Search

Background and Objectives: It remains unknown to what extent ictal scalp EEG can accurately predict the localization of the intracerebral seizure onset in presurgical evaluation of drug-resistant epilepsies. In this study, we aimed to define homogeneous ictal scalp EEG profiles (based on their first ictal abnormality) and assess their localizing value using simultaneously recorded scalp EEG and stereo-EEG., Methods: We retrospectively included consecutive patients with drug-resistant focal epilepsy who had simultaneous stereo-EEG and scalp EEG recordings of at least 1 seizure in the epileptology unit in Nancy, France. We analyzed 1 seizure per patient and used hierarchical cluster analysis to group similar seizure profiles on scalp EEG and then performed a descriptive analysis of their intracerebral correlates., Results: We enrolled 129 patients in this study. The hierarchical cluster analysis showed 6 profiles on scalp EEG first modification. None were specific to a single intracerebral localization. The "normal EEG" and "blurred EEG" clusters (early muscle artifacts) comprised only 5 patients each and corresponded to no preferential intracerebral localization. The "temporal discharge" cluster (n = 46) was characterized by theta or delta discharges on ipsilateral anterior temporal scalp electrodes and corresponded to a preferential mesial temporal intracerebral localization. The "posterior discharge" cluster (n = 42) was characterized by posterior ipsilateral or contralateral rhythmic alpha discharges or slow waves on scalp and corresponded to a preferential temporal localization. However, this profile was the statistically most frequent scalp EEG correlate of occipital and parietal seizures. The "diffuse suppression" cluster (n = 9) was characterized by a bilateral and diffuse background activity suppression on scalp and corresponded to mesial, and particularly insulo-opercular, localization. Finally, the "frontal discharge" cluster (n = 22) was characterized by bilateral frontal rhythmic fast activity or preictal spike on scalp and corresponded to preferential ventrodorsal frontal intracerebral localizations., Discussion: The hierarchical cluster analysis identified 6 seizure profiles regarding the first abnormality on scalp EEG. None of them were specific of a single intracerebral localization. Nevertheless, the strong relationships between the "temporal," "frontal," "diffuse suppression," and "posterior" profiles and intracerebral discharge localizations may contribute to hierarchize hypotheses derived from ictal scalp EEG analysis regarding intracerebral seizure onset., (© 2023 American Academy of Neurology.)

Objective: Surgery is an effective treatment for drug-resistant temporal-lobe epilepsy (TLE), but is still underutilized for older patients because of a perceived higher rate of perioperative complications, cognitive decline and worse seizure outcome., Methods: We retrospectively screened all patients operated on in our institution for drug-resistant TLE between 2007 and 2019. Data of patients aged ≥50 years versus <50 years at surgery were compared. The primary endpoint was freedom from disabling seizure (Engel I) at 2 years postoperatively., Results: In patients aged ≥50 years (n=19), mean age at surgery was 54.9 years and mean disease duration was 36.6 years. At 2 years postoperatively, rates of Engel I seizure outcome were not significantly different between the two groups (73.9% in the <50 years group versus 94.4% in the ≥50 years group). Although surgical complications were significantly (47.4%) in the older patients, neurological deficit was permanent in only 5.3% of cases. At 1 year postoperatively, neuropsychological outcome did not significantly differ between the two groups., Conclusions: Patients aged ≥50 years had an excellent seizure outcome at 2 years postoperatively. Early postoperative complications were more frequent in patients aged ≥50 years but were mostly transient. Cognitive outcome was similar to that in younger patients. These findings strongly suggest that age ≥50 years should not be an exclusion criterion for resective epilepsy surgery in patients with drug-resistant TLE., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

Background: Occipital lobe seizure are underrepresented in epilepsy surgery cases series. This may reflect the fear for post-surgical functional deficits but also the doubt about the ability of anatomo-electro-clinical correlations to localize precisely the epileptogenic zone in occipital lobe seizure., Methods: In this expert opinion paper, we review first the general clinical characteristics of occipital lobe seizures, describe the repertoire of visual phenomena and oculo-motor signes in occipital seizures, describe inter-ictal and ictal EEG and finally the possible schemes of epileptogenic zone organization., Results: Visual and oculo-motor semiology points towards occipital onset seizures but is neither pathognomonic nor constant. Eyes version and unilateral ictal discharge have a strong lateralizing value but inter-ictal spikes as well as eyes version can be falsely lateralizing., Conclusion: Although visual and oculo-motor phenomena are characteristic of occipital lobe seizures, they may be discrete, overlooked and should therefore be carefully assessed. There are no clear electro-clinical correlations of a sublobar organization of occipital seizures but the clinical pattern of propagation might help to differentiate complex occipito-temporal from occipito-parietal initial epileptogenic network., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

Objective: Anxiety disorders are a frequent psychiatric condition in patients with epilepsy. Anticipatory anxiety of seizures (AAS) is described as a daily persistent fear or excessive worry of having a seizure. AAS seems to be related to "subjective ictal anxiety" reported by patients. The current study aimed to assess the association between objective ictal features and the presence of AAS., Methods: Ninety-one patients with drug-resistant focal epilepsy underwent a standardized psychiatric assessment, specific for epilepsy, and presurgical long-term video-electroencephalography (EEG) or stereo-EEG (SEEG). We compared seizure semiology and epilepsy features of patients with AAS (n = 41) to those of patients without AAS (n = 50). We analyzed emotional and motor behavior ictal signs as well as ictal consciousness. We further assessed amygdala ictal involvement in seizures recorded with SEEG (n = 28)., Results: AAS was significantly associated with the presence of ictal emotional distress; negative emotional behavior (p < .01) and negative emotion were explicitly reported to the examiner during recording (p = .015), regardless of the ictal level of consciousness. Among the patients recorded with SEEG, we found a significant involvement of amygdala within the seizure onset zone (p < .01) for patients with AAS., Significance: Higher risk of developing AAS is associated with seizures expressing negative emotional symptoms, independently of ictal consciousness level. Persistent interictal fear of seizures might be viewed as the consequence of a reinforcement of the emotional networks secondary to amygdala involvement in seizures of temporal origin. Physicians should screen for AAS not only to assess the impact of epilepsy on daily life, but also as an interictal biomarker of ictal semiology and emotional network involvement at seizure onset., (© 2022 International League Against Epilepsy.)

Objective: The present study aimed to evaluate the prevalence of traumatic experienced seizures (TES) and of postepileptic seizure PTSD (PS-PTSD) in patients with pharmacoresistant focal epilepsy and to explore the determining factors of TES. Methods: We conducted an observational study enrolling 107 adult refractory epilepsy patients. We used the DSM-5 criteria of traumatic events and PTSD to define TES and PS-PTSD. We assessed all traumatic life events unrelated to epilepsy, general and specific psychiatric comorbidities, and quality of life. Results: Nearly half ( n = 48) of the 107 participants reported at least one TES (44.85%). Among these, one-third ( n = 16) developed PS-PTSD. The TES group was more likely to experience traumatic events unrelated to epilepsy ( p < 0.001), to have generalized anxiety disorder ( p = 0.019), and to have specific psychiatric comorbidities [e.g., interictal dysphoric disorder ( p = 0.024) or anticipatory anxiety of seizures ( p = 0.005)]. They reported a severe impact of epilepsy on their life ( p = 0.01). The determining factors of TES according to the multifactorial model were the experience of trauma ( p = 0.008), a history of at least one psychiatric disorder ( p = 0.03), and a strong tendency toward dissociation ( p = 0.03). Significance: Epileptic seizures may be a traumatic experience in some patients who suffer from pharmacoresistant epilepsy and may be the source of the development of PS-PTSD. Previous trauma unrelated to epilepsy and psychiatric history are determining factors of TES. These clinical entities should be explored systematically., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Mariotti, Valentin, Ertan, Maillard, Tarrada, Chrusciel, Sanchez, Schwan, Vignal, Tyvaert, El-Hage and Hingray.)

