Multiple Seizure Types Research Articles

Reiterating the role of corpus callosum in generalization of interictal and ictal epileptiform discharges: a case report with post-callosotomy intracranial electroencephalography in Lennox–Gastaut syndrome

Lennox–Gastaut syndrome (LGS) is an epileptic encephalopathy characterized by delayed mental development and intractable multiple seizure types, predominantly tonic. Drop attacks are the commonest and the most disabling type of seizures. Resective surgery is often not possible in LGS as the electroencephalogram (EEG) abnormalities are usually multifocal and generalized, and magnetic resonance image is often either normal or multilesional. We report a case of LGS with bilateral parieto-occipital gliosis where EEG before and after callosotomy demonstrated synchronized bilateral interictal epileptiform discharges and ictal discharges becoming desynchronized and running down. This phenomenon emphasizes the role of the corpus callosum in secondary bilateral synchrony.

Posterior Quadrant Disconnection for Childhood Onset Sub-Hemispheric Posterior Head Region Epilepsy: Indications in an Indian Cohort and Outcome

Background: Posterior quadrant disconnection (PQD) is an under-utilized surgical technique in the management of refractory epilepsy. There is a dearth of data pertinent to post-PQD seizure outcomes. Methods: This retrospective study analyzed patients with drug-resistant childhood-onset epilepsy who underwent PQD at our center from 2009 to 2018. The clinical, imaging, and electrophysiological data were reviewed. The seizure outcome was noted from the latest follow-up in all patients. Results: Fifteen patients underwent PQD, with a mean age at onset of epilepsy of 3.3 ± 4.6 years. All patients had seizure onset in childhood with focal onset of seizures, and in addition, 5 had multiple seizure types. All cases underwent presurgical workup with MRI, video-EEG, psychometry, while PET/MEG was done if required. Engel Ia and ILAE I outcomes were considered to be favorable. The histology of the specimen showed 9 patients (60%) had gliosis, 4 (26.7%) had focal cortical dysplasia (FCD), while 1 patient had nodular heterotopia and another had polymicrogyria-pachygyria complex. Postoperative follow-up was available in 14 cases. One patient was lost to follow-up. Mean follow-up duration for the cohort was 45 + 24 months. At last, follow-up (n = 14), 66.7% (10 cases) had favorable outcome (Engel Ia). At the end of 1-year follow-up, up to 73% (n = 11) of the patients were seizure-free. Four patients developed transient hemiparesis after surgery which improved completely by 3–6 months. Conclusions: Gliosis was more common etiology requiring PQD in our series than Western series, where FCD was more common. PQD is a safe and effective surgical modality in childhood-onset epilepsy with posterior head region epileptogenic focus.

Genotype and phenotype of children with DEPDC5 gene variants related epilepsy

Objective: To summarize the clinical characteristics and the features of electroencephalograph (EEG) of children with DEPDC5 gene variants related epilepsy. Methods: The clinical data, gene variation, EEG and head magnetic resonance image (MRI) of 20 epileptic children with DEPDC5 gene variants admitted to Department of Pediatrics, Peking University First Hospital from May 2017 to November 2020 were retrospectively analyzed. Results: Twenty patients with heterozygous DEPDC5 gene variants were enrolled, 8 of 20 patients were nonsense variants, 6 were missense variants, 3 were frame-shift variants, 2 were splicing variants, and 1 was large fragment deletion. Sixteen cases had hereditary variation and 4 had de novo variation. Fifteen of variations were novel. Nine were male, while 11 were female. Their latest follow-up age ranged from 10 months to 13 years and one month.The epilepsy onset age ranged from 3 hours to 11 years and 3 months, the median age was 10.5 months. Twelve (60%) patients had developmental delay. Nineteen patients had focal seizures, 7 had epileptic spasms, 1 had multiple seizure types including tonic, atypical absence, dystonic and myoclonic seizures. Epileptic form discharges were observed in 18 patients during the interictal phase, and 11 were focal discharges, 7 were multifocal discharges. Ten (50%) patients had abnormal brain MRI, including focal cortical dysplasia in 5 patients, undefined malformation of cortical development in 4 patients, hemimegalencephaly in 1 patient. Four patients were diagnosed as West syndrome and one patient was diagnosed as Lennox-Gastaut syndrome. Fourteen (70%) patients were diagnosed as drug-resistant epilepsy. Four patients became seizure-free by treatment with anti-epileptic drugs. Three children were treated with surgery, and 2 of them became seizure-free, 1 had more than 75% reduction in seizures. Conclusions: DEPDC5 gene variant epilepsy is inherited with incomplete penetrance and focal seizure is the major seizure type. However, epileptic spasms, generalized seizures can also be observed. Half of the patients brain malformations. Most of the patients are drug-resistant epilepsy. Patients with clear epileptogenic zones can be treated with surgery. Treatment-resistant patients are more likely to be complicated with developmental delay.

