Search

Objective: The aim was to compare the outcomes of subdural electrode (SDE) implantations versus stereotactic electroencephalography (SEEG), the 2 predominant methods of intracranial electroencephalography (iEEG) performed in difficult-to-localize drug-resistant focal epilepsy., Methods: The Surgical Therapies Commission of the International League Against Epilepsy created an international registry of iEEG patients implanted between 2005 and 2019 with ≥1 year of follow-up. We used propensity score matching to control exposure selection bias and generate comparable cohorts. Study endpoints were: (1) likelihood of resection after iEEG; (2) seizure freedom at last follow-up; and (3) complications (composite of postoperative infection, symptomatic intracranial hemorrhage, or permanent neurological deficit)., Results: Ten study sites from 7 countries and 3 continents contributed 2,012 patients, including 1,468 (73%) eligible for analysis (526 SDE and 942 SEEG), of whom 988 (67%) underwent subsequent resection. Propensity score matching improved covariate balance between exposure groups for all analyses. Propensity-matched patients who underwent SDE had higher odds of subsequent resective surgery (odds ratio [OR] = 1.4, 95% confidence interval [CI] 1.05, 1.84) and higher odds of complications (OR = 2.24, 95% CI 1.34, 3.74; unadjusted: 9.6% after SDE vs 3.3% after SEEG). Odds of seizure freedom in propensity-matched resected patients were 1.66 times higher (95% CI 1.21, 2.26) for SEEG compared with SDE (unadjusted: 55% seizure free after SEEG-guided resections vs 41% after SDE)., Interpretation: In comparison to SEEG, SDE evaluations are more likely to lead to brain surgery in patients with drug-resistant epilepsy but have more surgical complications and lower probability of seizure freedom. This comparative-effectiveness study provides the highest feasible evidence level to guide decisions on iEEG. ANN NEUROL 2021;90:927-939., (© 2021 American Neurological Association.)

Background: Accurate localization of the probable Epileptogenic Zone (EZ) from presurgical studies is crucial for achieving good prognosis in epilepsy surgery., Objective: To evaluate the degree of concordance at a sublobar localization derived from noninvasive studies (video electroencephalography, EEG; magnetic resonance imaging, MRI; 18-fluorodeoxyglucose positron emission tomography FDG-PET, FDG-PET) and EZ estimated by stereoEEG, in forecasting seizure recurrence in a long-term cohort of patients with focal drug-resistant epilepsy., Methods: We selected patients with a full presurgical evaluation and with postsurgical outcome at least 1 yr after surgery. Multivariate Cox regression analysis for seizure freedom (Engel Ia) was performed., Results: A total of 74 patients were included, 62.2% were in Engel class Ia with a mean follow-up of 2.8 + 2.4 yr after surgery. In the multivariate analysis for Engel Ia vs >Ib, complete resection of the EZ found in stereoEEG (hazard ratio, HR: 0.24, 95%CI: 0.09-0.63, P = .004) and full concordance between FDG-PET and stereoEEG (HR: 0.11, 95%CI: 0.02-0.65, P = .015) portended a more favorable outcome. Most of our results were maintained when analyzing subgroups of patients., Conclusion: The degree of concordance between noninvasive studies and stereoEEG may help to forecast the likelihood of cure before performing resective surgery, particularly using a sublobar classification and comparing the affected areas in the FDG-PET with EZ identified with stereoEEG., (Copyright © 2020 by the Congress of Neurological Surgeons.)