Medical international guidelines recommend regular psychiatric consultations for patients with epilepsy, in order to detect comorbidities. However, there is a lack of guidance about PNES that constitute both a differential diagnosis and a comorbidity of epilepsy. While waiting for the ideal collaboration between neurologists and psychiatrists, we develop a pragmatic approach. Wrong diagnosis between epilepsy and Psychogenic nonepileptic seizures (PNES) is frequent and may lead to iatrogenic consequences for patients. To limit the risk of misdiagnosis, psychiatrists and neurologists should collaborate and be more trained about epilepsy, PNES, and their comorbidities. We illustrate the aim of this collaboration through the case of a patient, initially diagnosed with epilepsy, then with PNES only and finally with comorbid epilepsy and PNES. The correct final diagnosis would not have been performed without the collaboration of psychiatrists and neurologists, trained in "Epi-Psy" approach., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: In drug-resistant temporal lobe epilepsy (TLE) patients, the authors evaluated early and late outcomes for decline in visual object naming after dominant temporal lobe resection (TLR) according to the resection status of the basal temporal language area (BTLA) identified by cortical stimulation during stereoelectroencephalography (SEEG)., Methods: Twenty patients who underwent SEEG for drug-resistant TLE met the inclusion criteria. During language mapping, a site was considered positive when stimulation of two contiguous contacts elicited at least one naming impairment during two remote sessions. After TLR ipsilateral to their BTLA, patients were classified as BTLA+ when at least one positive language site was resected and as BTLA- when all positive language sites were preserved. Outcomes in naming and verbal fluency tests were assessed using pre- and postoperative (means of 7 and 25 months after surgery) scores at the group level and reliable change indices (RCIs) for clinically meaningful changes at the individual level., Results: BTLA+ patients (n = 7) had significantly worse naming scores than BTLA- patients (n = 13) within 1 year after surgery but not at the long-term evaluation. No difference in verbal fluency tests was observed. When RCIs were used, 5 of 18 patients (28%) had naming decline within 1 year postoperatively (corresponding to 57% of BTLA+ and 9% of BTLA- patients). A significant correlation was found between BTLA resection and naming decline., Conclusions: BTLA resection is associated with a specific and early naming decline. Even if this decline is transient, naming scores in BTLA+ patients tend to remain lower compared to their baseline. SEEG mapping helps to predict postoperative language outcome after dominant TLR.

Objective: Fear of having a seizure called anticipatory anxiety of epileptic seizure (AAS), constitutes a daily life burden but has been rarely studied. Our aim was to assess the prevalence and the determining factors of AAS in patients with drug-resistant focal epilepsy, a dimension that has not been thoroughly investigated before., Methods: We conducted an observational, prospective study enrolling patients with drug-resistant focal epilepsy. The psychiatric assessment aimed to evaluate psychiatric comorbidities, trauma history, and quality of life using hetero-evaluation and self-assessment tools. Dimensions of anxiety specifically related to epilepsy (peri-and-inter-ictal) were explored as exhaustively as possible., Results: AAS was found in 53 % of the 87 patients. We compared the two groups of patients: with or without AAS. Patients with AAS had a significantly shorter duration of epilepsy (p = 0.04). There was no difference between groups with respect to psychiatric disorders, except for cannabis dependence, more frequent in patients with AAS (p = 0.02). Compared to patients without AAS, those with AAS presented more subjective ictal anxiety (p = 0.0003) and postictal anxiety (p = 0.02), were more likely to avoid outdoor social situations due to seizure fear (p = 0.001), and had a poorer quality of life (QOLIE emotional well-being; p = 0.03). Additionally, they had experienced more traumatic events in their lifetime (p = 0.005) and reported more frequently a feeling of being unsafe during their seizures (p = 0.00002)., Significance: AAS is a specific dimension of anxiety, possibly linked to trauma history. AAS is strongly linked to subjective ictal anxiety but not to the objective severity of seizures or frequency., (Copyright © 2020 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Interictal electrical source imaging (ESI) encompasses a risk of false localization due to complex relationships between irritative and epileptogenic networks. This study aimed to compare the localizing value of ESI derived from ictal and inter-ictal EEG discharges and to evaluate the localizing value of ESI according to three different subgroups: MRI lesion, presumed etiology and morphology of ictal EEG pattern. We prospectively analyzed 54 of 78 enrolled patients undergoing pre-surgical investigation for refractory epilepsy. Ictal and inter-ictal ESI results were interpreted blinded to- and subsequently compared with stereoelectroencephalography as a reference method. Anatomical concordance was assessed at a sub-lobar level. Sensitivity and specificity of ictal, inter-ictal and ictal plus inter-ictal ESI were calculated and compared according to the different subgroups. Inter-ictal and ictal ESI sensitivity (84% and 75% respectively) and specificity (38% and 50% respectively) were not statistically different. Regarding the sensitivity, ictal ESI was never higher than inter-ictal ESI. Regarding the specificity, ictal ESI was higher than inter-ictal ESI in malformations of cortical development (MCD) (60% vs. 43%) and in MRI positive patients (49% vs. 30%). Within the ictal ESI analysis, we showed a higher specificity for ictal spikes (59%) and rhythmic discharges > 13 Hz (50%) than rhythmic discharges < 13 Hz (37%) and (ii) for MCD (60%) than in other etiologies (29%). This prospective study demonstrates the relevance of a combined interpretation of distinct inter-ictal and ictal analysis. Inter-ictal analysis gave the highest sensitivity. Ictal analysis gave the highest specificity especially in patients with MCD or a lesion on MRI.

Objective: To evaluate the incidence of short-term recurrence (<1 month) after a first unprovoked seizure (FUS) and the associated risk factors., Methods: This is a prospective monocentric one-year observational study on all consecutive adult patients admitted to the Emergency Department (ED) and diagnosed as FUS. Patients underwent neurological consultation at one and three months after the FUS. Demographic information, clinical examination and seizure features, seizure recurrence at 1 and 3 months, electroencephalogram (EEG), brain imaging, precipitating factors, seizure type, and prescribed antiepileptic drugs (AED) were prospectively collected., Results: Among 140 patients diagnosed as FUS, 109 patients attended the neurological consultation at 1 month. FUS diagnosis was confirmed in 80/109 cases. Nine patients (11.2%) had seizure recurrence before the consultation at 1 month. Identified specific risk factors of short-term recurrence were focal seizure (P=0.015) and abnormal EEG in the first 48hours (P=0.048). In the group of patients followed for three months (38 patients), the risk of seizure relapse was 15.7%., Conclusion: Most patients with FUS diagnosed in the ED did not present seizure recurrence within the first month, especially if no specific risk factors were present (focal seizure, abnormal EEG within first 48hours). The systematic use of prophylactic AED (benzodiazepines) is not recommended in the ED in the clinical setting of FUS. A specialized consultation within a one-month period is safe and adequate for FUS follow-up., (Copyright © 2020. Published by Elsevier Masson SAS.)

