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Jean Gotman - One of the best experts on this subject based on the ideXlab platform.
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widespread interictal Epileptic Discharge more likely than focal Discharges to unveil the seizure onset zone in eeg fmri
Clinical Neurophysiology, 2019Co-Authors: Tomohiro Yamazoe, Hui Ming Khoo, Nicolas Von Ellenrieder, Natalja Zazubovits, Yaohsien Huang, Francois Dubeau, Jean GotmanAbstract:Abstract Objective We hypothesized that the number of interictal Epileptic Discharges (IEDs) during scan and their spatial extent are contributing factors in obtaining appropriate activations that reveal the seizure onset zone (SOZ) in EEG-fMRI. Methods 157 IED types, each corresponding to one EEG scalp distribution, in 64 consecutive EEG-fMRI studies from 64 patients with refractory localization-related epilepsy were reviewed. To determine reliable activation, we used the threshold corresponding to corrected whole-brain topological false discovery rate (FDR). The location with maximum activation was compared to the presumed SOZ as defined by a comprehensive evaluation for each patient. Results The number of IEDs was significantly higher in the types with t-value above FDR than with t-value below FDR. The presumed SOZ could be delineated in 30 of the 64 patients. Among these patients, the types of IED concordant with the SOZ had significantly larger extent on scalp EEG than the IED types discordant with the SOZ. Conclusions The number of IEDs is important factor in obtaining reliable activations in EEG-fMRI. IEDs with larger spatial extent are more likely to reveal, on maximum BOLD, accurate location of the SOZ. Significance Widespread Discharges are more likely to yield a reliable activation for SOZ in EEG-fMRI.
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deepied an Epileptic Discharge detector for eeg fmri based on deep learning
NeuroImage: Clinical, 2018Co-Authors: Yongfu Hao, Hui Ming Khoo, Nicolas Von Ellenrieder, Natalja Zazubovits, Jean GotmanAbstract:Presurgical evaluation that can precisely delineate the epileptogenic zone (EZ) is one important step for successful surgical resection treatment of refractory epilepsy patients. The noninvasive EEG-fMRI recording technique combined with general linear model (GLM) analysis is considered an important tool for estimating the EZ. However, the manual marking of interictal Epileptic Discharges (IEDs) needed in this analysis is challenging and time-consuming because the quality of the EEG recorded inside the scanner is greatly deteriorated compared to the usual EEG obtained outside the scanner. This is one of main impediments to the widespread use of EEG-fMRI in epilepsy. We propose a deep learning based semi-automatic IED detector that can find the candidate IEDs in the EEG recorded inside the scanner which resemble sample IEDs marked in the EEG recorded outside the scanner. The manual marking burden is greatly reduced as the expert need only edit candidate IEDs. The model is trained on data from 30 patients. Validation of IEDs detection accuracy on another 37 consecutive patients shows our method can improve the median sensitivity from 50.0% for the previously proposed template-based method to 84.2%, with false positive rate as 5 events/min. Reproducibility validation on 15 patients is applied to evaluate if our method can produce similar hemodynamic response maps compared with the manual marking ground truth results. We explore the concordance between the maximum hemodynamic response and the intracerebral EEG defined EZ and find that both methods produce similar percentage of concordance (76.9%, 10 out of 13 patients, electrode was absent in the maximum hemodynamic response in two patients). This tool will make EEG-fMRI analysis more practical for clinical usage.
