We aimed to 1) assess the concordance between various PMG types and the associated epileptogenic zone (EZ), as defined by stereo-electroencephalography (SEEG), and 2) determine the postsurgical seizure outcome in PMG-related... more
We aimed to 1) assess the concordance between various PMG types and the associated epileptogenic zone (EZ), as defined by stereo-electroencephalography (SEEG), and 2) determine the postsurgical seizure outcome in PMG-related drug-resistant epilepsy. We retrospectively analyzed 58 cases: 49 had SEEG and 39 corticectomy or hemispherotomy. Mean age at SEEG or surgery was 28.3 years (range 2-50). PMG was bilateral in 9 (16%) patients and unilateral in 49, including 17 (29%) unilobar, 12 (21%) multilobar, 15 (26%) perisylvian, and only 5 (9%) hemispheric. Twenty-eight (48%) patients additionally had schizencephaly, heterotopia or focal cortical dysplasia. The SEEG-determined EZ was fully concordant with the PMG in only 8 (16%) cases, partially concordant in 74% and discordant in 10%. The EZ included remote cortical areas in 21 (43%) cases and was primarily localized in those in 5 (10%), all related to the mesial temporal structures. All but one PMG patients with corticectomy or hemispher...
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Many patients with medically refractory epilepsy now undergo successful surgery based on noninvasive diagnostic information, but intracranial electroencephalography (IEEG) continues to be used as increasingly complex cases are considered... more
Many patients with medically refractory epilepsy now undergo successful surgery based on noninvasive diagnostic information, but intracranial electroencephalography (IEEG) continues to be used as increasingly complex cases are considered surgical candidates. The indications for IEEG and the modalities employed vary across epilepsy surgical centers; each modality has its advantages and limitations. IEEG can be performed in the same intraoperative setting, that is, intraoperative electrocorticography, or through an independent implantation procedure with chronic extraoperative recordings; the latter are not only resource intensive but also carry risk. A lack of understanding of IEEG limitations predisposes to data misinterpretation that can lead to denying surgery when indicated or, worse yet, incorrect resection with adverse outcomes. Given the lack of class 1 or 2 evidence on IEEG, a consensus-based expert recommendation on the diagnostic utility of IEEG is presented, with emphasis ...
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Research Interests:
There are at least five types of alterations of consciousness that occur during epileptic seizures: auras with illusions or hallucinations, dyscognitive seizures, epileptic delirium, dialeptic seizures, and epileptic coma. Each of these... more
There are at least five types of alterations of consciousness that occur during epileptic seizures: auras with illusions or hallucinations, dyscognitive seizures, epileptic delirium, dialeptic seizures, and epileptic coma. Each of these types of alterations of consciousness has a specific semiology and a distinct pathophysiologic mechanism. In this proposal we emphasize the need to clearly define each of these alterations/loss of consciousness and to apply this terminology in semiologic descriptions and classifications of epileptic seizures. The proposal is a consensus opinion of experienced epileptologists, and it is hoped that it will lead to systematic studies that will allow a scientific characterization of the different types of alterations/loss of consciousness described in this article.
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We aimed to 1) assess the concordance between various PMG types and the associated epileptogenic zone (EZ), as defined by stereo-electroencephalography (SEEG), and 2) determine the postsurgical seizure outcome in PMG-related... more
We aimed to 1) assess the concordance between various PMG types and the associated epileptogenic zone (EZ), as defined by stereo-electroencephalography (SEEG), and 2) determine the postsurgical seizure outcome in PMG-related drug-resistant epilepsy. We retrospectively analyzed 58 cases: 49 had SEEG and 39 corticectomy or hemispherotomy. Mean age at SEEG or surgery was 28.3 years (range 2-50). PMG was bilateral in 9 (16%) patients and unilateral in 49, including 17 (29%) unilobar, 12 (21%) multilobar, 15 (26%) perisylvian, and only 5 (9%) hemispheric. Twenty-eight (48%) patients additionally had schizencephaly, heterotopia or focal cortical dysplasia. The SEEG-determined EZ was fully concordant with the PMG in only 8 (16%) cases, partially concordant in 74% and discordant in 10%. The EZ included remote cortical areas in 21 (43%) cases and was primarily localized in those in 5 (10%), all related to the mesial temporal structures. All but one PMG patients with corticectomy or hemispher...
