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Intractable Epilepsy (intractable + epilepsy)

Distribution by Scientific Domains

Medical Sciences	95%
2 Other Domains	5%

Distribution within Medical Sciences

Neurology	87%
Pediatrics	3%
4 Other Subdomains	10%

Selected Abstracts

One-Year Postoperative Autobiographical Memory Following Unilateral Temporal Lobectomy for Control of Intractable Epilepsy

EPILEPSIA, Issue 3 2007
Virginie Voltzenlogel
Summary:,Purpose: To examine the effects of temporal lobectomy (TL), particularly concerning its lateralization. Methods: Patients completed autobiographical memory tests, preoperatively and 1-year postoperatively. Results: (a) right TL (RTL) patients recalled significantly more memories from the year after surgery than from the year before TL; (b) their pre to postoperative improvement on autobiographical memory scores was positively correlated to improvement of delayed story recall scores; and (c) 1 year after surgery, performance on recent personal memory recall was normalized for RTL patients only. Conclusion: We suggest that, in the absence of recurrent seizures, the relative integrity of the left hemisphere together with residual right hemisphere structures sustains postoperative autobiographical memory consolidation, at least 1 year postoperatively. [source]

Neocortical Microenvironment in Patients with Intractable Epilepsy: Potassium and Chloride Concentrations

EPILEPSIA, Issue 2 2006
Ali Gorji
Summary:,Purpose: The regulation of extracellular ion concentrations plays an important role in neuronal function and epileptogenesis. Despite the many studies into the mechanisms of epileptogenesis in human experimental models, no data are available regarding the fluctuations of extracellular potassium ([K+]o) and chloride ([Cl,]o) concentrations, which could underlie seizure susceptibility in human chronically epileptic tissues in vivo. Methods: By using cerebral microdialysis during surgical resection of epileptic foci, the basic [K+]o and [Cl,]o as well as their changes after epicortical electric stimulation were studied in samples of dialysates obtained from 11 patients by ion-selective microelectrodes. Results: The mean basal values of [K+]o and [Cl,]o in all patients were 3.83 ± 0.08 mM and 122.9 ± 2.6 mM, respectively. However, significant differences were observed in the basal levels of both [K+]o and [Cl,]o between different patients. Statistically, no correlation was found between basal [K+]o or [Cl,]o and electrocorticogram (ECoG) spike activity, but in one patient, dramatically lowered baseline [Cl,]o was accompanied by enhanced ECoG spike activity. Application of epicortical electrical stimulation increased [K+]o but not [Cl,]o in all cases. According to the velocity as well as spatial distribution of [K+]o reduction to the prestimulation levels, three different types of responses were observed: slow decline, fast decline, and slow and fast declines at adjacent sites. Conclusions: These data may represent abnormalities in ion homeostasis of the epileptic brain. [source]

High-resolution MRI Enhances Identification of Lesions Amenable to Surgical Therapy in Children with Intractable Epilepsy

EPILEPSIA, Issue 8 2004
Monisha Goyal
Summary:,Purpose: Many children with refractory epilepsy can achieve better seizure control with surgical therapy. An abnormality on magnetic resonance imaging (MRI), along with corroborating localization by other modalities, markedly increases chances of successful surgical outcome. We studied the impact of high-resolution MRI on the surgical outcome of intractable epilepsy. Methods: High-resolution MRI using four-coil phased surface array was obtained as part of the comprehensive presurgical protocol for children with focal onset intractable seizures evaluated by our epilepsy center during the first half of 2002. Results: Thirteen consecutive children, ages 5 to 18 years, entered this prospective study. For four patients with a lesion on a recent MRI examination with a standard head coil, management did not change with high-resolution MRI. Standard MRI in the other nine patients did not identify a lesion. However, high-resolution MRI with the phased-array surface coil found previously undiagnosed focal abnormalities in five of nine patients. These abnormalities included hippocampal dysplasia, hippocampal atrophy, and dual pathology with frontal cortical dysplasia. In four of nine patients, no identifiable lesion was identified on the high-resolution MRI. All patients underwent invasive monitoring. In three of five patients, newly diagnosed lesions correlated with EEG abnormalities, and resection was performed. Conclusions: In our center, high-resolution MRI identified lesions not detected by standard MRI in more than half the children (56%). Technical advances such as four-coil phased surface array MRI can help identify and better delineate lesions, improving the diagnosis of patients who are candidates for surgical treatment of refractory epilepsy. [source]

Response: Surgical Resection for Intractable Epilepsy in "Double Cortex" Syndrome Can Yield Adequate Results

EPILEPSIA, Issue 5 2004
Frederick Andermann
No abstract is available for this article. [source]

Validity of Three Measures of Health-related Quality of Life in Children with Intractable Epilepsy