Psychiatric comorbidities are 2 to 3 times more frequent in patients with epilepsy than in the general population. This study aimed to prospectively assess the following: (i) the prevalence of specific and nonspecific interictal psychiatric comorbidities in a population of patients with drug-resistant focal epilepsy and (ii) the influence of epilepsy lateralization and localization on these psychiatric comorbidities. In this prospective monocentric study, we collected demographic data, characteristics of the epilepsy, interictal psychiatric comorbidities, mood, anxiety, and alexithymia dimensions. We used criteria from Diagnostic and Statistical Manual of Mental Disorders IV ( DSM IV) (Mini International Mental Interview (MINI)), diagnosis criteria for specific comorbidities, and validated mood and anxiety scales (general and specific for epilepsy). Among the 87 enrolled patients (39 males, 48 females), 52.9% had at least one psychiatric comorbidity. The most common comorbidity was anxiety disorder (28.7% according to the MINI, and 38.4% screening by the Generalized Anxiety Disorder 7 (GAD 7)). Mood disorders were the second most frequent psychiatric comorbidity: 21.8% of our patients had interictal dysphoric disorders (IDDs), 16.1% presented major depressive disorders according to the MINI, and 17.2% screening by the Neurological Disorders Depression Inventory for Epilepsy (NDDIE). Patients with temporal lobe epilepsy had a higher prevalence of psychiatric comorbidities than patients with extratemporal lobe epilepsy (p = 0.002), which is probably related to a higher rate of anxiety disorders in this subgroup (p = 0.012). Prevalence of psychiatric disorders prior to epilepsy in patients was higher in right- than in left-sided epilepsy (p = 0.042). No difference was found according to limbic involvement at seizure onset. Overall, this article highlighted a very high proportion of anxiety disorders in these patients with drug-resistant focal epilepsy and the necessity to systematically detect them and thus lead to a specific treatment., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Study Objectives: Confusional arousals (CA) are characterized by the association of behavioral awakening with persistent slow-wave electroencephalographic (EEG) activity during non-rapid eye movement (NREM) sleep-suggesting that sensorimotor areas are "awake" while non-sensorimotor areas are still "asleep." In the present work, we aimed to study the precise temporo-spatial dynamics of EEG changes in cortical areas during CA using intracerebral recordings., Methods: Nineteen episodes of CA were selected in five drug-resistant epileptic patients suffering incidentally from arousal disorders. Spectral power of EEG signal recorded in 30 non-lesioned, non-epileptogenic cortical areas and thalamus was compared between CA and baseline slow-wave sleep., Results: Clear sequential modifications in EEG activity were observed in almost all studied areas. In the last few seconds before behavior onset, an increase in delta activity occurred predominantly in frontal regions. Behavioral arousal was associated with an increase of signal power in the whole studied frequency band in the frontal lobes, cingulate cortex, insular cortex, and precuneus. Afterwards, a diffuse cessation of very low frequencies (<1 Hz) occurred. Simultaneously, a hypersynchronous delta activity (HSDA) (1-1.5 Hz) arose in a broad network involving medial and lateral frontoparietal cortices, whereas higher frequency activities increased in sensorimotor, orbitofrontal, and temporal lateral cortices. This HSDA was predominantly observed in the inferior frontal gyrus., Conclusions: During CA, the level of activity changed in almost all the studied areas. The embedding of a broad frontoparietal network, especially the inferior frontal gyrus, in an HSDA might explain the participants' altered state of consciousness.

Background: Epileptic patients sometimes report experiential phenomena related to a previous dream they had during seizures or electrical brain stimulation (EBS). This has been alluded to in the literature as "déjà-rêvé" ("already dreamed"). However, there is no neuroscientific evidence to support its existence and this concept is commonly mixed up with déjà-vu. We hypothesized that déjà-rêvé would be a specific entity, i.e., different from other experiential phenomena reported in epileptic patients, induced by EBS of specific brain areas., Methods: We collected all experiential phenomena related to dreams induced by electrical brain stimulations (EBS) in our epileptic patients (2003-2015) and in a review of the literature. The content of these déjà-rêvé and the location of EBS were analyzed., Results: We collected 7 déjà-rêvé in our database and 35 from the literature, which corresponds to an estimated prevalence of 0.3‰ of all EBS-inducing déjà-rêvé. Déjà-rêvé is a generic term for three distinct entities: it can be the recollection of a specific dream ("episodic-like"), reminiscence of a vague dream ("familiarity-like") or experiences in which the subject feels like they are dreaming (literally "a dreamy state"). EBS-inducing "episodic-like" and "familiarity-like" déjà-rêvé were mostly located in the medial temporal lobes. "Dreamy states" were induced by less specific EBS areas although still related to the temporal lobes., Conclusions: This study demonstrates that déjà-rêvé is a heterogeneous entity that is different from déjà-vu, the historical "dreamy state" definition and other experiential phenomena. This may be relevant for clinical practice as it points to temporal lobe dysfunction and could be valuable for studying the neural substrates of dreams., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Stereoelectroencephalography (SEEG) was designed and developed in the 1960s in France by J. Talairach and J. Bancaud. It is an invasive method of exploration for drug-resistant focal epilepsies, offering the advantage of a tridimensional and temporally precise study of the epileptic discharge. It allows anatomo-electrical correlations and tailored surgeries. Whereas this method has been used for decades by experts in a limited number of European centers, the last ten years have seen increasing worldwide spread of its use. Moreover in current practice, SEEG is not only a diagnostic tool but also offers a therapeutic option, i.e., thermocoagulation. In order to propose formal guidelines for best clinical practice in SEEG, a working party was formed, composed of experts from every French centre with a large SEEG experience (those performing more than 10 SEEG per year over at least a 5 year period). This group formulated recommendations, which were graded by all participants according to established methodology. The first part of this article summarizes these within the following topics: indications and limits of SEEG; planning and management of SEEG; surgical technique; electrophysiological technical procedures; interpretation of SEEG recordings; and SEEG-guided radio frequency thermocoagulation. In the second part, those different aspects are discussed in more detail by subgroups of experts, based on existing literature and their own experience. The aim of this work is to present a consensual French approach to SEEG, which could be used as a basic document for centers using this method, particularly those who are beginning SEEG practice. These guidelines are supported by the French Clinical Neurophysiology Society and the French chapter of the International League Against Epilepsy., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Stereoelectroencephalography (SEEG) aims to define the epileptogenic zone (EZ), to study its relationship with functional areas and the causal lesion and to evaluate the possibility of surgical therapy. Planning of exploration is based on the validity of the hypotheses developed from electroclinical and imaging correlations. Further investigations can refine the implantation plan (e.g. fluorodeoxyglucose positron emission tomography [FDG-PET], single photon emission computerized tomography [SPECT], magnetoencephalography [MEG] and high resolution electroencephalography [EEG-HR]). The scheme is individualized according to the features of each clinical case, but a general approach can be systematized according to the regions involved (temporal versus extra-temporal), the existence of a lesion, its type and extent. It takes account of the hemispheric dominance for language if this can be determined. In "temporal plus" epilepsies, perisylvian and insular regions are among the key structures to investigate in addition to mesial and neocortical temporal areas. In frontal lobe epilepsies, determining the functional and anatomical organization of seizures (anterior versus posterior, mesial versus dorsolateral) allows better targeting of the implantation. Posterior epilepsies tend to have a complex organization leading to multilobar and often bilateral explorations. In lesional cases, it may be useful to implant one or several intralesional electrode(s), except in cases of vascular lesions or cyst. The strategy of implantation can be modified if thermocoagulations are considered. The management of SEEG implies continuous monitoring in a dedicated environment to determine the EZ with optimal safety conditions. This methodology includes spontaneous seizure recordings, low and high frequency stimulations and, if possible, sleep recording. SEEG is applicable in children, even the very young. Specific training of medical and paramedical teams is required., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

