Bilateral periventricular nodular heterotopia in France: frequency of mutations in FLNA, phenotypic heterogeneity and spectrum of mutations.

Bilateral periventricular nodular heterotopia (BPNH) is the most common form of periventricular heterotopia. Mutations in FLNA, encoding filamin A, are responsible for the X linked dominant form of BPNH (FLNA-BPNH). Recently, atypical phenotypes including BPNH with Ehlers-Danlos syndrome (BPNH-EDS) have been recognised. A total of 44 FLNA mutations have so far been reported in this phenotype. Most of these mutations lead to a truncated protein, but few missense mutations have also been described. Here, the results of a mutation screening conducted in a series of 32 BPNH patients with the identification of 12 novel point mutations in 15 patients are reported. Nine mutations were truncating, while three were missense. Three additional patients with BPNH-EDS and a mutation in FLNA are described. No phenotype-genotype correlations could be established, but these clinical data sustain the importance of cardiovascular monitoring in FLNA-BPNH patients.

[The epileptogenic zone]. / La zone épileptogène.

The definition of the epileptogenic zone is a concept proposed by Jean Bancaud and Jean Talairach based on the anatomical, electrical and clinical correlations established from stereoelectroencephalographic recordings. They believed the epileptogenic zone to be the "region of the beginning and the primary organization" of ictal discharges. The opinion of North American authors is different: the epileptogenic zone is the "what to remove area" to produce freedom from seizures. This surgical definition assumes postsurgical validation. The aim of this paper is to show how to define the epileptogenic zone from all the stereoelectroencephalographic recording data.

[Vagus nerve stimulation for the treatment of refractory epilepsy]. / Stimulation chronique du nerf vague dans le traitement del'épilepsie pharmacorésistante.

Proposed as an additive symptomatic treatment of refractory epilepsy, vagus nerve stimulation (VNS) has proven to be effective and well-tolerated in patients presenting with refractory epilepsy for whom cortical resection is not indicated. After two years of treatment, the overall reduction of seizure frequency averaged 40%. In 50% of the patients, the frequency of seizures decreased by at least 50%. Moreover, even in absence of a significant reduction of seizures, patients who undergo this treatment reported an improvement in their quality of life. Economic surveys also demonstrate a favorable impact of VNS on the management of refractory epilepsy. Since 1988, 65,000 patients with refractory epilepsy throughout the world have been treated by VNS for this indication (1000 in France). The surgical implantation technique used in our department, the effects of vagus nerve stimulation reported in the literature, and our experience with a cohort of 70 patients with refractory epilepsy who received implants over the last 10 years are described.

[From the analogic to the digital era: technical EEG progress for presurgical investigations of refractory partial epilepsies]. / De l'ère analogique à l'ère numérique: évolution des techniques électro-encéphalographiques dans le bilan préchirurgical des épilepsies partielles pharmacorésistantes.

Over the past two decades, exploration of epileptic patients has benefited from technological advances in electroencephalography. Computerized equipment can simultaneously retrieve cerebral electric activity and signs of the patient's ictal activity. The computer era has improved reliability, storage and analysis of the recorded data and provides easier communication tools for multidisciplinary staff and patient case studies. Therefore, an increasing number of patients could benefit from presurgical investigations and surgical treatment.

[On the best strategies on the best results for surgery of frontal epilepsy]. / Quelles stratégies pour quels résultats dans la chirurgie des épilepsies partielles frontales?

Frontal lobe epilepsy surgery is the second most common surgery performed for drug-resistant partial epilepsy. We investigated the longitudinal outcome in a cohort of patients investigated since 1990 with SEEG and modern diagnostic techniques. We reviewed 105 patients who underwent surgery between 1990 and 2005 (mean follow-up, six years; range: one to 17 years) and analyzed the year-per-year follow-up according to Engel's classification. Favorable outcome (Class I) was observed for 70% and this result was stable at least five years after surgery. More than 90% of patients with lesion-related epilepsies (focal cortical dysplasia and dysembryoplastic neuroepithelial tumors) became seizure-free. Less than 50% of patients classified as having cryptogenic epilepsy (defined as normal imaging and neuropathology on surgical specimen) had a favorable outcome. Permanent neurological sequelae were subtle and rare, especially after surgery for dysplasia in eloquent cortex (primary motor cortex). Our data indicate that frontal surgery is a successful treatment in patients when electrophysiological and morphological investigations demonstrate a well-defined epileptogenic zone or lesion to be surgically resected. Progress in electrophysiological and brain-imaging techniques will further improve the selection of frontal lobe epilepsy surgery candidates.