Research Interests:
Many patients with medically refractory epilepsy now undergo successful surgery based on noninvasive diagnostic information, but intracranial electroencephalography (IEEG) continues to be used as increasingly complex cases are considered... more
Many patients with medically refractory epilepsy now undergo successful surgery based on noninvasive diagnostic information, but intracranial electroencephalography (IEEG) continues to be used as increasingly complex cases are considered surgical candidates. The indications for IEEG and the modalities employed vary across epilepsy surgical centers; each modality has its advantages and limitations. IEEG can be performed in the same intraoperative setting, that is, intraoperative electrocorticography, or through an independent implantation procedure with chronic extraoperative recordings; the latter are not only resource intensive but also carry risk. A lack of understanding of IEEG limitations predisposes to data misinterpretation that can lead to denying surgery when indicated or, worse yet, incorrect resection with adverse outcomes. Given the lack of class 1 or 2 evidence on IEEG, a consensus-based expert recommendation on the diagnostic utility of IEEG is presented, with emphasis ...
Research Interests:
Research Interests:
A high rate of abnormal social behavioural traits or perceptual deficits is observed in children with unilateral temporal lobe epilepsy. In the present study, perception of auditory and visual social signals, carried by faces and voices,... more
A high rate of abnormal social behavioural traits or perceptual deficits is observed in children with unilateral temporal lobe epilepsy. In the present study, perception of auditory and visual social signals, carried by faces and voices, was evaluated in children or adolescents with temporal lobe epilepsy. We prospectively investigated a sample of 62 children with focal non-idiopathic epilepsy early in the course of the disorder. The present analysis included 39 children with a confirmed diagnosis of temporal lobe epilepsy. Control participants (72), distributed across 10 age groups, served as a control group. Our socio-perceptual evaluation protocol comprised three socio-visual tasks (face identity, facial emotion and gaze direction recognition), two socio-auditory tasks (voice identity and emotional prosody recognition), and three control tasks (lip reading, geometrical pattern and linguistic intonation recognition). All 39 patients also benefited from a neuropsychological examina...
Research Interests: Psychology, Auditory Perception, Audiology, Cognition, Epilepsy, and 15 moreFacial expression, Adolescent, Intellectual Disability, Medicine, Emotions, Memory, Social behavior, Prospective studies, Humans, Child, Temporal Lobe Epilepsy, Clinical Sciences, Social Behavior, Functional Laterality, and Child preschool
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Research Interests: Neurology, Malformations of Cortical Development, Magnetic Resonance Imaging, Medicine, Observation, and 14 moreHippocampus, Humans, Consensus, Female, Male, Temporal Lobe Epilepsy, Advisory Committees, Neurons, Epilepsia, Clinical Sciences, Glial Fibrillary Acidic Protein, Neurosciences, Age of Onset, and Sclerosis
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Research Interests:
Direct cortical stimulation (DCS) in epilepsy surgery patients has a long history of functional brain mapping and seizure triggering. Here, we review its findings when applied to the insula in order to map the insular functions, evaluate... more
Direct cortical stimulation (DCS) in epilepsy surgery patients has a long history of functional brain mapping and seizure triggering. Here, we review its findings when applied to the insula in order to map the insular functions, evaluate its local and distant connections, and trigger seizures. Clinical responses to insular DCS are frequent and diverse, showing a partial segregation with spatial overlap, including a posterior somatosensory, auditory, and vestibular part, a central olfactory-gustatory region, and an anterior visceral and cognitive-emotional portion. The study of cortico-cortical evoked potentials (CCEPs) has shown that the anterior (resp. posterior) insula has a higher connectivity rate with itself than with the posterior (resp. anterior) insula, and that both the anterior and posterior insula are closely connected, notably between the homologous insular subdivisions. All insular gyri show extensive and complex ipsilateral and contralateral extra-insular connections, ...