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electroencephalography functional magnetic resonance imaging responses help predict surgical outcome in focal epilepsy
Epilepsia, 2013Co-Authors: Firas Fahoum, Andre Olivier, Jean Gotman, Jeffery A Hall, Francois DubeauAbstract:Summary Purpose Simultaneous electroencephalography/functional magnetic resonance imaging (EEG/fMRI) recording can noninvasively map in the whole brain the hemodynamic response following an interictal Epileptic Discharge. EEG/fMRI is gaining interest as a presurgical evaluation tool. This study aims to determine how hemodynamic responses related to Epileptic activity can help predict surgical outcome in patients considered for epilepsy surgery. Methods Thirty-five consecutive patients with focal epilepsy who had significant hemodynamic responses and eventually surgical resection, were studied. The statistical map of hemodynamic responses were generated and coregistered to postoperative anatomic imaging. Patients were classified into four groups defined by the relative relationship between the location of the maximum hemodynamic response and the resection: group 1, fully concordant; group 2, partially concordant; group 3, partially discordant; and group 4, fully discordant. These findings were correlated with surgical outcome with at least 12-month follow-up. Key Findings Ten patients in group 1 had the maximum t value (t-max) inside the resection; nine in group 2 had the t-max outside but close to the resection and the cluster with t-max overlapped the resection; five in group 3 had the t-max remote from resection, but with another less significant cluster in the resection; and 11 in group 4 had no response in the resection. The degree of concordance correlated largely with surgical outcome: a good surgical outcome (Engel's class I) was found in 7 of 10 patients of group 1, 4 of 9 of group 2, 3 of 5 of group 3, and only 1 of 11 of group 4. These results indicate that the partially concordant and partially discordant groups are best considered as inconclusive. In contrast, in the fully concordant and fully discordant groups, the sensitivity, specificity, positive predictive value, and negative predictive value were high, 87.5%, 76.9%, 70%, and 90.9%, respectively. Significance This study demonstrates that hemodynamic responses related to Epileptic activity can help delineate the epileptogenic region. Full concordance between maximum response and surgical resection is indicative of seizure freedom, whereas a resection leaving the maximum response intact is likely to lead to a poor outcome. EEG/fMRI is noninvasive but is limited to patients in whom interictal Epileptic Discharges can be recorded during the 60–90 min scan.
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thalamic nuclei activity in idiopathic generalized epilepsy an eeg fmri study
Neurology, 2009Co-Authors: Louise Tyvaert, Francois Dubeau, Pierre Levan, S Chassagnon, A Sadikot, Jean GotmanAbstract:Objective: Idiopathic generalized epilepsies (IGE) are characterized by specific EEG changes including 3- to 5-Hz generalized spike-and-wave Discharges. The thalamus and its cortical interactions are considered essential in the production and propagation of spike-and-wave Discharges. In animal studies, corticoreticular and limbic system property changes have been observed in absence seizures and during spike-and-wave Discharges and suggest the involvement of different types of thalamic nuclei. With the development of deep brain stimulation in epilepsy, the role of the thalamic nuclei needs to be clarified in human IGE. Methods: Ten patients with IGE were recorded using 3T EEG-fMRI during spike-and-wave Discharges. Hemodynamic response functions were calculated for 4 regions of interest corresponding to the anterior thalamic and centromedian and parafascicular (CM-Pf) nuclei of each thalamus. The time to peak of the hemodynamic response function was compared within thalamic structures (left compared to right) and between structures (anterior thalamic compared to CM-Pf nucleus). Results: CM-Pf and anterior nucleus are both activated during GSWDs. However, the positive time to peak in the CM-Pf (4.4 ± 2.5 s) occurred significantly earlier than in the anterior nucleus (7.6 ± 3.2 s). Conclusions: We demonstrated in humans the involvement of the centromedian and parafascicular part of the corticoreticular system and of the anterior nucleus part of the limbic system during generalized spike-and-wave Discharges. The different time courses suggest that the posterior intralaminar nuclei may be involved in Epileptic Discharge initiation or early propagation, while the anterior nucleus may only play a role in its maintenance. These results may help to understand the clinical effect of deep brain stimulation within thalamic nuclei in intractable idiopathic generalized epilepsy patients.
