In JoVE (1)

Other Publications (58)

Articles by Rafael G. Sola in JoVE

 JoVE Medicine

Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients

1Neurosurgery & National Reference Unit for the Treatment of Refractory Epilepsy, Instituto de Investigación Sanitaria Hospital de la Princesa, 2Clinical Neurophysiology & National Reference Unit for the Treatment of Refractory Epilepsy, Instituto de Investigación Sanitaria Hospital de la Princesa, 3CONICET

JoVE 54746

Other articles by Rafael G. Sola on PubMed

Effects of Surgical Treatment on Intellectual Performance and Memory in a Spanish Sample of Drug-resistant Partial Onset-temporal Lobe Epilepsy Patients

Seizure. Apr, 2002  |  Pubmed ID: 12018957

Knowledge of the effects of surgical treatment of epilepsy on mnesic functions has been steadily increasing in recent years. However, while some authors claim that this function remains seriously impaired after surgery, others argue that there is some recovery. In this study, we compare the pre- and post-operative results (one-year follow-up) of 55 patients (30 with right-temporal localization and 25 with left) suffering from drug-resistant partial-temporal epilepsy. Results of pre-surgical evaluation show that 42% of the patients had memory alterations of both verbal and visuo-spatial types, this group being made up of those patients that had been ill for longest (mean of 20 years). The remaining patients showed more specific deficits related to a particular type of information. Post-surgical results show that the general IQ increase was significant, even though no significant differences were found for general memory.Nevertheless, patients with right-temporal localization showed considerable improvement in verbal memory tasks (contralateral to the area operated on), while the performance of patients with left-temporal localization deteriorated slightly in these tasks (ipsilateral to the area operated on). In the visual memory tests no changes occurred in any of the groups.

Spanish Language Mapping Using MEG: a Validation Study

NeuroImage. Nov, 2002  |  Pubmed ID: 12414296

The purpose of the present study was to compare magnetoencephalography (MEG) data with the results of the intracarotid amytal procedure (IAP). Twenty-one native Spanish-speaking patients with intractable epilepsy underwent MEG language mapping. A subset of 8 patients also underwent an IAP. With the exception of 2 patients who showed right hemisphere dominance, all other patients showed left hemisphere dominance for language on the MEG recording. The IAP findings were consistent with MEG results in 7 patients. The eighth patient who, according to the MEG data, had probable right hemisphere dominance for language did not show clear hemispheric specialization for language on the IAP and suffered a transient global aphasia following a right temporal lobotomy. These results suggests that MEG-based language mapping can play an important role in presurgical clinical evaluation.

Dipole Density of Low-frequency and Spike Magnetic Activity: a Reliable Procedure in Presurgical Evaluation of Temporal Lobe Epilepsy

Journal of Clinical Neurophysiology : Official Publication of the American Electroencephalographic Society. Jul-Aug, 2004  |  Pubmed ID: 15509915

Conventional visual analysis and dipole density analysis of magnetoencephalographic data for both spike and low-frequency magnetic activity were compared for presurgical evaluation in temporal lobe epilepsy (TLE) in a sample of 26 drug-resistant operated TLE patients. A series of logistic regression analyses were performed. Dipole density sensitivity was superior to visual localization analysis. Three separated logistic models were calculated for interictal spikes, low-frequency magnetic activity, and the combination of both measures. A combined interictal spike/low-frequency magnetic activity model predicted correctly the operated temporal lobe in all patients. Clear-cut criteria for the probability model are proposed that are valid for 92.3% of cases in the sample. The quantitative approach proposed by this study is an evidence-based model for presurgical evaluation of temporal lobe epilepsy, which improves previous magnetoencephalographic investigations and establishes working clinical criteria for patient evaluation in TLE.

Voltage Sources in Mesial Temporal Lobe Epilepsy Recorded with Foramen Ovale Electrodes

Clinical Neurophysiology : Official Journal of the International Federation of Clinical Neurophysiology. Dec, 2006  |  Pubmed ID: 17029955

We introduce a monopole model to examine the sources of ictal and interictal activity in mesial temporal lobe epilepsy (MTLE) recorded using foramen ovale electrodes (FOE).

Synchronization Clusters of Interictal Activity in the Lateral Temporal Cortex of Epileptic Patients: Intraoperative Electrocorticographic Analysis

Epilepsia. Feb, 2008  |  Pubmed ID: 17825075

Drug-resistant temporal lobe epilepsy (TLE) can be treated by tailored surgery guided by electrocorticography (ECoG). Although its value is still controversial, ECoG activity can provide continuous information on intracortical interactions that may be useful to understand the pathophysiology of TLE. The goal of this study is to characterize local interactions in multichannel ECoG recordings of the lateral cortex of TLE patients using three synchronization measures and to link this information with surgical outcome.