Purpose: To retrospectively analyse a single-centre consecutive surgical series of patients with temporal lobe epilepsy (TLE) and negative MRI. To identify factors associated with postoperative seizure outcome among several presurgical, surgical and postsurgical variables., Methods: Clinical records of 866 patients who received temporal lobe resections and with a minimum follow-up of 12 months were retrospectively searched for MRI-negative cases. Anamnestic, clinical, neurophysiological, surgical, histopathological and postsurgical data were collected. Seizure outcome was categorised as favourable (Engel's class I) and unfavourable (Engel's classes II-IV). Uni- and multivariate statistical analysis was performed to identify variables having a significant association with seizure outcome., Results: Forty-eight patients matched the inclusion criteria. 26 (54.1%) patients required invasive EEG evaluation with Stereo-electro-encephalography (SEEG) before surgery. Histological evaluation was unremarkable in 34 cases (70.8%), revealed focal cortical dysplasias in 13 cases and hippocampal sclerosis in 2. 28 (58.3%) patients were in Engel's class I after a mean follow-up of 82 months (SD ± 74; range 12-252). Multivariate analysis indicated auditory aura, contralateral diffusion of the discharge at Video-EEG monitoring and use of 18 F-FDG PET as variables independently associated with seizure outcome., Conclusion: Carefully selected patients with MRI-negative TLE can be good candidates for surgery. Surgery should be considered with caution in patients with clinical features of neocortical seizure onset and contralateral propagation of the discharge. Use of 18 F-FDG PET may be helpful to improve SEEG and surgical strategies. The presented data help in optimising the selection of patients with MRI-negative TLE with good chances to benefit from surgery.

Objective: Long-term recording with intracerebral electrodes is commonly utilized to identify brain areas responsible for seizure generation (epileptogenic zone) and to tailor therapeutic surgical resections in patients with focal drug-resistant epilepsy. This invasive diagnostic procedure generates a wealth of data that contribute to understanding human epilepsy. We analyze intracerebral signals to identify and classify focal ictal patterns., Methods: We retrospectively analyzed stereo-electroencephalographic (EEG) data in a cohort of patients either cryptogenic (magnetic resonance imaging negative) or presenting with noncongruent anatomoelectroclinical data. A computer-assisted method based on EEG signal analysis in frequency and space domains was applied to 467 seizures recorded in 105 patients submitted to stereo-EEG presurgical monitoring., Results: Two main focal seizure patterns were identified. P-type seizures, typical of neocortex, were observed in 73 patients (69.5%), lasted 22 ± 13 seconds (mean +SD), and were characterized by a sharp-onset/sharp-offset transient superimposed on low-voltage fast activity (126 ± 19 Hz). L-type seizures were observed in 43 patients (40.9%) and consistently involved mesial temporal structures; they lasted longer (93 ± 48 second), started with 116 ± 21 Hz low-voltage fast activity superimposed on a slow potential shift, and terminated with large-amplitude, periodic bursting activity. In 23 patients (21.9%), the L-type seizure was preceded by a P seizure. Spasmlike and unclassifiable EEG seizures were observed in 11.4% of cases., Significance: The proposed computer-assisted approach revealed signal information concealed to visual inspection that contributes to identifying two principal seizure patterns typical of the neocortex and of mesial temporal networks., (Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.)

Sleep-related hypermotor epilepsy (SHE) is an epilepsy syndrome that is characterized by the occurrence of sleep-related hypermotor seizures of variable complexity and duration. Seizures usually arise in the frontal lobe, but extrafrontal seizure onset zones are well described. To identify clinically relevant ictal features of SHE that could distinguish a frontal from an extrafrontal onset zone, we conducted a retrospective analysis of seizure characteristics in 58 patients with drug-resistant SHE (43 frontal and 15 extrafrontal) who underwent video-stereo-electroencephalographic recordings and became seizure-free after epilepsy surgery. We found that the mean duration of electrographic seizures and clinically observable ictal manifestations were significantly shorter in frontal SHE compared to extrafrontal SHE. The mean latency between electrographic seizure onset and the onset of hypermotor manifestations was also shorter in frontal SHE. Accordingly, a latency > 5 seconds between the first video-detectable movement (eg, eye opening or a minor motor event) and the onset of hypermotor manifestations yielded a sensitivity of 75% and a specificity of 90% for an extrafrontal onset, thereby indicating that specific ictal features in SHE can provide clinically useful clues to increase diagnostic accuracy in this syndrome., (Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.)

