated to intracranial use has significantly widened the applicability of endovascular therapy to many intracranial aneurysms that would otherwise have been untreatable by endovascular techniques. Recent Food and Drug Administration approval of the Enterprise Vascular Reconstruction Device and Delivery System (Cordis) has added a new option for self-expanding stent-assisted intracranial aneurysm coiling.

Influence of Intracranial Aneurysm-to-parent Vessel Size Ratio on Hemodynamics and Implication for Rupture: Results from a Virtual Experimental Study

Neurosurgery. Apr, 2009  |  Pubmed ID: 19349824

The effectiveness of intracranial aneurysm (IA) size as a predictor for rupture has been debated. We recently performed a retrospective analysis of IA morphology and found that a new index, namely, aneurysm-to-parent vessel size ratio (SR), was strongly correlated with IA rupture, with 77% of ruptured IAs showing an SR of more than 2, and 83% of unruptured IAs showing an SR of 2 or less. As hemodynamics have been implicated in both IA development and rupture, we examine how varying SR influences intra-aneurysmal hemodynamics.

Response to Open Peer Commentaries on "Bioethical Considerations in Translational Research: Primate Stroke"

The American Journal of Bioethics : AJOB. May, 2009  |  Pubmed ID: 19396670

Bioethical Considerations in Translational Research: Primate Stroke

The American Journal of Bioethics : AJOB. May, 2009  |  Pubmed ID: 19396671

Controversy and activism have long been linked to the subject of primate research. Even in the midst of raging ethical debates surrounding fertility treatments, genetically modified foods and stem-cell research, there has been no reduction in the campaigns of activists worldwide. Playing their trade of intimidation aimed at ending biomedical experimentation in all animals, they have succeeded in creating an environment where research institutions, often painted as guilty until proven innocent, have avoided addressing the issue for fear of becoming targets. One area of intense debate is the use of primates in stroke research. Despite the fact that stroke kills more people each year than AIDS and malaria, and less than 5% of patients are candidates for current therapies, there is significant opposition to primate stroke research. A balanced examination of the ethics of primate stroke research is thus of broad interest to all areas of biomedical research.

Pharos Neurovascular Intracranial Stent: Elective Use for a Symptomatic Stenosis Refractory to Medical Therapy

Catheterization and Cardiovascular Interventions : Official Journal of the Society for Cardiac Angiography & Interventions. Oct, 2009  |  Pubmed ID: 19496116

The Warfarin-Aspirin Symptomatic Intracranial Disease study investigators demonstrated that medically managed patients with symptomatic intracranial stenosis experience a 7-11% annual stroke risk. Early treatment efforts utilized balloon-mounted coronary stents, which provided excellent angiographic results (postprocedure stenoses <10%), versus percutaneous transluminal angioplasty (PTA) alone (40%). However, the rigidity of balloon-mounted coronary stents provided limited access to the tortuous cerebrovasculature. Self-expanding stents became available for intracranial stenosis treatment in 2002. With increased flexibility, immediate results were encouraging (approximately 30% residual stenosis). However, midterm results have demonstrated disappointingly high rates of restenosis. To address these issues, the Pharos Neurovascular Stent System (Pharos, Micrus Endovascular, San Jose, CA) was developed. The Pharos is a balloon-expandable stent mounted on a rapid-exchange PTA catheter especially designed for intracranial endovascular applications. Utilizing the Pharos, we obtained an outstanding angiographic result (0% residual stenosis), with no associated morbidity. The patient was discharged home on postprocedure day 1 and remained symptom-free, with no in-stent stenosis, 3 months later. Our experience with the Pharos supports early literature suggesting that this stent may be a valuable treatment option for patients with medically refractory intracranial stenosis.

Molecular Alterations Associated with Aneurysmal Remodeling Are Localized in the High Hemodynamic Stress Region of a Created Carotid Bifurcation

Neurosurgery. Jul, 2009  |  Pubmed ID: 19574839

Although elevated hemodynamics has been speculated to play a key role in intracranial aneurysm (IA) initiation, little is known about the specific hemodynamic microenvironment that triggers aneurysmal vascular degradation. We previously demonstrated maladaptive remodeling characteristic of IA initiation occurring in hemodynamic regions of combined high wall shear stress (WSS) and high WSS gradient near the apex of an experimentally created carotid bifurcation. This study examines whether this remodeling recapitulates the molecular changes found in IAs and whether molecular changes also correspond to specific hemodynamic environments.

The Complement Cascade: New Avenues in Stroke Therapy

Current Vascular Pharmacology. Jul, 2009  |  Pubmed ID: 19601853

Recent evidence has shown that after the initial occlusion, a large portion of stroke patients achieve some degree of reperfusion either through collateral circulation or clot dissolution. However, it appears that this reperfusion may lead to increased inflammation-induced damage. Even though the exact mechanism of this secondary injury is unclear, several experimental studies have indicated an intimate connection between complement and this secondary form of damage. We review the available literature and attempt to identify promising clinical therapeutic targets.

First Food and Drug Administration-approved Prospective Trial of Primary Intracranial Stenting for Acute Stroke: SARIS (stent-assisted Recanalization in Acute Ischemic Stroke)

Stroke; a Journal of Cerebral Circulation. Nov, 2009  |  Pubmed ID: 19696415

Acute revascularization is associated with improved outcomes in ischemic stroke patients. However, it is unclear which method of intraarterial intervention, if any, is ideal. Numerous case series and cardiac literature parallels suggest that acute stenting may yield high revascularization levels with low associated morbidity. We therefore conducted a Food and Drug Administration-approved prospective pilot trial to evaluate the safety of intracranial stenting for acute ischemic stroke.

Early History of the Stereotactic Apparatus in Neurosurgery

Neurosurgical Focus. Sep, 2009  |  Pubmed ID: 19722814

Stereotactic neurosurgery has a rich history, beginning with the first stereotactic frame described by Horsley and Clarke in 1908. It is now widely used for delivery of radiation, surgical targeting of electrodes, and resection to treat tumors, epilepsy, vascular malformations, and pain syndromes. These treatments are now available due to the pioneering efforts of neurosurgeons and scientists in the beginning of the 20th century. Their efforts focused on the development of stereotactic instruments for accurate lesion targeting. In this paper, the authors review the history of the stereotactic apparatus in the early 20th century, with a focus on the fascinating people key to its development.

Stereotactic Radiosurgery and the Linear Accelerator: Accelerating Electrons in Neurosurgery

Neurosurgical Focus. Sep, 2009  |  Pubmed ID: 19722815

The search for efficacious, minimally invasive neurosurgical treatment has led to the development of the operating microscope, endovascular treatment, and endoscopic surgery. One of the most minimally invasive and exciting discoveries is the use of targeted, high-dose radiation for neurosurgical disorders. Radiosurgery is truly minimally invasive, delivering therapeutic energy to an accurately defined target without an incision, and has been used to treat a wide variety of pathological conditions, including benign and malignant brain tumors, vascular lesions such as arteriovenous malformations, and pain syndromes such as trigeminal neuralgia. Over the last 50 years, a tremendous amount of knowledge has been garnered, both about target volume and radiation delivery. This review covers the intense study of these concepts and the development of linear accelerators to deliver stereotactic radiosurgery. The fascinating history of stereotactic neurosurgery is reviewed, and a detailed account is given of the development of linear accelerators and their subsequent modification for radiosurgery.