Skin Erosion over Implants in Deep Brain Stimulation Patients

Stereotactic and Functional Neurosurgery. 2008  |  Pubmed ID: 18270483

We analyzed factors associated with skin erosion in 55 patients treated with deep brain stimulation (Kinetra or Soletra) for Parkinson's (PD) or other diseases. Nine of 55 patients developed erosion, all of whom were PD patients who had been fitted with a Kinetra device (r = 0.9292; p < 0.005). Erosions may be due to an increased pressure over the skin resulting from the larger size and weight of the Kinetra device. Alternatively, erosions in patients with the Kinetra device and bilateral leads may arise from the larger size of the 2 extension wires into the same subcutaneous tunnel and from the larger size of the 2 close parieto-occipital connections on the same cranial side. In PD patients, erosions were not related to age, immobility or PD severity. Specific studies examining the role of the skin of PD patients in erosion development and the use of smaller stimulation systems may help minimize the erosion rate.

Morbidity Associated with the Use of Foramen Ovale Electrodes

Epilepsia. Mar, 2008  |  Pubmed ID: 18494094

The identification of the epileptic zone in patients with mesial temporal lobe epilepsy sometimes requires intracranial recordings, for example, with foramen ovale electrodes (FOE). This paper reviews and analyzes the resulting complications in a series of patients studied with bilateral FOE for presurgical evaluation.

Chordoid Glioma of the Third Ventricle Attached to the Optic Chiasm. Successful Removal Through a Trans-lamina Terminalis Approach

Clinical Neurology and Neurosurgery. Sep, 2008  |  Pubmed ID: 18597929

Chordoid glioma of the third ventricle constitutes a rare, very recently recognized histological entity. Most reports of this neoplasm, focused on its distinct histological features, have hypothesized about a probable origin of the lesion at the third ventricle floor and/or the lamina terminalis. We report on a new case, presenting neuroradiological and intraoperative pictorial evidences of the tumoral attachment, limited to the chiasm-lamina terminalis junction. A 53-year-old woman debuted with acute symptoms of obstructive hydrocephalus, visual disturbances and confusion. MRI investigation showed a large solid-cystic third ventricle mass bulging through the lamina terminalis and ventricular floor. After placing a ventriculoperitoneal shunt, the tumor was completely removed through a trans-lamina terminalis approach. A tight tumoral attachment to the junction of the posterior chiasm to the lamina terminalis was identified and dissected. No other adhesions to the third ventricle boundaries were found. A chordoid glioma was diagnosed on histological examination. One year after the surgical procedure the patient does not present new neurological deficits, and there are no signs of tumoral regrowth on the follow-up postoperative MRI. Chordoid glioma should be included in the differential diagnosis of third ventricle tumors. Preoperative neuroradiological suspicion of this lesion should alert the neurosurgeon about the presence of a tight tumoral adherence at the level of the chiasm-lamina terminalis junction. The trans-lamina terminalis approach provides a suitable route for an early control of this attachment under direct vision, allowing a safe dissection of the mass from the third ventricle.

First True Initial Ictal SPECT in Partial Epilepsy Verified by Electroencephalography

Neuropsychiatric Disease and Treatment. Feb, 2008  |  Pubmed ID: 18728803

Drug-resistant epilepsy can sometimes be treated by surgery. In these cases, an accurate identification of the epileptogenic area must be addressed before resection. Ictal SPECT is one of the presurgical evaluations that can be performed, but usually, the increase in the regional cerebral perfusion observed is produced by diffusion of ictal activity. Here we describe a patient studied with v-EEG and foramen ovale electrodes that suffered a seizure after intravenous infusion of etomidate. The sequence of etomidate administration, followed by radiotracer and seizure was good enough for us to suspect that a true initial ictal SPECT was observed. We have implemented a kinetic model with four compartments, previously described (Andersen 1989), in order to estimate the fraction of hydrophilic radiotracer in the brain during the pre-ictal and ictal periods. This model has shown that the fraction of hydrophilic radiotracer during the seizure into the brain would be between 18.9% and 42.3% of total infused. We show the first true initial ictal SPECT demonstrated by bioelectrical recordings of the brain activity, obtained by a correct succession of events and compatible with theoretical data obtained from the kinetic model.