Epilepsy is the most common neurological symptom in tuberous sclerosis complex (TSC), occurring in 72-85% of affected individuals. Despite the large number of patients reported, their electroclinical phenotype has been rarely described. We analyzed seizure semiology through ictal video-electroencephalography (V-EEG) recordings in a large series of patients. In this multicenter study, we reviewed V-EEGs of 51 patients: ictal recordings were analyzed in correlation with their clinical variables. The median age of epilepsy onset was six months (one day-16 years), with onset in the first year of life in 71% patients (36/51), in 10 of them during the neonatal period. Sixty-five percent of patients (33/51) experienced epileptic spasms in their life, with late-onset (>two years) in five; 42% of the epileptic spasms persisted after age two years, despite the onset in the first year of life. We identified four different electroclinical subsets: focal epilepsy (35%, 18/51), Lennox-Gastaut Syndrome evolution (27%, 14/51), focal seizures with persisting spasms (33%, 17/51), and spasms only (4%, 2/51). We reviewed 45 focal seizures, 13 clusters of epileptic spasms, and seven generalized seizures. In 12 patients, we recorded different seizure types. In 71% of the focal seizures (32/45), the ictal pattern was focal without diffusion. In 38% of the patients (5/13) epileptic spasms were related to typical diffuse slow wave pattern associated with superimposed fast activity, with focal predominance. Focal seizures and focal spasms resulted as the most frequent seizure types in TSC. Seizure onset was variable but showing a predominant involvement of the frontocentral regions (40%). Discrete clinical signs characterized the seizures, and behavioral arrest was the predominant first clinical objective sign. Epileptic spasms were a typical presentation at all ages, frequently asymmetrical and associated with lateralizing features, especially in older patients., (Copyright © 2018. Published by Elsevier Inc.)

