Cortex Epilepsy Research Articles

Long-term Effect of Multichannel tDCS Protocol in Patients with Central Cortex Epilepsies Associated with Epilepsia Partialis Continua.

Epilepsia partialis continua (EPC) is a rare type of focal motor status epilepticus that causes continuous muscle jerking in a specific part of the body. Experiencing this type of seizure, along with other seizure types, such as focal motor seizures and focal to bilateral tonic-clonic seizures, can result in a disabling situation. Non-invasive brain stimulation methods like transcranial direct current stimulation (tDCS) show promise in reducing seizure frequency (SF) when medications are ineffective. However, research on tDCS for EPC and related seizures is limited. We evaluated personalized multichannel tDCS in drug-resistant EPC of diverse etiologies for long-term clinical efficacy We report three EPC patients undergoing a long-term protocol of multichannel tDCS. The patients received several cycles (11, 9, and 3) of five consecutive days of stimulation at 2mA for 2 × 20min, targeting the epileptogenic zone (EZ), including the central motor cortex with cathodal electrodes. The primary measurement was SF changes. In three cases, EPC was due to Rasmussen's Encephalitis (case 1), focal cortical dysplasia (case 2), or remained unknown (case 3). tDCS cycles were administered over 6 to 22 months. The outcomes comprised a reduction of at least 75% in seizure frequency for two patients, and in one case, a complete cessation of severe motor seizures. However, tDCS had no substantial impact on the continuous myoclonus characterizing EPC. No serious side effects were reported. Long-term application of tDCS cycles is well tolerated and can lead to a considerable reduction in disabling seizures in patients with various forms of epilepsy with EPC.

Combined neuromodulation and resection for functional cortex epilepsy: a case series

OBJECTIVE Medically refractory epilepsy (MRE) often requires resection of the seizure onset zone (SOZ) for effective treatment. However, when the SOZ is in functional cortex (FC), achieving complete and safe resection becomes difficult, due to the seizure network overlap with function. The authors aimed to assess the safety and outcomes of a combined approach involving partial resection combined with focal neuromodulation for FC refractory epilepsy. METHODS The authors performed a retrospective analysis of individuals diagnosed with MRE who underwent surgical intervention from January 2015 to December 2022. Patients whose SOZ was located in FC and were treated with resection combined with simultaneous implantation of a focal neuromodulation device (responsive neurostimulation [RNS] device) with more than 12 months of follow-up data were included. All patients underwent a standard epilepsy preoperative assessment including intracranial electroencephalography and extraoperative stimulation mapping. Resections were performed under general anesthesia, followed by the concurrent implantation of an RNS device. RESULTS Seven patients (4 males, median age 32.3 years, all right-handed) were included. The median interval from seizure onset to surgery was 17.4 years. The epileptogenic network included sensorimotor areas (cases 2, 3, and 6), visual cortex (case 1), language areas (cases 4 and 7), and the insula (case 5). The median follow-up was 3 years (range 1–5.8 years). No significant changes in neuropsychological tests were reported. One permanent nondisabling planned neurological deficit (left inferior quadrantanopia) was observed. Six patients had stimulation activated at a median of 4.7 months after resection. All patients achieved good seizure outcomes (5 with Engel class I and 2 with Engel class II outcomes). CONCLUSIONS Maximal safe resection combined with focal neuromodulation presents a promising alternative to stand-alone resections for MRE epileptogenic zones overlapping with functional brain. This combined approach prioritizes the preservation of function while improving seizure outcomes.

The role of magnetoencephalography in preoperative localization and postoperative outcome prediction in patients with posterior cortical epilepsy.

We aimed to explore the value of magnetoencephalography in the presurgical evaluation of patients with posterior cortex epilepsy. A total of 39 patients with posterior cortex epilepsy (PCE) and intact magnetoencephalography (MEG) images were reviewed from August 2019 to July 2022. MEG dipole clusters were classified into single clusters, multiple clusters, and scatter dipoles based on tightness criteria. The association of the surgical outcome with MEG dipole classifications was evaluated using Fisher's exact tests. Among the 39 cases, there were 24 cases of single clusters (61.5%), nine cases of multiple clusters (23.1%), and six cases of scattered dipoles (15.4%). Patients with single dipole clusters were more likely to become seizure-free. Among single dipole cluster cases (n = 24), complete MEG dipole resection yielded a more favorable surgical outcome than incomplete resection (83.3% vs. 16.7%, p = 0.007). Patients with concordant MRI and MEG findings achieved a significantly more favorable surgical outcome than discordant patients (66.7% vs. 33.3%, p = 0.044), especially in single dipole cluster patients (87.5% vs. 25.0%, p = 0.005). MEG can provide additional valuable information regarding surgical candidate selection, epileptogenic zone localization, electrode implantation schedule, and final surgical planning in patients with posterior cortex epilepsy.