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Ripples are high-frequency bouts of coordinated hippocampal activity believed to be crucial for information transfer and memory formation. We used intracortical macroelectrodes to record neural activity in the human hippocampus of awake... more
Ripples are high-frequency bouts of coordinated hippocampal activity believed to be crucial for information transfer and memory formation. We used intracortical macroelectrodes to record neural activity in the human hippocampus of awake subjects undergoing surgical treatment for refractory epilepsy and distinguished two populations of ripple episodes based on their frequency spectrum. The phase-coupling of one population, slow ripples (90-110 Hz), to cortical delta oscillations was differentially modulated by cognitive task; whereas the second population, fast ripples (130-170 Hz), was not seemingly correlated to local neural activity. Furthermore, as cognitive tasks changed, the ongoing coordination of neural activity associated to slow ripples progressively augmented along the parahippocampal axis. Thus, during resting states, slow ripples were coordinated in restricted hippocampal territories; whereas during active states, such as attentionally-demanding tasks, high frequency act...
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Interictal [18F]fluorodeoxyglucose-positron emission tomography (FDG-PET) is used in the presurgical evaluation of patients with drug-resistant focal epilepsy. We aimed at clarifying its relationships with ictal high-frequency... more
Interictal [18F]fluorodeoxyglucose-positron emission tomography (FDG-PET) is used in the presurgical evaluation of patients with drug-resistant focal epilepsy. We aimed at clarifying its relationships with ictal high-frequency oscillations (iHFOs) shown to be a relevant marker of the seizure-onset zone. We studied the correlation between FDG-PET and epileptogenicity maps in an unselected series of 37 successive patients having been explored with stereo-electroencephalography (SEEG). At the group level, we found a significant correlation between iHFOs and FDG-PET interictal hypometabolism only in cases of temporal lobe epilepsy. This correlation was found with HFOs, and the same comparison between FDG-PET and ictal SEEG power of lower frequencies during the same epochs did not show the same significance. This finding suggests that interictal FDG-PET and ictal HFOs may share common underlying pathophysiologic mechanisms of ictogenesis in temporal lobe epilepsy, and combining both feat...
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Research Interests:
Research Interests: Psychology, Cognitive Science, Magnetic Resonance Imaging, Electroencephalography, Medicine, and 15 moreBrain Mapping, Humans, Cerebral Cortex, Insula, Female, Male, Gamma, Reaction Time, Motor Cortex, Performance Monitoring, Adult, Neurosciences, Anterior cingulate cortex, ECoG, and Psychomotor Performance
Face processing depends on the orchestrated activity of a large-scale neuronal network. Its activity can be modulated by attention as a function of task demands. However, it remains largely unknown whether voluntary, endogenous attention... more
Face processing depends on the orchestrated activity of a large-scale neuronal network. Its activity can be modulated by attention as a function of task demands. However, it remains largely unknown whether voluntary, endogenous attention and reflexive, exogenous attention to facial expressions equally affect all regions of the face-processing network, and whether such effects primarily modify the strength of the neuronal response, the latency, the duration, or the spectral characteristics. We exploited the good temporal and spatial resolution of intracranial electroencephalography (iEEG) and recorded from depth electrodes to uncover the fast dynamics of emotional face processing. We investigated frequency-specific responses and event-related potentials (ERP) in the ventral occipito-temporal cortex (VOTC), ventral temporal cortex (VTC), anterior insula, orbitofrontal cortex (OFC), and amygdala when facial expressions were task-relevant or task-irrelevant. All investigated regions of ...
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Research Interests:
After intensive practice, unfamiliar letter strings become familiar words and reading speed increases strikingly from a slow processing to a fast and with more global recognition of words. While this effect has been well documented at the... more
After intensive practice, unfamiliar letter strings become familiar words and reading speed increases strikingly from a slow processing to a fast and with more global recognition of words. While this effect has been well documented at the behavioral level, its neural underpinnings are still unclear. The question is how the brain modulates the activity of the reading network according to the novelty of the items. Several models have proposed that familiar and unfamiliar words are not processed by separate networks but rather by common regions operating differently according to familiarity. This hypothesis has proved difficult to test at the neural level because the effects of familiarity and length on reading occur (a) on a millisecond scale, shorter than the resolution of fMRI and (b) in regions which cannot be isolated with non-invasive EEG or MEG. We overcame these limitations by using invasive intra-cerebral EEG recording in epileptic patients. Neural activity (gamma-band respons...