Background: Cerebrovascular dysfunction and inflammation occur in epilepsy. Here we asked whether pericytes, a pivotal cellular component of brain capillaries, undergo pathological modifications during experimental epileptogenesis and in human epilepsy. We evaluated whether pro-inflammatory cytokines, present in the brain during seizures, contribute to pericyte morphological modifications., Methods: In vivo, unilateral intra-hippocampal kainic acid (KA) injections were performed in NG2DsRed/C57BL6 mice to induce status epilepticus (SE), epileptogenesis, and spontaneous recurrent seizures (SRS). NG2DsRed mice were used to visualize pericytes during seizure progression. The effect triggered by recombinant IL-1β, TNFα, or IL-6 on pericytes was evaluated in NG2DsRed hippocampal slices and in human-derived cell culture. Human brain specimens obtained from temporal lobe epilepsy (TLE) with or without sclerosis (HS) and focal cortical dysplasia (FCD-IIb) were evaluated for pericyte-microglial cerebrovascular assembly., Results: A disarray of NG2DsRed + pericyte soma and ramifications was found 72 h post-SE and 1 week post-SE (epileptogenesis) in the hippocampus. Pericyte modifications topographically overlapped with IBA1 + microglia clustering around the capillaries with cases of pericytes lodged within the microglial cells. Microglial clustering around the NG2DsRed pericytes lingered at SRS. Pericyte proliferation (Ki67 + ) occurred 72 h post-SE and during epileptogenesis and returned towards control levels at SRS. Human epileptic brain tissues showed pericyte-microglia assemblies with IBA1/HLA microglial cells outlining the capillary wall in TLE-HS and FCD-IIb specimens. Inflammatory mediators contributed to pericyte modifications, in particular IL-1β elicited pericyte morphological changes and pericyte-microglia clustering in NG2DsRed hippocampal slices. Modifications also occurred when pro-inflammatory cytokines were added to an in vitro culture of pericytes., Conclusions: These results indicate the occurrence of pericytosis during seizures and introduce a pericyte-microglial mediated mechanism of blood-brain barrier dysfunction in epilepsy., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Wikipedia is the most commonly accessed source of health information by both healthcare professionals and the lay public worldwide. We aimed to evaluate information-seeking behavior of Internet users searching the Italian Wikipedia for articles related to epilepsy and its treatment. Using Pageviews Analysis, we assessed the total and mean monthly views of articles from the Italian Wikipedia devoted to epilepsy, epileptic syndromes, seizure type, and antiepileptic drugs (AEDs) from January 1, 2015 to October 31, 2017. We compared the views of the article on epilepsy with those of articles focusing on Alzheimer's disease, migraine, multiple sclerosis, syncope, and stroke and adjusted all results for crude disease prevalence. With the only exception of the article on multiple sclerosis, the adjusted views for the Italian Wikipedia article on epilepsy were higher than those for the other neurological disorders. The most viewed articles on seizure type were devoted to tonic-clonic seizure, typical absence seizure, tonic convulsive seizures, and clonic convulsive seizures. The most frequently accessed articles on epilepsy syndromes were about temporal lobe epilepsy and Lennox-Gastaut syndrome. The most frequently viewed articles on AEDs were devoted to valproic acid, carbamazepine, and levetiracetam. Wikipedia searches seem to mirror patients' fears and worries about epilepsy more than its actual epidemiology. The ultimate reasons for searching online remain unknown. Epileptologists and epilepsy scientific societies should make greater efforts to work jointly with Wikipedia to convey more accurate and up-to-date information about epilepsy., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: The objective of the study was to assess common practice in pediatric epilepsy surgery in Italy between 2008 and 2014., Methods: A survey was conducted among nine Italian epilepsy surgery centers to collect information on presurgical and postsurgical evaluation protocols, volumes and types of surgical interventions, and etiologies and seizure outcomes in pediatric epilepsy surgery between 2008 and 2014., Results: Retrospective data on 527 surgical procedures were collected. The most frequent surgical approaches were temporal lobe resections and disconnections (133, 25.2%) and extratemporal lesionectomies (128, 24.3%); the most frequent etiologies were FCD II (107, 20.3%) and glioneuronal tumors (105, 19.9%). Volumes of surgeries increased over time independently from the age at surgery and the epilepsy surgery center. Engel class I was achieved in 73.6% of patients (range: 54.8 to 91.7%), with no significant changes between 2008 and 2014. Univariate analyses showed a decrease in the proportion of temporal resections and tumors and an increase in the proportion of FCDII, while multivariate analyses revealed an increase in the proportion of extratemporal surgeries over time. A higher proportion of temporal surgeries and tumors and a lower proportion of extratemporal and multilobar surgeries and of FCD were observed in low (<50surgeries/year) versus high-volume centers. There was a high variability across centers concerning pre- and postsurgical evaluation protocols, depending on local expertise and facilities., Significance: This survey reveals an increase in volume and complexity of pediatric epilepsy surgery in Italy between 2008 and 2014, associated with a stable seizure outcome., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: The contribution of recurring seizures to the progression of epileptogenesis is debated. Seizure-induced brain damage is not conclusively demonstrated either in humans or in animal models of epilepsy. We evaluated the expression of brain injury biomarkers on postsurgical brain tissue obtained from 20 patients with frequent seizures and a long history of drug-resistant focal epilepsy., Methods: The expression patterns of specific glial, neuronal, and inflammatory molecules were evaluated by immunohistochemistry in the core of type II focal cortical dysplasias (FCD-II), at the FCD boundary (perilesion), and in the adjacent normal-appearing area included in the epileptogenic region. We also analyzed surgical specimens from cryptogenic patients not presenting structural alterations at imaging., Results: Astroglial and microglial activation, reduced neuronal density, perivascular CD3-positive T-lymphocyte clustering, and fibrinogen extravasation were demonstrated in the core of FCD-II lesions. No pathological immunoreactivity was observed outside the FCD-II or in cryptogenetic specimens, where the occurrence of interictal and ictal epileptiform activity was confirmed by either stereo-electroencephalography or intraoperative electrocorticography., Interpretation: Recurrent seizures do not induce the expression of brain damage markers in nonlesional epileptogenic cortex studied in postsurgical tissue from cryptogenic and FCD patients. This evidence argues against the hypothesis that epileptiform activity per se contributes to focal brain injury, at least in the neocortical epilepsies considered here. Ann Neurol 2017;82:331-341., (© 2017 American Neurological Association.)