Patient and Caregiver Health State Utilities in Tuberous Sclerosis Complex.

BackgroundTuberous sclerosis complex (TSC) is a rare multisystem disorder often associated with treatment-resistant epilepsy. Cost-effectiveness analysis for new antiseizure medications typically requires health state utilities (HSUs) that reflect the burden of a given condition.ObjectiveThis study aimed to estimate HSUs, with a focus on valuing the impact of seizure type and seizure frequency on health-related quality of life (HRQL) for patients with TSC and their caregivers.MethodsA targeted literature review and qualitative research with healthcare professionals and caregivers informed the development of health state vignettes describing the experience of living with TSC or caring for a child with TSC. Vignettes were evaluated in interviews with the UK general population using the time trade-off (TTO) method.ResultsSixteen vignettes were developed describing patient HRQL (n = 8) and caregiver HRQL (n = 8). Two hundred interviews were conducted via online video calls due to COVID-19 pandemic restrictions. Two hundred participants evaluated the patient (n = 100) and caregiver (n = 100) health state vignettes. Estimated utility scores varied consistently according to seizure type and seizure frequency. Patient TTO utility scores ranged between −0.234 (highest seizure frequency and multiple seizure types) and 0.725 (seizure-free state). Caregiver TTO utility scores ranged from 0.221 to 0.905.ConclusionsFindings highlight the substantial burden of living with TSC and caring for a child with TSC. Patient and caregiver burden was greater for generalised versus focal seizures. The burden was greatest for a combination of both seizure types and worsened with increasing seizure frequency.Supplementary InformationThe online version contains supplementary material available at 10.1007/s41669-021-00296-1.

Long-term response and response patterns to antiepileptic drugs in patients with newly diagnosed epilepsy

ObjectiveThis study investigated the long-term response and response patterns to antiepileptic drugs (AEDs) in patients with newly diagnosed epilepsy. MethodsPatients who had been newly diagnosed with epilepsy and had at least 3-year follow-up records were enrolled. Their long-term response and response patterns to AEDs were retrospectively analyzed. Patients were divided into two groups, a controlled group and an uncontrolled group, according to whether 3-year seizure freedom (3YSF) was achieved. Multiple logistic regression analyses were used to identify risk factors associated with a poor drug response. ResultsOf the 472 patients with epilepsy, 180 achieved immediate seizure control, 36 achieved early seizure control, 118 achieved late seizure control, and 138 did not achieve 3YSF. Patients who achieved 3YSF (334/472, 70.8%) were categorized into the controlled group. Among them, 53.9% (180/334) achieved 3YSF immediately, 10.8% (36/334) achieved 3YSF within 6 months, and 35.3% (118/334) achieved 3YSF after 6 months. Also in this group, 228 (228/472, 48.3%), 84 (84/472, 17.8%), 15 (15/472, 3.2%), and 7 (7/472, 1.5%) patients achieved 3YSF on the first, second, third, and fourth regimen, respectively. Multivariate analyses showed that multiple seizure types (odds ratio [OR] = 3.903, 95% confidence interval [CI]: 2.098–7.264; P < 0.001] and polytherapy (OR = 5.093, 95% CI: 3.183–8.149; P < 0.001) were independent risk factors for a poor drug response. ConclusionThe 3YSF rate in this cohort was 70.8%. More than half of the patients achieved long-term remission immediately after treatment. The probability of attaining 3YSF decreased with the increase in number of drug regimens, especially in patients who experienced failure of two treatment regimens.

Safety and efficacy of rufinamide in children and adults with Lennox-Gastaut syndrome: A post hoc analysis from Study 022