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Research Interests: Neuroscience, Psychology, Visual perception, Speech perception, Magnetic Resonance Imaging, and 15 moreAttention, Reading, Speech, Visual Cortex, Brain Mapping, Humans, Female, Male, Adult, Auditory Cortex, Reading Process, Acoustic Stimulation, photic stimulation, Psychology and Cognitive Sciences, and Medical and Health Sciences
Research Interests: Neuroscience, Psychology, Visual perception, Epilepsy, Electroencephalography, and 15 moreFace recognition (Psychology), Adolescent, Medicine, Brain Mapping, Humans, Female, Male, Young Adult, Adult, Time Factors, Parahippocampal Gyrus, Visual Evoked Potentials, photic stimulation, Psychology and Cognitive Sciences, and Medical and Health Sciences
Research Interests: Psychology, Computer Science, Electroencephalography, Medicine, High Frequency, and 15 moreBrain Mapping, Fourier Analysis, Evoked Potentials, Humans, Cerebral Cortex, Orientation, Functional Imaging, Neuroimage, Gamma Band, Neural pathways, Frontal Lobe, Oculomotor Nerve, Psychology and Cognitive Sciences, Medical and Health Sciences, and Electric stimulation
Research Interests: Computer Science, Algorithms, Magnetic Resonance Imaging, Epilepsy, Functional MRI, and 15 moreElectroencephalography, Medicine, Brain Mapping, Humans, Neuroimage, Magnetic Resonance, Artifacts, Oscillations, Cross Validation, Adult, Reproducibility of Results, Sensitivity and Specificity, Experimental Data, Psychology and Cognitive Sciences, and Medical and Health Sciences
Research Interests: Psychology, Radiology, Magnetic Resonance Imaging, Functional MRI, Electroencephalography, and 15 moreMedicine, Brain Mapping, Case Report, Humans, Cerebral Cortex, Gamma Band Oscillations, Insula, Female, Young Adult, Brain Waves, Reflex Epilepsy, Frontal Lobe, Postoperative Complications, Psychology and Cognitive Sciences, and Medical and Health Sciences
Reading sentences involves a distributed network of brain regions acting in concert surrounding the left sylvian fissure. The mechanisms of neural communication underlying the extraction and integration of verbal information across... more
Reading sentences involves a distributed network of brain regions acting in concert surrounding the left sylvian fissure. The mechanisms of neural communication underlying the extraction and integration of verbal information across subcomponents of this reading network are still largely unknown. We recorded intracranial EEG activity in 12 epileptic human patients performing natural sentence reading and analyzed long-range corticocortical interactions between local neural activations. During a simple task contrasting semantic, phonological, and purely visual processes, we found process-specific neural activity elicited at the single-trial level, characterized by energy increases in a broad gamma band (40-150 Hz). Correlation analysis between task-induced gamma-band activations revealed a selective fragmentation of the network into specialized subnetworks supporting sentence-level semantic analysis and phonological processing. We extend the implications of our results beyond reading, ...