Ventral Simultanagnosia as an Aura of Posterior Cortex Epilepsy.

Ventral Simultanagnosia as an Aura of Posterior Cortex Epilepsy.

Increased number and domain of interlaminar astrocytes in layer I of the temporal cortex in epilepsy.

The functions of the interlaminar astrocytes in layer I of the human cortex are currently unknown. Here, we aimed to explore whether there is any morphological remodelling of interlaminar astrocytes in layer I of the temporal cortex in epilepsy. Tissues were obtained from 17 epilepsy surgery patients and 17 post-mortem age-matched controls. In addition, 10 Alzheimer's disease (AD) patients and 10 age-matched controls were used as the disease control group. Paraffin sections (6μm) and frozen sections (35 or 150 μm) of inferior temporal gyrus tissue were used for immunohistochemistry. With the use of tissue transparency, 3D reconstruction and hierarchical clustering, we performed a quantitative morphological analysis of astrocytes. Upper and lower zones were identified in layer I of the human cortex. Compared with the astrocytes in layers IV-V, layer I interlaminar astrocytes occupied a significantly smaller volume and exhibited shorter and fewer process intersections. Increased Chaslin's gliosis (consisting of types I and II subpial interlaminar astrocytes) and number of glial fibrillary acidic protein (GFAP)-immunoreactive interlaminar astrocytes in layer I of the temporal cortex were confirmed in patients with epilepsy. There was no difference in the number of interlaminar astrocytes in layer I between AD and age-matched control groups. Using tissue transparency and 3D reconstruction technology, the astrocyte domain in the human temporal cortex was classified into four clusters, among which the interlaminar astrocytes in cluster II were more abundant in epilepsy, showing specific topological structures in patients with epilepsy. Furthermore, there was a significant increase in the astrocyte domain of interlaminar cells in layer I of the temporal cortex in patients with epilepsy. The observed significant astrocytic structural remodelling in the temporal cortex of epilepsy patients showed that the astrocyte domain in layer I may play an important role in temporal lobe epilepsy.

Executive functioning in children with posterior cortex epilepsy compared to temporal and frontal lobe epilepsies

ObjectivePeople with epilepsy are at an increased risk of experiencing executive dysfunction, particularly those with frontal lobe epilepsy (FLE). The literature has also demonstrated alterations in executive functioning (EF) in patients with temporal lobe epilepsy (TLE). However, few studies have examined the neuropsychological profile of posterior cortex epilepsy (PCE), and little attention has been given to cognitive impairments in the pediatric population with PCE. This study aims to investigate EF performance in children with drug-resistant PCE compared to patients with FLE and TLE. MethodsWe analyzed neuropsychological data from 217 patients aged 6–18 years who underwent preoperative evaluation for epilepsy surgery. The EF of patients with PCE was compared to patients with FLE and TLE. ResultsThere was no significant difference in Full-Scale Intelligence Quotient (FSIQ) means between groups. However, we found a significant effect of brain region on the Coding task, in which patients with PCE and FLE performed worse than those with TLE (p = 0.034). We also observed performance differences between groups on the Stroop test (p = 0.005), with patients with PCE and FLE performing worse than the TLE group. SignificanceThese findings suggest that children with PCE have alterations in their EF that are similar to the deficits found in FLE compared to patients with TLE. This emphasizes the importance of understanding the neuroanatomy of executive functions and the model of neural networks extending beyond the prefrontal cortex.

Outcome Predictors of Lesional Posterior Cortex Epilepsy Surgery.