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variability of the hemodynamic response as a function of age and frequency of Epileptic Discharge in children with epilepsy
NeuroImage, 2008Co-Authors: Julia Jacobs, Colin Hawco, Eliane Kobayashi, Rainer Boor, Pierre Levan, Ulrich Stephani, Michael Siniatchkin, Jean GotmanAbstract:EEG-fMRI is a non-invasive tool to investigate epileptogenic networks in patients with epilepsy. Different patterns of BOLD responses have been observed in children as compared to adults. A high intra- and intersubject variability of the hemodynamic response function (HRF) to Epileptic Discharges has been observed in adults. The actual HRF to Epileptic Discharges in children and its dependence on age are unknown. We analyzed 64 EEG-fMRI event types in 37 children (3 months to 18 years), 92% showing a significant BOLD response. HRFs were calculated for each BOLD cluster using a Fourier basis set. After excluding HRFs with a low signal-to-noise ratio, 126 positive and 98 negative HRFs were analyzed. We evaluated age-dependent changes as well as the effect of increasing numbers of spikes. Peak time, amplitude and signal-to-noise ratio of the HRF and the t-statistic score of the cluster were used as dependent variables. We observed significantly longer peak times of the HRF in the youngest children (0 to 2 years), suggesting that the use of multiple HRFs might be important in this group. A different coupling between neuronal activity and metabolism or blood flow in young children may cause this phenomenon. Even if the t-value increased with frequent spikes, the amplitude of the HRF decreased significantly with spike frequency. This reflects a violation of the assumptions of the General Linear Model and therefore the use of alternative analysis techniques may be more appropriate with high spiking rates, a common situation in children.
Francois Dubeau - One of the best experts on this subject based on the ideXlab platform.
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widespread interictal Epileptic Discharge more likely than focal Discharges to unveil the seizure onset zone in eeg fmri
Clinical Neurophysiology, 2019Co-Authors: Tomohiro Yamazoe, Hui Ming Khoo, Nicolas Von Ellenrieder, Natalja Zazubovits, Yaohsien Huang, Francois Dubeau, Jean GotmanAbstract:Abstract Objective We hypothesized that the number of interictal Epileptic Discharges (IEDs) during scan and their spatial extent are contributing factors in obtaining appropriate activations that reveal the seizure onset zone (SOZ) in EEG-fMRI. Methods 157 IED types, each corresponding to one EEG scalp distribution, in 64 consecutive EEG-fMRI studies from 64 patients with refractory localization-related epilepsy were reviewed. To determine reliable activation, we used the threshold corresponding to corrected whole-brain topological false discovery rate (FDR). The location with maximum activation was compared to the presumed SOZ as defined by a comprehensive evaluation for each patient. Results The number of IEDs was significantly higher in the types with t-value above FDR than with t-value below FDR. The presumed SOZ could be delineated in 30 of the 64 patients. Among these patients, the types of IED concordant with the SOZ had significantly larger extent on scalp EEG than the IED types discordant with the SOZ. Conclusions The number of IEDs is important factor in obtaining reliable activations in EEG-fMRI. IEDs with larger spatial extent are more likely to reveal, on maximum BOLD, accurate location of the SOZ. Significance Widespread Discharges are more likely to yield a reliable activation for SOZ in EEG-fMRI.
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electroencephalography functional magnetic resonance imaging responses help predict surgical outcome in focal epilepsy
Epilepsia, 2013Co-Authors: Firas Fahoum, Andre Olivier, Jean Gotman, Jeffery A Hall, Francois DubeauAbstract:Summary Purpose Simultaneous electroencephalography/functional magnetic resonance imaging (EEG/fMRI) recording can noninvasively map in the whole brain the hemodynamic response following an interictal Epileptic Discharge. EEG/fMRI is gaining interest as a presurgical evaluation tool. This study aims to determine how hemodynamic responses related to Epileptic activity can help predict surgical outcome in patients considered for epilepsy surgery. Methods Thirty-five consecutive patients with focal epilepsy who had significant hemodynamic responses and eventually surgical resection, were studied. The statistical map of hemodynamic responses were generated and coregistered to postoperative anatomic imaging. Patients were classified into four groups defined by the relative relationship between the location of the maximum hemodynamic response and the resection: group 1, fully concordant; group 2, partially concordant; group 3, partially discordant; and group 4, fully discordant. These findings were correlated with surgical outcome with at least 12-month follow-up. Key Findings Ten patients in group 1 had the maximum t value (t-max) inside the resection; nine in group 2 had the t-max outside but close to the resection and the cluster with t-max overlapped the resection; five in group 3 had the t-max remote from resection, but with another less significant cluster in the resection; and 11 in group 4 had no response in the resection. The degree of concordance correlated largely with surgical outcome: a good surgical outcome (Engel's class I) was found in 7 of 10 patients of group 1, 4 of 9 of group 2, 3 of 5 of group 3, and only 1 of 11 of group 4. These results indicate that the partially concordant and partially discordant groups are best considered as inconclusive. In contrast, in the fully concordant and fully discordant groups, the sensitivity, specificity, positive predictive value, and negative predictive value were high, 87.5%, 76.9%, 70%, and 90.9%, respectively. Significance This study demonstrates that hemodynamic responses related to Epileptic activity can help delineate the epileptogenic region. Full concordance between maximum response and surgical resection is indicative of seizure freedom, whereas a resection leaving the maximum response intact is likely to lead to a poor outcome. EEG/fMRI is noninvasive but is limited to patients in whom interictal Epileptic Discharges can be recorded during the 60–90 min scan.