We report the case of a patient (MB, young female human subject) who systematically experienced confusion between perceived facial identities specifically when electrically stimulated inside the lateral section of the right fusiform gyrus. In the presence of a face stimulus (an experimenter or a photograph), intracerebral electrical stimulation in this region generated a perceptual hallucination of an individual facial part integrated within the whole perceived face, i.e., facial palinopsia. In the presence of a distracting stimulus (visual scene or object picture), the patient also experienced an individual face percept superimposed on the non-face stimulus. The stimulation site evoking this category-selective transient palinopsia was localized in a region showing highly selective responses to faces both with functional magnetic resonance imaging ("Fusiform Face Area", "FFA") and intracerebral electrophysiological recordings during fast periodic visual stimulation (FPVS). Importantly, the largest electrophysiological response to fast periodic changes of facial identity was also found at this location. Altogether, these observations suggest that the face-selective right lateral fusiform gyrus plays a role in generating vivid percepts of individual faces, supporting the active role of this region in individual face representation., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: The exploration of the insula in pre-surgical evaluation of epilepsy is considered to be associated with a high vascular risk resulting in an incomplete exploration of the insular cortex., Objective: To report a retrospective observational study of insular exploration using stereoelectroencephalography (sEEG) with transopercular and parasagittal oblique intracerebral electrodes from January 2008 to January 2016. The first purpose of this study was to evaluate the surgical risks of insular cortex sEEG exploration. The second purpose was to define the ability of placing intracerebral contacts in the whole insular cortex., Methods: Ninety-nine patients underwent 108 magnetic resonance imaging (MRI)-guided stereotactic implantations of intracerebral electrodes in the context of preoperative assessment of drug-resistant epilepsy, including at least 1 electrode placed in the insular cortex. On postoperative computed tomography images co-registered with MRI, followed by MRI segmentation and application of a transformation matrix, intracerebral contact coordinates of the insular electrodes' contacts were anatomically localized in the Talairach space. Finally, dispersion and clustering analysis was performed., Results: There was no morbidity, in particular hemorrhagic complications, or mortality related to insular electrodes. Statistical comparison of intracerebral contact positions demonstrated that whole insula exploration is possible on the left and right sides. In addition, the clustering analysis showed the homogeneous distribution of the electrodes within the insular cortex., Conclusion: In the presurgical evaluation of drug-resistant epilepsy, the insular cortex can be explored safely and comprehensively using transopercular sEEG electrodes. Parasagittal oblique trajectories may also be associated to achieve an optimal exploration., (Copyright © 2017 by the Congress of Neurological Surgeons)

While object naming is traditionally considered asa left hemisphere function, neuroimaging studies have reported activations related to naming in the ventral temporal cortex (VTC) bilaterally. Our aim was to use intracerebral electrical stimulation to specifically compare left and right VTC in naming. In twenty-three epileptic patients tested for visual object naming during stimulation, the proportion of naming impairments was significantly higher in the left than in the right VTC (31.3% vs 13.6%). The highest proportions of positive naming sites were found in the left fusiform gyrus and occipito-temporal sulcus (47.5% and 31.8%). For 17 positive left naming sites, an additional semantic picture matching was carried out, always successfully performed. Our results showed the enhanced role of the left compared to the right VTC in naming and suggest that it may be involved in lexical retrieval rather than in semantic processing., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The temporal lobe is classically divided in two functional systems: the ventral visual pathway and the medial temporal memory system. However, their functional separation has been challenged by studies suggesting that the medial temporal lobe could be best understood as an extension of the hierarchically organized ventral visual pathway. Our purpose was to investigate (i) whether cerebral regions within the temporal lobe could be grouped into distinct functional assemblies, and (ii) which regions were central within these functional assemblies. We studied low intensity and low frequency electrical stimulations (0.5 mA, 1 Hz, 4 ms) performed during sixteen pre-surgical intracerebral EEG investigations in patients with medically intractable temporal or temporo-occipital lobe epilepsies. Eleven regions of interest were delineated per anatomical landmarks such as gyri and sulci. Effective connectivity based on electrophysiological feature (amplitude) of cortico-cortical evoked potentials (CCEPs) was evaluated and subjected to graph metrics. The amplitudes discriminated one medial module where the hippocampus could act as a signal amplifier. Mean amplitudes of CCEPs in regions of the temporal lobe showed a generalized Pareto distribution of probability suggesting neural synchronies to be self-organized critically. Our description of effective interactions within the temporal lobe provides a regional electrophysiological model of effective connectivity which is discussed in the context of the current hypothesis of pattern completion., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: To describe the hippocampal stereo-electroencephalogram during sleep according to sleep stages (including N2 sleep) and cycles, together with the hippocampal spindles., Methods: All patients with drug-resistant focal epilepsy undergoing intra-hippocampal implantation between August 2012 and June 2013 at Nancy University Hospital were screened. Six patients with explored hippocampus devoid of pathological features were analyzed. During one night, we identified continuous periods of successive N2, N3 and REM sleep for two full cycles. We performed a spectral analysis of the hippocampal signal for each labeled sleep period., Results: N2, N3 and REM sleeps were individualized according to their spectral powers, for each frequency band and sleep cycle. Hippocampal spindles showed dynamic intrinsic properties, the 11.5-16Hz frequency band being mainly dominant, whereas the 9-11.5Hz frequency band heightening during the beginning and the end of the transient. For N3 and REM sleep stages, the power of the hippocampal signal was significantly decreased between the first and the second sleep cycle., Conclusion: Distinct N2 sleep, fast spindles and homeostatic profile are all common properties shared by hippocampus and cortex during sleep., Significance: The close functional link between hippocampus and cortex may have various sleep-related substrates., (Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Objective: We aimed to prospectively assess the anatomical concordance of electric source localizations of interictal discharges with the epileptogenic zone (EZ) estimated by stereo-electroencephalography (SEEG) according to different subgroups: the type of epilepsy, the presence of a structural MRI lesion, the aetiology and the depth of the EZ., Methods: In a prospective multicentric observational study, we enrolled 85 consecutive patients undergoing pre-surgical SEEG investigation for focal drug-resistant epilepsy. Electric source imaging (ESI) was performed before SEEG. Source localizations were obtained from dipolar and distributed source methods. Anatomical concordance between ESI and EZ was defined according to 36 predefined sublobar regions. ESI was interpreted blinded to- and subsequently compared with SEEG estimated EZ., Results: 74 patients were finally analyzed. 38 patients had temporal and 36 extra-temporal lobe epilepsy. MRI was positive in 52. 41 patients had malformation of cortical development (MCD), 33 had another or an unknown aetiology. EZ was medial in 27, lateral in 13, and medio-lateral in 34. In the overall cohort, ESI completely or partly localized the EZ in 85%: full concordance in 13 cases and partial concordance in 50 cases. The rate of ESI full concordance with EZ was significantly higher in (i) frontal lobe epilepsy (46%; p  = 0.05), (ii) cases of negative MRI (36%; p  = 0.01) and (iii) MCD (27%; p  = 0.03). The rate of ESI full concordance with EZ was not statistically different according to the depth of the EZ., Significance: We prospectively demonstrated that ESI more accurately estimated the EZ in subgroups of patients who are often the most difficult cases in epilepsy surgery: frontal lobe epilepsy, negative MRI and the presence of MCD.