[Surgical resection of focal cortical dysplasias in the central region]. / Chirurgie des dysplasies corticales focales en région centrale.

BACKGROUND AND PURPOSE: Taylor-type focal cortical dysplasias (TTFCD) represent a particular pathological entity responsible for severe drug-resistant epilepsy of extratemporal location. Epilepsy can be surgically cured if complete removal of the lesion can be performed. However, identification on imaging may be difficult and negative standard MRIs are not rare. The frequent location of TTFCD in the central region restrains the possibilities of complete resection. We report a series of patients operated on for intractable epilepsy associated with TTFCD in the central area. PATIENTS AND METHODS: Between 2000 and 2006, of 34 consecutive patients with TTFCD, 17 had a lesion located in the central area. MRI was considered normal in eight, although in five a subtle gyral abnormality was disclosed on further analysis. A (18)FDG PET scan performed in 16 cases demonstrated focal hypometabolism in 15 that correlated with abnormalities on MRI when visible. SEEG performed in 13 cases revealed typical abnormalities for TTFCD in 10 cases. At resection, cortical and subcortical stimulations of the dysplastic cortex did not elicit a motor response. RESULTS: Postoperative motor or sensory deficit was observed in 13 patients--severe in four--which subsequently resolved completely in seven. Six patients had a minor permanent, motor or sensory deficit. Four patients were reoperated for seizure recurrence and residual dysplastic tissue was found at reoperation in three cases. Average postoperative follow-up was 3.7 years. Sixteen patients (94%) were in Engel Class I (65% in Class IA). CONCLUSION: This study suggests that surgical resection of central region TTFCD may be associated with favorable seizure outcome and no or minor functional permanent disability. In cases of seizure relapse, reoperation can be performed without further permanent deficit and lead to seizure-free outcome. Future techniques for intraoperative detection of these lesions could optimize their complete resection in functional areas.

[Surgical resections in functional areas: report of 89 cases]. / Résections en région fonctionnelle: étude d'une série de 89 cas.

Surgical resections for intractable epilepsy are generally associated with a high risk of permanent neurological deficit and a poor rate of seizure control. We present a series of 89 patients operated on from 1992 through 2007 for drug-resistant partial epilepsy, in whom surgery was performed in a functional area of the brain: the central (sensorimotor and supplementary motor areas) region in 48 cases, posterior regions (parietal and occipital) in 27, the insula in eight, and the language areas in six. Epilepsy was cryptogenic in 12 patients, and lesion-related in 77: malformation of cortical development in 43, tumor in 17, perinatal cicatrix in 13, vascular lesion in three, and another prenatal lesion in one. Seventy patients underwent stereoelectroencephalographic (SEEG) exploration. The surgical procedure was resective (lesionectomy or SEEG-guided corticectomy) in 83 patients and multiple stereotactic thermocoagulations in six. Ten patients were reoperated because of early seizure recurrence. A postoperative complication was observed in 12 patients. Postoperative deficits were observed in 54 patients (61%) and resolved completely in 29. In 25, a permanent deficit persisted, minor in 19 and moderate to severe in six, which did not correlate with localization or etiology. With a one-year follow-up in 74 patients (mean, 3.6 years), 53 (72%) were in Engel's class I, including 38 (51%) in class IA. Seizure outcome was significantly associated with etiology: 93% of Taylor-type focal cortical dysplasia, whereas only 40% of cryptogenic epilepsies were in class I (p<0.05). This suggests that resective or disconnective surgery for intractable partial epilepsy in functional areas of the brain may be followed by excellent results on seizures and a moderate risk of permanent neurological sequelae.

[Medicoeconomic assessment of epilepsy surgery in adults with medically intractable partial epilepsy. Three-year outcomes from a multicenter French cohort]. / Evaluation médicoéconomique de la chirurgie des épilepsies partielles pharmacorésistantes de l'adulte. Résultats à trois ans d'une étude prospective multicentrique française.