Retrograde Angioplasty for Basilar Artery Stenosis: Bypassing Bilateral Vertebral Artery Occlusions

Journal of Neurosurgery. Mar, 2009  |  Pubmed ID: 19012478

Basilar artery angioplasty with or without stenting is an emerging and promising treatment for vertebrobasilar insufficiency that is refractory to medical therapy. The usual approach is via a transfemoral route, with access directly through the vertebral artery (VA). An approach from the anterior circulation via the posterior communicating artery has been reported for optimal stent positioning and deployment across basilar apex aneurysms. No similar technique has been reported for treatment of midbasilar stenosis. The authors report a case of severe symptomatic basilar stenosis in which both VAs were occluded. The only option was to perform retrograde basilar angioplasty via the posterior communicating artery. This useful technique should be part of the armamentarium for the percutaneous treatment of symptomatic vertebrobasilar insufficiency for the occasional patient in whom occlusion or tortuosity precludes direct access to the VA.

Endovascular Intervention for Acute Thromboembolic Stroke in Young Patients: an Ideal Population for Aggressive Intervention?

Journal of Neurosurgery. Jan, 2009  |  Pubmed ID: 18821835

Endovascular treatment of acute thromboembolic stroke is a rapidly developing field that appears to hold great promise. Young patients may be particularly suited to benefit from endovascular acute stroke therapy. The authors sought to identify outcomes in young patients with thromboembolic stroke who underwent endovascular intervention.

The Asymmetric Vascular Stent: Efficacy in a Rabbit Aneurysm Model

Stroke; a Journal of Cerebral Circulation. Mar, 2009  |  Pubmed ID: 19131663

Development of hemodynamic modifying devices to treat intracranial aneurysms is an active area of research. The asymmetrical vascular stent (AVS), a stent containing a low-porosity patch, is such device. We evaluate AVS efficacy in an in vivo intracranial aneurysm model.

Intraoperative Magnesium Infusion During Carotid Endarterectomy: a Double-blind Placebo-controlled Trial

Journal of Neurosurgery. May, 2009  |  Pubmed ID: 19199498

Recent data from both experimental and clinical studies have supported the use of intravenous magnesium as a potential therapy in the setting of cerebral ischemia. This study assessed whether intraoperative magnesium therapy improves neuropsychometric testing (NPT) following carotid endarterectomy (CEA).

Temporary Endovascular Bypass: a Novel Treatment for Acute Stroke

AJNR. American Journal of Neuroradiology. Sep, 2009  |  Pubmed ID: 19279279

Intracranial stent placement is emerging as an effective treatment for acute stroke. As a means to avoid stent-associated complications and capitalize on stent-placement-related advantages, the concept of a "temporary endovascular bypass" (TEB) for stroke therapy was recently reported. In this technique, a stent is temporarily deployed for instant recanalization. Once sufficient flow is established to maintain vessel patency, the stent is recaptured and withdrawn. We report a second case to further characterize the merits of TEB.

Rapidly Successive, Symptomatic, Bilateral, Spontaneous Vertebral Artery Dissections: Treatment with Stent Reconstruction

Surgical Neurology. Sep, 2009  |  Pubmed ID: 18514287

Vertebral artery dissection has been increasingly identified as a cause of ischemic stroke in young adults. This condition is typically secondary to trauma, with spontaneous VA dissection accounting for only a minority of cases. We report the case of a patient with bilateral symptomatic spontaneous VA dissections, presenting in rapid succession. Each ictal event was successfully managed with stent reconstruction and antiplatelet therapy.

Direct Thrombolysis for Cerebral Venous Sinus Thrombosis

Neurosurgical Focus. Nov, 2009  |  Pubmed ID: 19877797

Cerebral venous sinus thrombosis (CVST) is an increasingly diagnosed disease with a wide range of symptoms, ranging from a mild headache to cerebral herniation. A potentially devastating syndrome, CVST has been associated with a mortality rate of 6-10%. In prospective studies, the overall rate of death and dependency from CVST ranges from 8.8 to 44.4%. Systemic anticoagulation remains the first-line treatment. However, a percentage of patients deteriorate despite medical therapy. These cases have resulted in the development of thrombolysis or endovascular treatment for CVST. Initial reports of the use of endovascular treatment of CVST have been promising. However, enthusiasm for the use of endovascular thrombolysis and thrombectomy should be tempered by an understanding of possible risks such as intracerebral hemorrhage and/or vessel dissection. The authors review the literature regarding endovascular treatment of CVST with a description of the chemical and mechanical thrombolytic techniques.

Novel Application of an Intermediate Sized Bridging Catheter As an Adjunct to Aneurysm Coiling in Patients with Tortuous Vasculature

Interventional Neuroradiology : Journal of Peritherapeutic Neuroradiology, Surgical Procedures and Related Neurosciences. Dec, 2009  |  Pubmed ID: 20465884

Summary: Selective microcatheterization of intracranial aneurysms during coiling can be limited by tortuous vasculature. Stabilization of the microcatheter via distal placement of the guide catheter in the intracranial vasculature may cause vessel dissection or vasospasm. We describe the application of an intermediate sized bridging catheter in four patients with tortuous vasculature who underwent successful coiling of ruptured aneurysms. No complications occurred. The intermediate sized bridging catheter is a useful adjunct for navigation of tortuous parent artery vasculature.

Impact of Systemic Inflammatory Response Syndrome on Vasospasm, Cerebral Infarction, and Outcome After Subarachnoid Hemorrhage: Exploratory Analysis of CONSCIOUS-1 Database

Neurocritical Care. Oct, 2010  |  Pubmed ID: 20593247

Systemic inflammatory response syndrome (SIRS) may develop after aneurysmal subarachnoid hemorrhage (SAH). We investigated factors associated with SIRS after SAH, whether SIRS was associated with complications of SAH such as vasospasm, cerebral infarction, and clinical outcome, and whether SIRS could contribute to a difference in outcome between patients treated by endovascular coiling or neurosurgical clipping of the ruptured aneurysm.

Characterization of Critical Hemodynamics Contributing to Aneurysmal Remodeling at the Basilar Terminus in a Rabbit Model

Stroke; a Journal of Cerebral Circulation. Aug, 2010  |  Pubmed ID: 20595660

Hemodynamic insult by bilateral common carotid artery ligation has been shown to induce aneurysmal remodeling at the basilar terminus in a rabbit model. To characterize critical hemodynamics that initiate this remodeling, we applied a novel hemodynamics-histology comapping technique.