Complex Network Analysis of Human ECoG Data

Neuroscience Letters. Dec, 2008  |  Pubmed ID: 18848970

Localization of the epileptogenic zone (EZ) is an important issue in epileptology, even though there is not a unique definition of the epileptic focus. By using complex network analysis of electrocorticographic (ECoG) data we identify three singular areas in the temporal lobe of epileptic patients, the node with highest local synchronization power, the most connected node, and the node with highest interactions load. Connectivity in the data is extracted from the Minimum Spanning Tree (MST) of global correlations. We address the question whether removal of these nodes during the surgery is crucial in the suppression or reduction in the quantity of post-operative seizures. From five ECoG records, local areas with high synchronization power appear to be significantly involved in the development of epileptic seizures. The other two areas seem not to be fundamental in the seizures onset and development. Moreover, the approach proposed shed new light in cortical connectivity patterns in the human temporal lobe. All the analyzed records are during the inter-ictal state.

Cavernous Angiomas of the Lateral Ventricles

Acta Neurochirurgica. Feb, 2009  |  Pubmed ID: 19194650

Cavernous angiomas are vascular malformations which rarely involve the cavities of the lateral ventricles. Knowledge of the specific clinical and neuroradiological features displayed by these lesions is limited by the scarcity of patients included in the reported series.

Alterations of the Microvascular Network in Sclerotic Hippocampi from Patients with Epilepsy

Journal of Neuropathology and Experimental Neurology. Aug, 2009  |  Pubmed ID: 19606060

The main hallmarks of human hippocampal sclerosis are neuronal loss and gliosis; reductions in microvasculature labeling in the cornu Ammonis 1 in this condition have been detected using alkaline phosphatase histochemistry. To determine whether the reduction in alkaline phosphatase activity is coupled with a loss of blood vessels,we examined the volume fraction occupied by blood vessels in toluidine blue-stained hippocampal sections from 24 epilepsy patient resections (19 with hippocampal sclerosis, 5 without hippocampal sclerosis) and 5 normal autopsy controls. Light and electron microscopy and immunohistochemistry were used to determine the distribution of collagen Type IV in relation to the fine structure of the hippocampal microvascular network. We found a consistent and highly significant loss of microvessels in the sclerotic hippocampal cornu Ammonis 1 field; a variety of vascular alterations including spinelike protrusions, disruptions, and atrophic branching, were observed in the remaining blood vessels. We suggest that blood vessel alterations are an additional pathological hallmark of hippocampal sclerosis associated with temporal lobe epilepsy and that they may relate to the pathogenesis of this condition.

Kernohan-Woltman Notch Phenomenon Caused by an Acute Subdural Hematoma

Journal of Clinical Neuroscience : Official Journal of the Neurosurgical Society of Australasia. Dec, 2009  |  Pubmed ID: 19766003

Uncal herniation through the tentorial notch is occasionally associated with false localizing ipsilateral hemiparesis, known as the Kernohan-Woltman notch phenomenon (KWNP). We report an 81-year-old female who presented with a decreased level of consciousness, a right mydriasis and an ipsilateral motor deficit caused by a large right hemispheric subdural hematoma that was immediately evacuated. The patient recovered well, although her right hemiplegia persisted. A follow-up MRI showed a residual lesion in the left cerebral peduncle, corresponding to KWNP. The presence of such a structural lesion suggests a poor prognosis for recovery from the initial motor deficit.

Monitoring of Motor and Somatosensory Systems in a 26-week Pregnant Woman

Acta Neurochirurgica. Jul, 2010  |  Pubmed ID: 20084411

We report the case of a 34-year-old woman who was 26 weeks pregnant and needed a brain surgery.

[Giant Epicranial Pseudocyst Following Disconnection from a Ventriculoperitoneal Shunt System]

Revista De Neurologia. Feb 1-15, 2010  |  Pubmed ID: 20146192

Etomidate Accurately Localizes the Epileptic Area in Patients with Temporal Lobe Epilepsy

Epilepsia. Apr, 2010  |  Pubmed ID: 20163444

A variety of drugs have been used to activate and identify the epileptogenic area in patients during presurgical evaluation. We have evaluated the safety and usefulness of etomidate in identifying the epileptic zone by measuring bioelectrical brain activity and cerebral blood flow (CBF).

Treatment of Refractory Epilepsy in Adult Patients with Right-sided Vagus Nerve Stimulation

Epilepsy Research. Jun, 2010  |  Pubmed ID: 20488666

Vagus nerve stimulation (VNS) was introduced as a novel method for the treatment of patients with medically and/or surgically refractory epilepsy. VNS typically involves placement of the electrode on the left vagus nerve. However, there are some patients who cannot be implanted on this side because of complications related to the surgical procedure or side effects or infections forcing the left side VNS (L-VNS) explant. Because right side VNS (R-VNS) implants have shown similar effectiveness compared to L-VNS in reducing the frequency of seizures in animal models, treatment with R-VNS should be considered in patients who may not tolerate L-VNS. We present two adult patients who underwent R-VNS. One of the patients improved dramatically after L-VNS, but the device had to be removed because of mechanical malfunction. This patient was thought to be at high risk for nerve injury if L-VNS reimplantation was done, thus R-VNS was chosen. In the other patient, L-VNS was first attempted, but the operation had to be stopped due to significant bleeding caused by the accidental tearing of an ectopic vein. Both patients had a marked reduction in their seizure activity and none of them had cardiac side effects from therapeutic R-VNS. We conclude that R-VNS therapy is an alternative, promising therapy for reducing seizure activity in those patients who cannot undergo L-VNS implantation. Close follow-up and frequent ECG monitoring is required to detect the presence of cardiac side effects.