PURPOSE: To compare resective surgery and medical therapy in a cost-effectiveness analysis in a multicenter cohort of adult patients with partial intractable epilepsy. POPULATION AND METHODS: Adult patients with partial, medically intractable, potentially operable epilepsy were eligible and followed every year over five years. Effectiveness was defined as one year without seizure. The long-term costs and effectiveness were extrapolated over the patients' lifetime with a Markov model. Productivity (indirect costs) and quality of life (QOLIE-31, SEALS) were also assessed. Changes before and after surgery were compared between the two groups. RESULTS: Two hundred and eighty-nine patients were included (119 with surgery, 161 medically treated, six not eligible, three lost to follow-up). One year after surgery, 81% of the patients were seizure-free; at two and three years, this rate was 78%. In the medical group, these rates were 10, 18, and 15%, respectively. The cost of the explorations was euro 8464; including surgery, it was euro 19,700. In the medical group, the average annual direct costs were between 3500 and euro 6000. At two years after surgery, the annual direct cost decreased to euro 2768, at three years, it was euro 1233, predominately antiepileptic drug costs. Surgery became cost-effective between seven and eight years. In the surgical group, all the quality-of-life scores improved at one year after surgery and were stable during the second and third years. CONCLUSION: Surgical therapy was cost-effective at the middle term even though indirect costs were not considered.

Prevention and management of postoperative seizures in neuro-oncology.

INTRODUCTION: Epilepsy related to brain tumors is often difficult to treat and may impact the quality of life. We performed a review of current recommendations for the prevention of postoperative seizures and optimizing the anti-epileptic treatment. MATERIAL AND METHODS: Based on studies performed since 2000 we conducted the review by (1) analyzing the incidence of tumoral epilepsy and mechanisms of epileptogenicity; (2) describing the current medical and surgical strategy according to oncologic treatments; (3) discussing the management of postoperative seizures; (4) considering the drug withdrawal after oncologic therapy. RESULTS: Epilepsy related to supra-tentorial brain tumors is frequent (40-60%) especially in low-grade gliomas, glioneuronal tumors, fronto-temporal and eloquent cortex locations. Seizures can occur as a presenting symptom or during the course of the tumor, including after surgery and oncological treatments. Maximal safe surgical resection is the more effective therapy, alone or combined with adjuvant therapy (chemotherapy, radiotherapy). Anti-epileptic drugs are not indicated for epilepsy prophylaxis in patients without seizures but only after the first seizure due to high risk of recurrence. As they may generate adverse effects and interfere with oncological treatments, the choice is based on efficacy, tolerability and potential interactions. New anti-epileptic non-enzyme-inducing drugs are recommended in first-line monotherapy in association with adjuvant oncological therapies. Enzyme-inhibiting drugs could have a favorable effect on survival. Late seizures are often related to tumor progression or recurrence. Discontinuation of anti-epileptic drugs could be considered after successful oncological treatment and a stable medical condition. CONCLUSION: These guidelines are helpful for a rational therapy in tumoral epilepsy.

Surgery for dysembryoplastic neuroepithelial tumors and gangliogliomas in eloquent areas. Functional results and seizure control.

INTRODUCTION: Dysembryoplastic neuroepithelial tumors and gangliogliomas are developmental glioneuronal tumors usually revealed by partial epilepsy. High epileptogenicity, childhood epilepsy onset, drug-resistance, temporal location, and seizure freedom after complete resection are common characteristics of both tumors. We report the specificity of surgical management, functional results and seizure outcome in cases of a tumor location in eloquent areas. METHODS: Among 150 patients (88 males, 3-55 years) operated on for refractory epilepsy due to a glioneuronal tumor (1990-2015), 30 (20%, dysembryoplastic neuroepithelial tumors=21; gangliogliomas=9) had a tumor located in an eloquent cortex (sensory-motor, insular or language areas). Surgery was performed after a preoperative work-up, including stereo-electroencephalography in 48 patients (26%) and functional MRI in 100 (67%). MRI-guided lesionectomy was mainly performed in extra-temporal location, whereas an additional corticectomy was performed in a temporal location. Tumor microsurgical resections were guided using neuronavigation and cortical/subcortical electrical stimulations. Multiple stereotactic thermocoagulations were performed in two insular tumors. RESULTS: New motor/language deficits related to eloquent areas occurred postoperatively in 6/30 patients (20%) without any major permanent disability. Minor sensorimotor (n=2) and moderate language disturbance (n=1) persisted in three of them. Postoperative seizure-free outcome (mean follow-up>5 years) was obtained in 81% of the entire series, but significantly decreased to 60% in eloquent areas. Incomplete tumor resection was the main cause of surgical failure. However, unfavorable seizure outcome was also observed despite complete tumor resection. Malignant transformation occurred in one ganglioglioma. CONCLUSION: Epilepsy surgery for benign glioneuronal tumors in eloquent areas provides acceptable results regarding the functional risks. Complete tumor resection is crucial for long-term favorable outcome.

