Ictal EEG Recordings Research Articles

Postictal recovery of orientation in person, place and time relates to restoration of cortical activity after electroconvulsive therapy

IntroductionMost patients show temporary impairments in clinical orientation (i.e., orientation in person, place, and time) after electroconvulsive therapy (ECT)-induced seizures. It is unclear whether postictal reorientation is related to electroencephalography (EEG) restoration. This tentative relationship may shed light on mechanistic aspects of reorientation after ECT.ObjectivesTo study whether postictal EEG restoration after an ECT-induced seizure is related to recovery of clinical orientation in the cognitive domains person, place and time.MethodsWe performed a longitudinal study in ECT patients and collected continuous postictal EEGs. Postictal EEG restoration was estimated by the evolution of the normalized alpha/delta ratio (ADR). Recovery of orientation in the cognitive domains of person, place, and time was assessed using the Reorientation Time (ROT) questionnaire. In each cognitive domain, a linear mixed model was fitted to investigate the relationship between ROT and postictal EEG restoration. In these models, other (ECT-)parameters including seizure duration, use of benzodiazepines and electrode placement were included.ResultsIn total, 272 ictal and postictal EEG recordings of 32 patients were included. In all domains, longer ROT was associated with slower postictal EEG recovery. Longer seizure duration and use of benzodiazepines were related to longer ROT in all domains. Increased total charge of the ECT-stimulus was associated with increased ROT in place and age was positively associated with ROT in time.Image:Image 2:ConclusionsWe show a relationship between restoration of the postictal EEG and clinical reorientation in person, place and time after ECT-induced seizures. This indicates that clinical reorientation probably depends on gradual cortical synaptic recovery. Increased seizure duration and the use of benzodiazepines were also related to increased ROT values. Longer seizures and use of benzodiazepines may induce longer postictal synaptic depression.Disclosure of InterestNone Declared

WWOX developmental and epileptic encephalopathy: Understanding the epileptology and the mortality risk.

WWOX is an autosomal recessive cause of early infantile developmental and epileptic encephalopathy (WWOX-DEE), also known as WOREE (WWOX-related epileptic encephalopathy). We analyzed the epileptology and imaging features of WWOX-DEE, and investigated genotype-phenotype correlations, particularly with regard to survival. We studied 13 patients from 12 families with WWOX-DEE. Information regarding seizure semiology, comorbidities, facial dysmorphisms, and disease outcome were collected. Electroencephalographic (EEG) and brain magnetic resonance imaging (MRI) data were analyzed. Pathogenic WWOX variants from our cohort and the literature were coded as either null or missense, allowing individuals to be classified into one of three genotype classes: (1) null/null, (2) null/missense, (3) missense/missense. Differences in survival outcome were estimated using the Kaplan-Meier method. All patients experienced multiple seizure types (median onset=5 weeks, range=1day-10months), the most frequent being focal (85%), epileptic spasms (77%), and tonic seizures (69%). Ictal EEG recordings in six of 13 patients showed tonic (n= 5), myoclonic (n= 2), epileptic spasms (n= 2), focal (n= 1), and migrating focal (n= 1) seizures. Interictal EEGs demonstrated slow background activity with multifocal discharges, predominantly over frontal or temporo-occipital regions. Eleven of 13 patients had a movement disorder, most frequently dystonia. Brain MRIs revealed severe frontotemporal, hippocampal, and optic atrophy, thin corpus callosum, and white matter signal abnormalities. Pathogenic variants were located throughout WWOX and comprised both missense and null changes including five copy number variants (four deletions, one duplication). Survival analyses showed that patients with two null variants are at higher mortality risk (p-value=.0085, log-rank test). Biallelic WWOX pathogenic variants cause an early infantile developmental and epileptic encephalopathy syndrome. The most common seizure types are focal seizures and epileptic spasms. Mortality risk is associated with mutation type; patients with biallelic null WWOX pathogenic variants have significantly lower survival probability compared to those carrying at least one presumed hypomorphic missense pathogenic variant.