[Hemispheric Transcranial Electrical Stimulation: Clinical Results]

Revista De Neurologia. Jul, 2010  |  Pubmed ID: 20602311

Transcranial electrical stimulation (TES) is a technique widely used in intraoperative neurophysiological monitoring. However, there are theoretical limitations to their use in supratentorial surgery.

[Differential Contribution of Preoperatory Studies to Diagnosis in Temporal Lobe Epilepsy Surgery]

Revista De Neurologia. Oct, 2010  |  Pubmed ID: 20859920

It is necessary to know the degree of concordance of preoperative studies in temporal lobe epilepsy (TLE). AIM. To analyze the relative importance of different preoperative tests (vEEG, EEG, SPECT and MRI), the degree of agreement between them, and to develop a Bayesian probability model for diagnosis.

[Acute Interhemispheric Subdural Haematoma in a Patient with Cirrhosis]

Revista De Neurologia. Oct, 2010  |  Pubmed ID: 20859927

What Do Changes in Brain Perfusion Induced by Etomidate Suggest About Epilepsy in Human Patients?

Epilepsy Research and Treatment. 2010  |  Pubmed ID: 22937226

Epilepsy is one of the major neurological disorders, affecting roughly 1-2% of the world's population, of which approximately 20-25% of patients are drug resistant. A variety of drugs have been used to activate and identify the epileptic area in patients during presurgical evaluation. We studied the cerebral blood flow (CBF) by single photon-emission computed tomography (SPECT) and bioelectrical brain activity responses to etomidate in 11 patients. Etomidate (0.1 mg/kg) was administered while patients were monitored by video-electroencephalography with foramen ovale electrodes (FOEs). After etomidate administration, a brief period of high-frequency activity was observed, followed by a generalized, high-voltage delta pattern. Increased regional CBF was observed bilaterally in thalamus, putamen, and posterior hippocampus. Besides, the only interhemispheric difference was observed in the posterior hippocampus, where CBF decreased in the epileptic temporal lobe. Activation by etomidate induces a specific and repetitive response in the bioelectrical activity. In addition, CBF changes induced by etomidate may serve as a diagnostic tool in the near future.

Impaired Mesial Synchronization in Temporal Lobe Epilepsy

Clinical Neurophysiology : Official Journal of the International Federation of Clinical Neurophysiology. Jun, 2011  |  Pubmed ID: 21185775

Temporal lobe epilepsy is commonly associated with synchronous, hyper-synchronous and des-synchronous activity. The aim of the present work is to explore synchronization activity in both mesial areas in temporal lobe epileptic patients during the interictal state.

[Significance of Complex Analysis of Electrical Activity in Temporal Lobe Epilepsy: Foramen Ovale Electrodes Records]

Revista De Neurologia. Jan, 2011  |  Pubmed ID: 21246488

Temporal lobe epilepsy (TLE) is commonly associated with the process of synchronisation during the interictal stage, which show up as 'spikes' on neurophysiological recordings, and also with hypersynchronic activity during clinical seizures. Nevertheless, desynchronisation also seems to play an important role in the epileptogenic process, favouring the onset of seizures.

[Psychogenic Non-epileptic Seizures in an Epilepsy Surgery Unit]

Revista De Neurologia. Apr, 2011  |  Pubmed ID: 21425097

The psychogenic non-epileptic seizures (PNES) represent a significant percentage of patients in different units of epilepsy surgery. AIMS. To analyze the characteristics of patients with PNES and compared with epileptic patients, to analyze the early response to the application of placebo and to discuss the multidisciplinary approach to these patients.

[Family History of Epilepsy Resistant to Treatment]

Revista De Neurologia. May, 2011  |  Pubmed ID: 21484723

Family aggregation can help determine the risk of epilepsy among relatives. Our aims are to describe the prevalence of family precedents of epilepsy among the diagnosed patients' relatives of the first and second degree, and to look for an association with diverse clinical variables.