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thalamic nuclei activity in idiopathic generalized epilepsy an eeg fmri study
Neurology, 2009Co-Authors: Louise Tyvaert, Francois Dubeau, Pierre Levan, S Chassagnon, A Sadikot, Jean GotmanAbstract:Objective: Idiopathic generalized epilepsies (IGE) are characterized by specific EEG changes including 3- to 5-Hz generalized spike-and-wave Discharges. The thalamus and its cortical interactions are considered essential in the production and propagation of spike-and-wave Discharges. In animal studies, corticoreticular and limbic system property changes have been observed in absence seizures and during spike-and-wave Discharges and suggest the involvement of different types of thalamic nuclei. With the development of deep brain stimulation in epilepsy, the role of the thalamic nuclei needs to be clarified in human IGE. Methods: Ten patients with IGE were recorded using 3T EEG-fMRI during spike-and-wave Discharges. Hemodynamic response functions were calculated for 4 regions of interest corresponding to the anterior thalamic and centromedian and parafascicular (CM-Pf) nuclei of each thalamus. The time to peak of the hemodynamic response function was compared within thalamic structures (left compared to right) and between structures (anterior thalamic compared to CM-Pf nucleus). Results: CM-Pf and anterior nucleus are both activated during GSWDs. However, the positive time to peak in the CM-Pf (4.4 ± 2.5 s) occurred significantly earlier than in the anterior nucleus (7.6 ± 3.2 s). Conclusions: We demonstrated in humans the involvement of the centromedian and parafascicular part of the corticoreticular system and of the anterior nucleus part of the limbic system during generalized spike-and-wave Discharges. The different time courses suggest that the posterior intralaminar nuclei may be involved in Epileptic Discharge initiation or early propagation, while the anterior nucleus may only play a role in its maintenance. These results may help to understand the clinical effect of deep brain stimulation within thalamic nuclei in intractable idiopathic generalized epilepsy patients.
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generalized Epileptic Discharges show thalamocortical activation and suspension of the default state of the brain
Proceedings of the National Academy of Sciences of the United States of America, 2005Co-Authors: Jean Gotman, Eliane Kobayashi, Christophe Grova, Andrew P Bagshaw, Yahya Aghakhani, Francois DubeauAbstract:Our objective was to evaluate the brain regions showing increased and decreased metabolism in patients at the time of generalized bursts of Epileptic Discharges in order to understand their mechanism of generation and effect on brain function. By recording the electroencephalogram during the functional MRI, changes in the blood oxygenation level-dependent signal were obtained in response to Epileptic Discharges observed in the electroencephalogram of 15 patients with idiopathic generalized epilepsy. A group analysis was performed to determine the regions of positive (activation) and negative (deactivation) blood oxygenation level-dependent responses that were common to the patients. Activations were found bilaterally and symmetrically in the thalamus, mesial midfrontal region, insulae, and midline and bilateral cerebellum and on the borders of the lateral ventricles. Deactivations were bilateral and symmetrical in the anterior frontal and parietal regions and in the posterior cingulate gyri and were seen in the left posterior temporal region. Activations in thalamus and midfrontal regions confirm known involvement of these regions in the generation or spread of generalized Epileptic Discharges. Involvement of the insulae in generalized Discharges had not previously been described. Cerebellar activation is not believed to reflect the generation of Discharges. Deactivations in frontal and parietal regions remarkably followed the pattern of the default state of brain function. Thalamocortical activation and suspension of the default state may combine to cause the actual state of reduced responsiveness observed in patients during spike-and-wave Discharges. This brief lapse of responsiveness may therefore not result only from the Epileptic Discharge but also from its effect on normal brain function.