BackgroundLennox-Gastaut syndrome (LGS) is a developmental and epileptic encephalopathy with the first symptoms usually appearing during early childhood. Due to the highly variable underlying etiologies, LGS cannot be considered as one disease but as an electro-clinical entity, often challenging to diagnose early and treat accordingly. The anti-seizure medication, rufinamide, is indicated for the adjunctive treatment of patients with LGS aged ≥1 year. This post hoc analysis assessed the safety and efficacy of adjunctive rufinamide for total and tonic-atonic seizures during Study 022 in children (aged <16 years) and adults (aged ≥16 years). MethodsRandomized, placebo-controlled, phase III Study 022 included patients with a diagnosis of LGS and a history of multiple seizure types (including tonic-atonic or astatic seizures and atypical absence seizures; ≥90 seizures in the month prior to baseline). Assessments included monitoring of treatment-emergent adverse events (TEAEs), percent change in tonic-atonic seizure frequency/28 days during the double-blind phase relative to study baseline (a primary endpoint), and percentage of patients with ≥25%, ≥50%, or ≥75% reduction in seizure frequency relative to baseline. ResultsOf 138 enrolled patients, 74 received rufinamide (<16 years, n = 49 [66%]) and 64 received placebo (<16 years, n = 43 [67%]). Incidence of TEAEs was generally similar between age groups. The frequency (per 28 days) of tonic-atonic seizures was reduced with rufinamide (vs. placebo) in both younger and older patients: age <16 years (−41% vs. −6%), age ≥16 years (−55% vs. +16%) (p < 0.025; both age groups). In patients aged <16 years receiving rufinamide, 38% and 17% achieved ≥50% and ≥75% reductions in tonic-atonic seizure frequency vs. 18% and 3% with placebo, respectively. Corresponding responder rates for patients aged ≥16 years were 52% and 32% (rufinamide) vs. 15% and 5% (placebo), respectively. ConclusionsIn this post hoc analysis, adjunctive rufinamide was well tolerated and improved seizure control in patients with LGS, irrespective of age.

Genotypes and clinical features of neonatal-onset genetic epilepsy in 141 patients

Objective: To summarize the genotypes and clinical features of neonatal-onset genetic epilepsy. Methods: Patients (114 cases) with identified gene variants were collected from May 2013 to May 2019 in Peking University First Hospital, retrospectively. The genotype, clinical, electroencephalographic and neuroimaging characteristics were analyzed. Results: A total of 141 neonatal-onset epilepsy patients with identified gene variants were enrolled, including 76 males and 65 females and involving 33 epilepsy genes. Top five genes were KCNQ2 (56 cases), SCN2A (25 cases), STXBP1 (9 cases), CDKL5 (8 cases) and KCNT1 (6 cases), accounting for 73.8% (104/141). The age of seizure onset was 3(1-28) days of age, 71.6% (101/141) were within 1 week of age. The age of genetic diagnosis was 4 months (1 month to 13 years) of age. A total of 130 patients presented focal seizures; 47 patients presented epileptic spasms. Other seizure types included generalized tonic-clonic seizures, clonic seizures, myoclonic seizures, tonic seizures and absence seizures. Fifty-eight patients experienced multiple seizure types. The results of video-electroencephlogram (VEEG) were abnormal in 127 patients and in 62 patients clinical seizures were captured. Global developmental delay was presented in 122 patients. Epilepsy syndromes were diagnosed in 59 patients. Thirteen patients were diagnosed as Ohtahara syndrome (OS), 9 as epilepsy of infancy with migrating focal seizures (EIMFS), 17 as West syndrome (WS), 4 as OS developed to WS, 9 as benign neonatal epilepsy (BNE), 2 as benign familiar neonatal-infantile epilepsy (BFNIE), 2 as benign infantile epilepsy (BIE) and 3 as benign familial infantile epilepsy (BFIE). Sixty-seven patients were diagnosed as unclassified early infantile epileptic encephalopathy (EIEE), 13 patients could not be diagnosed as any epilepsy syndrome, and 2 patients were diagnosed as pyridoxine-dependent epilepsy. Forty-six patients had abnormal neuroimaging including cortical atrophy, corpus callosum dysplasia and cerebellar atrophy, involving 19 genes. Conclusions: Neonatal-onset epilepsy is related to many different genes. Seizure onset age of most patients is within one week after birth. Focal seizures and epileptic spasms are more common. Some patients show abnormal neuroimaging.

A splicing variation in NPRL2 causing familial focal epilepsy with variable foci: additional cases and literature review

NPRL2 (nitrogen permease regulator like 2) is a component of the GATOR1(GAP activity towards rags complex 1) proteins, which is an inhibitor of the amino acid-sensing branch of the mTORC1 pathway. GATOR1 complex variations were reported to correlate with familial focal epilepsy with variable foci (FFEVF). However, FFEVF caused by NPRL2 variants has not been widely explored. Here, we describe a variant, 339+2T>C, in NPRL2 identified by trio whole-exome sequencing (WES) in a family. This splicing variant that occurred at the 5′ end of exon 3 was confirmed by minigene assays, which affected alternative splicing and led to exon 3 skipping in NPRL2. Our cases presented multiple seizure types (febrile seizures, infantile spasms, focal seizures, or focal to generalized tonic-clonic seizures). Electroencephalogram (EEG) showed frequent discharges in the left frontal and central regions. A favorable prognosis was achieved in response to vitamin B6 and topiramate when the patient was seven months old. Our study expands the phenotype and genotype spectrum of FFEVF and provides solid diagnostic evidence for FFEVF.