[Thalamic Deep Brain Stimulation for Refractory Epilepsy]

Revista De Neurologia. Jul, 2011  |  Pubmed ID: 21720980

Epilepsy is a neurological disorder that affects 1-2% of the population. Despite the available treatments (drug therapy, resective surgery, vagus nerve stimulation), there is a significant subgroup of patients that continues to have disabling seizures. The indications of deep brain stimulation are exponentially growing, and there is a wide experience with deep brain stimulation (DBS) for the treatment of abnormal movements. DBS for epilepsy may be a new therapy for the subgroup of patients that remain disabled despite other treatments. Experiments with animal models, and the new advances in our knowledge about the neurophysiological processes that govern the genesis of epilepsy, have led to the selection of various brain targets for stimulation. The thalamus is a fundamental relay centre in the corticothalamic and corticostriatal thalamocortical circuits, and it has been studied with this purpose. Studies on epileptic patients have shown various degrees of effectiveness; however, controlled studies do not permit definitive conclusions about the role of DBS in the treatment of epilepsy. Probably a better patient selection would lead to more decisive conclusions. Further randomised studies are needed to draw reliable conclusions and scientific evidence on the effectiveness of DBS for refractory epilepsy.

[Neurosurgical Techniques for the Neuromodulation of Pain]

Revista De Neurologia. Dec, 2011  |  Pubmed ID: 22086430

Neuromodulation for treating pain goes back to the times of the ancient Egyptians, who applied natural electric currents to modulate the painful sensation. Since then, this concept has been developed in parallel with the scientific and technological development, and various forms of neuromodulation with different indications and characteristics have originated. Chronic pain may produce significant disability, which leads to important physical, social and psychological consequences. Peripheral nerve, spinal cord, deep brain and motor cortex stimulation are safe and effective techniques that control pain and improve quality of life in selected patients.

[Intracerebral Neurenteric Cysts in Newborn Infants]

Revista De Neurologia. Jul, 2012  |  Pubmed ID: 22718406

Intracranial neurenteric cysts are very infrequent congenital lesions. Within the nervous system, they are most commonly located in the rachis. Another frequent site is the craniocervical junction. Few cases of supratentorial location have been reported. A differential diagnosis is required to distinguish them from other cysts. They are not often diagnosed in the paediatric age. The clinical features they give rise to are due to the mass effect or episodes of chemical meningitis. Magnetic resonance imaging is the best diagnostic method although on many occasions they cannot be distinguished from arachnoid cysts. Treatment consists in surgery with complete resection of the membranes in order to prevent recurrences.

[Significance of Complex Analysis of Electrical Activity in Temporal Lobe Epilepsy: Electrocorticography]

Revista De Neurologia. Aug, 2012  |  Pubmed ID: 22829084

Locating and excising epileptogenic zones is the traditional treatment in pharmacoresistant temporal lobe epilepsy. Some patients, however, continue to suffer from attacks even after surgery. Therefore, new hypotheses must be formulated in order to account for the apparent shortcomings of correctly performed surgical procedures.

Extrahippocampal Desynchronization in Nonlesional Temporal Lobe Epilepsy

Epilepsy Research and Treatment. 2012  |  Pubmed ID: 22957245

Although temporal lobe epilepsy (TLE) is traditionally associated with both hypersynchronous activity in the form of interictal epileptic discharges and hippocampal sclerosis, recent findings suggest that desynchronization also plays a central role in the dynamics of this pathology. The objective of this work is to show the imbalance existing between mesial activities in patients suffering from mesial TLE, with normal mesial structures. Foramen ovale recordings from six patients with mesial TLE and one with lateral TLE were analyzed through a cluster analysis and synchronization matrices. None of the patients present findings in the MRI presurgical evaluation. Numerical analysis was carried out in three different situations: awake and sleep interictal and also during the preictal stage. High levels of desynchronization ipsilateral to the epileptic side were present in mesial TLE patients. Low levels of desynchronization were present in the lateral TLE patient during the interictal stage and almost zero in the preictal stage. Implications of these findings in relation with seizure spreading are discussed.

[Continuous Monitoring of Cortical Visual Evoked Potentials by Means of Subdural Electrodes in Surgery on the Posterior Optic Pathway. A Case Report and Review of the Literature]

Revista De Neurologia. Sep, 2012  |  Pubmed ID: 22972576

Intraoperative monitoring of functional language and motor areas is a commonly used technique which makes it possible to minimise the post-operative sequelae and to perform an optimal resection of lesions in these areas. Monitoring of the visual cortex, however, is not usually carried out nowadays. The scarce spatial resolution and its sensitivity to anaesthesia are some of the technical difficulties that reduce its clinical usefulness. The study reports a case of resection of an occipital lesion under general anaesthetic, with intraoperative monitoring of the cortical visual evoked potentials (VEP) by means of subdural electrodes.