Clinical and electroencephalography characteristics of 45 patients with neonatal seizures

ObjectivesThe aim of our study was to retrospectively research the semiology of neonatal seizures (NSs) based on the 2021 classification scheme of the International League Against Epilepsy, and the relationship between etiology and electroclinical features. MethodsPatients admitted to Children's Hospital of Chongqing Medical University from May 1, 2020 to March 30, 2022 and diagnosed with NSs were included to retrospectively investigate the etiology, seizure characteristics, prognosis, and ictal and interictal video electroencephalography (EEG) characteristics. ResultsOf the 45 patients, 73.3% had definite etiology. Twenty-seven patients had electro-clinical seizures, of which two had both electro-clinical and electrographic-only seizures. Electrographic-only seizures were reported in 18 patients. The tonic, clonic, and electrographic-only seizures were associated with various etiologies. Both tonic and clonic seizures occurred in acute symptomatic seizures and were associated with neonatal epilepsy. 50% of tonic seizures were related to genetic factors. Among the clonic seizures, 50.0% occurred in acute symptomatic seizures. Epileptic spasms always indicated neonatal epilepsy. There were few patients who experienced automatisms and sequential seizures, and these two seizure types were associated with brain malformation and genetic factors, respectively. Patients with a normal interictal EEG had acute symptomatic seizures. whereas the interictal EEG of patients with neonatal epilepsy mainly showed burst-suppression or multifocal discharges. The ictal EEG recordings were related to seizure semiology. ConclusionSeizure semiology and video EEG are suggestive of potential causes but do not provide a definite etiology.

An application of dynamical directed connectivity of ictal intracranial EEG recordings in seizure onset zone localization

BackgroundIdentification of the seizure onset zone (SOZ) is a challenging task in epilepsy surgery. Patients with epilepsy have an altered brain network, allowing connectivity-based analyses to have a great potential in SOZ identification. We investigated a dynamical directed connectivity analysis utilizing ictal intracranial electroencephalographic (iEEG) recordings and proposed an algorithm for SOZ identification based on grouping iEEG contacts. New methodsGranger Causality was used for directed connectivity analysis in this study. The intracranial contacts were grouped into visually detected contacts (VDCs), which were identified as SOZ by epileptologists, and non-resected contacts (NRCs). The intragroup and intergroup directed connectivity for VDCs and NRCs were calculated around seizure onset. We then proposed an algorithm for SOZ identification based on the cross-correlation of intragroup outflow and inflow of SOZ candidate contacts. ResultsOur results revealed that the intragroup connectivity of VDCs (VDC→VDC) was significantly larger than the intragroup connectivity of NRCs (NRC→NRC) and the intergroup connectivity between NRCs and VDCs (NRC→VDC) around seizure onset. We found that the proposed algorithm had 90.1 % accuracy for SOZ identification in the seizure-free patients. Comparison with existing methodsThe existing connectivity-based methods for SOZ identification often use either outflow or inflow. In this study, SOZ contacts were identified by integrating outflow and inflow based on the cross correlation between these two measures. ConclusionsThe proposed group-based dynamical connectivity analysis in this study can aid our understanding of underlying seizure network and may be used to assist in identifying the SOZ contacts before epilepsy surgery.

Ictal-Interictal Epileptic State Classification with Traditional and Deep Learning Architectures

Epileptic seizures are caused by disturbances in the electrical activity of the brain. Failure to correctly classify epileptic forms may result in inappropriate treatment. Activities occurring prior to ictal activity may be causal and require further investigation. Therefore, it is important in the diagnosis of epilepsy to distinguish between ictal and interictal EEG using Electroencephalography (EEG) signs. In this study, ictal (absence seizure) and interictal EEG recordings were scored using 4 bipolar (C3-P3, T5-O1, FP2-F8, C4-T4) channel EEGs from Temple University Hospital (TUH) EEG Seizure Corpus (TUSZ) data. The data were divided into 3-second epochs and various features were obtained from the data. The data in each epoch were filtered using the Discrete Wavelet Transform (DWT) Daubechies-2 wavelet and were 0-32 Hz. range has been studied. Feature selection was made with Correlation based Feature Selection (CFS). The performances of traditional and deep learning classifier algorithms (Support vector machine (SVM), Long Short-term Memory (LSTM)) were compared and the results were discussed. The highest success rate was 96.96% in 84.86 seconds with the LSTM classifier model and 96.36% in 0.05 seconds with the SVM classifier algorithm