EPILEPSIA, Issue 10 2002
Elisabeth M. S. Sherman
Summary: ,Purpose: Validity studies on health-related quality of life (HRQOL) scales for pediatric epilepsy are few, and cross-validation with other samples has not been reported. This study was designed to assess the validity of three parent-rated measures of HRQOL in pediatric epilepsy: (a) the Impact of Childhood Illness Scale (ICI), (b) the Impact of Child Neurologic Handicap Scale (ICNH), and (c) the Hague Restrictions in Epilepsy Scale (HARCES). Methods: Retrospective data were examined for 44 children with intractable epilepsy. Validity was assessed by evaluating differences across epilepsy severity groups as well as correlations between HRQOL scales and neurologic variables (seizure severity, epilepsy duration, current/prior antiepileptic medications) and psychosocial measures (emotional functioning, IQ, social skills, adaptive behavior). Scale overlap with a global QOL rating also was assessed. Results: The HRQOL measures were moderately to highly intercorrelated. The scales differed in terms of their associations with criterion measures. The HARCES was related to the highest number of neurologic variables and the ICNH to the fewest. All three scales were related to psychosocial functioning and to global quality of life. Conclusions: The results of this study suggest that the three measures are likely adequate measures of HRQOL for use in intractable childhood epilepsy. The measures were highly intercorrelated, and they were all broadly related to criterion measures reflecting specific domains of HRQOL as well as global QOL. Some differences between scales emerged, however, that suggest care in choosing HRQOL instruments for children with epilepsy. [source]

Cognitive Skills in Children with Intractable Epilepsy: Comparison of Surgical and Nonsurgical Candidates

EPILEPSIA, Issue 6 2002
Mary Lou Smith
Summary: ,Purpose: To compare neuropsychological performance of two groups of children with intractable epilepsy: those who are surgical candidates, and those who are not. Methods: Intelligence, verbal memory, visual memory, academic skills, and sustained attention were measured in children aged 6,18 years. The effects of number of antiepileptic drugs (AEDs), seizure frequency, age at seizure onset, and duration of seizure disorder were examined. Results: Both groups had high rates of impairment. Group differences were found only on the verbal memory task. Children who experienced seizures in clusters had higher IQ, reading comprehension, and arithmetic scores. Age at seizure onset and proportion of life with seizures were related to IQ. Performance did not vary with AED monotherapy versus polytherapy. Conclusions: Few differences exist in cognitive performance between children with intractable seizures who are and those who are not surgical candidates. These findings suggest that children who are not surgical candidates can serve as good controls in studies on cognitive outcome of surgery. [source]

The Family Experience of "Sudden Health": The Case of Intractable Epilepsy

FAMILY PROCESS, Issue 4 2003
DAVID B. SEABURN Ph.D.
This article reports the experience of "sudden health" among six families who participated in an exploratory qualitative study of families with a member who elects to have corrective surgery for intractable epilepsy. Families were interviewed pre- and post surgery (6,8months) and the interviews were analyzed using a constant comparative methodology. Findings indicated that (1) families were organized in two primary ways (nesting and crisis) to deal with epilepsy and the aftermath of surgery and (2) "sudden health" had differing effects on these families depending on their organizational style, emotional communication process, and developmental dynamics. [source]

Vagus Nerve Stimulation for Intractable Epilepsy: Outcomes in Children and Adults

NEUROMODULATION, Issue 1 2010
Won Chul Namgung MD
ABSTRACT Objectives.,Vagus nerve stimulation (VNS) is an accepted treatment for medically intractable epilepsy. However, predictive factors associated with responsiveness to VNS remained unclear. We therefore sought to identify predictive factors that influence responsiveness to VNS in both children and adults. Materials and Methods.,We evaluated a retrospective series of 31 patients who underwent VNS for intractable epilepsy at Asan Medical Center from 1998 to 2006. Eighteen patients were younger than 18 years, while 13 patients were aged 18 years or older. We assessed mean seizure frequency, the number of antiepileptic drugs each patient was taking, seizure type, etiology, age at seizure onset, age at implantation, and duration of epilepsy. Results.,Forty-three percent of all patients had a seizure reduction of more than 50%. Ten (59%) children had a 50% reduction in their seizures, while three adults (23%) had such a response. Two factors were significantly different between responders and non-responders: age at implantation and age of seizure onset. In a logistic regression analysis, however, no factors were independently associated with the response to VNS. Transient hoarseness and cough were observed in eight of all patients and wound infection and generator failure in one patient each. Conclusions.,These results suggest that VNS may be a more effective treatment in children with intractable epilepsy than in adults. It remains difficult to predict which patients will respond to VNS therapy. [source]

Intractable epilepsy: Expression of substance P in cortical dysplastic neurons

PEDIATRICS INTERNATIONAL, Issue 3 2009
Masanori Sakagami
First page of article [source]