Electrical brain stimulations (EBS) sometimes induce reminiscences, but it is largely unknown what type of memories they can trigger. We reviewed 80 years of literature on reminiscences induced by EBS and added our own database. We classified them according to modern conceptions of memory. We observed a surprisingly large variety of reminiscences covering all aspects of declarative memory. However, most were poorly detailed and only a few were episodic. This result does not support theories of a highly stable and detailed memory, as initially postulated, and still widely believed as true by the general public. Moreover, memory networks could only be activated by some of their nodes: 94.1% of EBS were temporal, although the parietal and frontal lobes, also involved in memory networks, were stimulated. The qualitative nature of memories largely depended on the site of stimulation: EBS to rhinal cortex mostly induced personal semantic reminiscences, while only hippocampal EBS induced episodic memories. This result supports the view that EBS can activate memory in predictable ways in humans., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: Despite its well-known effectiveness, the cost-effectiveness of epilepsy surgery has never been demonstrated in France. We compared cost-effectiveness between resective surgery and medical therapy in a controlled cohort of adult patients with partial intractable epilepsy., Methods: A prospective cohort of adult patients with surgically remediable and medically intractable partial epilepsy was followed over 5 years in the 15 French centers. Effectiveness was defined as 1 year without a seizure, based on the International League Against Epilepsy (ILAE) classification. Clinical outcomes and direct costs were compared between surgical and medical groups. Long-term direct costs and effectiveness were extrapolated over the patients' lifetimes with a Monte-Carlo simulation using a Markov model, and an incremental cost-effectiveness ratio (ICER) was computed. Indirect costs were also evaluated., Results: Among the 289 enrolled surgery candidates, 207 were operable-119 in the surgical group and 88 in the medical group-65 were not operable and not analyzed here, 7 were finally not eligible, and 10 were not followed. The proportion of patients completely seizure-free during the last 12 months (ILAE class 1) was 69.0% in the operated group and 12.3% in the medical group during the second year (p < 0.001), and it was respectively 76.8% and 21% during the fifth year (p < 0.001). Direct costs became significantly lower in the surgical group the third year after surgery, as a result of less antiepileptic drug use. The value of the discounted ICER was 10,406 (95% confidence interval [CI] 10,182-10,634) at 2 years and 2,630 (CI 95% 2,549-2,713) at 5 years. Surgery became cost-effective between 9 and 10 years after surgery, and even earlier if indirect costs were taken into account as well., Significance: Our study suggests that in addition to being safe and effective, resective surgery of epilepsy is cost-effective in the medium term. It should therefore be considered earlier in the development of epilepsy., (Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.)

According to neuropsychological evidence, a distributed network of regions of the ventral visual pathway - from the lateral occipital cortex to the temporal pole - supports face recognition. However, functional magnetic resonance imaging (fMRI) studies have generally confined ventral face-selective areas to the posterior section of the occipito-temporal cortex, i.e., the inferior occipital gyrus occipital face area (OFA) and the posterior and middle fusiform gyrus fusiform face area (FFA). There is recent evidence that intracranial electrical stimulation of these areas in the right hemisphere elicits face matching and recognition impairments (i.e., prosopagnosia) as well as perceptual face distortions. Here we report a case of transient inability to recognize faces following electrical stimulation of the right anterior fusiform gyrus, in a region located anteriorly to the FFA. There was no perceptual face distortion reported during stimulation. Although no fMRI face-selective responses were found in this region due to a severe signal drop-out as in previous studies, intracerebral face-selective event-related potentials and gamma range electrophysiological responses were found at the critical site of stimulation. These results point to a causal role in face recognition of the right anterior fusiform gyrus and more generally of face-selective areas located beyond the "core" face-processing network in the right ventral temporal cortex. It also illustrates the diagnostic value of intracerebral electrophysiological recordings and stimulation in understanding the neural basis of face recognition and visual recognition in general., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Purpose: To investigate cognition, particularly anterograde and remote memory, in patients suffering from unilateral drug-responsive mesial temporal lobe epilepsy (mTLE) patients and to compare their performance with that observed in drug-resistant mTLE patients., Methods: Sixteen drug-responsive mTLE patients, with only infrequent seizures in their lifetime, were matched for demographic and clinical variables to 18 patients suffering from drug-resistant unilateral mTLE. A comprehensive neuropsychological examination, including baseline, anterograde memory tasks, and a large range of remote memory tests was carried out., Results: Patients with drug-responsive epilepsy obtained average scores on every anterograde memory test. Although in general, they obtained lower scores than the healthy controls on remote memory tests, the differences failed to reach significance. Moreover, the drug-responsive group performed significantly better than the drug-resistant group on anterograde recall tests and an episodic autobiographical memory test. Performance was not significantly different between the patient groups in personal semantics or memory for public events., Conclusion: Our results show that a mild clinical course of mTLE with no cognitive deficits can occur notwithstanding hippocampal sclerosis. The differences in cognitive function between the two groups are likely due to distinct pathophysiology of the underlying cause of epilepsy. Drug-resistant seizures and cognitive deficits may be the consequence of a more severe underlying cerebral process. Better understanding of the variety of pathogenesis of mTLE could help to answer this open question., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Mesial temporal sources are presumed to escape detection in scalp electroencephalographic recordings. This is attributed to the deep localization and infolded geometry of mesial temporal structures that leads to a cancellation of electrical potentials, and to the blurring effect of the superimposed neocortical background activity. In this study, we analyzed simultaneous scalp and intracerebral electroencephalographic recordings to delineate the contribution of mesial temporal sources to scalp electroencephalogram. Interictal intracerebral spike networks were classified in three distinct categories: solely mesial, mesial as well as neocortical, and solely neocortical. The highest and earliest intracerebral spikes generated by the leader source of each network were marked and the corresponding simultaneous intracerebral and scalp electroencephalograms were averaged and then characterized both in terms of amplitude and spatial distribution. In seven drug-resistant epileptic patients, 21 interictal intracerebral networks were identified: nine mesial, five mesial plus neocortical and seven neocortical. Averaged scalp spikes arising respectively from mesial, mesial plus neocortical and neocortical networks had a 7.1 (n = 1,949), 36.1 (n = 628) and 10 (n = 1,471) µV average amplitude. Their scalp electroencephalogram electrical field presented a negativity in the ipsilateral anterior and basal temporal electrodes in all networks and a significant positivity in the fronto-centro-parietal electrodes solely in the mesial plus neocortical and neocortical networks. Topographic consistency test proved the consistency of these different scalp electroencephalogram maps and hierarchical clustering clearly differentiated them. In our study, we have thus shown for the first time that mesial temporal sources (1) cannot be spontaneously visible (mean signal-to-noise ratio -2.1 dB) on the scalp at the single trial level and (2) contribute to scalp electroencephalogram despite their curved geometry and deep localization.