Ictal EEG recording is not mandatory in all candidates for paediatric epilepsy surgery with clear MRI lesions and corresponding seizure semiology

Epilepsy surgery can potentially cure drug-resistant epilepsy, but careful presurgical evaluation is vital to select patients who will profit from such an intervention. Many epilepsy surgery programs offer extensive presurgical evaluation including several days of video-EEG monitoring. Non-lesional epilepsy cases are rare among epilepsy surgery patients. We set up a lesion-orientated paediatric epilepsy surgery program for patients with clearly localized lesions with limited presurgical diagnostics, in particular, with a maximum of 48 hours of non-invasive EEG monitoring that did not necessarily include ictal EEGs. We retrospectively evaluated the outcome of patients who were operated on within our epilepsy surgery program with respect to seizure freedom. Fifty-two children and adolescents with MRI lesions at a mean age of 8.27 ±4.83 years (range: 0.17-18.87) underwent a resective procedure. The most frequent surgery was a hemispherotomy. Overall seizure freedom was 81.8% after 12 months and 85.6% after a median observation period of 20.45 months. Seizure frequency was reduced >50% in all other patients. Preoperative recording of an ictal EEG on the side of surgery had no effect on postoperative seizure outcome (p= 0.697), nor did recording of epileptiform discharges on the ipsilateral (p= 0.538) and contralateral side (p= 0.147). Our findings highlight the high success rate using a lesion-orientated epilepsy surgical approach with reduced presurgical video-EEG monitoring in the paediatric epilepsy population. Our data show that it is possible to reduce the complex pre-surgical work-up for epilepsy in children and adolescents by asking the basic question: "Is there any reason why the lesion should not be resected".

Neuropsychological performance in patients with focal drug-resistant epilepsy and different factors that affect their performance

BackgroundDrug-resistant epilepsy (DRE) accounts for nearly 30% of patients with epilepsy, which is associated with high incidence of cognitive comorbidity. The aim of this work was to study the role of neuropsychological assessment in patients with epilepsy, and different factors that affect their performance in patients with multiple factors (focal onset DRE).Methods118 patients were recruited from Kasr Alainy hospital, epilepsy outpatient clinic with focal DRE. The patients’ demographic and clinical data were collected, Electroencephalograph (EEG) interictal/ictal (when available), and brain imaging (MRI epilepsy protocol). Neuropsychological assessment by Wechsler Adult Intelligence Scale (WAIS-IV), proposed neurocognitive assessment battery and mood assessment was done. Their performance in neuropsychological assessment was correlated with the collected data. Concordance between different assessment modalities and brain lesion were done.ResultsAmong recruited patients, 67.3% of patients showed Full-scale Intelligence Quotient (FSIQ) was less than average. FSIQ score significantly correlated with years of education, and number of anti-seizure medications (ASMs). Neurocognitive assessment battery could achieve cognitive profile of the patients but with poor lateralizing value. Executive function was the most affected cognitive domain. History of status epilepticus significantly affect FSIQ and executive function performance. Fifty-six percent of patients had depression. Among the analyzed factors, FSIQ and lesional brain imaging significantly affected neurocognitive performance of studied patients. Clinical semiology had better concordance in lateralization (74.7%) and localization (69.5%) with brain imaging compared to ictal EEG. Among patients who had ictal EEG recording, 36.4% patients (25% were temporal lobe) had complete concordance, while 38.6% patients had partial concordance.ConclusionsAmong analyzed factors, FSIQ was the most significant determinant of studied population’s neurocognitive performance. Clinical semiology were the best correlated with brain lesion. Complete concordance was best detected at the temporal lobe.

The coexistence of psychogenic nonepileptic and epileptic seizures in the same patient is more frequent than expected: Is there any clinical feature for defining these patients?