Seizure patterns identified in focal epilepsies caused by diverse etiologies are likely due to different pathogenic mechanisms. We describe here a novel, region-specific focal seizure pattern that mimics seizure activity observed in a subpopulation of patients submitted to presurgical monitoring with intracerebral electrodes. Distinctive seizure-like events (SLEs) are induced in the olfactory regions by acute treatment of both tangential brain slices and the isolated guinea pig brain with the potassium channel blocker 4-aminopyridine. Analysis of field potentials, intracellular activities, and extracellular potassium changes demonstrates that SLEs in the piriform cortex initiate in the superficial layer 1 lacking principal neurons with an activity-dependent increase of extracellular potassium. SLE progression (but not onset) does not require the participation of synaptic transmission and is mediated by diffusion of potassium to deep cortical layers. The novel seizure pattern here described is not observed in other cortical regions; it is proposed to rely on the peculiar organization of the superficial piriform cortex layers, which are characterized by unmyelinated axons and perisynaptic astroglial envelopes. This study reveals a sequence of ictogenic events in the olfactory cortex that were never described before in other cortical structures and supports the notion that altered potassium homeostasis and unmyelinated fibers may represent a potential vehicle for focal ictogenesis. SIGNIFICANCE STATEMENT We describe a novel seizure pattern peculiar of the olfactory cortex that resembles focal seizures with low-voltage fast activity at onset observed in humans. The findings suggest that network mechanisms responsible for seizure onset can be region specific., (Copyright © 2017 the authors 0270-6474/17/373544-11$15.00/0.)

There is currently no international consensus procedure for performing comprehensive periictal testing of patients in the epilepsy monitoring units (EMUs). Our primary goal was to develop a standardized procedure for managing and testing patients during and after seizures in EMUs. The secondary goal was to assess whether it could be implemented in clinical practice (feasibility). A taskforce was appointed by the International League Against Epilepsy (ILAE)-Commission on European Affairs and the European Epilepsy Monitoring Unit Association, to develop a standardized ictal testing battery (ITB) based on expert opinion and experience with various local testing protocols. ITB contains a comprehensive set of 10 items that evidence the clinically relevant semiologic features, and it is adaptive to the dynamics of the individual seizures. The feasibility of the ITB was prospectively evaluated on 250 seizures from 152 consecutive patients in 10 centers. ITB was successfully implemented in clinical practice in all 10 participating centers and was considered feasible in 93% of the tested seizures. ITB was not feasible for testing seizures of very short duration., (Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.)