Cortical Dysplasias and Epilepsy: Multi-Institutional Survey in Japan

EPILEPSIA, Issue 2000
Morimi Shimada
Purpose: Cortical dysplasia (CD) is a major brain malformation causing intractable epilcpsy. Neurosurgery now succcssfully controls some intractable epilepsies associated with CD. In this study, thc incidence 11 epilepsy and thc frequency of seizurcs were analyzed in different types 01 CD. Methods: This study, supported by a rcse;lrch grant from the Ministry of Health and Wellare of Japan, is part of a research project on the clinical presentation and pathogcnesis of brain dysgenesis. Questionnaires regarding the type of CD, family and pact historics, clinical signs and symptoms and their severity were distributed to I200 institutions comprising child neurologists or pediatricians. CDs werc classified into following 6 types; lissencephaly (agyria-pachygyria spcctrum), cobblestone lissencephaly, polymicrogyria including schizencephaly and hilateral perisylvian syndrome, diffuse heterotopia, focal heterotopia, and hemiinegalencephaly. All patients who had been diagnoscd as CD either by MRI, CT, autopsy or histological cxamination at or after surgical treatment wcre included. Diagnosis of CD by CT or MRI was mainly made by a radiologist, child neurologist, or pediatrician. Double classification was corrected. Epilepsy was classified according to criteria of the ILEA. Seizure frcquencies wcre recorded. Results: A total or 676 cases from 328 institutions was availablc, and distributed as follows: 277 of lissencephaly, I48 of cobblestone lissencephaly (10 cases of Walkcr-Warburg syndrome and 138 Fukuyaina type congcnital muscular dystrophy), I30 of polymicrogyria, 40 of diffuse heterotopia (24 subcortical band hetcrotopia and I6 perivcntricular nodular hcterotopia), 37 of focal heterotopia, and 44 of hemimegalencephaly. In 130 cases of polymicrogyria, 13 cases of bilatcral perisylvian syndrome, and 38 cases of schizencephaly were includcd. Of 667 cases available for study, 500 (75.0%) had epilepsy in which generalized epilepsy including West and Lcnnox syndromes comprised 54.1 % and localization-related epilepsies comprised 46.7%. Thc frequency of seizures could be ascertained in 455 cases, of which 36.0% had daily seizures, and I I .4%) had more than onc seizure per week. The incidencc of epilepsy in cach type of CD was as follows: 86% inlissencephaly, 50% in cobblestone lissencephaly (patients with WalkcrWarburg syndrome had epilepsy in 90%, whercas those with Fukuyama type congenital muscular dystrophy had epilepsy in 46.7%), 71.3% in polymicrogyria, 77.5% in diffusc hetcrotopia (9 1.7% in subcortical band heterotopia and 56.2% in periventricular nodular heterotopia), 74.3% in focal heterotopia, and 93.2% in hemimegalcncephaly. Conclusion: As recent investigations have reported, this study confirmed the high incidence of intractable cpilepsy in CDs. Epilepsy was more prevalcnt in cases with subcortical heterotopia than i n cascs with periventricular nodular helcrotopia. Thc incidcnce or epilepsy was also higher in the focal hcterotopias located subcortically than those dccper in white matter or in the periventricular region. Thcse differences in incidence of epilepsy depending on the location of hcterotopia may give somc clues to the nature of epileptogenesis in CD. [source]

Language-Related Potentials in Temporal Lobe Epilepsy Before and After Surgical Treatment

EPILEPSIA, Issue 2000
Toshihiko Ito
Purpose: Temporal lobectomy has contributed to treatment for medically intractable epilepsies. However, influence of the surgical treatment on cognitive function is not still clear, especially from the electrophysiological viewpoint. N400, an event related potential (ERP) named for its negative polarity and peak latency of 400 ms, is reported to be an electrophysiological sign of neural activities associated with semantic priming in language perception. In the present study, ERPs are applied to evaluate the cognitive function of temporal lobe epilepsy before and after temporal lobectomy. Methods: Two patients with intractable temporal lobe epilepsy participated in this study. Fifteen normal subjects served as controls. The incongruous sentence task (Kutas and Hillyard 1980) was used to record N400 components in an auditory modality. Two types of sentences (40 Japanese sentences for each type) were prepared, in which the terminal words were either semantically congruent or incongruent. The scntences were randomly presented at approximately 65 dB SPL peak intensity. ERPs were recorded according to the international 10,20 system, with a balanced non-cephalic electrode reference and 2 1 channels. The band-pass filter was set from 0.5 to 30 Hz, and the ERPs were sampled at 500 Hz from 200 ms before the onset of terminal words to 824 ms post-stimulus. Waves were calculated by subtracting ERPs in the congruent condition from those in the incongruent condition. N400 was scored as the most negative point between 250 and 450 ms in the subtraction waves. Amplitudes were measured from the baseline of 100 ms before the terminal words. Motor responses were also measured with a right index finger, to estimate the accuracy of understanding sentences. Results: Case I was a 22-year-old male who had intractable epilepsy for 7 years. Magnetic resonance imaging (MRI) showed high-intensity signals in the right amygdalo-hippocampal region. The epileptic seizures were confirmed to originate from the region hy electroencephalography/closed-circuit television monitoring, and single-photon-emission computed tomography. ERPs were recorded I month before and after the right anterior temporal lobectomy. Before the surgery, the rate of correct responses showed no difference between the patient (96 %) and the controls (96 %). The amplitudes of N400 for the patient reduced in the right frontal and central areas (F4, C4), comparing to 99 % confidence limit for control subjects. After the surgery, the rate of correct responses was 97 %, and the amplitudes reduced in the right central, parietal, and posterior temporal areas (C4, P4, 0 2, T6). Case 2 (37-year-old female) had intractable epilepsy for 30 years. MRI showed brain atrophy in the right hippocampal region. The epileptic seizures were confirmed to originate from the region. N400 was recorded 3 months after the resection. The rate of correct responses was 95 %. The amplitudes of N400 were lower in the right frontal, parietal, and temporal areas (electrodes Fp2, F4, P4, T6, Pz), comparing to 99 % confidence limit of controls. Conclusions: Before the lpbectomy, the reduction of amplitudes of N400 indicated that the pathogenesis of intractable temporal lobe epilepsy would influence the process of semantic priming in language perception. After the resection, it was suggested that the right temporal lobectomy might affect the cognitive function in the brain from electrophysiological aspects. We could benefit from further study including analysis of the discrepancy between the amplitudes of N400 and behavioral responses. [source]