ObjectivesThis study aimed to investigate the prevalence of psychogenic nonepileptic seizures (PNES) and PNES-epilepsy coexistence within all video-electroencephalography (EEG) monitoring unit (VEMU) referrals and to identify semiological and electrophysiological features to differentiate patients with PNES-epilepsy coexistence from PNES-only. MethodsWe retrospectively reviewed medical files, VEMU reports, and videos of 1983 adult patients. Demographical, historical, clinical, neuroimaging, and electrophysiological parameters of all patients were recorded. We classified patients into five groups as definite PNES-only, definite PNES-epilepsy coexistence, definite PNES-probable epilepsy coexistence, probable PNES-definite epilepsy coexistence, and probable PNES-only. We defined a “definite” group when we saw the ictal EEG and/or video recording of the seizure. The “probable” term is used when there is strong evidence from the history of a particular seizure type and suggestive interictal EEGs without video recordings. ResultsTwo hundred and three of 1983 patients (10.23%) had PNES. Sixty-six of patients with PNES (32.51%) had definite PNES-epilepsy coexistence. When probable cases were included, the PNES-epilepsy coexistence ratio was 53.69% within all patients with PNES. The prevalence of PNES-epilepsy coexistence was 3.32% within all our VEMU referrals. Lower high school graduation rate, earlier age of disease onset, history of status epilepticus, febrile convulsion and brain surgery, use of three or more antiepileptic drugs, and abnormal magnetic resonance imaging (MRI) findings supported PNES-epilepsy coexistence (p < 0.05). On the contrary, seizure duration longer than 10 min was in favor of PNES-only (p < 0.05). ConclusionsThe prevalence of PNES-epilepsy coexistence might be more frequent in VEMUs than expected. Some demographic and semiological features and electrophysiological findings might be useful in differentiating patients with PNES-epilepsy coexistence from patients with PNES-only.

The clinical and genetic spectrum in infants with (an) unprovoked cluster(s) of focal seizures.

Self-limited (familial) infantile epilepsy (S(F)IE), formerly known as benign (familial) infantile convulsions (B(F)IC), is an infantile cluster epilepsy with in rule a complete recovery. This form of epilepsy is most often caused by variations in the PRRT2 gene (OMIM #605751). To describe the clinical and genetic spectrum of sudden onset clusters of focal seizures in infancy. We retrospectively reviewed all individuals, who presented with unprovoked infantile seizures and selected all infants who had unprovoked clustered focal seizures between 1 and 20 months of age. We described the clinical and genetic spectrum of this cohort. The data of 23 patients from 21 families were collected. All had an initial diagnosis of S(F)IE which was adjusted in 5 individuals. In 12 individuals a pathogenic variation in PRRT2 gene or complete deletion was identified. Pathogenic variants in PCDH19 and KCNQ2 were found in respectively 3 and 1 individuals. One individual had a non-pathogenic variant in ATP1A3 and in 6 others no variants were identified. The mean cluster duration was 2.9 days (range 1-13) (see Table1). Twelve infants had only one cluster. All patients had focal motor or non-motor seizures, in 12 (52%) followed by bilateral (tonic)clonic seizures. Positive family history was present in 74% of individuals. In 11/12 (92%) tested families, ≥1 family member carried the pathogenic PRRT2 variant. Age of seizure onset (ASO) averaged 6.2 months (range 2-20 months). Age of latest seizure averaged 16 months (range 2-92). In several interictal EEG (electroencephalogram) recordings multifocal spikes or spike-wave abnormalities were detected. Ictal EEG recordings detected primary focal abnormalities. We described 23 individuals with unprovoked cluster(s) of focal seizures at infancy. It appears to be a heterogeneous group. Half of them had a pathogenic variation in PRRT2 gene. Most had only one cluster of seizures. When clusters reoccur frequently, when seizures are more therapy-resistant and when seizures persist beyond the age of 2 years, another diagnosis or causative gene is likely.