Background: Half of patients who have resective brain surgery for drug-resistant epilepsy have recurrent postoperative seizures. Although several single predictors of seizure outcome have been identified, no validated method incorporates a patient's complex clinical characteristics into an instrument to predict an individual's post-surgery seizure outcome., Methods: We developed nomograms to predict complete freedom from seizures and Engel score of 1 (eventual freedom from seizures allowing for some initial postoperative seizures, or seizures occurring only with physiological stress such as drug withdrawal) at 2 years and 5 years after surgery on the basis of sex, seizure frequency, secondary seizure generalisation, type of surgery, pathological cause, age at epilepsy onset, age at surgery, epilepsy duration at time of surgery, and surgical side. We designed the models from a development cohort of patients who had resective surgery at the Cleveland Clinic (Cleveland, OH, USA) between 1996 and 2011. We then tested the nomograms in an external validation cohort operated on over a similar period in four epilepsy surgery centres, in Brazil, France, Italy, and the USA. We assessed performance of the nomogram by calculating concordance statistics and assessing the calibration of predicted freedom from seizures with the reported freedom from seizures and Engel score of 1., Findings: The development cohort included 846 patients and the validation cohort included 604 patients. Variables included in the nomograms were sex, seizure frequency, secondary seizure generalisation, type of surgery, and pathological cause. In the development cohort, the baseline risk of complete freedom from seizures was 0·57 at 2 years and 0·40 at 5 years. The baseline risk of Engel score of 1 was 0·69 at 2 years and 0·62 at 5 years. In the validation cohort, the models had a concordance statistic of 0·60 for complete freedom from seizures and 0·61 for Engel score of 1. Calibration curves showed adequate calibration (judged by eye) of predicted and reported freedom from seizures, throughout the range of seizure outcomes., Interpretation: If validated in prospective cohorts, these nomograms could be used to predict seizure outcomes in patients who have been judged eligible for epilepsy surgery., Funding: Cleveland Clinic Epilepsy Center., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Purpose: To analyze the clinical outcome of epilepsy surgery in children, and to identify the factors related with a favorable seizure control among several presurgical, surgical and postsurgical variables., Methods: One-hundred twenty children, younger than 16 years (69 male and 51 female), operated on for medically refractory focal epilepsy at the "C.Munari" Epilepsy Surgery Center of the Niguarda Hospital in Milan from 1998 to 2009, were identified. Seizure outcome was assessed according to the Engel's classification. Statistical analysis was performed to identify predictive elements of seizure outcome among several presurgical, surgical, and postsurgical variables., Key Findings: There were 84 (70%) seizure-free patients (Engel's classes Ia and Ic), 93 (77.5%) in class I, 8 (6.7%) in class II, 9 in class III (7.5%), and 10 (8.3%) in class IV., Significance: Our study confirms that epilepsy surgery is an established and effective treatment for partial epilepsy in children and suggest criteria to help identify early potential surgical candidates., (Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.)

Purpose: Sleep-related complex motor seizures are a common feature of nocturnal frontal lobe epilepsy. Nevertheless, recent studies also suggest that sleep-related hypermotor seizures can originate in the insula. The present study describes the electroclinical features of eight drug-resistant epileptic patients with insular-opercular seizures manifesting with nocturnal complex motor seizures., Methods: Patients underwent a comprehensive presurgical evaluation, which included history, interictal electroencephalography (EEG), scalp video-EEG monitoring, high-resolution magnetic resonance imaging (MRI), and intracerebral recording by stereo-EEG., Key Findings: Almost all patients reported an initial sensation consisting of viscerosensitive or somatosensory symptoms. Ictal clinical signs were represented by tonic-dystonic asymmetric posturing and/or hyperkinetic automatisms, including bimanual/bipedal activity and ballistic movements. Some patients exhibited dysarthric speech, hypersalivation, and apnea. Interictal and ictal EEG provided lateralizing information in the majority of patients. In three patients, MRI showed a focal anatomical abnormality in the insular-opercular region. Stereo-EEG ictal recordings demonstrated that the epileptic discharge involved simultaneously the insular cortex and the opercular region. Complex motor manifestations appeared when the ictal discharge showed an extrainsular spreading to frontomesial regions (cingulum, superior frontal gyrus, and supplementary motor area) and/or to internal and neocortical temporal lobe structures. Six patients received an insular-opercular cortical resection; three of them are seizure free (minimum follow-up 24 months) and in one a marked reduction in seizure frequency was obtained. Two patients have been operated on recently. Histology revealed a focal cortical dysplasia in three patients. One patient excluded from surgery died for sudden unexpected death in epilepsy during sleep., Significance: Our data strengthen the concept that sleep-related complex motor attacks can originate in the insula, and provide useful electroclinical information to differentiate this localization from those with similar clinical characteristics. Furthermore, this study indicates that in these drug-resistant patients, surgical treatment represents a highly effective treatment option., (Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.)