Purpose: Seizure frequency, although considered as an important factor in memory impairment in mesial temporal epilepsy (mTLE), is mostly confounded with other clinical variables, making it unclear to what extent recurrent seizures actually interfere with memory. The present study focuses on the influence of seizure frequency, studied as a main variable, on anterograde and remote memory., Methods: Seventy-one patients with unilateral mTLE were divided into two subgroups, as a function of their seizure frequency (monthly versus weekly seizures). Other seizure-related variables were controlled, namely, lateralisation and type of lesion, age at onset, years of ongoing seizures, etiologic factors, and number of AED. A comprehensive neuropsychological examination, including anterograde memory (verbal and non verbal recognition memory and free recall) tasks together with a large range of tests exploring different domains of remote memory, was carried out., Results: Despite similar results on IQ, executive functions and attention, the low seizure-frequency group performed significantly better than the high seizure-frequency group on anterograde memory tests. Loss of autobiographical episodes and public-events memory, concomitant with spared personal semantic knowledge, was observed in both patient groups compared with healthy subjects. A worsening effect of high seizure frequency was recorded for autobiographical incidents and news-events memory, but unexpectedly, not for memory for famous people., Conclusion: The study of seizure frequency as the main variable leads us to suggest that high seizure frequency, itself, potentiates the effects of mesial temporal lobe damage on episodic memory deficits., (Copyright © 2014 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

During intracerebral stimulation of the right inferior occipital cortex, a patient with refractory epilepsy was transiently impaired at discriminating two simultaneously presented photographs of unfamiliar faces. The critical electrode contact was located in the most posterior face-selective brain area of the human brain (right "occipital face area", rOFA) as shown both by low- (ERP) and high-frequency (gamma) electrophysiological responses as well as a face localizer in fMRI. At this electrode contact, periodic visual presentation of 6 different faces by second evoked a larger electrophysiological periodic response at 6 Hz than when the same face identity was repeated at the same rate. This intracerebral EEG repetition suppression effect was markedly reduced when face stimuli were presented upside-down, a manipulation that impairs individual face discrimination. These findings provide original evidence for a causal relationship between the face-selective right inferior occipital cortex and individual face discrimination, independently of long-term memory representations. More generally, they support the functional value of electrophysiological repetition suppression effects, indicating that these effects can be used as an index of a necessary neural representation of the changing stimulus property., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objectives: Self-face hallucination (autoscopic hallucination or AH) has been reported in patients with widespread brain damage or retrospectively after epileptic seizures. The neural basis and the self-processing operations underlying AH remain unknown., Methods: We report the results of intracerebral electrical stimulations of the right medial occipitoparietal cortex (right precuneus and occipitoparietal sulcus) in 2 patients with epilepsy who underwent a stereo-EEG., Results: Immediately after the onset of the stimulation, the 2 patients reported seeing their current own face, facing themselves, in their left visual field., Conclusions: Our study shows that the medial occipitoparietal junction has a key role in generating AH. This region has been shown to have a central role in various self-processing operations and especially in self-face recognition. Our observations further reveal that this region is involved in a visual representation of our own face, which is generated during the pathologic phenomenon of AH. This visual representation of our own face may be useful for self-face recognition and social cognition processes involving judgment of self-facial resemblance to others., (© 2014 American Academy of Neurology.)

Electrical brain stimulation can provide important information about the functional organization of the human visual cortex. Here, we report the visual phenomena evoked by a large number (562) of intracerebral electrical stimulations performed at low-intensity with depth electrodes implanted in the occipito-parieto-temporal cortex of 22 epileptic patients. Focal electrical stimulation evoked primarily visual hallucinations with various complexities: simple (spot or blob), intermediary (geometric forms), or complex meaningful shapes (faces); visual illusions and impairments of visual recognition were more rarely observed. With the exception of the most posterior cortical sites, the probability of evoking a visual phenomenon was significantly higher in the right than the left hemisphere. Intermediary and complex hallucinations, illusions, and visual recognition impairments were almost exclusively evoked by stimulation in the right hemisphere. The probability of evoking a visual phenomenon decreased substantially from the occipital pole to the most anterior sites of the temporal lobe, and this decrease was more pronounced in the left hemisphere. The greater sensitivity of the right occipito-parieto-temporal regions to intracerebral electrical stimulation to evoke visual phenomena supports a predominant role of right hemispheric visual areas from perception to recognition of visual forms, regardless of visuospatial and attentional factors., (Copyright © 2013 Wiley Periodicals, Inc.)

Objective: Delineation of the epileptogenic zone (EZ) in refractory epilepsy related to malformations of cortical development (MCDs) often requires intracranial electroencephalography (EEG) recordings, especially in cases of negative magnetic resonance imaging (MRI) or discordant MRI and video-EEG findings. It is therefore crucial to promote the development of noninvasive methods such as electrical source imaging (ESI). We aimed to (1) analyze the localization concordance of ESI derived from interictal discharges and EZ estimated by stereo-EEG (SEEG); (2) compare the concordance of ESI, MRI, and electroclinical correlations (ECCs) with SEEG-EZ; and (3) assess ESI added value in the EZ localization., Methods: We prospectively analyzed 28 consecutive patients undergoing presurgical investigation for MCD-related refractory epilepsy in 2009-2012. ESI derived from 64-channel scalp EEG was interpreted with blinding to, and subsequently compared with, SEEG-estimated EZ. Anatomic concordance of ESI with SEEG-EZ was compared with that of video-EEG and MRI. We further assessed ESI added value to ECC and MRI., Results: Twelve patients (43%) had temporal and 16 (57%) had extratemporal epilepsy. MRI was negative in 11 (39%) and revealed a cortical malformation in 17 (61%). ESI was fully concordant with the EZ in 10 (36%) and partly concordant in 15 (53%). ECC presented a full and partial concordance with EZ in 11% and 82% of cases, respectively, and MRI in 11% and 46%, respectively. Of 11 patients with negative MRI, ESI was fully concordant with the EZ in 7 (64%) and partly concordant in 4 (36%). ESI correctly confirmed restricted or added localizations to ECC and MRI in 12 (43%) of 28 patients and in 8 (73%) of 11 patients with negative MRI., Significance: ESI contributes to estimating the EZ in MCD-related epilepsy. The added value of ESI to ECC is particularly high in patients with MCD and negative MRI, who represent the most challenging cases for epilepsy surgery. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here., (Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.)