Expression of CD34 as a novel marker for glioneuronal lesions associated with chronic intractable epilepsy

NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 5 2006
P. Deb
The spectrum of glioneuronal lesions underlying intractable epilepsies includes malformative pathologies like focal cortical dysplasia (FCD); and neoplastic lesions like gangliogliomas (GG) and dysembryoplastic neuroepithelial tumours (DNT). These may occur either singly or as dual lesions, having simultaneous presence of both elements. Currently, the relationship between the malformative and neoplastic glioneuronal lesions is poorly understood. Recently, CD34, a stem cell marker transiently expressed during early neurulation, has been identified in these tumours. This study was undertaken to (i) evaluate the role of CD34 as a diagnostic marker for glioneuronal lesions of epilepsy, namely, GG, DNT and FCD, and (ii) attempt to define the relationship among these lesions, using CD34 as a marker. Tissues resected from 47 patients with intractable epilepsy due to glioneuronal lesions (GG, FCD, DNT) were studied. These were evaluated for CD34 expression, using immunohistochemistry. Dysplastic or atypically differentiated neural precursors which could not be identified on routine haematoxylin and eosin (H&E) staining were highlighted by CD34 immunostaining. The pattern of immunostaining was diffuse in GGs, unlike FCDs, wherein cells were present singly or in small clusters. However, cases of DNT and control tissue were largely CD34-immunonegative. Based on these findings, we propose a possible common origin of GG and FCD, from a bipotent precursor that undergoes abnormal glioneuronal development, while DNTs possibly have a different origin. The CD34-immunoreactive cells represent dysplastic or undifferentiated neural precursors, which may signify a valuable marker for the diagnostic evaluation of neoplastic and/or malformative pathologies in patients with intractable epilepsy. [source]

Ring chromosome 20 syndrome with intractable epilepsy

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 5 2005
Asude Alpman MD
Ring chromosome 20 (r[20]) syndrome is characterized by mild to moderate learning disability*, behavioural disorders, epilepsy, and various dysmorphic features. Although still considered rare, r(20) syndrome is being increasingly diagnosed. More than 30 cases have been described in the literature since 1976. Here we report an additional case of a 14-year-old male with r(20). He had moderate to severe learning disability and epileptic seizures manifesting at about 18 months of age. During the 13 years' follow-up period he showed intractable epileptic seizures, behavioural disorders, and mild dysmorphological features including microcephaly, strabismus, micrognathia, down-slanting eyelids, and ear abnormalities. Frequent episodes of atypical absence or non-convulsive status associated with electroencephalogram changes were seen in follow-up. He was treated with several classical and new antiepileptic drugs, including intravenous immunoglobulin, corticotropin, and vagal nerve stimulation, with unsuccessful control of seizures. Finally, surgical treatment (corpus callosotomy) was performed at the age of 13 years; severity of tonic seizures was diminished, but frequency was unchanged. Although his behavioural problems, e.g. hyperactivity, were mild in early childhood they became more severe when he was 11 years old. Aggressiveness, compulsiveness with self-injury, and panic attacks developed at the age of 13 years, and were more pronounced after callosotomy. This case report provides the first description of deterioration in psychological situation in patients with r(20) intractable epilepsy. The patient was diagnosed with r(20) syndrome after 13 years of clinical follow-up. Karyotype analysis should, therefore, be performed in every patient with intractable epilepsy of unknown aetiology. [source]

Stroke in the developing brain and intractable epilepsy: effect of timing on hippocampal sclerosis

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 9 2003
Waney Squier FRCP FRC Path
A detailed study was made of the pathology of specimens removed by hemispherectomy for the treatment of intractable epilepsy in children with unilateral middle cerebral artery stroke. Neuropathological criteria were used to differentiate strokes that occurred in early intrauterine development (before 28 weeks gestational age) from those occurring in the last trimester, at birth, or after birth: 19 children had early strokes and 21 late. There was no difference in seizure history or occurrence of febrile convulsions in these two groups. Hippocampal tissue was available in 20 patients; pathology in the hippocampus, remote from the infarcted area, showed a marked difference between early-onset and late-onset groups. Hippocampal sclerosis was uncommon in children with early-onset strokes but developed in most of the children whose strokes were of later origin. However, hippocampal sclerosis was more closely related to a clinical history of a late initial precipitating insult irrespective of infarct timing. These findings demonstrate the changing vulnerability of the developing brain and show that hippocampal pathology is more closely related to the timing of an insult than seizure history or the occurrence of febrile convulsions. [source]

Growth of children on the ketogenic diet

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 12 2002
Eileen P G Vining MD
This is a prospective cohort study of 237 children (130 males, 107 females) placed on the ketogenic diet for control of intractable epilepsy (mean age at starting diet 3 years 8 months; age range 2 months to 9 years 10 months); average length of follow-up was 308 days. There were 133 children on the diet at 1 year and 76 at 2 years. Height and weight measurements were converted into age- and sex-appropriate z scores. There was a rapid drop in weight z scores in the first 3 months. After this initial period, the weight z score remained constant in children who started the diet below the median weight for their age and sex, although z scores continued to decrease in children starting above the median. There was a small decrease in height z scores in the first 6 months (<0.5); however, there were larger changes by 2 years. There was no difference based on sex for either height or weight. The ketogenic diet generally provides sufficient nutrition to maintain growth within normal parameters over a defined period. Very young children grow poorly on the diet and should be followed-up carefully over long periods of use. [source]