Sophie Dupont - One of the best experts on this subject based on the ideXlab platform.
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the new approach to classification of focal epilepsies Epileptic Discharge and disconnectivity in relation to cognition
Epilepsy & Behavior, 2016Co-Authors: Vera Dinkelacker, Sophie Dupont, Severine SamsonAbstract:Abstract The new classification of epilepsy stratifies the disease into an acute level, based on seizures, and an overarching chronic level of Epileptic syndromes (Berg et al., 2010). In this new approach, seizures are considered either to originate and evolve in unilateral networks or to rapidly encompass both hemispheres. This concept extends the former vision of focal and generalized epilepsies to a genuine pathology of underlying networks. These key aspects of the new classification can be linked to the concept of cognitive curtailing in focal epilepsy. The present review will discuss the conceptual implications for acute and chronic cognitive deficits with special emphasis on transient and structural disconnectivity. Acute transient disruption of brain function is the hallmark of focal seizures. Beyond seizures, however, interictal Epileptic Discharges (IEDs) are increasingly recognized to interfere with physiological brain circuitry. Both concomitant EEG and high-precision neuropsychological testing are necessary to detect these subtle effects, which may concern task-specific or default-mode networks. More recent data suggest that longstanding IEDs may affect brain maturation and eventually be considered as a biomarker of pathological wiring. This brings us to the overarching level of chronic cognitive and behavioral comorbidity. We will discuss alterations in structural connectivity measured with diffusion-weighted imaging and tractography. Among focal epilepsies, much of our current insights are derived from temporal lobe epilepsy and its impact on neuropsychological and psychiatric functioning. Structural disconnectivity is maximal in the temporal lobe but also concerns widespread language circuitry. Eventually, pathological wiring may contribute to the clinical picture of cognitive dysfunction. We conclude with the extrapolation of these concepts to current research topics and to the necessity of establishing individual patient profiles of network pathology with EEG, high-precision neuropsychological testing, and state-of-the-art neuroimaging. This article is part of a Special Issue entitled "The new approach to classification: Rethinking cognition and behavior in epilepsy".
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interictal Epileptic Discharge correlates with global and frontal cognitive dysfunction in temporal lobe epilepsy
Epilepsy & Behavior, 2016Co-Authors: Vera Dinkelacker, Xu Xin, Michel Baulac, Severine Samson, Sophie DupontAbstract:Abstract Objective Temporal lobe epilepsy (TLE) with hippocampal sclerosis has widespread effects on structural and functional connectivity and often entails cognitive dysfunction. EEG is mandatory to disentangle interactions in Epileptic and physiological networks which underlie these cognitive comorbidities. Here, we examined how interictal Epileptic Discharges (IEDs) affect cognitive performance. Methods Thirty-four patients (right TLE = 17, left TLE = 17) were examined with 24-hour video-EEG and a battery of neuropsychological tests to measure intelligence quotient and separate frontal and temporal lobe functions. Hippocampal segmentation of high-resolution T1-weighted imaging was performed with FreeSurfer. Partial correlations were used to compare the number and distribution of clinical interictal spikes and sharp waves with data from imagery and psychological tests. Results The number of IEDs was negatively correlated with executive functions, including verbal fluency and intelligence quotient (IQ). Interictal Epileptic Discharge affected cognitive function in patients with left and right TLE differentially, with verbal fluency strongly related to temporofrontal spiking. In contrast, IEDs had no clear effects on memory functions after corrections with partial correlations for age, age at disease onset, disease duration, and hippocampal volume. Conclusion In patients with TLE of long duration, IED occurrence was strongly related to cognitive deficits, most pronounced for frontal lobe function. These data suggest that IEDs reflect dysfunctional brain circuitry and may serve as an independent biomarker for cognitive comorbidity.
Fabrice Bartolomei - One of the best experts on this subject based on the ideXlab platform.