Lesional posterior cortex epilepsy (PCE) is often drug resistant and may benefit from surgical intervention. In this study, we aimed to identify potential predictive factors associated with seizure recurrence after epilepsy surgery in lesional PCE. We retrospectively reviewed patients with PCE who underwent surgery between 1998 and 2021. They were divided into 2 groups according to seizure outcome; the seizure-free group (group 1) and the non-seizure-free group (group 2). The relationship among clinical factors, electroencephalography (EEG) or cranial magnetic resonance imaging findings, disease, and seizure outcome was investigated. A total of 60 patients, with a mean age of 27.26 ± 12.35 years (range, 9-61 years), were included in the study. There were 31 patients (51.66%) in group 1 (Engel class I) and 29 patients (48.33%) in group 2 (13 [21.66%], 10 [16.66%], and 6 [10%] patients in Engel class II, III, and IV, respectively), with a mean follow-up of 8.95 ± 6.96 years (range, 1-24 years). No difference was observed regarding age, gender, age at seizure onset, operation type, treatment gap, and presence of bilateral lesions between the groups (P > 0.05). However, bilateral findings on interictal EEG and gliosis as the underlying disease were predictors of seizure recurrence (P < 0.05). More than half of the patients (including 2 with bilateral magnetic resonance imaging lesions) were seizure free at long-term follow-up. However, patients with bilateral findings on interictal EEG and gliosis were more likely to have recurrent seizures after surgery. Because lesional PCE is almost always drug resistant and has a potential for favorable outcomes, epilepsy surgery should be considered early.

Semiology characteristics and location of epileptogenic zone in motor seizures of axial and shoulder girdle muscles assessed by video stereoelectroencephalography study in 65 patients.

To study the semiology characteristics of motor seizures of axial and shoulder girdle muscles (ASMs) by stereoelectroencephalography (SEEG) and its value in determining location of epileptogenic zone. A total of 598 patients underwent SEEG assessment in Sanbo Brain Hospital were reviewed; 65 patients with ASMs selected. Thirteen semiology feature items were extracted according to the location and symmetry of involved axial muscles, direction of movement, etc. Seizures were grouped with items, and the k-means was used to analyze association between ASMs semiology characteristics and seizure-onset zone (SOZ). The SOZs of ASMs involved 23 combinations of seven different brain regions: 31 patients (47.7%) had one brain region, 19 (29.2%) had two, 14 (21.5%) had three, and one patient (1.5%) had four. One hundred and fifteen brain regions were analyzed. Seven brain regions accounted for a significant difference in chi-square test, χ2 = 62.79, p < 0.0001, with the highest proportion of insular and perisylvian. The k-means method identified two clusters: cluster 1 had a high degree of agreement with temporal lobe epilepsy (12/15), characterized by less shrug-like movement, later involvement of axial shoulder girdle muscles, longer duration, and lower seizure frequency; cluster 2 had a high degree of agreement with posterior cortex epilepsy (14/18), characterized by earlier involvement of axial shoulder girdle muscles, shorter duration, and higher seizure frequency. In frontal lobe, insular and perisylvian, anterior and middle cingulate gyrus, are the two categories accounted for similar proportion. Seizure-onset lateralized at the contralateral of unilateral cervical tonic, with rate of seizure-free was 73.7%. The incidence of ASMs is high in insular and perisylvian. Unilateral cervical tonic seizures have good lateralizing value. Based on semiology characteristics, ASMs can be roughly clustered into two categories, which can only effectively distinguish the origins of temporal lobe and posterior cortex, with low discrimination for the seizure-onset of other lobes.

Multimodal imaging-based diagnostic approach for MRI-negative posterior cortex epilepsy.

Posterior cortex epilepsy (PCE) primarily comprises seizures originating from the occipital, parietal, and/or posterior edge of the temporal lobe. Electroclinical dissociation and subtle imaging representation render the diagnosis of PCE challenging. Improved methods for accurately identifying patients with PCE are necessary. To develop a novel voxel-based image postprocessing method for better visual identification of the neuroimaging abnormalities associated with PCE. Multicenter, retrospective study. Clinical and imaging features of 165 patients with PCE were retrospectively reviewed and collected from five epilepsy centers. A total of 37 patients (32.4% female, 20.2 ± 8.9 years old) with magnetic resonance imaging (MRI)-negative PCE were finally included for analysis. Image postprocessing features were calculated over a neighborhood for each voxel in the multimodality data. The postprocessed maps comprised structural deformation, hyperintense signal, and hypometabolism. Five raters from three different centers were blinded to the clinical diagnosis and determined the neuroimaging abnormalities in the postprocessed maps. The average accuracy of correct identification was 55.7% (range from 43.2 to 62.2%) and correct lateralization was 74.1% (range from 64.9 to 81.1%). The Cronbach's alpha was 0.766 for the correct identification and 0.683 for the correct lateralization with similar results of the interclass correlation coefficient, thus indicating reliable agreement between the raters. The image postprocessing method developed in this study can potentially improve the visual detection of MRI-negative PCE. The technique could lead to an increase in the number of patients with PCE who could benefit from the surgery.