[Neurophysiological Assisted Transsulcal Approach to a High Grade Glioma Without Affect Neither Motor nor Somatosensory Function]

Revista De Neurologia. Apr, 2013  |  Pubmed ID: 23520006

Intraoperative mapping and neuronavigation permitted a safe approach through the rolandic sulcus, minimizing the impact onto the motor or somatosensory functions. Fluorescence-guide resection defines a limit that allows a total resection without exceed the border of the tumor.

Machine Learning Approach for the Outcome Prediction of Temporal Lobe Epilepsy Surgery

PloS One. 2013  |  Pubmed ID: 23646148

Epilepsy surgery is effective in reducing both the number and frequency of seizures, particularly in temporal lobe epilepsy (TLE). Nevertheless, a significant proportion of these patients continue suffering seizures after surgery. Here we used a machine learning approach to predict the outcome of epilepsy surgery based on supervised classification data mining taking into account not only the common clinical variables, but also pathological and neuropsychological evaluations. We have generated models capable of predicting whether a patient with TLE secondary to hippocampal sclerosis will fully recover from epilepsy or not. The machine learning analysis revealed that outcome could be predicted with an estimated accuracy of almost 90% using some clinical and neuropsychological features. Importantly, not all the features were needed to perform the prediction; some of them proved to be irrelevant to the prognosis. Personality style was found to be one of the key features to predict the outcome. Although we examined relatively few cases, findings were verified across all data, showing that the machine learning approach described in the present study may be a powerful method. Since neuropsychological assessment of epileptic patients is a standard protocol in the pre-surgical evaluation, we propose to include these specific psychological tests and machine learning tools to improve the selection of candidates for epilepsy surgery.

Long-term Results of Posteromedial Hypothalamic Deep Brain Stimulation for Patients with Resistant Aggressiveness

Journal of Neurosurgery. Aug, 2013  |  Pubmed ID: 23746102

Erethism describes severe cases of unprovoked aggressive behavior, usually associated with some degree of mental impairment and gross brain damage. The etiology can be epileptic, postencephalitic, or posttraumatic, or the condition can be caused by brain malformations or perinatal insults. Erethism is often refractory to medication, and patients must often be interned in institutions, where they are managed with major restraining measures. The hypothalamus is a crucial group of nuclei that coordinate behavioral and autonomic responses and play a central role in the control of aggressive behavior. Deep brain stimulation (DBS) of the posteromedial hypothalamus (PMH) has been proposed as a treatment for resistant erethism, although experience with this treatment around the world is scarce. The objective of this study was to examine the long-term outcome of PMH DBS in 6 patients with severe erethism treated at the authors' institution.


Journal of Neurosurgery. Aug, 2013  |  Pubmed ID: 23905718

Deep Brain Stimulation of the Subcallosal Cingulate for Medication-resistant Type I Bipolar Depression: Case Report

Bipolar Disorders. Sep, 2013  |  Pubmed ID: 23930934

Deep Brain Stimulation of the Centromedian Thalamic Nucleus for the Treatment of Generalized and Frontal Epilepsies

Epilepsia. Oct, 2013  |  Pubmed ID: 24032641

Deep brain stimulation (DBS) of the thalamus is an emerging surgical option for people with medically refractory epilepsy that is not suitable for resective surgery, or in whom surgery has failed. Our main aim was to evaluate the efficacy of bilateral centromedian thalamic nucleus (CMN) DBS for seizure control in generalized epilepsy and frontal lobe epilepsy with a two-center, single-blind, controlled trial.

Role of Intraoperative Neurophysiological Monitoring During Fluorescence-guided Resection Surgery

Acta Neurochirurgica. Dec, 2013  |  Pubmed ID: 24072425

Fluorescence-guided resection (FGR) using 5-aminolevulinic acid (5-ALA) exhibits a potential risk of permanent neurological deficits that can be minimized using intraoperative neurophysiological monitoring (IONM). We assessed the role of IONM in FGR surgery in patients harboring tumors in or near eloquent areas.

Primary Central Neurocytoma of the Mesencephalic Tectum in a Pediatric Patient

Child's Nervous System : ChNS : Official Journal of the International Society for Pediatric Neurosurgery. May, 2014  |  Pubmed ID: 23958899

Neurocytomas are tumors or neuronal differentiation, typically located within the supratentorial ventricular system. The extraventricular location is uncommon. A limited number of cases involving the brainstem have been reported and may be misdiagnosed as brainstem gliomas. Furthermore, midbrain neurocytomas are extremely rare, and no similar cases in pediatric patients have been reported in the literature to date. Brainstem location of neurocytomas often precludes gross total removal of the lesion, and in these cases, adjuvant therapies may be helpful.