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Fast Epileptic Discharges associated with ictal negative motor phenomena
Clinical Neurophysiology, 2014Co-Authors: Louis Maillard, Martine Gavaret, Jean Régis, Fabrice Wendling, Fabrice BartolomeiAbstract:Objective : Focal motor negative phenomena have been described in seizures primarily involving “negative” motor areas (opercular pre-motor and medial pre-motor regions) and the rolandic region (post-central or pre-central). The localizing value of such signs and the mechanisms by which an Epileptic Discharge may generate negative phenomena remain debated. Methods : Ictal positive and negative motor phenomena occurring during seizures affecting the rolandic area were studied in a patient having intracerebral recordings (stereo-electro-encephalography, SEEG) for drug resistant epilepsy. Results : During the video-SEEG and EMG recording, nine positive and 27 negative motor seizures were recorded. All were generated within the same area (right opercular central area, Brodmann Area 4). The 2 different types of clinical seizure were differentiable by their power/frequency spectrum: positive motor seizures were associated with a prominent alpha–beta band Discharge while negative motor seizures were associated with a gamma band Discharge (>45 Hz). Conclusions : We propose that within the primary motor cortex, high frequency sustained Discharges may disrupt the ongoing excitatory drive to the peripheral motoneurons and produce negative motor signs, while sustained lower frequency Discharges (alpha and beta bands) may activate the cortico-nuclear or cortico-spinal pathway and produce positive motor signs. Significance : Both positive and negative ictal motor phenomena can be observed in the primary motor cortex depending on the properties of the Epileptic Discharge.
Massimo Cossu - One of the best experts on this subject based on the ideXlab platform.
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intracerebral recordings of minor motor events paroxysmal arousals and major seizures in nocturnal frontal lobe epilepsy
Neurological Sciences, 2005Co-Authors: Lino Nobili, Laura Tassi, Stefano Francione, Roberto Mai, Francesco Cardinale, Laura Castana, Ivana Sartori, Massimo Cossu, Michele Terzaghi, Lo G RussoAbstract:The clinical features of nocturnal frontal lobe epilepsy (NFLE) consist of a spectrum of paroxysmal motor manifestations ranging from minor motor events (MMEs) to paroxysmal arousals (PAs) and major seizures. During MMEs and PAs scalp EEG generally does not show definite ictal abnormalities. We describe the clinical and electrophysiological features of three patients affected by drug-resistant NFLE studied with intracerebral electrodes during a presurgical evaluation. The stereo-EEG (SEEG) investigation revealed that MMEs can be fragments of the major seizure and occur during a brief Epileptic Discharge or on the following arousal. PAs, in the same subject, do not show a definite stereotypy despite the morphological and topographic similarity of the Epileptic Discharges, thus indicating that other variables may influence the clinical features of PAs.
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nocturnal frontal lobe epilepsy intracerebral recordings of paroxysmal motor attacks with increasing complexity
Sleep, 2003Co-Authors: Lino Nobili, Laura Tassi, Stefano Francione, Roberto Mai, Francesco Cardinale, Laura Castana, Ivana Sartori, Giorgio Lo Russo, Massimo CossuAbstract:Purposes: To show the results of the investigation conducted with intracerebral electrodes in a patient with drug-resistant nocturnal frontal lobe epilepsy, characterized by sleep-related paroxysmal motor attacks of increasing complexity ranging from simple and brief stereotyped motor events to paroxysmal arousals and major attacks. Methods: The patient was studied with long-term video-stereo-electroencephalographic monitoring by means of stereotactically implanted intracerebral electrodes. Results: Video-stereo-electroencephalography demonstrated that minor events and paroxysmal arousals, as well as major attacks, were correlated with a Discharge in the right supplementary motor area and central cingulate gyrus. The increasing complexity of these sleep-related ictal motor behaviors reflected a different pattern of Discharge, with a progressive spread to other frontal and extrafrontal areas in the fully developed attacks. Surgical resection of the right supplementary motor area and central cingulate gyrus was performed. In the 5 years since the operation, the patient has remained completely seizure free. Conclusion: This study clearly demonstrates the ictal origin of minor events in nocturnal frontal lobe epilepsy. The increasing complexity of the motor behaviors from minor to major attacks reflects different duration, amplitude, and spread of the Epileptic Discharge.