The comparison of decision-making in ambiguous situations and galvanic skin responses as somatic markers in patients with posterior cortex epilepsy and mesial temporal lobe epilepsy with hippocampal sclerosis

ABSTRACT Introduction Decision-making behaviors of patients with mesial temporal lobe epilepsy (MTLE) is a subject that has been studied frequently. However, determining the neuropsychological profiles of patients with different types of epilepsy is also important. Our main purpose was to examine the decision-making behaviors of patients with posterior cortex epilepsy (PCE) through the assumptions of somatic marker hypothesis (SMH) and to compare their performances with those of a MTLE group and a control group. Method Participants comprised of 13 patients with PCE (mean age 30.92 ± 9.99 years); 14 patients with MTLE with hippocampal sclerosis (MTLE-HS) (mean age 25.53 ± 7.40 years) and 15 controls (mean age 24.60 ± 8.45 years). Decision-making performances were assessed with the Iowa gambling test (IGT) and anticipatory skin responses before each choice were recorded. A comprehensive neuropsychological test battery was also given to all participants in order to examine the relationship of decision-making with other cognitive functions. Results Anticipatory responses before choosing from disadvantageous decks were significantly larger than choosing from advantageous decks in the PCE group (p = 0.00). No significant difference was found between the PCE and control group’s total net scores. IGT total net scores was significantly correlated with Stroop test interference time (p = 0.03). Conclusion The study reveals that cognitive impairments of patients with PCE are not limited to brain’s posterior areas’ functions, and provides evidence for the current paradigm which understands epilepsy as a network disorder.

Epileptic opsoclonus due to cortical dysplasia of the left posterior temporal cortex: A simultaneous electroencephalogram and electrooculogram study

This is the first report of opsoclonus seizures due to left posterior cortex epilepsy, which was documented with oculogram (see supplementary discussion) [1], scalp, and subdural EEG. The child has been seizure free for 44 months after resection of the left posterior temporal cortex. Review of literature and the index case support posterior cortex as the epileptogenic zone of ictal opsoclonus.

The intellectual profile of pediatric patients with posterior cortex epilepsy

BackgroundCognitive functioning in epileptic syndromes has been widely explored in patients with temporal lobe epilepsy (TLE), but few studies have investigated the neuropsychological profile in posterior cortex epilepsy (PCE). In this study, we investigated the presurgical intellectual profile of children and adolescents with drug-resistant PCE. MethodsChildren and adolescents diagnosed with PCE (n = 25) participated in this study. The data were obtained from medical records, with assessments carried out between the years 2003 and 2019. To compare the intellectual profile, we also included patients diagnosed with frontal (n = 26) and temporal lobe epilepsy (n = 40). The Wechsler Intelligence Scales were used for the assessment of general intelligence. ResultsThere was an effect of the brain region on the Working Memory Index (p < 0.01), in which patients with TLE had significantly higher scores than groups with FLE (p < 0.01) and PCE (p < 0.05). We also demonstrated that patients with PCE tended to perform worse in the Processing Speed Index than patients with TLE (p = 0.055). The Full-Scale Intelligence Quotient, Verbal Comprehension, and Perceptual Reasoning indexes did not differ among the brain regions. ConclusionsChildren and adolescents with PCE demonstrated significant impairment in working memory and processing speed. The pattern of cognitive dysfunction in PCE was similar to that observed in FLE, which expands the evidence of the involvement of frontoparietal networks on cognitive proficiency.