Influence of Paroxysmal Activity on Background Synchronization in Epileptic Recordings

Journal of Neuroscience Methods. Feb, 2014  |  Pubmed ID: 24333290

The presence of spikes and sharp waves in recordings of epileptic patients contaminates background signal synchronization. When estimating functional connectivity between extended cortical areas, the influence of epileptic spikes in specific areas should be considered; however, this step is sometimes overlooked. We present a simple method for quantifying the influence of epileptic activity on background signal synchronization.

Aggressive Behavior. Response

Journal of Neurosurgery. Jan, 2014  |  Pubmed ID: 24520574

[Functional Connectivity and Complex Networks in Focal Epilepsy. Pathophysiology and Therapeutic Implications]

Revista De Neurologia. May, 2014  |  Pubmed ID: 24777769

The traditional surgical approach to treat drug-resistant focal epileptic patients is in the resection or disconnection of the epileptic focus. However, a significant minority of patients continue to experience seizures after surgery, which shows the incomplete level of knowledge that currently we have of this pathology.

[Electroclinical Characteristics of a Patient with Ring Chromosome 20 Syndrome]

Revista De Neurologia. May, 2014  |  Pubmed ID: 24819941

The ring chromosome 20 syndrome (r20) is a rare genetic disorder with a late diagnosis.

Plasma Albumin Induces Cytosolic Calcium Oscilations and DNA Synthesis in Human Cultured Astrocytes

BioMed Research International. 2014  |  Pubmed ID: 24967376

So far, a little is known about transition from normal to focal epileptic brain, although disruption in blood-brain barrier and albumin had recently involved. The main objective of this work is to characterize the response of cultured human astrocytes to plasma albumin, including induction of DNA synthesis. Cortical tissue was obtained from 9 patients operated from temporal lobe epilepsy. Astrocytes were cultured for 3-4 weeks and cytosolic calcium concentration ([Ca(2+)]c) was measured. Bovine and human plasma albumin were used. We observed that low albumin concentration decreases [Ca(2+)]c, while higher concentration, induces increase in [Ca(2+)]c. It was shown that increase in [Ca(2+)] c was mediated by inositol 1,4,5-trisphosphate and released from internal stores. Increase in [Ca(2+)]c was reduced to 19% by blocking the transforming growth factor-beta (TGF-βR) receptor. Albumin induces DNA synthesis in a dose-response manner. Finally, induction of DNA synthesis can be partially blocked by heparin and block of TGF-β; however, the combination of both incompletely inhibits DNA synthesis. Therefore, results suggest that mechanisms other than Ca(2+) signals and TGF-β receptor activation might induce DNA synthesis in a lesser degree. These results may be important to further understand the mechanisms involved in the transition from normal to focal epileptic brain.

[Chronic Subdural Haematomas. The Internal Architecture of the Haematoma As a Predictor of Recurrence]

Revista De Neurologia. Oct, 2014  |  Pubmed ID: 25245873

The internal architecture of a chronic subdural haematoma (CSDH) is an important factor that must be taken into account as a predictor of recurrence.

Integrating Diffusion Tensor Imaging-based Tractography into Deep Brain Stimulation Surgery: a Review of the Literature

Stereotactic and Functional Neurosurgery. 2014  |  Pubmed ID: 25248076

It has been generally accepted that deep brain stimulation (DBS) not only acts in the nucleus where it is being applied, as initially thought, but that chronic stimulation activates axons located in its scope, and that this activation can exert its effects in distant areas. Considering this, DBS target identification should be made based on techniques that identify white matter tracts, such as tractography, rather than only by identifying specific nuclei on conventional magnetic resonance imaging.

Inhomogeneous Cortical Synchronization and Partial Epileptic Seizures

Frontiers in Neurology. 2014  |  Pubmed ID: 25309507

Interictal synchronization clusters have recently been described in several publications using diverse techniques, including neurophysiological recordings and fMRI, in patients suffering from epilepsy. However, little is known about the role of these hyper-synchronous areas during seizures. In this work, we report an analysis of synchronization clusters jointly with several network measures during seizure activity; we then discuss our findings in the context of prior literature.

