In JoVE (1)

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Articles by Jesús Pastor 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 Jesús Pastor on PubMed

Accumulating Behaviour of Lupinus Albus L. Growing in a Normal and a Decalcified Calcic Luvisol Polluted with Zn

Journal of Plant Physiology. Dec, 2003  |  Pubmed ID: 14717438

Lupinus albus L. is a leguminous plant that is starting to generate interest for the phytoremediation soils showing intermediate metal pollution. Among these metals, Zn causes major phytotoxicity problems and is common in polluted soils of central Spain. The purpose of this study was to explore the nutritional behaviour of this plant species towards increasing Zn concentrations in two calcic luvisol soils: a normal basic soil and a decalcified acid soil. For this purpose the effects of different Zn concentrations on mineral nutrition, growth, nodulation and nitrogenase activity of nodulated Lupinus albus cv. Multolupa plants has been investigated. A 12-week trial was performed in pots under greenhouse conditions. In each soil, four replicate pots were set up per treatment (100, 150, 300, 500 and 700 ppm Zn). Seeds were inoculated with a Bradyrhizobium sp. (Lupinus) strain ISLU-16. Statistical analysis of data revealed significant effects of soil Zn on grown, plant mineral composition and nodulation. Lupin growth was better in acid soil than in basic soil with the low dose of Zn applied, although plant growth in acid soil was severely affected from 300 ppm Zn, where the pH of the soil was 4.7. Zn application produce nutritional imbalances, especially with the higher dose added. Most of Zn accumulation occurred in the roots in both types of soils. In acid soil, lupin absorbs high amounts of Zn in both root (4650 ppm) and aerial part (3605 ppm), when the doses of Zn applied was 300 ppm. This feature permits Lupinus albus cv. Multolupa to be considered as potential phytoremediator and also for the revegetation of degraded landfill areas with slightly acid or neutral soils polluted with Zn.

Correlation of Transcriptome Profile with Electrical Activity in Temporal Lobe Epilepsy

Neurobiology of Disease. May, 2006  |  Pubmed ID: 16480884

The biology underlying epileptic brain activity in humans is not well understood and likely depends on changes in gene expression. We performed a microarray transcriptome profiling of 12 anterolateral temporal cortical samples originating from five individuals who suffered with temporal lobe epilepsy for at least 10 years. Prior to partial lobectomy, intraoperative electrocorticography was performed on the cortical surface of each patient. These recordings showed characteristic differences in frequency and amplitude that were defined as "spiking" (abnormal) or "non-spiking" (normal). Between the transcriptome of the two sample groups, transferrin (TF) was the most differentially expressed gene. Furthermore, gene expression profiling also revealed a downregulation of multiple GABA system-related genes (GABRA5, GABRB3, ABAT) in the spiking samples and an upregulation of oligodendrocyte and lipid metabolism transcripts (MOG, CA2, CNP, SCD, PLP1, FA2H, ABCA2). In addition, several transcripts related to the classical MAPK cascade showed expression level alterations between the spiking and non-spiking samples (G3BP2, MAPK1, PRKAR1A, and MAP4K4). Out of 12 genes chosen for verification by RT qPCR, 9 showed significant expression changes in the microarray-predicted direction. Furthermore, the microarray and qPCR data were highly correlated (r = 0.98; P < 0.001). We conclude that abnormal electrical brain activity in the spiking samples is strongly correlated with gene expression changes and we speculate that some of the observed transcriptome changes may be directly involved in the induction or prevention of the ictal events seen in epilepsy.

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).

Soil Degradation in the Tropical Forests of the Dominican Republic's Pedernales Province in Relation to Heavy Metal Contents

The Science of the Total Environment. May, 2007  |  Pubmed ID: 17307235

Two of the National Parks of the only Biosphere Reserve in the Caribbean Islands, the Jaragua-Bahoruco-Enriquillo reserve, occur mostly within the Pedernales province (Dominican Republic). In these National Parks, Jaragua and Bahoruco, almost every tropical forest ecosystem is represented, as are the land uses most common to the Dominican Republic. Despite soil being a key natural resource that needs to be considered in any sustainable development programme, the literature contains very little information on the soils of this region. In this study, we analysed 41 topsoil samples representing the main forest types and land uses of the province. The factors examined were fertility (OM, N, P, K) and heavy metal contents (Cu, Cr, Pb, Cd, Ni, Zn). Mean OM, N and total and available metal levels were almost invariably higher in the natural forest soils compared to those given over to human activities, especially cultivated soils. This difference suggests the uptake of metals by the crops and, to a lesser extent, by animals feeding on crop remains and grassland plants. This hypothesis is supported by high total and available metal contents, especially of Zn, Cu, Pb and, in smaller measure, of Cr recorded in the solid waste landfill of the city of Pedernales. It appears that the cutting down and burning practices of a nomad type of cultivation, as well as the pressures of intensive agriculture and livestock rearing have resulted in heavy metals bound to the soil's OM. We propose this is an important point to consider for the management of these lands.