Structural and functional motor-network disruptions predict selective action-concept deficits: Evidence from frontal lobe epilepsy

Built on neurodegenerative lesions models, the disrupted motor grounding hypothesis (DMGH) posits that motor-system alterations selectively impair action comprehension. However, major doubts remain concerning the dissociability, neural signatures, and etiological generalizability of such deficits. Few studies have compared action-concept outcomes between disorders affecting and sparing motor circuitry, and none has examined their multimodal network predictors via data-driven approaches. Here, we first assessed action- and object-concept processing in patients with frontal lobe epilepsy (FLE), patients with posterior cortex epilepsy (PCE), and healthy controls. Then, we examined structural and functional network signatures via diffusion tensor imaging and resting-state connectivity measures. Finally, we used these measures to predict behavioral performance with an XGBoost machine learning regression algorithm. Relative to controls, FLE (but not PCE) patients exhibited selective action-concept deficits together with structural and functional abnormalities along motor networks. The XGBoost model reached a significantly large effect size only for action-concept outcomes in FLE, mainly predicted by structural (cortico-spinal tract, anterior thalamic radiation, uncinate fasciculus) and functional (M1-parietal/supramarginal connectivity) motor networks. These results extend the DMGH, suggesting that action-concept deficits are dissociable markers of frontal/motor (relative to posterior) disruptions, directly related to the structural and functional integrity of motor networks, and traceable beyond canonical movement disorders.

Multimodal neurocognitive markers of frontal lobe epilepsy: Insights from ecological text processing

The pressing call to detect sensitive cognitive markers of frontal lobe epilepsy (FLE) remains poorly addressed. Standard frameworks prove nosologically unspecific (as they reveal deficits that also emerge across other epilepsy subtypes), possess low ecological validity, and are rarely supported by multimodal neuroimaging assessments. To bridge these gaps, we examined naturalistic action and non-action text comprehension, combined with structural and functional connectivity measures, in 19 FLE patients, 19 healthy controls, and 20 posterior cortex epilepsy (PCE) patients. Our analyses integrated inferential statistics and data-driven machine-learning classifiers. FLE patients were selectively and specifically impaired in action comprehension, irrespective of their neuropsychological profile. These deficits selectively and specifically correlated with (a) reduced integrity of the anterior thalamic radiation, a subcortical structure underlying motoric and action-language processing as well as epileptic seizure spread in this subtype; and (b) hypoconnectivity between the primary motor cortex and the left-parietal/supramarginal regions, two putative substrates of action-language comprehension. Moreover, machine-learning classifiers based on the above neurocognitive measures yielded 75% accuracy rates in discriminating individual FLE patients from both controls and PCE patients. Briefly, action-text assessments, combined with structural and functional connectivity measures, seem to capture ecological cognitive deficits that are specific to FLE, opening new avenues for discriminatory characterizations among epilepsy types.

Sensory profile alterations in patients with insular epilepsy surgery: Preliminary findings

The insular cortex is now well-established as a potential site of epileptogenesis in patients with drug-resistant epilepsy, and its resection has been associated with good outcomes in terms of seizure control. However, given the role of the insula in sensory processing and in visceral information integration, it remains unclear whether insular cortex epilepsy and its surgery are associated with disturbances in sensory information processing and visceral sensation processes as experienced in daily life. In the present study, we examined such sensory disturbances in a group of patients (n = 17) who underwent epilepsy surgery involving a resection of the insula and compared them to a lesion-control group of patients with temporal epilepsy surgery (n = 22) and a healthy control group (n = 29) matched for age, gender, and education. Participants were assessed on the self-report “Adolescent/Adult Sensory Profile” questionnaire at least four months after surgery. Our series of one-way analyses of variance (ANOVAs) revealed that insular and temporal resections in patients with drug-refractory epilepsy were associated with a low “sensation seeking” behavior reflecting a lack of engagement with sensory inputs from the environment. Furthermore, insular resections were associated with impairments in the “active behavioral responses” for the gustatory/olfactory modalities. These preliminary findings suggest that insular resections may be associated with mild to moderate alterations in sensory processing.

Analysis of Interictal EEG Signal Correlations for Diagnostics of Epilepsy

Principles are described for diagnosing epilepsy on the basis of the Memory Function Formalism. Auto- and cross-correlations of electroencephalograms from healthy subjects and patients with epilepsy recorded during the interictal period are studied. Characteristic types of the memory function power spectra and substantial changes in statistical memory effects in pathology are found. Disorders are revealed in the dynamic interconnection in areas of the cerebral cortex in epilepsy.

Is bad brain worse than no brain? Salvaging the cerebral cortex in epilepsy.

This scientific commentary refers to ‘Resective surgery prevents progressive cortical thinning in temporal lobe epilepsy’, by Galovic et al. (doi:10.1093/brain/awaa284).

Biomarkers Obtained by Transcranial Magnetic Stimulation of the Motor Cortex in Epilepsy.