Can epileptologists without access to intracranial EEG use reliably the International League Against Epilepsy classification of the localization-related epileptic syndromes? A stereo-electroencephalographic study.

The goal of the present study was to investigate the reliability of clinical and electroencephalographic (EEG) criteria for the classification of localization-related epileptic syndromes as listed in the Proposals of Revised Classification of Epilepsies and Epileptic Syndromes 1989 (ICE). ICE distinguishes between multiple syndromes within epilepsies of a given lobe. Intracranial recordings were the main element in the development of the revised ICE. Considering that most epilepsy centers have no access to such invasive techniques for precise anatomic localization, it was of interest to assess how accurately the seizure origin could be determined from the scalp EEG and clinical data as reported in ICE. In this retrospective study, we compared the accuracy of the topographic diagnosis made by two groups of physicians evaluating the same patients-one group with and the other without access to results of stereo-EEG (SEEG). Medical files of 87 patients with intractable localization-related epilepsy were analyzed: 38 with frontal, 37 with temporal, 10 with parietal, and 2 with occipital lobe epilepsy were included in the study. All patients underwent previous SEEG and successful cortectomy. Minimum follow-up was 5 years. In most cases, noninvasive techniques and criteria suggested by ICE allowed topographic diagnosis of focal epilepsies according to brain lobe involvement. More detailed diagnosis, localizing the origin of critical activity within a lobe, was often unreliable. Further data are required for a definition of the epileptogenic zone. A spatiotemporal evaluation of critical events, including the intracranial EEG recording, remains the best method for topographic diagnosis of localization-related epilepsy.

[Comparison of SPECT and quantified EEG features in Alzheimer's type dementia]. / Comparaison des aspects SPECT et EEG quantifié dans les démences de type Alzheimer.

Forty-one patients with probable dementia of the Alzheimer type (DAT) have been studied by computerized EEg (C-EEG) and single photon emission tomography (SPECT) using 123-IMP. Four groups have been distinguished according to SPECT hypoperfusion topography: frontal, temporo-parietal, fronto-parietal and fronto-temporo-parietal. C-EEG parameters were much more disturbed in the 2 latter than in the 2 former groups. Thus a normal C-EEG could indicate a dominant frontal or temporo-parietal form of DAT. Therefore some bias due to duration or rate of disease progression cannot be excluded. So far the important finding is that EEG changes are diffuse and do not reflect the topography of SPECT hypoperfusion questioning the value of EEG topographical analysis in DTA.

[Quantified EEG in the diagnosis of Alzheimer's type dementia]. / Apport de l'EEG quantifié au diagnostic de démence de type Alzheimer.

79 subjects (mean age 70.2 ans, 31 males, 48 females) selected as probable dementia of the Alzheimer type, at the early stage of the disease and 17 normal aged people (mean age: 72.2, 5 males, 12 females) were recorded with a 16 channel computerized-EEG (C-EEG) with topographical analysis of the observed changes and with classical visual analysis of the EEG. Quite simple C-EEG parameters as mean dominant frequency (MF) and alpha to theta ratio are able to discriminate patients from normal with a greater accuracy than visual analysis. The values of 8.6 for the MF and 1.3 for the alpha/theta ratio are proposed as cut off values between normal and DAT patients. The topographical analysis appear to be of no additional usefulness in the discrimination of the two groups.

[EEG value for the prediction of the evolution of Alzheimer's type dementia]. / Intérêt de l'EEG pour la prédiction de l'évolution des démences de type Alzheimer.