Gliomatosis cerebri in a 10,year-old girl masquerading as diffuse encephalomyelitis and spinal cord tumour

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 2 2001
Sandeep Jayawant
Gliomatosis cerebri is the unifying term used when diffuse glial infiltration occurs throughout the cerebral hemispheres. The very few cases reported in children have presented with intractable epilepsy, corticospinal tract deficits, unilateral tremor, headaches, and developmental delay. Antemortem diagnosis is difficult because of the vagueness of the physical, radiological and pathological findings. Adult cases may simulate an acute diffuse encephalomyelitis and show postmortem evidence of a marked swelling of the spinal cord. Apparently benign intracranial hypertension with papilloedema has also been recorded. We report a 10,year-old girl who presented with a history and physical signs suggestive of benign intracranial hypertension. A diffuse encephalomyelopathy occurred, which was complicated by spinal cord swelling, followed by deterioration and death. Gliomatosis cerebri affecting the brain and spinal cord was found at postmortem examination. [source]

Long-term outcomes of children treated with the ketogenic diet in the past

EPILEPSIA, Issue 7 2010
Amisha Patel
Summary Purpose:, The ketogenic diet has well-established short- and long-term outcomes for children with intractable epilepsy, but only for those actively receiving it. However, no information exists about its long-term effects years after it has been discontinued. Methods:, Living subjects were identified who were treated at the Johns Hopkins Hospital with the ketogenic diet from November 1993 to December 2008 for ,1 month, and had discontinued it ,6 months prior to this study. Of 530 patients who were eligible, 254 were successfully contacted by phone or e-mail with a survey and request for laboratory studies. Results:, Questionnaires were completed by 101 patients, with a median current age of 13 years (range 2,26 years). Median time since discontinuing the ketogenic diet was 6 years (range 0.8,14 years). Few (8%) still preferred to eat high fat foods. In comparison to the 52% responder rate (>50% seizure reduction) at ketogenic diet discontinuation, 79% were now similarly improved (p = 0.0001). Ninety-six percent would recommend the ketogenic diet to others, yet only 54% would have started it before trying anticonvulsants. Lipids were normal (mean total cholesterol 158 mg/dl), despite most being abnormal while on the ketogenic diet. The mean Z scores for those younger than age 18 years were ,1.28 for height and ,0.79 for weight. In those 18 years of age or older, the mean body mass index (BMI) was 22.2. Discussion:, This is the first study to report on the long-term effects of the ketogenic diet after discontinuation. The majority of subjects are currently doing well with regard to health and seizure control. [source]

Outcome of vagus nerve stimulation for epilepsy in Budapest

EPILEPSIA, Issue 2010
Katalin Müller
Summary Vagus nerve stimulation (VNS) is a nonpharmacologic therapeutic option for patients with intractable epilepsy. Better clinical outcomes were recorded in nonfocal and Lennox-Gastaut syndrome (LGS). We conducted a 2-year, open label, prospective study to measure the seizure outcome of 26 VNS patients. The seizure numbers were assessed using clinician's global impression scale (CGI) and patient diaries. The average seizure reduction was 23% at the first year and 22% at the second year. Seizure reduction was more pronounced among patients with nonfocal than with focal epilepsy. The response rate was 50% at first year and 30% at the second year. The best CGI record for clinically significant improvement was 15% in the LGS group. The only statistically significant result was the reduction of the generalized tonic,clonic seizures (GTCS). The side-effect profile was good; however, the large number of mild and reversible effects influenced the stimulation parameters and thus probably the effectiveness of the therapy. We suggest that VNS is an optional treatment mostly in cases of therapy-resistant Lennox-Gastaut syndrome. Patients with GTCS may experience improvement such as reduction of seizure severity. We conclude that VNS is a safe neuromodulatory treatment, but future developments of neuromodulatory approaches are needed. [source]

Interictal EEG spikes identify the region of electrographic seizure onset in some, but not all, pediatric epilepsy patients

EPILEPSIA, Issue 4 2010
Eric D. Marsh
Summary Purpose:, The role of sharps and spikes, interictal epileptiform discharges (IEDs), in guiding epilepsy surgery in children remains controversial, particularly with intracranial electroencephalography (IEEG). Although ictal recording is the mainstay of localizing epileptic networks for surgical resection, current practice dictates removing regions generating frequent IEDs if they are near the ictal onset zone. Indeed, past studies suggest an inconsistent relationship between IED and seizure-onset location, although these studies were based upon relatively short EEG epochs. Methods:, We employ a previously validated, computerized spike detector to measure and localize IED activity over prolonged, representative segments of IEEG recorded from 19 children with intractable, mostly extratemporal lobe epilepsy. Approximately 8 h of IEEG, randomly selected 30-min segments of continuous interictal IEEG per patient, were analyzed over all intracranial electrode contacts. Results:, When spike frequency was averaged over the 16-time segments, electrodes with the highest mean spike frequency were found to be within the seizure-onset region in 11 of 19 patients. There was significant variability between individual 30-min segments in these patients, indicating that large statistical samples of interictal activity were required for improved localization. Low-voltage fast EEG at seizure onset was the only clinical factor predicting IED localization to the seizure-onset region. Conclusions:, Our data suggest that automated IED detection over multiple representative samples of IEEG may be of utility in planning epilepsy surgery for children with intractable epilepsy. Further research is required to better determine which patients may benefit from this technique a priori. [source]