P.052 Benign spasms of infancy - a mimicker of infantile epileptic disorders

Background: Benign spasms of infancy (BSI), previously described as benign non-epileptic infantile spasms or benign myoclonus of early infancy, are non-epileptic movements manifesting during the first year of life and spontaneously resolving in the second year of life. BSI are characterized by spasms typically lasting 1-2 seconds, involving to varying degrees the head, neck, trunk, shoulders and upper extremities. Ictal and interictal EEG recordings are normal. BSI are not associated with developmental retardation and do not require treatment. Distinction between BSI and infantile epileptic disorders, such as epileptic spasms or myoclonic epilepsy of infancy, can be challenging given the clinical similarities. Moreover, interictal EEGs can be normal in all conditions. Epileptic spasms and myoclonic epilepsy require timely treatment to improve neurodevelopmental outcomes. Methods: We describe a 6-month old infant presenting with spasm-like movements. His paroxysms as well as a positive family history for epileptic spasms were in keeping with a likely diagnosis of West syndrome. Results: Surprisingly, ictal video EEG did not reveal epileptiform activity, and suggested a diagnosis of BSI. Conclusions: We emphasize that ictal EEG is the gold standard for classification of infantile paroxysms as either epileptic or non-epileptic, thereby avoiding overtreatment of BSI and facilitating timely targeted treatment of infantile epilepsies.

P09-T An extraordinary EEG phenomenon misdiagnosed as nonconvulsive status epilepticus: Subclinical ictal discharges interrupted by verbal stimuli

Background Triggering or modulation of seizures and rhythmic EEG patterns by external stimuli are well-known but an exclusive stopping effect by sound was not reported before. Here, we report a peculiar manifestation of stimulus-related ictal discharges, namely, subclinical ictal discharges interrupted by sudden verbal stimuli. Case The patient is a 20-year-old woman with recurrent febrile seizure history between the age of 4 months to one year and marked psychomotor developmental delay of unknown cause. She also had brief episodes of staring and sometimes bilateral tonic-clonic seizures. Neurological examination revealed strabismus and microcephaly. Brain MRI did not show any abnormality. At age of 8 years, self-mutilating and agitated behaviors were noted. First EEGs revealed bifrontal 2.5–3.5 Hz spike and waves with impaired background activity. Video-EEG showed frequent patterns of long-lasting (10–60 s) bilateral paroxysmal high-voltage slow waves with occasional spikes, misdiagnosed as non-convulsive status epilepticus. However, no apparent clinical change was noted by the technician, physician and mother during these subclinical ictal EEG recordings. Interestingly, these epileptic discharges were abruptly interrupted with sudden verbal stimuli. Lysosomal enzyme activities and metabolic screening tests were unremarkable. Molecular genetic investigations for ring 20 chromosome analysis and SLC2A1 gene analysis were also unremarkable. Her seizures were partly controlled with levetiracetam, valproic acid and primidone. Conclusion We report the “reverse” type of stimulus-induced, rhythmic, periodic or ictal discharges (SIRPIDS), that is stopped by the external sound in a patient with developmental delay. External modulation of ictal-appearing EEG patterns may show clues for hidden mechanisms of epileptogenesis.

EEG based epileptiform pattern recognition inside and outside the seizure states

Abstract Automatic diagnosis of epilepsy by computers based on Electroencephalography (EEG) analysis is a beneficial practice which increases recognition rate, speeds up diagnosis and saves physicians from long hours of EEG inspection. Most studies on this subject report results on detecting seizures; but seizures, which appear during the ictal states are very rare to catch. Therefore, an efficient algorithm must be able to detect epilepsy during nonseizure periods, or in other words interictal states as well. We present a novel algorithm to detect epileptiform patterns during both states: ictal and interictal. For this purpose, we use wavelet packet analysis (WPA) rather than traditional time and frequency domain methods. WPA, by providing arbitrary time-frequency resolution, enables analyzing signals of stationary and non-stationary nature. It has better time representation than Fourier analysis and better high frequency resolution than Wavelet analysis. WPA subimages are analyzed further to obtain feature vectors of Log Energy Entropy, Norm Entropy and Energy. These features are fed into a classifier, multilayer perceptron (MLP). We test our method on a well-known and widely studied database which includes healthy, ictal and interictal EEG recordings. Normal vs. Ictal and Interictal vs. Ictal zone classifications are realized at 100% accuracy by using any of the three features. Nonseizure vs. Seizure state classification is realized with 100% accuracy using Norm entropy. Normal vs. Interictal zone classification is achieved with 100% accuracy using Log Energy Entropy. Normal vs. Interictal vs. Ictal Zone classifications are considered as two-step binary classifications of Nonseizure vs. Seizure state followed by Normal vs. Interictal zone both of which are realized at 100% accuracy. Therefore, jointly use of Log Energy Entropy and Norm entropy is able to realize all possible classifications with 100% accuracy. We make the most comprehensive comparison of results belonging to all possible classification categories reported on the same datasets. The proposed method outperforms all the other results in all possible classifications by achieving 100% accuracy in all possible classifications. The method presented is the only single method that achieves this. Overall, the method provides us with a promising tool for the detection of epileptiform patterns during and outside the seizure states.