Intrasellar Chordoma Associated with a Primitive Persistent Trigeminal Artery

Turkish Neurosurgery. 2015  |  Pubmed ID: 25640561

Chordomas located primarily in the sellar region are uncommon, and may be misdiagnosed non-functioning pituitary adenoma. Furthermore, the association of a persistent primitive trigeminal artery (PPTA) with an intrasellar chordoma is extremely rare, and no similar cases have been reported in the literature to date. The coexistence of intrasellar chordoma (ISC) and PPTA makes safe and complete tumor resection challenging, and preoperative endovascular occlusion of this artery may be helpful. We report a case of a 32-year-old man who developed right hemifacial paresthesias and a cranial nerve six palsy. MRI study demonstrated the presence of a primary ISC associated with a PPTA. Angiographic balloon test occlusion of the PPTA revealed no neurological changes, so this vessel was endovascularly occluded by coiling. The lesion was subtotally removed through a sublabial transsphenoidal approach, without intraoperative bleeding complications. Histological examination of the lesion was consistent with the diagnosis of chordoma. Detailed preoperative neurovascular evaluation may be useful to detect vascular anomalies associated with intracranial chordomas, such as PPTA. In this report we emphasize the importance of appropriate treatment of vascular anomalies prior intrasellar lesions resection that may facilitate surgery and avoid potential hazardous intraoperative bleeding complications.

[Occipital Nerve Stimulation for Refractory Chronic Migraine]

Revista De Neurologia. Jun, 2015  |  Pubmed ID: 26005075

Occipital nerve stimulation (ONS) is an emerging and promising preventive treatment for refractory chronic migraine.

[Stimulation of the Centromedian Nucleus in Refractory Epilepsy Associated to Ring Chromosome 20]

Revista De Neurologia. Jun, 2015  |  Pubmed ID: 26062827

Ring chromosome 20 syndrome is a rare genetic disorder, with a late diagnosis.

Identification of Redundant and Synergetic Circuits in Triplets of Electrophysiological Data

Journal of Neural Engineering. Dec, 2015  |  Pubmed ID: 26447632

Neural systems are comprised of interacting units, and relevant information regarding their function or malfunction can be inferred by analyzing the statistical dependencies between the activity of each unit. While correlations and mutual information are commonly used to characterize these dependencies, our objective here is to extend interactions to triplets of variables to better detect and characterize dynamic information transfer.

Disrupted Ipsilateral Network Connectivity in Temporal Lobe Epilepsy

PloS One. 2015  |  Pubmed ID: 26489091

The current practice under which patients with refractory epilepsy are surgically treated is based mainly on the identification of specific cortical areas, mainly the epileptogenic zone, which is believed to be responsible for generation of seizures. A better understanding of the whole epileptic network and its components and properties is required before more effective and less invasive therapies can be developed. The aim of the present study was to partially characterize the evolution of the functional network during the preictal-ictal transition in partial seizures in patients with temporal lobe epilepsy (TLE).

Assessing the Equivalence Between Etomidate and Seizure Network Dynamics in Temporal Lobe Epilepsy

Clinical Neurophysiology : Official Journal of the International Federation of Clinical Neurophysiology. Jan, 2016  |  Pubmed ID: 26070516

Etomidate mimics some typical epileptic neurophysiological features, such as the appearance of spikes and high frequency oscillations, when it is administrated to epileptic patients. However, little is known about its influence on the underlying cortical network. An assessment of comparable cortical dynamics between seizures and etomidate would allow for a more detailed study of the network parameters underlying the ictal stage by using etomidate as a proxy. The objective of the present work is to show that temporal lobe seizures produce network changes comparable to the ones elicited by etomidate administration.

Infratentorial Angioleiomyoma: Case Report and Review of the Literature

Revista De Neurologia. Jan, 2016  |  Pubmed ID: 26758353

Intracranial angioleiomyomas are extremely rare lesions. Only 22 intracranial angioleiomyomas have been described in the literature and only three were infratentorial.

[Classification of Structural Lesions in Magnetic Resonance Imaging. Surgical Implications in Drug-resistant Epilepsy Patients. Reply]

Revista De Neurologia. Jan, 2016  |  Pubmed ID: 26758359

[Myelopathy Secondary to an Aneurysmal Bone Cyst of Thoracic Spine]

Revista De Neurologia. Feb, 2016  |  Pubmed ID: 26815849

Spinal aneurysmal bone cysts are very infrequent benign osteolytic lesions consisting of blood-filled cavities that are separated by osteo-connective septa and osteoclast-type giant cells. Clinically they manifest with local pain, neurological symptoms secondary to spinal cord compression, and fractures, deformities and vertebral instability. We report a case of an aneurysmal bone cyst in the thoracic spine with neurological signs and symptoms treated by means of a full microsurgical resection, with no associated neurological sequelae.

Long-term Results of Deep Brain Stimulation of the Subcallosal Cingulate for Medication-Resistant Bipolar I Depression and Rapid Cycling Bipolar II Depression

Biological Psychiatry. Jun, 2016  |  Pubmed ID: 27524499

Corrigendum to "Plasma Albumin Induces Cytosolic Calcium Oscilations and DNA Synthesis in Human Cultured Astrocytes"

BioMed Research International. 2016  |  Pubmed ID: 27529065

[This corrects the article DOI: 10.1155/2014/539140.].

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