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Research Interests:
Research Interests: Cognitive Science, Auditory Perception, Cognition, Magnetoencephalography, Epilepsy, and 15 moreAttention, Electroencephalography, Medicine, Memory, Brain Mapping, Brain, Evoked Potentials, Humans, Oscillations, Gamma Band, Human Brain, Human Brain Mapping, Neurosciences, Functional Mapping, and Gamma band activity
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Research Interests:
Research Interests: Psychology, Electroencephalography, Adolescent, Medicine, Brain Mapping, and 13 moreBrain, Humans, Cerebral Cortex, Female, Male, Temporal Lobe Epilepsy, Middle Aged, Adult, Reproducibility of Results, Seizures, Sensitivity and Specificity, Psychology and Cognitive Sciences, and Medical and Health Sciences
Research Interests: Psychology, Cognitive Science, Magnetic Resonance Imaging, Electroencephalography, Medicine, and 15 moreHigh Frequency, Brain, Humans, Eye Movements, Cognitive Process, Artifacts, Gamma Band, Clinical Sciences, Eye Movement, Brain Structure, Electrooculography, Neurosciences, Frontal Lobe, Muscle Activity, and Gamma band activity
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Research Interests:
To compare resective surgery and medical therapy in a cost-effectiveness analysis in a multicenter cohort of adult patients with partial intractable epilepsy. Adult patients with partial, medically intractable, potentially operable... more
To compare resective surgery and medical therapy in a cost-effectiveness analysis in a multicenter cohort of adult patients with partial intractable epilepsy. Adult patients with partial, medically intractable, potentially operable epilepsy were eligible and followed every year over five years. Effectiveness was defined as one year without seizure. The long-term costs and effectiveness were extrapolated over the patients' lifetime with a Markov model. Productivity (indirect costs) and quality of life (QOLIE-31, SEALS) were also assessed. Changes before and after surgery were compared between the two groups. Two hundred and eighty-nine patients were included (119 with surgery, 161 medically treated, six not eligible, three lost to follow-up). One year after surgery, 81% of the patients were seizure-free; at two and three years, this rate was 78%. In the medical group, these rates were 10, 18, and 15%, respectively. The cost of the explorations was euro 8464; including surgery, it...
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Temporal lobe epilepsy (TLE) is the most common form of intractable partial epilepsy in adults. Surgery (lobectomy or amygdalohippocampectomy) is effective in most patients. However, some complications can occur and brain shift, hematoma... more
Temporal lobe epilepsy (TLE) is the most common form of intractable partial epilepsy in adults. Surgery (lobectomy or amygdalohippocampectomy) is effective in most patients. However, some complications can occur and brain shift, hematoma into the post operative cavity and occulomotor nerve palsy have been reported due to the surgical technic. We report the technique, safety and efficacy of temporal disconnection in nonlesional TLE. Forty-seven patients (18 males, 29 females; handedness: 12 left, 33 right; aged 35 years+/-10; mean duration of epilepsy: 24+/-10 years) underwent temporal disconnection (20 left, 27 right) guided by neuronavigation. Sixteen patients (35 %) underwent additional presurgical evaluation with SEEG. The outcome was assessed using Engel's classification. At the two-year follow-up, 85 % of the patients were seizure-free (Engel I), 26 (58 %) of whom were Ia. Postoperative persistent morbidity included mild hemiparesis (n=1), mild facial paresis (n=1), quadran...
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... Invasive EEG in the definition of the seizure onset zone: depth electrodes. Philippe Kahane a , Corresponding Author Contact Information , E-mail The Corresponding Author , Lorella Minotti a , Dominique Hoffmann b , Jean-Philippe... more
... Invasive EEG in the definition of the seizure onset zone: depth electrodes. Philippe Kahane a , Corresponding Author Contact Information , E-mail The Corresponding Author , Lorella Minotti a , Dominique Hoffmann b , Jean-Philippe Lachaux c and Philippe Ryvlin d. ...
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Short-term changes of intrinsic properties of neural networks play a critical role in brain dynamics. In that context, epilepsy is a typical pathology where the fast transition between interictal and ictal states is probably associated to... more
Short-term changes of intrinsic properties of neural networks play a critical role in brain dynamics. In that context, epilepsy is a typical pathology where the fast transition between interictal and ictal states is probably associated to intrinsic modifications of underlying networks. In this study, we focused on the correlates of plastic neural mechanisms in the intracerebral electroencephalogram (iEEG). Data were obtained during 1 Hz electrical stimulation in twenty patients suffering from temporal lobe epilepsy and implanted with intracerebral electrodes for clinical evaluation before resective surgery. First, we developed a procedure of analysis for localisation of the seizure onset zone based on brain excitability and plasticity defined as the average, and as the first-order (linear) modulation respectively, of the standard deviation of iEEG responses over stimulations. Our results suggest that the candidate epileptic focus is particularly prone to exhibiting short-term plasti...