Acute Intraprocedural Thrombus Formation During Wingspan Intracranial Stent Placement for Intracranial Atherosclerotic Disease

Neurosurgery. Sep, 2010  |  Pubmed ID: 20679932

Treatment of intracranial atherosclerotic disease with the Wingspan-Gateway intracranial stent and balloon angioplasty system has been reported in several multicenter registries. To date, the incidence of acute intraprocedural thrombus formation during Wingspan stent placement has not been reported.

Effect of Weekend Compared with Weekday Stroke Admission on Thrombolytic Use, In-hospital Mortality, Discharge Disposition, Hospital Charges, and Length of Stay in the Nationwide Inpatient Sample Database, 2002 to 2007

Stroke; a Journal of Cerebral Circulation. Oct, 2010  |  Pubmed ID: 20724715

A stroke "weekend effect" on mortality has been demonstrated in other countries with a possible slight effect in the United States. We studied patients with stroke in the Nationwide Inpatient Sample database for a weekend effect on thrombolytic use, in-hospital mortality, discharge disposition, hospital charges, and length of stay.

Data Presentation in Rodent Stroke Studies and the Predictive Value of Confidence Intervals

Journal of Clinical Neuroscience : Official Journal of the Neurosurgical Society of Australasia. Jan, 2010  |  Pubmed ID: 19963387

The clinical failure of neuroprotective agents stems partly from inappropriate statistical presentation of preclinical data, which causes an overestimation of effect size and underpowered clinical studies. We searched for studies utilizing neuroprotective agents in a rodent middle cerebral artery occlusion model. We identified all experimental groups demonstrating statistically significant claims of neuroprotection within these studies and calculated the mean, 95% confidence intervals (CI), and meta-analyses of effect size for each agent. The lower limits of the CI (LLCI) of effect size were less than 0.2 in 161/221 (73%) of all experimental groups, corresponding to small effects. After meta-analysis, 29/60 (48%) and 11/18 (61%) of the agents had an effect size LLCI<0.2 for infarct volume and neurological function, respectively. This difference was statistically significant (p<0.05). These results suggest that the preclinical neuroprotective effect size of many of these drugs is small, although that of neurological function is smaller and is thus a more conservative and appropriate estimate of effect.

The Influence of Race on Outcome Following Subarachnoid Hemorrhage

Journal of Clinical Neuroscience : Official Journal of the Neurosurgical Society of Australasia. Jan, 2010  |  Pubmed ID: 20004103

The goal of this study was to examine the relationship between race and outcome following subarachnoid hemorrhage (SAH). We identified all SAH discharges in New York City during 2003. An adverse outcome was defined as in-hospital death or discharge other than to home. While correcting for age and gender, we examined the effect of race and payor status on outcome following SAH. Forty-four percent of patients with SAH were white. Being white had a significant relationship with outcome when controlled for payor status (odds ratio 0.56). Among self-pay/Medicaid patients, fewer white (52%) individuals suffered poor outcomes than non-white (66%, p=0.03). Our results establish that white patients in New York City with SAH have better outcomes than non-whites. While it is unclear whether this discrepancy is secondary to pathophysiological differences or unidentified social factors, our findings demonstrate that this effect is independent of insurance status, and emphasize the need for further investigation into racial disparities in outcome following SAH.

Length of Stay and Total Hospital Charges of Clipping Versus Coiling for Ruptured and Unruptured Adult Cerebral Aneurysms in the Nationwide Inpatient Sample Database 2002 to 2006

Stroke; a Journal of Cerebral Circulation. Feb, 2010  |  Pubmed ID: 20044522

We have previously reported the difference in length of stay and hospital charges for patients with cerebral aneurysms treated with either clipping or coiling at our institution. We now report an analysis of the same comparison at a national level conducted using the Nationwide Inpatient Sample database.

Aneurysmal Changes at the Basilar Terminus in the Rabbit Elastase Aneurysm Model

AJNR. American Journal of Neuroradiology. Mar, 2010  |  Pubmed ID: 20053800

Mapping Vascular Response to in Vivo Hemodynamics: Application to Increased Flow at the Basilar Terminus

Biomechanics and Modeling in Mechanobiology. Aug, 2010  |  Pubmed ID: 20054605

Hemodynamic forces play critical roles in vascular pathologies such as atherosclerosis, aneurysms, and stenosis. However, detailed relationships between the specific in vivo hemodynamic microenvironment and vascular responses leading to the triggering or exacerbation of pathological remodeling of the vessel remain elusive. We have developed a hemodynamics-biology co-mapping technique that enables in situ correlation between the in vivo blood flow field and vascular changes secondary to hemodynamic insult. The hemodynamics profile is obtained from computational fluid dynamics simulation within the vascular geometry reconstructed from three-dimensional in vivo images, whereas the vascular response is obtained from histology or immunohistochemistry on harvested vascular tissue. The hemodynamics field is virtually sectioned in the histological slicing planes and digitally co-mapped with the histological images, thereby enabling correlation of the specific local vascular responses with the inciting hemodynamic stresses. We demonstrate application of this technique to rabbit basilar terminus subjected to elevated flow. Morphological changes at the basilar terminus 5 days after the flow increase were co-mapped with the initial wall shear stress and wall shear stress gradient distributions, from which localization of destructive remodeling in a specific hemodynamic zone was noticed. This method paves the way for further investigations to determine the connection between in vivo mechanical stimuli and biological responses, such as initiation of aneurysmal remodeling.

Size Ratio for Clinical Assessment of Intracranial Aneurysm Rupture Risk

Neurological Research. Jun, 2010  |  Pubmed ID: 20092677

We previously used three-dimensional (3D) volumetric analysis to identify a novel intracranial aneurysm (IA) morphological metric, aneurysm-to-parent vessel size ratio (SR), which strongly correlated with aneurysm rupture. However, complex 3D analysis is not easily obtained, and ubiquitous IA risk assessment is traditionally performed with two-dimensional (2D) imaging, typically with size being the sole considered morphometric. Because only easily applicable 2D measurements will be of clinical value, we sought to investigate the correlation of SR determined from 2D angiography with IA rupture status.

Size Ratio Correlates with Intracranial Aneurysm Rupture Status: a Prospective Study

Stroke; a Journal of Cerebral Circulation. May, 2010  |  Pubmed ID: 20378866

The prediction of intracranial aneurysm (IA) rupture risk has generated significant controversy. The findings of the International Study of Unruptured Intracranial Aneurysms (ISUIA) that small anterior circulation aneurysms (<7 mm) have a 0% risk of subarachnoid hemorrhage in 5 years is difficult to reconcile with other studies that reported a significant portion of ruptured IAs are small. These discrepancies have led to the search for better aneurysm parameters to predict rupture. We previously reported that size ratio (SR), IA size divided by parent vessel diameter, correlated strongly with IA rupture status (ruptured versus unruptured). These data were all collected retrospectively off 3-dimensional angiographic images. Therefore, we performed a blinded prospective collection and evaluation of SR data from 2-dimensional angiographic images for a consecutive series of patients with ruptured and unruptured IAs.