Effects of Two Chelating Agents (EDTA and DTPA) on the Autochthonous Vegetation of a Soil Polluted with Cu, Zn and Cd

The Science of the Total Environment. May, 2007  |  Pubmed ID: 17307245

Chelating agents are thought to be useful for the remediation of metal-polluted soils with adequate organic matter, but the effects of these substances on the plants or seed bank of plant communities that occur in the soils are relatively unknown. In this work, the effects of two chelating substances (EDTA and DTPA) on a wet grassland plant community affected by the presence of the abandoned copper mine "Fernandito" (Garganta de los Montes, Madrid) were compared. A microcosm bioassay (6 months) was designed using the soil's top layer containing the grassland's seed bank. This soil showed a high Cu pollution level, significant contents of Zn and Cd (1120, 190, and 15 ppm, respectively), a pH of 5 and an OM content of 6.2%. The soil was subjected to three different treatments: a) untreated soil (control), b) the addition of 1 g/kg EDTA, or of c) 1 g/kg DTPA. The results presented here are those related to the plant cover, species richness, aboveground and subterranean biomass and chemical composition of the most abundant plants. Neither EDTA nor DTPA caused intense negative effects on the plants rather they significantly increased the amount of copper accumulated in aboveground parts and roots. In particular, Agrostis castellana and Corrigiola telephiifolia extracted high amounts of copper when grown in the soil with added EDTA, although they showed some nutritional imbalances (lower P contents). In contrast, lower metal concentrations were detected in plants grown in the DTPA amended soil.

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.

Low-frequency Bilateral Hypothalamic Stimulation for Treatment of Drug-resistant Aggressiveness in a Young Man with Mental Retardation

Stereotactic and Functional Neurosurgery. 2008  |  Pubmed ID: 18480600

Stereotactic bilateral electrode implantation in the medial portion of the posterior hypothalamus was performed on a 22-year-old male with drug-resistant aggressiveness. To localize the targets during implantation, microrecording was performed, and the clinical and electroencephalographic responses to intraoperative stimulation were monitored. The patient had an improved response to low-frequency stimulation that was sustained 18 months later at a follow-up examination.

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.

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.

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.

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.

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.

[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.

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.

[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.

Stability of Synchronization Clusters and Seizurability in Temporal Lobe Epilepsy

PloS One. 2012  |  Pubmed ID: 22844524

Identification of critical areas in presurgical evaluations of patients with temporal lobe epilepsy is the most important step prior to resection. According to the "epileptic focus model", localization of seizure onset zones is the main task to be accomplished. Nevertheless, a significant minority of epileptic patients continue to experience seizures after surgery (even when the focus is correctly located), an observation that is difficult to explain under this approach. However, if attention is shifted from a specific cortical location toward the network properties themselves, then the epileptic network model does allow us to explain unsuccessful surgical outcomes.

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.

Astrocyte Calcium Signal and Gliotransmission in Human Brain Tissue

Cerebral Cortex (New York, N.Y. : 1991). May, 2013  |  Pubmed ID: 22581850

Brain function is recognized to rely on neuronal activity and signaling processes between neurons, whereas astrocytes are generally considered to play supportive roles for proper neuronal function. However, accumulating evidence indicates that astrocytes sense and control neuronal and synaptic activity, indicating that neuron and astrocytes reciprocally communicate. While this evidence has been obtained in experimental animal models, whether this bidirectional signaling between astrocytes and neurons occurs in human brain remains unknown. We have investigated the existence of astrocyte-neuron communication in human brain tissue, using electrophysiological and Ca(2+) imaging techniques in slices of the cortex and hippocampus obtained from biopsies from epileptic patients. Cortical and hippocampal human astrocytes displayed spontaneous Ca(2+) elevations that were independent of neuronal activity. Local application of transmitter receptor agonists or nerve electrical stimulation transiently elevated Ca(2+) in astrocytes, indicating that human astrocytes detect synaptic activity and respond to synaptically released neurotransmitters, suggesting the existence of neuron-to-astrocyte communication in human brain tissue. Electrophysiological recordings in neurons revealed the presence of slow inward currents (SICs) mediated by NMDA receptor activation. The frequency of SICs increased after local application of ATP that elevated astrocyte Ca(2+). Therefore, human astrocytes are able to release the gliotransmitter glutamate, which affect neuronal excitability through activation of NMDA receptors in neurons. These results reveal the existence of reciprocal signaling between neurons and astrocytes in human brain tissue, indicating that astrocytes are relevant in human neurophysiology and are involved in human brain function.