High seizure frequency prior to antiepileptic treatment is a predictor of pharmacoresistant epilepsy in a rat model of temporal lobe epilepsy

EPILEPSIA, Issue 1 2010
Wolfgang Löscher
Summary Purpose:, Progress in the management of patients with medically intractable epilepsy is impeded because we do not fully understand why pharmacoresistance happens and how it can be predicted. The presence of multiple seizures prior to medical treatment has been suggested as a potential predictor of poor outcome. In the present study, we used an animal model of temporal lobe epilepsy to investigate whether pharmacoresistant rats differ in seizure frequency from pharmacoresponsive animals. Methods:, Epilepsy with spontaneous recurrent seizures (SRS) was induced by status epilepticus. Frequency of SRS was determined by video/EEG (electroencephalography) monitoring in a total of 33 epileptic rats before onset of treatment with phenobarbital (PB). Results:, Thirteen (39%) rats did not respond to treatment with PB. Before treatment with PB, average seizure frequency in PB nonresponders was significantly higher than seizure frequency in responders, which, however, was due to six nonresponders that exhibited > 3 seizures per day. Such high seizure frequency was not observed in responders, demonstrating that high seizure frequency predicts pharmacoresistance in this model, but does not occur in all nonresponders. Discussion:, The data from this study are in line with clinical experience that the frequency of seizures in the early phase of epilepsy is a dominant risk factor that predicts refractoriness. However, resistance to treatment also occurred in rats that did not differ in seizure frequency from responders, indicating that disease severity alone is not sufficient to explain antiepileptic drug (AED) resistance. These data provide further evidence that epilepsy models are useful in the search for predictors and mechanisms of pharmacoresistance. [source]

Interobserver and intraobserver reproducibility in focal cortical dysplasia (malformations of cortical development)

EPILEPSIA, Issue 12 2009
Wendy A. Chamberlain
Summary Purpose:, Malformations of cortical development (MCD) (cortical dysplasias) are well-recognized causes of intractable epilepsy. Although a histologic classification system for MCD has been proposed by Palmini et al. (Neurology; 2004; 62:S2), studies to date have not assessed reproducibility. The purpose of this study was to analyze inter- and intraobserver agreement among eight experienced neuropathologists (NPs) with respect to this classification system. Methods:, Sections from 26 epilepsy resections were selected to represent the range of pathologies described by Palmini et al. Recuts of single sections from each case were sent to the NPs to classify. The slides were resent at a later date for reclassification. Kappa analysis for both inter- and intraobserver concordance was performed. Results:, Interobserver agreement was moderate (, = 0.4968). There was ,62.5% (5 of 8 NPs) agreement for 19 of 26 cases. The greatest concordance was present when making focal cortical dysplasia (FCD) types IIA/B classifications (12 of the 14 cases with ,75% consensus). Mild MCD (types I/II) and FCD types IA/B classifications were the least reproducible, and used most frequently in cases without consensus. Intraobserver concordance was moderate to very good (range , = 0.4654,0.8504). The category with the fewest classification changes made on reevaluation was FCD type IIB (4.2%), whereas that with the most changes was mild MCD (types I/II) (52.9%). Discussion:, Interobserver concordance using this approach was moderate. The classification categories with the greatest concordance were FCD type IIA/B, and the least, mild MCD and FCD types IA/B. In addition, difficulty in differentiating Mild MCD/FCD type I lesions from normal and/or gliotic tissue was noted. [source]

Distributed source modeling of language with magnetoencephalography: Application to patients with intractable epilepsy

EPILEPSIA, Issue 10 2009
Carrie R. McDonald
Summary Purpose:, To examine distributed patterns of language processing in healthy controls and patients with epilepsy using magnetoencephalography (MEG), and to evaluate the concordance between laterality of distributed MEG sources and language laterality as determined by the intracarotid amobarbital procedure (IAP). Methods:, MEG was performed in 10 healthy controls using an anatomically constrained, noise-normalized distributed source solution (dynamic statistical parametric map, dSPM). Distributed source modeling of language was then applied to eight patients with intractable epilepsy. Average source strengths within temporoparietal and frontal lobe regions of interest (ROIs) were calculated, and the laterality of activity within ROIs during discrete time windows was compared to results from the IAP. Results:, In healthy controls, dSPM revealed activity in visual cortex bilaterally from ,80 to 120 ms in response to novel words and sensory control stimuli (i.e., false fonts). Activity then spread to fusiform cortex ,160,200 ms, and was dominated by left hemisphere activity in response to novel words. From ,240 to 450 ms, novel words produced activity that was left-lateralized in frontal and temporal lobe regions, including anterior and inferior temporal, temporal pole, and pars opercularis, as well as bilaterally in posterior superior temporal cortex. Analysis of patient data with dSPM demonstrated that from 350 to 450 ms, laterality of temporoparietal sources agreed with the IAP 75% of the time, whereas laterality of frontal MEG sources agreed with the IAP in all eight patients. Discussion:, Our results reveal that dSPM can unveil the timing and spatial extent of language processes in patients with epilepsy and may enhance knowledge of language lateralization and localization for use in preoperative planning. [source]