Primary Intracranial Stenting in Acute Ischemic Stroke

Current Cardiology Reports. Jan, 2010  |  Pubmed ID: 20425179

Acute intracranial stroke is a major source of morbidity and mortality in the United States. Recent studies have shown improved clinical outcomes for patients who achieve timely arterial recanalization. Multimodal therapies have evolved to meet this end point and include intravenous and/or intra-arterial thrombolysis and mechanical thrombolysis. Modifications to existing balloon-mounted stents commonly used in cardiology have yielded more easily navigable and safer self-expanding intracranial stents that provide rapid arterial recanalization. We review the evolution of acute stroke therapy over the past few decades and the recent results of mechanical thrombolysis, focusing on intracranial stenting in the setting of acute stroke.

Timing of Aneurysm Surgery: the International Cooperative Study Revisited in the Era of Endovascular Coiling

Journal of Neurointerventional Surgery. Jun, 2010  |  Pubmed ID: 21990592

The International Cooperative Study on the Timing of Aneurysm Surgery demonstrated that subarachnoid hemorrhage (SAH) patients who underwent surgery on post-hemorrhage days 4-10 had worse outcomes than patients treated on days 0-3 and days 11-14. Based on these findings, it was concluded that patients who present with SAH on days 4-10 should have aneurysm surgery delayed until after day 10. Since the study, coiling has become a treatment option and it is unclear whether these results apply to this new treatment modality. Our institution is a regional referral center for SAH, and patients are transferred at different time points after hemorrhage. We wanted to determine whether patients that arrive on days 4-10 were safe to undergo coiling immediately rather than waiting until after day 10.

The Balloon Anchor Technique: a Novel Technique for Distal Access Through a Giant Aneurysm

Journal of Neurointerventional Surgery. Dec, 2010  |  Pubmed ID: 21990649

A novel technique is reported that helps the operator in achieving reliable access to the distal parent vessel with a microcatheter for stent assisted aneurysm coiling. Distal parent vessel access was obtained by allowing the microwire to follow the local hemodynamics into a giant internal carotid artery aneurysm and around its dome. Various traditional methods were tried before attempting the balloon anchor. In this technique, an over-the-wire balloon was inflated in the distal vessel followed by gentle retraction of the balloon catheter and microwire allowed only a wire bridge across the aneurysm neck, thereby allowing the stent catheter to be brought up in a standard fashion. This technique may facilitate the use of new stent technologies for the treatment of aneurysms that would otherwise be untreatable with endovascular therapies.

Promising New Aneurysm Occlusion and Clinical Outcome Results from CCT and HELPS

World Neurosurgery. Oct-Nov, 2010  |  Pubmed ID: 21492575

Use of a Vascular Reconstruction Device to Salvage Acute Ischemic Occlusions Refractory to Traditional Endovascular Recanalization Methods

Journal of Neurosurgery. Mar, 2010  |  Pubmed ID: 19764826

Acute revascularization has been associated with improved stroke outcomes. The Prolyse in Acute Cerebral Thromboembolism (PROACT II) trial achieved recanalization rates of 66%. The Multi Mechanical Embolus Removal in Cerebral Ischemia (Multi MERCI) trial achieved recanalization in 70% of patients. However, these interventional tools are not always successful. The Enterprise vascular reconstruction device was recently introduced for treatment of cerebral aneurysms previously untreatable with endovascular techniques. The authors evaluated a multicenter experience using this stent as a salvage revascularization tool for acute stroke treatment.

Aggressive Intervention to Treat a Young Woman with Intracranial Hemorrhage Following Unsuccessful Intravenous Thrombolysis for Left Middle Cerebral Artery Occlusion. Case Report

Journal of Neurosurgery. Aug, 2011  |  Pubmed ID: 21495825

Stroke patients whose condition does not improve after intravenous administration of tissue plasminogen activator (tPA) may be candidates for endovascular intervention. Patients with new intracerebral hemorrhage noted during such interventions pose a difficult challenge to neurointerventionists and are often sequestered as treatment failures and deemed inappropriate for intraarterial recanalization efforts. The authors present a case in which aggressive intervention was performed despite evidence of contrast extravasation on preintervention angiography. This 37-year-old woman presented with an occlusion of the M(1) segment of the left middle cerebral artery and a National Institutes of Health Stroke Scale score of 24. She received intravenous tPA without improvement. Angiography revealed M(1) thrombus as well as active contrast extravasation without arterial displacement. Thromboaspiration was performed in light of her known hemorrhage with excellent recanalization. Immediate postprocedure imaging demonstrated a large insular hematoma and emergent craniectomy and hematoma evacuation were performed. At 4 months' follow-up, the patient was living at home, was ambulating, and had excellent comprehension with mild expressive aphasia. There is little peer-reviewed data in the literature to aid in the decision-making process when contrast extravasation is recognized at the time of preinterevention angiography. Continuation of mechanical endovascular stroke intervention, in light of active contrast extravasation, may be warranted in young patients with major deficits and absence of arterial displacement or delayed global filling. Further thrombolytics are not advised. In select stroke patients, continuation of a planned attempt at mechanical recanalization without the further use of thrombolytics may be warranted in light of known intracerebral hemorrhage.

Incidence of Seizures or Epilepsy After Clipping or Coiling of Ruptured and Unruptured Cerebral Aneurysms in the Nationwide Inpatient Sample Database: 2002-2007

Neurosurgery. Sep, 2011  |  Pubmed ID: 21499155

It is not clear whether treatment modality (clipping or coiling) affects the risk of seizures after treatment for cerebral aneurysms.

Midterm Clinical and Angiographic Follow-up for the First Food and Drug Administration-approved Prospective, Single-Arm Trial of Primary Stenting for Stroke: SARIS (Stent-Assisted Recanalization for Acute Ischemic Stroke)

Neurosurgery. Oct, 2011  |  Pubmed ID: 21552168

Although early data demonstrate encouraging angiographic results following intracranial stent deployment for acute ischemic stroke, longer-term follow-up is necessary to evaluate the clinical outcomes, as well as the durability of angiographic results.

Cellular and Molecular Responses of the Basilar Terminus to Hemodynamics During Intracranial Aneurysm Initiation in a Rabbit Model

Journal of Vascular Research. 2011  |  Pubmed ID: 21625176

Hemodynamics constitute a critical factor in the formation of intracranial aneurysms. However, little is known about how intracranial arteries respond to hemodynamic insult and how that response contributes to aneurysm formation. We examined early cellular responses at rabbit basilar termini exposed to hemodynamic insult that initiates aneurysmal remodeling.