Long-term Results of Vagal Nerve Stimulation for Adults with Medication-resistant Epilepsy Who Have Been on Unchanged Antiepileptic Medication

Seizure. Jan, 2013  |  Pubmed ID: 23041031

Several studies suggest that vagal nerve stimulation (VNS) is an effective treatment for medication-resistant epileptic patients, although patients' medication was usually modified during the assessment period. The purpose of this prospective study was to evaluate the long-term effects of VNS, at 18 months of follow-up, on epileptic patients who have been on unchanged antiepileptic medication.

[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.

Response to "Vagus Nerve Stimulation: Urgent Need for the Critical Reappraisal of Clinical Effectiveness"

Seizure. Jul, 2013  |  Pubmed ID: 23587867

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.

Assessment of Field Portable X-ray Fluorescence Spectrometry for the in Situ Determination of Heavy Metals in Soils and Plants

Environmental Science. Processes & Impacts. Aug, 2013  |  Pubmed ID: 23793270

In soil pollution studies, large numbers of soil samples collected at random need to be processed and analyzed to determine their heavy metal contents. This study was designed to assess the use of a field portable X-ray fluorescence (FPXRF) spectrometry system for the in situ determination of heavy metal levels in both soil and plant samples. First, we optimised the method using 84 reference soil standards and soil samples from known polluted sites. The optimised method was then used to determine heavy metals at three abandoned mine sites and two sealed landfills in central Spain. Given that knowledge of heavy metal levels in plants is important for the ecotoxicological study of these sites, the FPXRF device was also used to determine heavy metals in plants. Our results indicate the acceptable to high quality of the data provided by the system especially for soil samples. The cost-benefits and sustainability of this instrument in relation to other techniques were also examined. The use of the FPXRF system for the study of potentially polluted sites was found to save on costs, time and materials. Results indicate its suitable use for the preliminary screening of heavy-metal polluted sites.

Response

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

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.

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.

[Cortical Mapping and Neurophysiological Monitoring During Resection of an Arteriovenous Malformation in the Rolandic Region]

Revista De Neurologia. Jul, 2014  |  Pubmed ID: 24965927

INTRODUCTION. Surgery of arteriovenous malformations of eloquent areas has a significant risk of causing severe neurological deficits. CASE REPORT. A 39 years old woman having a headache, showed an arteriovenous malformation in right rolandic region. During resection, performed under general anesthesia, a neurophysiological mapping and subsequently intraoperative neurophysiological monitoring of motor and somatosensory functions was performed. The temporary closure of an artery resulted in a severe motor impairment, reversible after remove the clipping, so that artery had to be respected during the intervention. After resection, the motor and sensory responses were normal. The patient was discharged without any neurological deficits. CONCLUSION. Functional mapping and intraoperative neurophysiological monitoring were very helpful for the identification and protection of eloquent areas. The use of these techniques for resection of arteriovenous malformations located in functionally relevant areas, allows a safely surgery in patients under general anesthesia.

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.

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.

[Cortical Mapping and Neurophysiological Monitoring During Resection of an Arteriovenous Malformation in the Rolandic Region. Reply]

Revista De Neurologia. Dec, 2014  |  Pubmed ID: 25418151

4-Aryl-3,5-bis(arylethynyl)aryl-4H-1,2,4-triazoles: Multitasking Skeleton As a Self-assembling Unit

Chemistry (Weinheim an Der Bergstrasse, Germany). Jan, 2015  |  Pubmed ID: 25413614