As in other chronic diseases, adherence to medication in epilepsy is critical for seizure control. Its assessment remains challenging in research as in clinical practice. Recent evidences showed another face of nonadherence: the overconsumption of antiepileptic drugs. Some educational interventions with easy implementation were found to be effective in improving adherence and should be therefore more used in everyday practice., (© 2013 Société Française de Pharmacologie et de Thérapeutique.)

Purpose: To define the relationship between the epileptogenic zone and the polymicrogyric area using intracranial electroencephalography (EEG) recordings in patients with structural epilepsy associated with regional infrasylvian polymicrogyria (PMG)., Methods: We retrospectively reviewed the medical charts, scalp, and intracranial video-EEG recordings, neuroimaging findings, and neuropsychological evaluations of four patients with refractory temporal lobe epilepsy related to PMG who consequently underwent resective surgery., Key Findings: High-resolution magnetic resonance imaging (MRI) revealed temporal lobe PMG in all cases, accompanied by hippocampal malrotation and closed lip schizencephaly in 3/4 cases, respectively. In intracranial recordings, interictal spike activity was localized within the PMG in only 2/4 and within the amygdala, hippocampus, and entorhinal cortex in all cases. In the first patient, two epileptogenic networks coexisted: the prevailing network initially involved the mesial temporal structures with spread to the anterior PMG; the secondary network successively involved the anterior part of the PMG and later the mesial temporal structures. In the second patient, the epileptogenic network was limited to the mesial temporal structures, fully sparing the PMG. In the third patient, the epileptogenic network first involved the mesial temporal structures and later the PMG. Conversely, in the last case, part of the PMG harbored an epileptogenic network that propagated to the mesial temporal structures. Consistent with these findings a favorable outcome (Engel class I in three of four patients; Engel class II in one of four) at last follow-up was obtained by a resection involving parts of the PMG cortex in three of four and anteromesial temporal lobe structures in another three of four cases., Significance: Infrasylvian PMG displays a heterogeneous epileptogenicity and is occasionally and partially involved in the epileptogenic zone that commonly includes the mesial temporal structures. Our results highlight the intricate interrelations between the MRI-detectable lesion and the epileptogenic zone as delineated by intracranial recordings. Seizure freedom can be accomplished as a result of a meticulous intracranial study guiding a tailored resection that may spare part of the PMG., (Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.)

The adherence to medication in drug-resistant focal epilepsy (RFE) remains largely unknown. The present work aimed to assess the frequency of recent adherence to antiepileptic drugs (AEDs) in patients with RFE. This prospective observational study screened all patients with RFE, admitted to the Nancy University Hospital between April 2006 and September 2008, for a 5-day hospitalization without AED tapering. The adherence to AEDs was assessed by measuring serum drug levels on day 1 (reflecting the recent "at home" adherence) and day 5 (reflecting the individual reference concentration when drug ingestion was supervised). A patient was considered nonadherent if at least one of their serum drug levels was different between days 1 and 5. The day-1 value was considered different from day 5 when it was at least 30% lower (underdosed) or 30% higher (overdosed). Nonadherent patients were classified as under-consumers in the case of one or more underdosed day-1 values, over-consumers in the case of one or more overdosed day-1 values, or undefined if they exhibited both underdosed and overdosed day-1 values. Forty-four of the 48 screened patients were included. Eighteen (40.9%) of 44 patients were nonadherent. Among them, 12 (66.7%) were over-consumers, 4 (22.2%) were under-consumers, and 2 (11.1%) were undefined nonadherents. The study indicates that recent adherence to antiepileptic medication in this group of patients with RFE is poor. Overconsumption is the most frequent form of nonadherence in this population and should be specifically assessed to prevent its possible consequences in terms of AEDs dose-dependent adverse events., (Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.)

Objective: To assess the one-year outcome of patients referred to the emergency room for a first paroxysmal event of clinically certain or uncertain epileptic origin., Methods: This prospective observational cohort study included 175 adult patients who were consecutively referred for a first paroxysmal event and excluding clinically certain syncope faints. Simple descriptive clinical criteria were used by emergency room physicians for epileptic assessment. Follow-up and final diagnosis were made by neurologists specialized in epilepsy. The risk of recurrence and epilepsy over time was described using Kaplan-Meier estimates. The effect of risk factors (including EEG results) was assessed using univariate log-rank tests and a Cox regression multivariate model. Negative and positive predictive values (NPV and PPV) at 1 year of significant factors were calculated., Results: Clinical criteria were positive in 67 patients and negative in 108. At 1 year, the rate of recurrence was respectively 8% in the negative clinical criteria group (NCC) and 30% in the positive clinical criteria group (PCC) (RR=9.3; 95% CI=[1.22; 71.4]). The risk of subsequent epilepsy was respectively 16% in the NCC group and 57% in PCC group (RR=5.6; 95% CI=[2.0; 15.6]). Positive predictive value (PPV) of clinical criteria was 28.8% for recurrence and 57.6% for definite epilepsy. Negative predictive value (NPV) of clinical criteria was 93.2% for recurrence and 83.5% for definite epilepsy. The presence of significant abnormalities on early EEG (paroxysms or focal abnormalities) supported an epileptic origin in 17% of clinically uncertain seizures. It was associated with a higher risk of subsequent epilepsy (RR=2.50; 95% CI [1.37; 4.41]; P=0.007), but did not significantly improve the PPV of clinical criteria alone., Conclusion: These results may help provide a prognosis at 1 year after a first paroxysmal event of certain or uncertain epileptic origin. Future studies focusing on the outcome after a first epileptic seizure should take into consideration the degree of certainty of the clinical diagnosis and integrate the group of patients with uncertain epileptic seizure., (Copyright © 2012. Published by Elsevier SAS.)

Face perception is subtended by a large set of areas in the human ventral occipito-temporal cortex. However, the role of these areas and their importance for face recognition remain largely unclear. Here we report a case of transient selective impairment in face recognition (prosopagnosia) induced by focal electrical intracerebral stimulation of the right inferior occipital gyrus. This area presents with typical face-sensitivity as evidenced by functional neuroimaging right occipital face area (OFA). A face-sensitive intracerebral N170 was also recorded in this area, supporting its contribution as a source of the well-known N170 component typically recorded on the scalp. Altogether, these observations indicate that face recognition can be selectively impaired by local disruption of a single face-sensitive area of the network subtending this function, the right OFA., (Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.)