Delayed Thrombosis or Stenosis Following Enterprise-assisted Stent-coiling: is It Safe? Midterm Results of the Interstate Collaboration of Enterprise Stent Coiling

Neurosurgery. Oct, 2011  |  Pubmed ID: 21670718

Stent-assisted coiling of intracranial aneurysms with self-expanding stents has widened the applicability of neuroendovascular therapies to those aneurysms previously considered "uncoilable" because of poor morphology. The Enterprise Vascular Reconstruction Device and Delivery System (Cordis) has demonstrated promising initial short-term results. However, the rates of delayed in-stent stenosis or thrombosis are not known.

Lentivirus-mediated Overexpression of Angiotensin-(1-7) Attenuated Ischaemia-induced Cardiac Pathophysiology

Experimental Physiology. Sep, 2011  |  Pubmed ID: 21685447

Myocardial infarction (MI) results in cell death, development of interstitial fibrosis, ventricular wall thinning and ultimately, heart failure. Angiotensin-(1-7) [Ang-(1-7)] has been shown to provide cardioprotective effects. We hypothesize that lentivirus-mediated overexpression of Ang-(1-7) would protect the myocardium from ischaemic injury. A single bolus of 3.5 × 10(8) transducing units of lenti-Ang-(1-7) was injected into the left ventricle of 5-day-old male Sprague-Dawley rats. At 6 weeks of age, MI was induced by ligation of the left anterior descending coronary artery. Four weeks after the MI, echocardiography and haemodynamic parameters were measured to assess cardiac function. Postmyocardial infarction, rats showed significant decreases in fractional shortening and dP/dt (rate of rise of left ventricular pressure), increases in left ventricular end-diastolic pressure, and ventricular hypertrophy. Also, considerable upregulation of cardiac angiotensin-converting enzyme (ACE) mRNA was observed in these rats. Lentivirus-mediated cardiac overexpression of Ang-(1-7) not only prevented all these MI-induced impairments but also resulted in decreased myocardial wall thinning and an increased cardiac gene expression of ACE2 and bradykinin B2 receptor (BKR2). Furthermore, in vitro experiments using rat neonatal cardiac myocytes demonstrated protective effects of Ang-(1-7) against hypoxia-induced cell death. This beneficial effect was associated with decreased expression of inflammatory cytokines (tumour necrosis factor-α and interleukin-6) and increased gene expression of ACE2, BKR2 and interleukin-10. Our findings indicate that overexpression of Ang-(1-7) improves cardiac function and attenuates left ventricular remodelling post-MI. The protective effects of Ang-(1-7) appear to be mediated, at least in part, through modulation of the cardiac renin-angiotensin system and cytokine production.

Interventional Neurovascular Disease: Avoidance and Management of Complications and Review of the Current Literature

Journal of Neurosurgical Sciences. Sep, 2011  |  Pubmed ID: 21968586

There has been a substantial increase in the number of neuroendovascular procedures performed over the last 15 years. Although rare, complications of cerebral angiography and neuroendovascular procedures have the potential to be devastating. Fortunately, dedication to careful patient selection, meticulous attention to technical detail, and standardization of endovascular treatment protocols results in an acceptably low complication rate. Factors that may predispose one to complications with cerebral angiography include age, smoking, functional stats, medical comorbidities, and duration of the procedure. The most common complication of angiography is vascular access site complication, with a rate of up to 5%. The overall neurologic complication rate for diagnostic angiography is 1.3-2.6%, with a permanent neurologic deficit rate of 0.14-0.50%. Neuroendovascular interventions are more invasive, take longer to perform, and have higher rates of complication. Procedure specific complications include aneurysm rupture, arterial dissection, stroke, hemorrhage, thromboembolism, and microembolism, and rates of neurologic deficit are higher than those for diagnostic angiography. With knowledge of the common complications, strategies to minimize them, and a meticulous attention to the technical detail of the procedure, complications of neuroendovascular interventions can be minimized.

Computed Tomographic Perfusion Imaging of Non-hemorrhagic Cerebral Hyperperfusion Syndrome and Reversal Following Medical Treatment After Carotid Artery Angioplasty and Stenting

Journal of Neurointerventional Surgery. Jun, 2011  |  Pubmed ID: 21990434

Objective and importance Cerebral hyperperfusion syndrome (CHS) is an infrequent syndrome observed in carotid endarterectomy and carotid angioplasty and stenting (CAS). The case history is presented of a patient with CT perfusion imaging of non-hemorrhagic CHS and reversal following medical treatment after CAS. Clinical presentation A right-handed Caucasian man in his late 70s presented with sudden onset right upper extremity plegia and anesthesia and right facial parasthesias with complete resolution within 24 h. CT angiography (CTA) revealed 75% left cervical carotid artery stenosis. The patient underwent uneventful left CAS. Six hours after the procedure he developed verbal perseveration and right upper extremity paresis. CT perfusion imaging showed increased mean transient time in the left parieto-occipital lobe without changes in cerebral blood flow or cerebral blood volume. A clinical diagnosis of CHS was suspected. Several hours after lowering the blood pressure his symptoms improved. A follow-up CTA with CT perfusion was performed which showed complete resolution of the previously observed changes in mean transient time. The patient was discharged home without neurological sequelae. Conclusion This is the first report to our knowledge of CT perfusion imaging for CHS with post-symptomatic imaging following clinical resolution. Prompt CHS evaluation may include CT perfusion imaging to assist diagnostic accuracy. Rigorous blood pressure control remains the mainstay of treatment.

Impact of Intracranial Self-expanding Stents in the Treatment of Acute Ischemic Stroke: Efficacy and Limitations

Journal of Neurointerventional Surgery. Feb, 2011  |  Pubmed ID: 21990463

In recent years, endovascular self-expanding stents have become a viable option for neurointerventionalists treating acute ischemic stroke. Timely intervention for stroke could mean the difference between complete recovery and significant morbidity or death. Since 2006, a handful of clinical trials have demonstrated the potential of self-expanding stents in dependably achieving quick revascularization. These devices are expanding in utilization as new designs offer greater procedural flexibility and better clinical results. We discuss these clinical investigations, focusing on the procedural capabilities and limitations of each self-expanding stent design.

Perioperative Safety of Hydrosoft Coils

Journal of Neurointerventional Surgery. Oct, 2011  |  Pubmed ID: 21990538

ObjectiveHydrosoft coils were developed to serve as finishing coils to prevent aneurysmal recurrence at the neck. Initial animal studies were encouraging since some studies showed endothelial healing across the neck without recurrence over time. However, theoretical concerns exist regarding the potential threat to parent vessels as the Hydrosoft coils at the neck expand, as well as whether such coils can be adequately supple to safely serve as a true finishing coil. A retrospective review of the initial clinical experience utilizing Hydrosoft coils from three high-volume centers was performed.MethodsEach center was asked to report angiographic (aneurysmal location, aneurysmal maximal size, neck size, incidence of intraprocedural parent vessel thrombosis, coil herniation, aneurysmal rupture as well as Raymond scale and percent occlusion after coiling) and clinical (rupture status, Hunt and Hess grade, incidence of stroke, hemorrhage, vasospasm and hydrocephalus) data on consecutive patients who underwent placement of Hydrosoft coils.ResultsA total of 141 patients were enrolled. Embolization achieved a Raymond Scale score of I (complete obliteration) in 79 aneurysms (56%), II (residual neck) in 40 aneurysms (28%) and III (residual dome) in 21 aneurysms (15%); in one case the Hydrosoft coil could not be placed. Procedural morbidity and mortality were 2.1% and 1.4%, respectively. No complications were definitively attributed to the use of Hydrosoft coils. There were three cases (2.1%) of parent vessel thrombosis, two of which resolved after intraprocedural administration of thrombolytic agents and did not lead to neurological sequelae. The incidences of intraprocedural or periprocedural aneurysmal rupture (2.1%), cerebral hemorrhage (3.5%), stroke (4.9%), vasospasm (26.2%) or hydrocephalus (31.1%) were comparable to contemporary literature.ConclusionThe use of Hydrosoft coils appears to be safe and does not lead to higher complication rates than are currently accepted in the literature. Further prospective studies are required to determine whether the use of Hydrosoft coils results in a lower incidence of aneurysmal recurrence.