Imaging for Epilepsy Surgery.

AbstractSuccessful epilepsy surgery requires accurate localization of the zone of seizure onset and its complete removal without causing any permanent neurological deficits. While clinical semiology, ictal EEG recordings, and neuropsychological testing are all useful in defining the seizure focus, advanced neuroimaging has emerged as the most important localizing tool. Structural and metabolic imaging can now identify subtle cortical abnormalities that if consistent with other presurgical evaluation investigations, can improve surgical outcomes. Functional imaging can also be helpful in defining eloquent cortex and its relationship to planned surgical resection sites to reduce the risk of neurological impairment. This article explores several advanced neuroimaging techniques and their role in the surgical treatment of epilepsy.

Can developmental venous anomalies cause seizures?

Developmental venous anomalies (DVAs) are congenital anatomical variants of normal venous drainage of normal brain. Although DVAs are often discovered on the occasion of a seizure, their involvement in epilepsy is poorly studied. Our objective was to determine whether DVA can cause seizures, in the cases where there is no associated lesion, including no cavernoma or dysplasia. Based on clinical history, cerebral MRI, EEG recording, and 18F-FDG PET, we report 4 patients with DVA revealed by seizures. The first patient had a convulsive seizure caused by a hemorrhagic infarction due to thrombosis of her DVA. The second patient had a left temporo-parietal DVA next to a nonspecific lesion, possibly a sequelae of a venous infarction. The last two patients disclosed an isolated and uncomplicated DVA with a concordant epileptic focus confirmed on ictal video EEG recording. We reviewed literature and identified 21 other published cases of seizures caused by complications of a DVA and 9 patients that may have a direct link between epilepsy and an isolated and uncomplicated DVA. Seizures are linked to a DVA in two main situations: presence of an associated epileptogenic lesion, such as cavernoma or dysplasia, and occurrence of a complication of the DVA. Before concluding that a seizure is caused by a DVA, it is essential to perform full MRI protocols to search them. It remains rare and uncertain that isolated and uncomplicated DVA can cause seizures. In this last situation, physiopathological processes are probably different in each patient.

Drug-resistant parietal lobe epilepsy: clinical manifestations and surgery outcome.

We reviewed a large surgical cohort to investigate the clinical manifestations, EEG and neuroimaging findings, and postoperative seizure outcome in patients with drug-resistant parietal lobe epilepsy (PLE). All drug-resistant PLE patients, who were investigated for epilepsy surgery at Jefferson Comprehensive Epilepsy Center between 1986 and 2015, were identified. Demographic data, seizure data, EEG recordings, brain MRI, pathological findings, and postsurgical seizure outcome were reviewed. In total, 18 patients (11 males and seven females) were identified. Sixteen patients (88%) had tonic-clonic seizures, 12 (66%) had focal seizures with impaired awareness, and 13 (72%) described auras. Among 15 patients who had brain MRI, 14 patients (93%) had parietal lobe lesions. Only three of 15 patients (20%) who had interictal scalp EEG recordings showed parietal interictal spikes. Of 12 patients with available ictal surface EEG recordings, only three patients (25%) had parietal ictal EEG onset. After a mean follow-up duration of 8.6 years, 14 patients (77.7%) showed a favourable postoperative seizure outcome. In patients with PLE, semiology and EEG may be misleading and brain MRI is the most valuable tool to localize the epileptogenic zone. Postsurgical seizure outcome was favourable in our patients with drug-resistant parietal lobe epilepsy.