This prospective study investigated and compared psychiatric features of 25 consecutive patients with psychogenic nonepileptic seizures (PNES) on the basis of presence of reported trauma. The "trauma" group comprised 19 patients (76%) and the "no-trauma" group comprised 6 patients (34%). We compared history of PNES, psychiatric comorbidity, alexithymia, and symptoms of dissociation. The study clearly characterized two distinct profiles of patients with PNES on the basis of trauma history. Patients with trauma had at least one psychiatric comorbidity or antecedent (vs 0% in the no-trauma group NT, P<0.001) and a higher median score of dissociation (P<0.001). Patients without trauma had more frequent "frustration situations" as a factor triggering PNES and subsequent sick leaves as perpetuating factors (P=0.001). Trauma antecedents correlated with a high rate of psychiatric comorbidity and a strong dissociative mechanism. Patients without trauma had no psychiatric comorbidity and a weaker dissociative mechanism., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Psychogenic non-epileptic seizures (PNES) or attacks consist of paroxysmal behavioural changes that resemble an epileptic seizure but are not associated with electrophysiological epileptic changes. They are caused by a psychopathological process and are primarily diagnosed on history and video-EEG. Clinical presentation comprises a wide range of symptoms and signs, which are individually neither totally specific nor sensitive, making positive diagnosis of PNES difficult. Consequently, PNES are often misdiagnosed as epilepsy. The aim of this study was to identify homogeneous groups of PNES based on specific combinations of clinical signs with a view to improving timely diagnosis., Methods: The authors first retrospectively analysed 22 clinical signs of 145 PNES recorded by video-EEG in 52 patients and then conducted a multiple correspondence analysis and hierarchical cluster analysis., Results: Five clusters of signs were identified and named according to their main clinical features: dystonic attack with primitive gestural activity (31.6%); pauci-kinetic attack with preserved responsiveness (23.4%); pseudosyncope (16.9%); hyperkinetic prolonged attack with hyperventilation and auras (11.7%); axial dystonic prolonged attack (16.4%). When several attacks were recorded in the same patient, they were automatically classified in the same subtype in 61.5% of patients., Conclusion: This study proposes an objective clinical classification of PNES based on automatic clustering of clinical signs observed on video-EEG. It also suggests that PNES are stereotyped in the same patient. Application of these findings could help provide an objective diagnosis of patients with PNES.

Objective: To determine prospectively the efficacy of hyperventilation (HV) to activate epileptic seizures and the contribution of antiepileptic drug tapering., Methods: Eighty patients with proven epilepsy and referred for long-term video-EEG monitoring were consecutively enrolled from November 2007 to December 2008. A seizure was considered as 'activated' if it occurred during HV or within 5 min after completion. The rate of activated seizures (number of seizures/h) was compared with the rate of spontaneous seizure. The authors finally compared the effect of HV before and during antiepileptic drug (AED) tapering., Results: The authors analysed 247 days of monitoring. Among 52 recorded seizures, 18 were activated by HV. The rate of activated seizure was nine times higher than the rate of control seizures (p=0.001). In the subgroup of patients with no AED tapering, there was no significant activating effect of HV on seizures. In the subgroup undergoing AED tapering, the effect of HV was not significant before (p=0.257) but very significant during AED tapering (p<0.004)., Discussion: The findings confirm that hyperventilation is efficient to activate epileptic seizures in epileptic patients referred for long-term video-EEG monitoring and that this activating effect is mainly related to the potentiating effect of AED tapering. Repeated HVs combined with AED tapering increase the rate of recorded seizures and the diagnostic yield of daytime video-EEG monitoring.

Epilepsy is responsible for falls that are not systematically associated with seizures and that therefore suggest postural impairment. There are very few studies of postural control in patients with epilepsy and none of them focus on temporal lobe epilepsy (TLE), although part of the vestibular cortex is located in the temporal cortex. The aim of this study was to evaluate the characteristics of postural control in a homogeneous population of patients with complex partial TLE. Twenty-six patients with epilepsy and 26 age-matched healthy controls underwent a sensory organization test combining six conditions, with and without sensory conflicting situations. Patients with epilepsy displayed poorer postural control, especially in situations where vestibular information is necessary to control balance. In addition to potential antiepileptic drug side effects, vestibular dysfunction could be related to the temporal pathology. Our study allows for a better understanding of the mechanism underlying falls in this population of patients., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Introduction: Several studies have assessed the impact of surgery on both anterograde and remote memory in patients with temporal lobe epilepsy (TLE). The majority of results have shown an extensive memory deficit in patients after temporal resection (TL). However, few protocols have used a prospective longitudinal design. Moreover, the postoperative delays were variable from one study to the next, instead of regular monitoring to identify the potential effect of time elapsed after surgery on memory performance. In addition, some studies have not used strict inclusion criteria to establish homogeneous patient groups. Finally, the impact of surgery on memory has been often assessed by comparing memory skills between epileptic patients and healthy controls. Our aim was to examine the impact of TL on memory in patients with TLE, recruited according to clear-cut clinical criteria. Moreover, we focused on memory performance progression per se in epileptic patients pre- and postoperatively, rather than on memory performance analysis expressed as "deficient" or "normal"., Methods: We assessed 30 patients with unilateral TLE (17 right TLE and 13 left TLE) on four anterograde memory tests and six remote memory tasks. Patients completed all tests preoperatively, and 5 and 12 months after TL., Results: Five months after surgery, performance was equivalent to the preoperative scores for both groups in anterograde memory tasks and remote memory tests. One year after TL, patients with right TLE showed enhanced performance in the verbal anterograde memory tests and in retrieving recent autobiographical memories. Results for left TL showed improved scores only in a recognition memory test of faces., Conclusions: In the present study, surgical patients were "double winners" gaining seizure freedom and potential of memory stability or recovery. The gain was observed only 12 months after surgery and following temporal resection lateralisation. Our data showed postoperative memory improvement in patients with temporal lobe epilepsy presenting with specific clinical characteristics., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

High resolution electroencephalography (HR-EEG) combined with source localization methods has mainly been used to study interictal spikes and there have been few studies comparing source localization of scalp ictal patterns with depth EEG. To address this issue, 10 patients with four different scalp ictal patterns (ictal spikes, rhythmic activity, paroxysmal fast activity, obscured) were investigated by both HR-EEG and stereoelectroencephalography (SEEG). Sixty-four scalp-EEG sensors and a sampling rate of 1kHz were used to record scalp ictal patterns. Five different source models (moving dipole, rotating dipole, MUSIC, LORETA, and sLORETA) were used in order to perform source localization. Seven to 10 intracerebral electrodes were implanted during SEEG investigations. For each source model, the concordance between ictal source localization and epileptogenic zone defined by SEEG was assessed. Results were considered to agree if they localized in the same sublobar area as defined by a trained epileptologist. Across the study population, the best concordance between source localization methods and SEEG (9/10) was obtained with equivalent current dipole modeling. MUSIC and LORETA had a concordance of 7/10 whereas sLORETA had a concordance of only 5/10. Four of our patients classified into different groups (ictal spikes, paroxysmal fast activity, obscured) had complete concordance between source localization methods and SEEG. A high signal to noise ratio, a short time window of analysis (<1s) and bandpass filtering around the frequency of rhythmic activity allowed improvement of the source localization results. A high level of agreement between source localization methods and SEEG can be obtained for ictal spike patterns and for scalp-EEG paroxysmal fact activities whereas scalp rhythmic discharges can be accurately localized but originated from seizure propagation network., (Copyright 2010 Elsevier Inc. All rights reserved.)