Delayed Intraparenchymal Hemorrhage Following Pipeline Embolization Device Treatment for a Giant Recanalized Ophthalmic Aneurysm

Journal of Neurointerventional Surgery. Sep, 2011  |  Pubmed ID: 21990545

The pipeline embolization device has demonstrated clinical success in the management of complex intracranial aneurysms arising along the anterior intracranial circulation with a relatively low complication profile. A case report is presented which describes a novel complication of delayed intraparenchymal hemorrhage following deployment of a pipeline embolization device for the treatment of a previously ruptured partially thrombosed ophthalmic segment aneurysm.

A Prospective Randomized Single-blind Trial of Patient Comfort Following Vessel Closure: Extravascular Synthetic Sealant Closure Provides Less Pain Than a Self-tightening Suture Vascular Compression Device

Journal of Neurointerventional Surgery. Sep, 2011  |  Pubmed ID: 21990828

The Mynx M5 (AccessClosure, Inc., Mountain View, California, USA), a novel vascular closure device (VCD) utilizing extravascular synthetic sealant, may effectively seal the arteriotomy while reducing the pain associated with arteriotomy closure seen with other VCDs. To date, no studies exist comparing the pain associated with deployment between differing VCDs as a primary end point.

Simulator Based Angiography Education in Neurosurgery: Results of a Pilot Educational Program

Journal of Neurointerventional Surgery. Oct, 2011  |  Pubmed ID: 22015637

IntroductionThe use of simulators in medical training has been on the rise over the past decade as a means to teach procedural skills to trainees in a risk free environment. The goal of this study was to pilot a simulator based skills course for inexperienced neurosurgical residents to teach the fundamentals of cervicocerebral catheterization and angiography, with the ultimate goal of defining a universal simulator based curriculum that could be incorporated into neurosurgical resident training in the future.MethodsSeven neurosurgery residents with no prior angiographic experience served as the pilot participants for this 2 day course. Four neurointerventional trained neurosurgeons served as faculty for instruction and evaluation. The majority of the course focused on hands-on simulator practice with close mentoring by faculty. Participants were evaluated with pre-course and post-course assessments.ResultsPost-course written test scores were significantly higher than pre-course scores (p<0.001). Faculty assessments of participants' technical skills with angiography (graded 0-10, with 10 being best) also improved significantly from pre-course to post-course (pre 2.1; post 5.9; p<0.001). Objective simulator recorded assessments demonstrated a significant decrease in the time needed to complete a four vessel angiogram (p<0.001) and total fluoroscopic time (p<0.001).ConclusionsParticipant angiography skills, based on both faculty and simulator assessments, as well as participant knowledge, improved after this didactic, hands-on simulator course. Neuroendovascular simulator training appears to be a viable means of training inexperienced neurosurgery residents in the early learning stages of basic endovascular neurosurgery. Further studies evaluating the translation of procedural skills learned on the simulator to actual clinical skills in the angiography suite is necessary.

Progressive Aneurysm Development Following Hemodynamic Insult

Journal of Neurosurgery. Apr, 2011  |  Pubmed ID: 20950086

Hemodynamic insult has been speculated to be a key factor in intracranial aneurysm formation; however, it is unclear whether a sustained insult is necessary. The authors examined whether aneurysmal degradation would continue despite the normalization of wall shear stress (WSS) by adaptive outward vascular remodeling.

Hemodynamic-morphologic Discriminants for Intracranial Aneurysm Rupture

Stroke; a Journal of Cerebral Circulation. Jan, 2011  |  Pubmed ID: 21106956

the purpose of this study was to identify significant morphological and hemodynamic parameters that discriminate intracranial aneurysm rupture status using 3-dimensional angiography and computational fluid dynamics.

Recanalization Therapy for Acute Ischemic Stroke, Part 2: Mechanical Intra-arterial Technologies

Neurosurgical Review. Jan, 2011  |  Pubmed ID: 21107630

Stroke therapy has been revolutionized in the past two decades with the widespread implementation of chemical thrombolysis for acute stroke. However, chemical thrombolysis continues to be limited in its efficacy secondary to relatively short time windows and a high associated risk of hemorrhage. In an attempt to minimize hemorrhagic complications and extend the available therapeutic window, mechanical devices designed specifically for thrombus removal, clot obliteration, and arterial revascularization have experienced a recent surge in development and utilization. As such, chemical thrombolytics now represent only one of many options in acute stroke therapy. These new mechanical devices have extended the potential treatment window and now provide alternatives to patients who do not respond to conventional intravenous thrombolysis. This review will discuss the development of these devices, supporting literature, and the individual strengths that each engenders towards a life-saving therapy for stroke.

Recanalization Therapy for Acute Ischemic Stroke, Part 1: Surgical Embolectomy and Chemical Thrombolysis

Neurosurgical Review. Jan, 2011  |  Pubmed ID: 21107631

Cerebral revascularization approaches for acute ischemic stroke greatly expanded during the past decade. Many new revascularization strategies are currently being assessed, while others continue to gain in popularity, offering hope to those with an otherwise refractory disease. We discuss historical and current progress toward successful recanalization, as well as the efforts being made to develop a safe and efficacious method of revascularization in the treatment of acute ischemic stroke.

Unruptured Cerebral Aneurysms Do Not Shrink when They Rupture: Multicenter Collaborative Aneurysm Study Group

Neurosurgery. Jan, 2011  |  Pubmed ID: 21150760

The International Study of Intracranial Aneurysms found that for patients with no previous history of subarachnoid hemorrhage, small (< 7 mm) anterior circulation and posterior circulation aneurysms had a 0% and 2.5% risk of subarachnoid hemorrhage over 5 years, respectively.

Stent-associated Flow Remodeling Causes Further Occlusion of Incompletely Coiled Aneurysms

Neurosurgery. Sep, 2011  |  Pubmed ID: 21430583

Incomplete coil occlusion is associated with increased risk of aneurysm recurrence. We hypothesize that intracranial stents can cause flow remodeling, which promotes further occlusion of an incompletely coiled aneurysm.