A randomized trial of classical and medium-chain triglyceride ketogenic diets in the treatment of childhood epilepsy

EPILEPSIA, Issue 5 2009
Elizabeth G. Neal
Summary Purpose:, To conduct the first randomized trial on classical and medium-chain triglyceride (MCT) versions of the ketogenic diet, examining efficacy and tolerability after 3, 6, and 12 months. Methods:, One hundred forty-five children with intractable epilepsy were randomized to receive a classical or an MCT diet. Seizure frequency was assessed after 3, 6, and 12 months. Treatment withdrawals were documented. Tolerability was assessed by questionnaire, and blood ketone levels were measured. Results:, Of the 61 children who started a classical diet and the 64 who started an MCT diet, data from 94 were available for analysis: 45 classical and 49 MCT. After 3, 6, and 12 months there were no statistically significant differences in mean percentage of baseline seizures between the two groups (3 months: classical 66.5%, MCT 68.9%; 6 months: classical 48.5%, MCT 67.6%; 12 months: classical 40.8%, MCT 53.2%; all p > 0.05). There were no significant differences between groups in numbers achieving greater than 50% or 90% seizure reduction. Serum acetoacetate and ,-hydroxybutyrate levels at 3 and 6 months were significantly higher in children on the classical diet (p < 0.01); this was the case at 12 months for acetoacetate. There were no significant differences in tolerability except increased reports in the classical group of lack of energy after 3 months and vomiting after 12 months. Discussion:, This study has shown classical and MCT ketogenic diet protocols to be comparable in efficacy and tolerability; both ways of implementing the diet have their place in the treatment of childhood epilepsy. [source]

Molecular and diffusion tensor imaging of epileptic networks

EPILEPSIA, Issue 2008
Aimee F. Luat
Summary Several studies have shown that seizure-induced cellular and molecular changes associated with chronic epilepsy can lead to functional and structural alterations in the brain. Chronic epilepsy, when medically refractory, may be associated with an expansion of the epileptic circuitry to involve complex interactions between cortical and subcortical neuroanatomical substrates. Progress in neuroimaging has led not only to successful identification of epileptic foci for surgical resection, but also to an improved understanding of the functional and microstructural changes in long-standing epilepsy. Positron emission tomography (PET), functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) are all promising tools that can assist in elucidating the underlying pathophysiology in chronic epilepsy. Studies using PET scanning have demonstrated dynamic changes associated with the evolution from acute to chronic intractable epilepsy. Among these changes are data to support the existence of secondary epileptogenesis in humans. MRI with DTI is a powerful tool which has the ability to characterize microstructural abnormalities in epileptic foci, and to demonstrate the white matter fibers and tracts participating in the epileptic network. In this review, we illustrate how PET and DTI can be applied to depict the functional and microstructural alterations associated with chronic epilepsy. [source]

Mechanisms of Epileptogenesis in Tuberous Sclerosis Complex and Related Malformations of Cortical Development with Abnormal Glioneuronal Proliferation

EPILEPSIA, Issue 1 2008
Michael Wong
Summary Malformations of cortical development (MCDs) are increasingly recognized as causes of medically intractable epilepsy. In order to develop more effective, rational therapies for refractory epilepsy related to MCDs, it is important to achieve a better understanding of the underlying mechanisms of epileptogenesis, but this is complicated by the wide variety of different radiographic, histopathological, and molecular features of these disorders. A subset of MCDs share a number of characteristic cellular and molecular abnormalities due to early defects in neuronal and glial proliferation and differentiation and have a particularly high incidence of epilepsy, suggesting that this category of MCDs with abnormal glioneuronal proliferation may also share a common set of primary mechanisms of epileptogenesis. This review critically analyzes both clinical and basic science evidence for overlapping mechanisms of epileptogenesis in this group of disorders, focusing on tuberous sclerosis complex, focal cortical dysplasia with balloon cells, and gangliogliomas. Specifically, the role of lesional versus perilesional regions, circuit versus cellular/molecular defects, and nonneuronal factors, such as astrocytes, in contributing to epileptogenesis in these MCDs is examined. An improved understanding of these various factors involved in epileptogenesis has direct clinical implications for optimizing current treatments or developing novel therapeutic approaches for epilepsy in these disorders. [source]

Posterior Quadrantic Epilepsy Surgery: Technical Variants, Surgical Anatomy, and Case Series