Twenty patients selected as probable dementia of the Alzheimer type (DAT) have been examined two times during a mean follow-up period of 14.5 months. Two groups have been distinguished at the end of this period: a cognitively impaired one and a stable one. EEG features at T1, at T2 or the difference T1-T2 does not allow an accurate and predictive discrimination between the two groups. But we cannot conclude that EEG is useless for prediction of the rate of progression of the disease in DAT because most of the cognitively stable patients are also stable for mean frequency. So mean frequency could be an interesting marker of evolutivity but this to be tested with more patients including more subjects reaching the severe stage of dementia.

Long term results of stereotactic endocavitary beta irradiation of craniopharyngioma cysts.

This study concerns 33 pts (age: 3-69 yrs; m: 22) with cystic craniopharyngiomas (36 cysts) treated with stereotactic beta endocavitary irradiation (TRT). Nine patients died (3 days to 36 months after TRT) and one was lost. In 23 the follow-up varied from 12 to 126 months (m: 45 months). The disappearance of 13 cysts was appreciated 5 to 24 months after TRT: no recurrence was observed after 22-126 months (m: 61). A greater than 70% reduction of the cyst volume occurred 3-36 months after TRT and persisted at 12-71 months (m: 35 m). In one patient, the cyst volume increased. Visual acuity improved in more than 50% of survivors, while endocrine disturbances did not change and memory troubles disappeared.

Inter-ictal brain SPET in frontal epilepsy: correlations with stereo-electroencephalography.

Single photon emission tomography (SPET) imaging holds promise for localization of the site of extratemporal seizures, but limited data currently exist; in particular, correlations with stereo-electroencephalography (S-EEG) have not been made. Ten patients aged 14-44 years (mean 25 years) with a proven frontal or central epilepsy by S-EEG and post-surgical follow-up were studied retrospectively: 7 patients had frontal cortectomy and one patient had a callosotomy for bifrontal epilepsy. All patients underwent clinical, inter-ictal and ictal video-EEG, computed tomography scan and/or magnetic resonance imaging, SPET and S-EEG examinations. SPET was performed inter-ictally, while on usual epileptic medications, using 99Tcm-HMPAO (n = 4) or 123I-IMP (n = 6) as the perfusion tracer. The SPET images were evaluated independently by two observers, blind to any data other than the diagnosis of frontral or central epilepsy. Localization of inter-ictal SPET hypoperfusion was compared with the epileptogenic (EZ), irritative (IZ) and lesional (LZ) zones, as defined by S-EEG. Six patients showed structural frontal abnormalities. One patient had normal SPET and one had a contralateral hypoperfusion. Therefore, concordance of sides was found in 8 of 10 patients (including one with bilateral SPET and S-EEG abnormalities). The hypoperfusion was equal to or larger than the EZ + IZ + LZ in 6 patients (5 had a frontal lesion). SPET hypoperfusion was smaller than the EZ in one patient, and different from the EZ, IZ and LZ in two patients. Although this was a retrospective study, it provides qualitative data regarding the significance of inter-ictal SPET abnormalities in frontal or central epilepsy.(ABSTRACT TRUNCATED AT 250 WORDS)

[Vagus nerve stimulation and refractory partial epilepsies]. / La stimulation du nerf vague dans le traitement des épilepsies partielles pharmaco-résistantes.

Since 1988, intermittent electric stimulation of the cervical portion of the left vagus nerve is proposed as additive treatment of epilepsy. The effects of vagus nerve stimulation (VNS) on the modulation of cerebral activity, shown in animals and confirmed by the data of functional imagery in human beings, can be apprehended by the anatomic and functional characteristics of this nerve, whereas the anti-epileptic mode of action remains unknown. Following five controlled multicentric studies, including 440 patients presenting refractory epilepsy, 20,000 patients worldwide have been treated by VNS for this indication. Proposed as additive symptomatic treatment of refractory epilepsies, VNS has proven effective and well tolerated by both children and adults with refractory partial epilepsy. After 2 years of treatment, patients achieve an overall average of 40 p. 100 reduction of seizure frequency. In 40 to 50 p. 100 of the patients, the frequency of seizure can even be decreased by 50 p. 100. Moreover, even in the absence of a significant reduction of seizure, patients subjected to this treatment have reported an improvement in their quality of life. The economic surveys also show a favorable impact of VNS on the management of refractory partial epilepsies.

[Cost-effectiveness of epilepsy surgery in a cohort of patients with medically intractable partial epilepsy--preliminary results]. / Evaluation médico-économique de la chirurgie des épilepsies partielles pharmaco-résistantes de l'adulte. Etude coût-efficacité--résultats préliminaires.