Direct Thrombectomy Using the Penumbra Thromboaspiration Catheter for the Treatment of Cerebral Venous Sinus Thrombosis

World Neurosurgery. Nov, 2011  |  Pubmed ID: 22120408

OBJECTIVE: Cerebral venous sinus thrombosis (CVST) is a rare cause of stroke. A 21 year-old female presented to our institution in a rapidly deteriorating neurological state following failed systemic heparin therapy for treatment of superior sagittal sinus (SSS) thrombosis. METHODS: The patient underwent emergent mechanical thrombectomy of the thrombosed SSS using the 0.054-inch Penumbra catheter. No adjuvant direct pharmacologic and/or mechanical thrombectomy was performed. RESULTS: Successful venous recanalization was achieved using the Penumbra system. The patient improved symptomatically following the intervention, and she made a complete neurological recovery within 30 days. At 6-month follow-up, the patient had returned to work and school and remained neurologically intact. A repeat MRV showed complete sinus recanalization. CONCLUSION: Direct mechanical thrombectomy using the Penumbra system provided rapid sinus recanalization for the treatment of symptomatic cerebral venous sinus thrombosis. This device is a valuable addition to the neurointerventional armamentarium.

Vasospasm After Aneurysmal Subarachnoid Hemorrhage: Review of Randomized Controlled Trials and Meta-analyses in the Literature

World Neurosurgery. Nov, 2011  |  Pubmed ID: 22152574

Cerebral vasospasm is a major source of morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). A variety of therapies have been utilized to prevent or treat vasospasm. Despite the large number of clinical trials, few randomized controlled trials (RCTs) of sufficient quality have been published. We review the RCTs and meta-analyses in the literature regarding the treatment and prevention of cerebral vasospasm following aneurysmal SAH.

Intracranial Stents for Treatment of Acute Ischemic Stroke: Evolution and Current Status

World Neurosurgery. Dec, 2011  |  Pubmed ID: 22182268

Intravascular stents have been applied to treat a variety of pathophysiologic conditions. With advances in stent design and delivery, stenting has become a viable treatment option in neurovascular disease. Recently, intracranial arterial stenting has received increasing interest as a modality to rapidly and effectively recanalize affected vessels in the setting of acute ischemic stroke.

Delayed Complication from a Percutaneous Vascular Closure Device Following a Neuro-interventional Procedure

Interventional Neuroradiology : Journal of Peritherapeutic Neuroradiology, Surgical Procedures and Related Neurosciences. Dec, 2011  |  Pubmed ID: 22192557

Percutaneous vascular closure devices are being increasingly used as alternatives to manual compression for the closure of femoral arteriotomy after endovascular procedures as they appear to reduce time to ambulate, improve patient's comfort, and are implicated with cost saving. However, vascular closure devices have been associated with an increased risk of complications including hematoma formation, local bleeding, arteriovenous fistula formation, pseudoaneurysm and arterial leg ischemia. To our knowledge, if the above complications occur it is usually within the first 30 days after the procedure. None have been reported in a delayed fashion ten months or longer after closure. We describe a 30-year-old man with a history of a giant basilar trunk aneurysm. He was placed on aspirin and clopidogrel prior to the procedure. He had bilateral femoral access with 6 French sheaths. Following the procedure, 6 French Angio-Seals (St. Jude Medical, St. Paul, MN, USA) were used for closure of bilateral femoral arteriotomies. Ten months after the procedure, the patient kicked a metal cart and developed a large right retroperitoneal iliopsoas hematoma. There was no evidence of pseudoaneurysm. The patient was managed conservatively and his serial hematocrit stayed stable. He did not require surgical intervention. Use of percutaneous vascular closure devices is associated with complications including risk of hematoma, pseudoaneurysm, intravenous fistula, rectal peritoneal hemorrhage, limb ischemia and possible surgical repair. Most complications occur peri-procedure or within 30 days post-procedure. This is the first reported case of a delayed complication at ten months after the initial procedure. Site-related complications associated with percutaneous vascular closure devices may occur in a delayed fashion, even ten months post-procedure, so should be considered in the management of patients.

Incidence of Ventricular Shunt Placement for Hydrocephalus with Clipping Versus Coiling for Ruptured and Unruptured Cerebral Aneurysms in the Nationwide Inpatient Sample Database: 2002 to 2007

World Neurosurgery. Dec, 2011  |  Pubmed ID: 22251503

Few studies have compared the incidence of ventricular shunt placement for hydrocephalus after clipping versus coiling of cerebral aneurysms.

A Simple Technique for Morphological Measurement of Cerebral Arterial Circle Variations Using Public Domain Software (Osiris)

Anatomy & Cell Biology. Dec, 2011  |  Pubmed ID: 22254161

This article describes a straightforward method to measure the dimensions and identify morphological variations in the cerebral arterial circle using the general-purpose software program Osiris. This user-friendly and portable program displays, manipulates, and analyzes medical digital images, and it has the capability to determine morphometric properties of selected blood vessels (or other anatomical structures) in humans and animals. To ascertain morphometric variations in the cerebral arterial circle, 132 brains of recently deceased fetuses, infants, and adults were dissected. The dissection procedure was first digitized, and then the dimensions were measured with Osiris software. Measurements of each vessel's length and external diameters were used to identify and classify morphological variations in the cerebral arterial circle. The most commonly observed anatomical variations were uni- and bilateral hypoplasia of the posterior communicating artery. This study demonstrates that public domain software can be used to measure and classify cerebral arterial circle vessels. This method could be extended to examine other anatomical regions or to study other animals. Additionally, knowledge of variations within the circle could be applied clinically to enhance diagnostic and treatment specificity.

Occurrence of Angiographic Femoral Artery Complications After Vascular Closure with Mynx and AngioSeal

Journal of Neurointerventional Surgery. Jan, 2012  |  Pubmed ID: 22266794

IntroductionThere have been recent reports of high vascular complication rates after the use of the Mynx vascular closure device (VCD). At our institution, vascular complications due to these devices have rarely been encountered. A study was undertaken to retrospectively compare angiographic abnormalities seen after femoral artery closure by both the Mynx and AngioSeal VCDs to provide further insight into the risks associated with VCDs.MethodsAll adult patients who underwent deployment of either a Mynx or AngioSeal VCD and subsequently underwent repeat angiography within the next 30 days between 1 July 2010 and 1 April 2011 were reviewed. Two independent blinded radiologists compared blinded pre-procedure and follow-up femoral angiograms for the presence of pseudoaneurysm or other vascular abnormality. Hospital records were reviewed for major or minor complications of the groin site or femoral artery.ResultsThirty patients (31 angiograms) underwent vascular closure with a Mynx and 57 patients (69 angiograms) received an AngioSeal. The average time elapse until repeat femoral angiography was 6.2 days (range 1-21, median 5.5 days) in the Mynx group and 6.3 days (range 0-30, median 5 days) in the AngioSeal group. Two pseudoaneurysms and one minor stenosis were identified in the AngioSeal group. No angiographic abnormalities were seen in the Mynx group. No intraluminal filling defects were demonstrated on any of the follow-up femoral angiograms. One patient who received an AngioSeal developed a delayed minor groin site hematoma that did not require surgical intervention.ConclusionsAngiographic complications were seen in only 3% of patients after closure with Mynx or AngioSeal VCDs. There were no clinically significant groin site or vascular complications. These data suggest that both VCDs are safe for use after angiography with a low rate of femoral artery complications.