The synthesis of a series of 4-aryl-3,5-bis(arylethynyl)aryl-4H-1,2,4-triazoles derivatives is reported and the influence exerted by peripheral substitution on the morphology of the aggregates generated from these 1,2,4-triazoles is investigated by SEM imaging. The presence of paraffinic side chains results in long fibrillar supramolecular structures, but unsubstituted triazoles self-assemble into thinner ribbons and needle-like aggregates. The crystals obtained from methoxy-substituted triazoles have been utilised to elaborate a model that helps to justify aggregation of the investigated 1,2,4-triazoles, in which the operation of arrays of C-H⋅⋅⋅π non-covalent interactions plays a significant role. The results presented herein demonstrate the ability of simple molecules to behave as multitasking scaffolds with different properties, depending on peripheral substitution. Thus, although 1,2,4-triazoles without long paraffinic side chains exhibit optical waveguiding behaviour, triazoles endowed with peripheral paraffinic side chains exhibit hexagonal columnar mesomorphism.

Heavy-Metal Phytostabilizing Potential of Agrostis Castellana Boiss. & Reuter

International Journal of Phytoremediation. 2015  |  Pubmed ID: 25789983

The soils of many abandoned mine sites in the central region of Spain are heavily polluted with a number of different metals. Having frequently found Agrostis castellana growing at these old mine sites, this study was designed to assess its remediation capacity for this type of setting. In an initial field study, plant specimens were collected from 4 abandoned mine sites to determine pollutant concentrations in their roots and shoots. This was followed by a 4-year bioassay in a controlled environment in which soils collected from the mines were used to set up microcosms. Maximum root concentrations of the most polluting elements present in the bioassay were 3625 mg kg(-1) Zn, 2793 mg kg(-1) Cu, 13042 mg kg(-1) Pb, 49 mg kg(-1) Cd and 957 mg kg(-1) As. These concentrations represent root bioaccumulation indices of over 1 and usually >2. In contrast, indices of transfer to above-ground phytomass were always < 1, indicating this species is a good candidate for use as a phytostabilizer. However, the high metal concentrations that could reach the above-ground mass of this plant determines a need for close monitoring and avoiding the use of areas under restoration for hunting or grazing.

[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.

Benefits of the Use of Sewage Sludge over EDTA to Remediate Soils Polluted with Heavy Metals

Journal of Environmental Quality. Sep, 2015  |  Pubmed ID: 26436275

Sewage sludges from urban wastewater treatment plants are often used to remediate degraded soils. However, the benefits of their use in metal-polluted soils remain unclear and need to be assessed in terms of factors besides soil fertility. This study examines the use of thermal-dried sewage sludge (TDS) as an amendment for heavy metal-polluted soil in terms of its effects on soil chemical properties, leachate composition, and the growth of native plant communities. To assess the response of the soil and its plant community to an increase in metal mobilization, the effects of TDS amendment were compared with those of the addition of a chelating agent (ethylenediaminetetraacetic acid [EDTA]). The experimental design was based on a real-case scenario in which soils from of an abandoned mine site were used in a greenhouse bioassay. Two doses of TDS and EDTA were applied to a soil containing high Pb, Zn, Cu, and Cd levels (4925, 5675, 404, and 25 mg kg, respectively). Soil pH was 6.4, and its organic matter content was 5.53%. The factors examined after soil amendment were soil fertility and heavy metal contents, leachate element losses, the plant community arising from the seed bank (plant cover, species richness and biodiversity, above/below ground biomass), and phytotoxic effects (chemical contents of abundant species). Thermal-dried sewage sludge emerged as a good phytostabilizer of Pb, Zn, Cu, and Cd given its capacity to reduce the plant uptake of metals and achieve rapid plant cover. This amendment also enhanced the retention of other elements in the plant root system and overall showed a better capacity to remediate soils polluted with several heavy metals. The addition of EDTA led to plant productivity losses and nutritional imbalances because it increased the mobility of several elements in the soil and its leachates.

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).

[Not Available]

Archivos Espanoles De Urologia. Jul-Aug, 2015  |  Pubmed ID: 26550646

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.

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

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

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.].

Effectiveness of Vagal Nerve Stimulation in Medication-resistant Epilepsy. Comparison Between Patients with and Without Medication Changes

Acta Neurochirurgica. Nov, 2016  |  Pubmed ID: 27878616

Vagal nerve stimulation (VNS) response is not immediate. A progressive decline in seizure frequency is usually found during a period of 12-18 months after implantation. During this time, the patient's medication is usually modified, which can create doubts about whether their clinical improvement is due to medication changes or to VNS itself. Our goal is to compare two groups of patients treated with VNS, with and without changes in their medication.

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