Preoperative prediction of temporal lobe epilepsy surgery outcome

PurposeThere is controversy about relative contributions of ictal scalp video EEG recording (vEEG), routine scalp outpatient interictal EEG (rEEG), intracranial EEG (iEEG) and MRI for predicting seizure-free outcomes after temporal lobectomy. We reviewed NIH experience to determine contributions at specific time points as well as long-term predictive value of standard pre-surgical investigations. MethodsRaw data was obtained via retrospective chart review of 151 patients. After exclusions, 118 remained (median 5 years follow-up). MRI-proven mesial temporal sclerosis (MTSr) was considered a separate category for analysis. Logistic regression estimated odds ratios at 6-months, 1-year, and 2 years; proportional hazard models estimated long-term comparisons. Subset analysis of the proportional hazard model was performed including only patients with commonly encountered situations in each of the modalities, to maximize statistical inference. ResultsAny MRI finding, MRI proven MTS, rEEG, vEEG and iEEG did not predict two-year seizure-free outcome. MTSr was predictive at six months (OR=2.894, p=0. 0466), as were MRI and MTSr at one year (OR=10.4231, p=0. 0144 and OR=3.576, p=0. 0091). Correcting for rEEG and MRI, vEEG failed to predict outcome at 6 months, 1year and 2 years. Proportional hazard analysis including all available follow-up failed to achieve significance for any modality. In the subset analysis of 83 patients with commonly encountered results, vEEG modestly predicted long-term seizure-free outcomes with a proportional hazard ratio of 1.936 (p=0.0304). ConclusionsIn this study, presurgical tools did not provide unambiguous long-term outcome predictions. Multicenter prospective studies are needed to determine optimal presurgical epilepsy evaluation.

Source localization of the seizure onset zone from ictal EEG/MEG data.

Surgical treatment of drug-resistant epilepsy relies on the identification of the seizure onset zone (SOZ) and often requires intracranial EEG (iEEG). We have developed a new approach for non-invasive magnetic and electric source imaging of the SOZ (MSI-SOZ and ESI-SOZ) from ictal magnetoencephalography (MEG) and EEG recordings, using wavelet-based Maximum Entropy on the Mean (wMEM) method. We compared the performance of MSI-SOZ and ESI-SOZ with interictal spike source localization (MSI-spikes and ESI-spikes) and clinical localization of the SOZ (i.e., based on iEEG or lesion topography, denoted as clinical-SOZ). A total of 46 MEG or EEG seizures from 13 patients were analyzed. wMEM was applied around seizure onset, centered on the frequency band showing the strongest power change. Principal component analysis applied to spatiotemporal reconstructed wMEM sources (0.4-1 s around seizure onset) identified the main spatial pattern of ictal oscillations. Qualitative sublobar concordance and quantitative measures of distance and spatial overlaps were estimated to compare MSI/ESI-SOZ with MSI/ESI-Spikes and clinical-SOZ. MSI/ESI-SOZ were concordant with clinical-SOZ in 81% of seizures (MSI 90%, ESI 64%). MSI-SOZ was more accurate and identified sources closer to the clinical-SOZ (P = 0.012) and to MSI-Spikes (P = 0.040) as compared with ESI-SOZ. MSI/ESI-SOZ and MSI/ESI-Spikes did not differ in terms of concordance and distance from the clinical-SOZ. wMEM allows non-invasive localization of the SOZ from ictal MEG and EEG. MSI-SOZ performs better than ESI-SOZ. MSI/ESI-SOZ can provide important additional information to MSI/ESI-Spikes during presurgical evaluation. Hum Brain Mapp 37:2528-2546, 2016. © 2016 Wiley Periodicals, Inc.