OBJECTIVE: Patients with medically intractable epilepsy are potential candidates for surgery if the epileptogenic tissue is localized and resectable. Surgical therapy can eliminate seizures but is very expensive. We followed a prospective adult cohort of intractable epileptic patients in order to perform a cost-effectiveness analysis. POPULATION AND METHODS: Adult patients with a suspected partial medically intractable and operable epilepsy were eligible for evaluation, explorations and/or surgery. Clinical and economical data were collected at the inclusion and every 6 months over at least two years. Two patient groups were analyzed: some underwent a surgery, others did not. Clinical data were compared between both groups. As the data collection was not yet complete, we compared the surgery to a continuation of the preoperative medical management in a cost-effectiveness analysis. Direct medical and nonmedical costs were evaluated according to a societal perspective. The effectiveness was defined as one year without seizure. We assessed the incremental cost-effectiveness ratio (ICER) for the first two years after the surgery. We also modeled long-term costs and effectiveness and extrapolated the results over the patients' lifetime with a Markov model. We computed the ICER and performed a sensitivity analysis. Indirect costs were measured in physical units and intangible costs were assessed with quality-of-life measures (QOLIE-31, SEALS). Data were compared before and after surgery. RESULTS: Among the 286 patients included, 119 did not enter in the analysis: 7 were not eligible, 44 not operable, 31 did not present a follow-up, 37 still underwent exams. Finally, 89 underwent a surgical treatment, and 78 were medically treated. Disease was more severe in surgical patients than in medical patients: seizures frequency, depressive disorders and cognitive impairment were greater. One year after the surgery, 83% patients were seizure free. During the year before inclusion and the year after surgery, direct costs were mainly due to hospitalization. During the second year after surgery, the cost of antiepileptic drugs predominated. One additional year without seizure costs 23 531 euro one year after surgery and 9533 euro two years after surgery. In a long-term perspective, the surgery became cost-effective between 7 and 8 years after the surgery. CONCLUSION: Surgical therapy is a cost-effective treatment in a middle-term even without indirect costs consideration.

[Spontaneous dissection of the exocranial internal carotid artery. Therapeutic aspects]. / Dissection spontanée de la carotide interne exocrânienne. Aspects thérapeutiques.

Spontaneous dissection of the extracranial internal carotid artery is uncommon and has been first described in 1959. Since then, 250 cases have been published. The authors report on 5 recent cases and on that occasion, they review the literature and discuss the different therapeutic possibilities. This pathology can be envisaged when a middle-aged adult, free of any previous pathology or trauma, presents with latero-cervical pain followed by cerebral ischemic stroke. The angiographic findings are of three types: regular or irregular extensive stenosis, pseudo-aneurysmal dilatation followed by luminal stenosis, funnel-like tapering of the vessel. The spontaneous course of such a dissection most often (80%) leads to an almost complete resolution of clinical and angiographic signs. Treatment, therefore, should essentially be based on anticoagulant and antiaggregant therapy, so as to prevent ischemic attacks or carotid thrombosis. Surgical indications should remain exceptional.

[Functional neurosurgery for epilepsy]. / La chirurgie fonctionnelle de l'épilepsie.

Introduced at the end of the last century, epilepsy surgery is indicated in patients with intractable partial seizures and based on the resection of the epileptogenic cerebral tissue from which ictal discharges originate. Palliative procedures include seizure spread pathways interruption (callosotomy, multiple subpial transections) and chronic stimulation of the vagus nerve. Complete preoperative investigations including seizure observation, clinical tests, video-EEG, MRI and functional MRI, and PET-scan are performed in order to identify the epileptogenic zone. In difficult cases, invasive seizure monitoring through depth electrode implantation (SEEG) is performed. Resections for temporal lobe seizures are associated with favorable outcome: 60 to 90% of patients will be seizure-free after surgery. A less favorable outcome is observed after extra-temporal resections: 40 to 60% seizure-free patients. A better outcome is observed after surgery for epilepsy associated with an image-defined lesion, most often a tumor, rather than for cryptogenic epilepsy. Tumors associated with chronic partial epilepsy are indolent, most of them are dysembryoplastic neuroepithelial tumors (DNET). Outcome after palliative procedures are more variable, depending on the etiology of epilepsy.