Genotype-phenotype correlation of CACNA1A variants in children with epilepsy.

To explore the genotypes and phenotypes of CACNA1A variants in children with epilepsy. Eighteen children (six males, 12 females) with CACNA1A variants were identified using next-generation sequencing. There were 14 missense variants, two nonsense variants, one frameshift variant, and one splice site variant. Sixteen variants were de novo. Age at seizure onset ranged from 1 day to 8 years; median age was 8 months. Multiple seizure types were observed, including focal, generalized tonic-clonic, myoclonic, and absence seizures, as well as epileptic spasms and tonic seizures. Focal motor status epilepticus occurred in 10 individuals and generalized motor status epilepticus occurred in two individuals. All 18 children showed developmental delay. Focal motor status epilepticus resulted in cerebral atrophy in five individuals, mainly on the contralateral side. Interictal electroencephalogram showed focal discharges in 12 individuals, whereas five individuals had generalized discharges. Three individuals were seizure-free, whereas 15 still had seizures and five had recurrent status epilepticus at last follow-up. Most children with epilepsy and CACNA1A variants had early seizure onset and developmental delay. Focal seizure was the most common seizure type. Most patients experienced status epilepticus. Unilateral cerebral atrophy could occur after focal motor status epilepticus. Patients with CACNA1A variants located in the transmembrane region may be at high risk of status epilepticus.

Pathogenic MAST3 Variants in the STK Domain Are Associated with Epilepsy.

The MAST family of microtubule-associated serine-threonine kinases (STKs) have distinct expression patterns in the developing and mature human and mouse brain. To date, only MAST1 has been conclusively associated with neurological disease, with de novo variants in individuals with a neurodevelopmental disorder, including a mega corpus callosum. Using exome sequencing, we identify MAST3 missense variants in individuals with epilepsy. We also assess the effect of these variants on the ability of MAST3 to phosphorylate the target gene product ARPP-16 in HEK293T cells. We identify de novo missense variants in the STK domain in 11 individuals, including 2 recurrent variants p.G510S (n=5) and p.G515S (n=3). All 11 individuals had developmental and epileptic encephalopathy, with 8 having normal development prior to seizure onset at <2 years of age. All patients developed multiple seizure types, 9 of 11 patients had seizures triggered by fever and 9 of 11 patients had drug-resistant seizures. In vitro analysis of HEK293T cells transfected with MAST3 cDNA carrying a subset of these patient-specific missense variants demonstrated variable but generally lower expression, with concomitant increased phosphorylation of the MAST3 target, ARPP-16, compared to wild-type. These findings suggest the patient-specific variants may confer MAST3 gain-of-function. Moreover, single-nuclei RNA sequencing and immunohistochemistry shows that MAST3 expression is restricted to excitatory neurons in the cortex late in prenatal development and postnatally. In summary, we describe MAST3 as a novel epilepsy-associated gene with a potential gain-of-function pathogenic mechanism that may be primarily restricted to excitatory neurons in the cortex. ANN NEUROL 2021;90:274-284.

Epilepsy Is Heterogeneous in Early-Life Tuberous Sclerosis Complex

BackgroundEpilepsy in tuberous sclerosis complex (TSC) typically presents with early onset, multiple seizure types, and intractability. However, variability is observed among individuals. Here, detailed individual data on seizure characteristics collected prospectively during early life were used to define epilepsy profiles in this population. MethodsChildren aged zero to 36 months were followed longitudinally. Caregivers kept daily seizure diaries, including onset and daily counts for each seizure type. Patients with >70% seizure diary completion and >365 diary days were included. Developmental outcomes at 36 months were compared between subgroups. ResultsEpilepsy was seen in 124 of 156 (79%) participants. Seizure onset occurred from zero to 29.5 months; 93% had onset before age 12 months. Focal seizures and epileptic spasms were most common. Number of seizures (for median 897 days) ranged from 1 to 9128. Hierarchical clustering based on six metrics of seizure burden (age of onset, total seizures, ratio of seizure days to nonseizure days, seizures per seizure day, and worst seven- and 30-day stretches) revealed two distinct groups with broadly favorable and unfavorable epilepsy profiles. Subpopulations within each group showed clinically meaningful differences in seizure burden. Groups with higher seizure burden had worse developmental outcomes at 36 months. ConclusionsAlthough epilepsy is highly prevalent in TSC, not all young children with TSC have the same epilepsy profile. At least two phenotypic subpopulations are discernible based on seizure burden. Early and aggressive treatments for epilepsy in TSC may be best leveraged by targeting specific subgroups based on phenotype severity.