The aim of this report is not to make a differential diagnosis between epileptic nocturnal seizures and non-epileptic sleep-related movement disorders, or parasomnias. On the contrary, our goal is to emphasize the commonly shared semiological features of some epileptic seizures and parasomnias. Such similar features might be explained by the activation of the same neuronal networks (so-called 'central pattern generators' or CPG). These produce the stereotypical rhythmic motor sequences - in other words, behaviours - that are adaptive and species-specific (such as eating/alimentary, attractive/aversive, locomotor and nesting habits). CPG are located at the subcortical level (mainly in the brain stem and spinal cord) and, in humans, are under the control of the phylogenetically more recent neomammalian neocortical structures, according to a simplified Jacksonian model. Based on video-polygraphic recordings of sleep-related epileptic seizures and non-epileptic events (parasomnias), we have documented how a transient "neomammalian brain" dysfunction - whether epileptic or not - can 'release' (disinhibition?) the CPG responsible for involuntary motor behaviours. Thus, in both epileptic seizures and parasomnias, we can observe: (a) oroalimentary automatisms, bruxism and biting; (b) ambulatory behaviours, ranging from the classical bimanual-bipedal activity of 'frontal' hypermotor seizures, epileptic and non-epileptic wanderings, and somnambulism to periodic leg movements (PLM), alternating leg muscle activation (ALMA) and restless legs syndrome (RLS); and (c) various sleep-related events such as ictal fear, sleep terrors, nightmares and violent behaviour.

We describe the case of an eight-year-old boy, who underwent a video-stereo EEG (SEEG) investigation for the presurgical assessment of drug-resistant epilepsy, related to a right fronto-lateral cortical dysplasia and who became seizure-free after epilepsy surgery. The unexpected finding of the investigations was that intracerebral, high frequency (50 Hz) electrical stimulation (HFS) triggered the emergence of automatic and involuntary forward-backward locomotion during a focal seizure while the boy was standing. This clinical manifestation was different from the chaotic motor activity described during epileptic wanderings. The stimulation of the same fronto-lateral region, while the patient was lying, produced only the subjective sensation that the legs were moving, although there was no physical manifestation of this. Human locomotion is an innate motor behavior that is normally due to the activation of the spinal network for locomotion (central pattern generator). The emergence of different stereotyped motor behaviors during focal epileptic seizures or sleep disorders has recently been interpreted as a release of subcortical central pattern generators (Tassinari et al. 2005). In view of this, we hypothesize that the involuntary and robot-like locomotion of our patient could be the ictal expression of the release of subcortical locomotor CPGs.

We investigated the role of the temporal pole (TP) in 48 consecutive patients with drug-refractory temporal lobe epilepsy (TLE). Chronic depth recordings of TP cortex activity were used in association with video recording of ictal symptoms during 48 spontaneous seizures. In 23 cases (48%, group 1) the TP was involved at the onset of the seizure, before or concurrently with the hippocampus. In the remaining 25 patients (52%, group 2) the TP was involved 16.4 +/- 13.8 s after the hippocampus. A past history of febrile seizures was found in both groups, with no statistical difference. Ictal symptoms did not differentiate TP seizures from seizures originating in the hippocampus but the first clinical sign occurred sooner in group 1 compared with group 2 (respectively 10.56 +/- 9 and 25.7 +/- 19 s, respectively, P = 0.005). Loss of awareness also occurred sooner in the case of TP seizures compared with mesiotemporal lobe (MTL) seizures (22.9 +/- 22.6 versus 42.2 +/- 18.6 s, P = 0.0002). MRI data analysis showed that hippocampal sclerosis was present in both groups of patients, although it was more frequent in patients with MTL onset. Anterior temporal white matter changes were found ipsilateral to the epileptogenic area and tended to be more frequent in patients with TP seizures. All the patients underwent tailored anterior temporal lobectomy that included the TP, the hippocampus, the parahippocampal gyrus and the anterior part of the lateral temporal cortex. A better postoperative outcome was achieved in group 1 compared with group 2 (Engel class 1, 95 and 72% respectively, P = 0.04). We conclude that the frequent TP involvement at the onset of seizures could be a supplementary explanation for some failures of selective amygdalohippocampectomy, which should be addressed preferentially to well-selected patients. Moreover, the involvement of the TP cortex at the onset of the seizures is a good predicting factor for postoperative seizure outcome.