Epilepsy is associated with numerous neurodevelopmental disorders. Transcranial magnetic stimulation (TMS) of the motor cortex coupled with electromyography (EMG) enables biomarkers that provide measures of cortical excitation and inhibition that are particularly relevant to epilepsy and related disorders. The motor threshold (MT), cortical silent period (CSP), short interval intracortical inhibition (SICI), intracortical facilitation (ICF), and long interval intracortical inhibition (LICI) are among TMS-derived metrics that are modulated by antiepileptic drugs. TMS may have a practical role in optimization of antiepileptic medication regimens, as studies demonstrate dose-dependent relationships between TMS metrics and acute medication administration. A close association between seizure freedom and normalization of cortical excitability with long-term antiepileptic drug use highlights a plausible utility of TMS in measures of anti-epileptic drug efficacy. Finally, TMS-derived biomarkers distinguish patients with various epilepsies from healthy controls and thus may enable development of disorder-specific biomarkers and therapies both within and outside of the epilepsy realm.

Cases with parietal and occipital lobe epilepsies

BackgroundFor seizures emerging from the posterior cortex it can be a challenge to differentiate if they belong to temporal, parietal or occipital epilepsies. Sensoric auras like visual phenomena may occur in all of these focal epilepsies. Ictal signs may mimic non- epileptic seizures.Case presentationsCase 1: Patient suffering from a pharmacoresistent focal epilepsy. Focal seizures with sudden visual disturbance, later during the seizure epigastric aura, vertigo-nausea, involvement to bilateral tonic-clonic seizures. MEG detected interictal spikes, source localization indicated focal epileptic activity parietal right.Case 2: Patient with focal pharmacoresistent epilepsy, semiology with focal unaware seizures, feeling that something like a coat is imposed from behind on him, then feeling cold over the whole body, goose bumbs from both arms to head, then block of motoric activity, later focal unaware seizures with stare gaze, blinking of eyes, clouding of consciousness, elevation of arms and legs, sometimes tonic-clonic convulsions. EEG/MEG source localization and MRI detected an epileptogenic lesion parietal left.Case 3: Patient with pharmacoresistent focal epilepsy, focal aware seizures, a dark spot occurring in the left visual field, sometimes anxiety during seizures (leading to the suspicion of non-epileptic psychogenic pseudo seizures). MRI demonstrated an atrophy occipito-temporal right after sinus vein thrombosis. Ictal video-EEG showed a focal seizure onset occipital right.ConclusionContribution of noninvasive and/or invasive confirmation of the localization of the underlying focal epileptic activity in posterior cortex is illustrated. Characteristics of posterior cortex epilepsies are ventilated.

Electroclinical features of insulo-opercular epilepsy: an SEEG and PET study.

ObjectiveTo report clinical experience with presurgical evaluation in patients with insulo‐opercular epilepsy. Quantitative analysis on PET imaging and stereoelectroencephalography (SEEG) signals was used to summarize their electroclinical features.MethodsTwenty‐two patients with focal epilepsy arising from the insular and/or opercular cortex according to SEEG were retrospectively analyzed. Presurgical noninvasive data were analyzed in detail. Interictal PET data of patients were then statistically compared with those of healthy controls to identify the interictal hypometabolic network. The epileptogenicity index (EI) of ictal SEEG signal was computed to identify areas of spread at the beginning of seizure onset.ResultsFocal tonic seizures of the face and/or neck (16/22, 73%) were the most prevalent early objective signs. Epileptic discharges in the interictal and ictal scalp‐EEG mostly showed an ipsilateral perisylvian distribution. Statistical analysis of interictal PET showed significant hypometabolism in the insular lobe, central operculum, supplementary motor area, middle cingulate cortex, bilateral caudate nuclei, and putamen. According to the EI analysis, insulo‐opercular epilepsy could be classified as insulo‐opercular epilepsy (50%), opercular epilepsy (41%), and insular cortex epilepsy (9%).SignificanceClinical diagnosis of insulo‐opercular epilepsy is challenging because of its complex seizure semiology and nonlocalizing discharges on scalp‐EEG. A common hypometabolic network involving the insulo‐opercular cortex, mesial frontal cortex and subcortical nuclei may be involved in the organization of the insulo‐opercular epilepsy network. Furthermore, quantified SEEG analysis suggested that pure insular epilepsy is rare, and the close connection between insular and opercular cortex necessitates SEEG implantation to define the epileptogenic zone.