Resection of a Pontine Cavernous Malformation Via an Endoscopic Endonasal Approach: A Case Report

Neurosurgery. Jan, 2012  |  Pubmed ID: 22286343

BACKGROUND AND IMPORTANCE: Cavernous malformations of the brainstem are a dilemma to decide when to operate, and also remain difficult to access surgically. We present a novel approach for resection of a brainstem cavernous malformation CLINICAL PRESENTATION: A 59 year-old female presented with a one-month history of intermittent dysarthria, right facial weakness, and left arm and leg weakness. A magnetic resonance image revealed a 2cm mass in the pons with blood products of differing ages, consistent with a cavernous malformation. We discussed with her the risks of surgical resection, as well as conservative management. She decided to pursue conservative management. Two weeks later she returned to the emergency room with diplopia and left sided hemiplegia. Acute hemorrhage within the right pons was seen. She then chose to undergo surgical resection. CONCLUSION: The patient underwent an endoscopic, transnasal approach for resection of a pontine cavernous malformation. Image guidance was used to identify key anatomic landmarks. A gross total resection was achieved without new neurologic deficits. With physical and occupational therapy she developed antigravity strength in her left upper and lower extremity prior to discharge. At her 4 week follow up she is ambulating independently, with the assistance of a cane. We report the successful gross total resection of a pontine cavernous malformation via an endoscopic, transnasal approach. This patient had improvement in neurologic symptoms after surgical resection with minimal surgical morbidity. Technologic advances in endoscopic skull base approaches have provided access to lesions of the skull base previously requiring more invasive approaches.

Endovascular Intervention for Acute Stroke Due to Infective Endocarditis

Neurosurgical Focus. Feb, 2012  |  Pubmed ID: 22296678

The overall incidence of neurological complications due to infective endocarditis is as high as 40%, with embolic infarcts more common than hemorrhagic strokes. The standard of care for typical strokes does not apply to infective endocarditis because there is a substantial risk of hemorrhage with thrombolysis. In the last decade there have been multiple case reports of intravenous and intraarterial thrombolysis with successful outcomes for acute strokes with related infective endocarditis, but successful endovascular interventions for acute strokes associated with infective endocarditis are rarely reported. To the authors' knowledge, this report is the first case in the literature to use a mechanical retrieval device in successful vegetation retrieval in an infective endocarditis acute stroke. Although an interventional approach for treatment of acute stroke related to infective endocarditis is a promising option, it is controversial and a cautious clinical decision should be made on a case-by-case basis. The authors conclude that this approach can be tested in a case series with matched controls, because this condition is rare and a randomized clinical trial is not a realistic option.

Reduction of Catheter-associated Urinary Tract Infections Among Patients in a Neurological Intensive Care Unit: a Single Institution's Success

Journal of Neurosurgery. Jan, 2012  |  Pubmed ID: 22224785

Object To date, there has been a shortage of evidence-based quality improvement initiatives that have shown positive outcomes in the neurosurgical patient population. A single-institution prospective intervention trial with continuous feedback was conducted to investigate the implementation of a urinary tract infection (UTI) prevention bundle to decrease the catheter-associated UTI rate. Methods All patients admitted to the adult neurological intensive care unit (neuro ICU) during a 30-month period were included. The study consisted of two 1-month preintervention observation periods (approximately 1200 catheter days) followed by a 30-month intervention phase (20,394 catheter days). A comprehensive evidence-based UTI bundle encompassing avoidance of catheter insertion, maintenance of sterility, product standardization, and early catheter removal was enacted. Results The urinary catheter utilization rate dropped from 100% to 73.3% during the intervention phase (p < 0.0001) without any increase in the rate of sacral decubitus ulcers or other skin breakdown. The rate of catheter-associated UTI was also significantly reduced from 13.3 to 4.0 infections per 1000 catheter days (p < 0.001). There was a linear relationship between the decreased quarterly catheter utilization rate and the decreased catheter-associated UTI rate (r(2) = 0.79, p < 0.0001). Conclusions This single-center prospective study demonstrated that a comprehensive UTI prevention bundle along with a continuous quality improvement program can significantly reduce the duration of urinary catheterization and rate of catheter-associated UTI in a neuro ICU.

Higher Complications and No Improvement in Mortality in the ACGME Resident Duty-Hour Restriction Era: An Analysis of Over 107,000 Neurosurgical Trauma Patients in the Nationwide Inpatient Sample Database

Neurosurgery. Jan, 2012  |  Pubmed ID: 22227483

BACKGROUND: The ACGME resident duty-hour restrictions were implemented in July 2003 based on the supposition that resident fatigue contributes to medical errors. OBJECTIVE: To examine the effect of duty-hour restrictions on outcome in neurotrauma patients. METHODS: The Nationwide Inpatient Sample database (NIS) was analyzed for a time period with no restrictions (years 1999-2002) compared to a period with restrictions (years 2005-2008) for: 1) mortality and 2) complications. We analyzed both teaching and non-teaching hospitals to account for potential differences due to non-resident related factors. RESULTS: There were 107,006 teaching hospital and 115,604 non-teaching hospital admissions for neurotrauma. Multivariate logistic regression demonstrated, in teaching hospitals, significantly higher complications in the time period with restrictions. In non-teaching hospitals, there was no difference in complications. In both teaching and non-teaching hospitals, there was no difference in mortality between the two time periods. For teaching and non-teaching hospitals, there was no difference in length of stay, but hospital charges were significantly higher in the period with restrictions. The occurrence of a complication was significantly associated with longer length of stay and higher hospital charges in both time periods in both teaching and non-teaching hospitals. CONCLUSION: The implementation of the ACGME resident duty-hour restrictions was associated with increased complications and no change in mortality for neurotrauma patients in teaching hospitals. In non-teaching hospitals, there was no change in complications and mortality. The occurrence of a complication was associated with longer length of stay and higher hospital charges in both time periods in both teaching and non-teaching hospitals.

Intentional Partial Coiling Dome Protection of Complex Ruptured Cerebral Aneurysms Prevents Acute Rebleeding and Produces Favorable Clinical Outcomes

Acta Neurochirurgica. Jan, 2012  |  Pubmed ID: 22068717

The coiling of ruptured cerebral aneurysms protects against acute rebleeding; however, whether partially coiling a ruptured cerebral aneurysm protects against acute rebleeding has never been demonstrated.