EPILEPSIA, Issue 8 2007
Roy Thomas Daniel
Summary:,Objective: Patients with intractable epilepsy due to extensive lesions involving the posterior quadrant (temporal, parietal, and occipital lobes) form a small subset of epilepsy surgery. This study was done with a view to analyze our experience with this group of patients and to define the changes in the surgical technique over the last 15 years. We also describe the microsurgical technique of the different surgical variants used, along with their functional neuroanatomy. Methods: In this series there were 13 patients with a median age of 17 years. All patients had extensive presurgical evaluation that provided concordant evidence localizing the lesion and seizure focus to the posterior quadrant. The objective of the surgery was to eliminate the effect of the epileptogenic tissue and preserve motor and sensory functions. Results: During the course of this study period of 15 years, the surgical procedure performed evolved toward incorporating more techniques of disconnection and minimizing resection. Three technical variants were thus utilized in this series, namely, (i) anatomical posterior quadrantectomy (APQ), (ii) functional posterior quadrantectomy (FPQ), and (iii) periinsular posterior quadrantectomy (PIPQ). After a median follow-up period of 6 years, 12/13 patients had Engel's Class I seizure outcome. Conclusion: The results of surgery for posterior quadrantic epilepsy have yielded excellent seizure outcomes in 92% of the patients in the series with no mortality or major morbidity. The incorporation of disconnective techniques in multilobar surgery has maintained the excellent results obtained earlier with resective surgery. [source]

Multivariate Neuropsychological Prediction of Seizure Lateralization in Temporal Epilepsy Surgical Cases

EPILEPSIA, Issue 8 2007
Therese A. Keary
Summary:,Purpose: Neuropsychological assessment can be of assistance in determining seizure lateralization in cases where EEG and MRI findings do not provide clear lateralizing data. While several studies have examined the lateralizing value of individual neuropsychological measures, clinicians are still in need of a statistically sound method that permits the incorporation of multiple neuropsychological variables to predict seizure lateralization in the individual patient. Method: The present study investigated the lateralizing value of several commonly used neuropsychological measures in a large sample of patients (n = 217) who eventually underwent surgical resection to treat their epilepsy. Side of surgery was used to operationally define seizure lateralization. A comparison of the relative utility of a multivariate versus univariate approach to predict seizure lateralization was conducted in temporal epilepsy cases. Results: The results provide evidence for the incremental validity of neuropsychological measures, other than memory and IQ tests, in the prediction of seizure lateralization in patients with medically intractable epilepsy. These data indicate that a multivariate approach increases the accuracy of prediction of seizure lateralization for temporal lobe epilepsy cases. Conclusion: This study supports the use of a multivariate approach using neuropsychological measures to predict seizure lateralization in temporal epilepsy surgical candidates. Regression formulas are provided to enhance the clinical utility of these findings. [source]

Combined Ketogenic Diet and Vagus Nerve Stimulation: Rational Polytherapy?

EPILEPSIA, Issue 1 2007
Eric H. Kossoff
Summary:,Objective: The concept of "rational polypharmacy" has been associated with anticonvulsant management for decades, but the term has not been applied to nonpharmacologic therapies. Methods: We conducted a multicenter, retrospective study of children who received concurrent diet (ketogenic or modified Atkins) and vagus nerve stimulation (VNS) treatment for medically intractable epilepsy. Results: Thirty children in total from six epilepsy centers were treated over a 6-yr period. The median age at the initiation of combination therapy was 10 yr (range, 4,24 yr). Sixteen (53%) received dietary therapy followed by VNS; no differences were noted between centers. After 3 months, 21 (70%) had seizure reduced by >50% over the previous single nonpharmacologic treatment, of whom 13 (62%) had improvement within the first month. A 5-min VNS off-time correlated with >90% seizure reduction (p = 0.02). The median duration of nonpharmacologic polytherapy was 12 months (range, 0.5,96 months); 17 (57%) remain on dual therapy at this time. No side effects were noted. Most patients who discontinued combination therapy did so because of a lack of efficacy rather than restrictiveness. Conclusions: In this small group, the combined use of diet and VNS appeared synergistic and yielded rapid benefits. It may be more effective with longer VNS off-times. Further prospective studies of this combination in refractory pediatric epilepsy are needed to help guide optimal use. [source]

Cortical Resection with Electrocorticography for Intractable Porencephaly-related Partial Epilepsy

EPILEPSIA, Issue 1 2005
Koji Iida
Summary:,Purpose: We evaluated the results of cortical resection of epileptogenic tissue for treatment of intractable porencephaly-related epilepsy. Methods: We examined clinical features, electrophysiological data, surgical findings, and seizure outcomes after cortical resection in eight patients with intractable epilepsy related to porencephalic cysts. Results: All eight patients had hemiparesis. Five retained motor function in the hemiparetic extremities; six retained visual fields. All had partial seizures, six with secondary generalization. Seven patients had simple and three had complex partial seizures (CPSs); two also had drop attacks. Four patients had multiple seizure types. Long-term scalp video-EEG (LVEEG) localized interictal epileptic abnormalities that anatomically corresponded to the cyst location in three patients. LVEEG recorded ictal-onset zones in five; these anatomically corresponded to the cyst location in three of the five. EEG recorded generalized seizures in two patients, hemispheric in one, and multifocal in two. Intraoperative electrocorticography (ECoG) revealed interictal epileptic areas extending beyond the margins of the cyst in seven patients. We resected ECoG-localized interictal epileptic areas completely in five patients and partially in two. Cortical resection was based on seizure semiology and LVEEG in one patient whose ECoG showed no epileptiform discharges. After a minimum follow-up of 1 year, six patients had excellent seizure outcome (Engel class I), and two had a >90% seizure reduction (Engel class III) without complications. Conclusions: Cortical resection guided by ECoG allows preservation of motor function and visual field and provides an effective surgical procedure for treatment of intractable epilepsy secondary to porencephaly. [source]