Epileptic spasms in clusters and associated syndromes other than West syndrome: A study of 48 patients

ObjectiveTo study the different epilepsy syndromes that included epileptic spasms (ES) in clusters without hypsarrhythmia (WoH). MethodsBetween 2/1990 and 7/2013, we registered 48 patients with the electroclinical diagnostic criteria of ES in clusters WoH. ResultsWe recognized two subgroups. In the first subgroup of 30 patients, ES started at a mean age of 10.6 months (range, 2–40 months). Ictal EEG recordings showed diffuse high-amplitude slow waves in 15 patients, diffuse slow waves followed by voltage attenuation in six patients, diffuse fast rhythms in five, diffuse slow waves with superimposed fast rhythms in three, and diffuse sharp waves in one.In the second subgroup of 18 patients, nine had electroclinical features of Lennox–Gastaut syndrome, four had epilepsy with myoclonic and atonic seizures, two had Dravet syndrome, one 6-year-old boy had a non-convulsive status epilepticus characterized by atypical absences associated with ES, one had epilepsy with migrating seizures of infancy, and one patient had clinical features of subacute sclerosing panencephalitis with ES. ES started at a mean age of 6.3 years (range, 0.5–13 years). The ictal EEG recording during the ES showed diffuse fast rhythms in 10 cases, diffuse slow waves with superimposed fast rhythms in four, and diffuse slow waves in four. ConclusionOur study shows two subgroups of children with ESWoH. The first subgroup had a well-defined electroclinical syndrome predominantly in infancy, and in the second subgroup ES was one more seizure type associated with an epileptic encephalopathy other than West syndrome predominantly occurring in childhood.

Epileptic spasms in clusters with focal EEG paroxysms: A study of 12 patients

ObjectiveWe analyzed the electroclinical features, etiology, treatment, and outcome of 12 patients with West syndrome (WS) associated with focal hypsarrhythmia (FH). MethodsBetween February 2005 and July 2013, 12 patients met the electroclinical diagnostic criteria of WS associated with FH. Hypsarrhythmia was considered to be focal when two or three brain lobes were involved. Patients with hemihypsarrhythmia were excluded. ResultsAll patients had epileptic spasms (ES) in clusters of a structural etiology. Four had a porencephalic cyst, two had focal cortical dysplasia, two had open-lip schizencephaly, and one each had unilateral polymicrogyria, shunted hydrocephalus, glioma, and cerebral hemiatrophy. Age at ES onset was between 2 and 8 months, with a mean age of 5 and a median age of 6 months. Seven patients had asymmetric ES, three had symmetric ES, and two patients had unilateral ES. FH was seen over the posterior regions in nine and over the anterior regions in three. Ictal EEG recordings showed diffuse high-amplitude slow waves in six patients, diffuse slow waves followed by voltage attenuation in three, and diffuse fast rhythms in three others. In three patients the ictal paroxysms were unilateral. Six patients responded well to surgery. ConclusionES associated with FH are secondary to structural lesions. Surgery should be considered earlier in the management of this group of patients.

Utility of invasive ictal EEG recordings in pre-surgical evaluation of patients with medically refractory temporal lobe epilepsy and normal MRI

PurposeSome previous studies have suggested that invasive ictal recording may be omitted in patients with medically refractory temporal lobe epilepsy (TLE) that have localizing scalp ictal recordings despite having normal magnetic resonance imaging (MRI). We investigated if and how often invasive ictal recording provided additional information to their pre-surgical evaluations. MethodsIn a retrospective review of 302 patients with intractable TLE who underwent pre-surgical evaluation between 1991 and 2006, we identified 45 patients who had normal MRI. Localization by scalp ictal recording, invasive ictal recording, and surgical procedures were obtained from medical records. Primary outcome was measured by comparing the concordance of localization by scalp and invasive ictal recordings and surgery to determine if invasive ictal recording provided additional information. ResultsTwenty-five patients were included in the analysis. Invasive ictal recordings were concordant in 72.0% (18/25) of the patients with unilateral temporal onset found on scalp ictal recording. 28.0% (7/25) of patients had their surgical plan altered by the results of invasive ictal recording. 61.1% (11/18) of patients who received anterior temporal lobectomies (ATL) remained seizure-free. Of the patients who received different surgeries based on invasive ictal recording, 80.0% (4/5) remained seizure-free. ConclusionsOur study showed that findings from invasive ictal recording changed the type of surgery in 28.0% of the patients. Invasive ictal recording may not be an absolute prerequisite for resective epilepsy surgery in some patients with intractable TLE with a supposedly normal MRI of the brain but may alter the surgical decision.