Epilepsy Associated With Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-Like Episodes.

Objectives: The present study explored the clinical characteristics and prognostic factors of epilepsy in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS).Methods: Thirty-four MELAS patients were included in the present study. They were diagnosed by clinical characteristics, genetic testing, muscle biopsy, and retrospective analysis of other clinical data. The patients were divided into three groups according to the effects of treatment after at least 2 years of follow-up.Results: Epilepsy was more common in male MELAS patients than in females (20/14). The age of onset ranged from 0.5 to 57 years, with an average of 22.6 years. Patients with epilepsy and MELAS had various forms of seizures. Focal seizures were the most common type affecting 58.82% of patients, and some patients had multiple types of seizures. The abnormal EEG waves were mainly concentrated in the occipital (69.57%), frontal (65.22%) and temporal lobes (47.83%). Overall, the prognosis of patients with epilepsy and MELAS was poor. Poor prognosis was associated with brain atrophy (P = 0.026), status epilepticus (P < 0.001), and use of anti-seizure medications with high mitochondrial toxicity (P = 0.015).Interpretation: Avoiding the application of anti-seizure medications with high mitochondrial toxicity, controlling seizures more actively and effectively, and delaying the occurrence and progression of brain atrophy as much as possible are particularly important to improve the prognosis of patients with MELAS and epilepsy.

Identification of a novel variant p.Ser606Gly in SCN3A associated with childhood absence epilepsy

Sodium (Na+) channels are the basis for action potential generation and propagation, which play a key role in the regulation of neuronal excitability. SCN3A is a gene encoding for sodium channel protein type 3 subunit alpha (or known as Nav1.3). This study aimed to explore SCN3A genetic variants in a cohort of childhood absence epilepsy (CAE) via whole exome sequencing. A novel SCN3A missense variant (c.A1816G, p.Ser606Gly) was identified in a patient with CAE. This variant had not been reported in both 1000G and ExAC databases. Bioinformatics analysis revealed that this variant was pathogenic and could transform the protein structure of Nav1.3. The reported phenotypes of SCN3A-related central nerve system disorders included multiple seizure types, polymicrogyria and different degrees of developmental delay/intellectual disability. The patient with p.Ser606Gly variant exhibited typical absence seizures. The MRI and CT scan results were normal, and EEG showed that 3-Hz spike-slow wave discharges. In conclusion, our findings not only broaden the pathogenic spectrum of SCN3A, but also extend the clinical phenotypes of SCN3A-related CAE.

Phenotypes of GNAO1 Variants in a Chinese Cohort.

This study aimed to analyze the genotypes and phenotypes of GNAO1 variants in a Chinese cohort. Seven male and four female patients with GNAO1 variants were enrolled, including siblings of brothers. Ten different GNAO1 variants (nine missense and one splicing site) were identified, among which six were novel. All the variants were confirmed to be de novo in peripheral blood DNA. Eight (73%, 8/11) patients had epilepsy; the seizure onset age ranged from 6 h after birth to 4 months (median age, 2.5 months). Focal seizures were observed in all eight patients, epileptic spasms occurred in six (75%, 6/8), tonic spasm in four (50%, 4/8), tonic seizures in two, atypical absence in one, and generalized tonic–clonic seizures in one. Seven patients had multiple seizure types. Eight (73%, 8/11) patients had movement disorders, seven of them having only dystonia, and one having dystonia with choreoathetosis. Varying degrees of developmental delay (DD) were present in all 11 patients. The phenotypes were diagnosed as early infantile epileptic encephalopathy (EIEE) in two (18%) patients, which were further diagnosed as West syndrome. Movement disorders (MD) with developmental delay were diagnosed in two (18%) brothers. EIEE and MD were overlapped in six (55%) patients, among which two were diagnosed with West syndrome, one with Ohtahara syndrome, and the other three with non-specific EIEE. One (9%) patient was diagnosed as DD alone. The onset age of GNAO1-related disorders was early infancy. The phenotypic spectrum of GNAO1 included EIEE, MD with DD, and DD alone.

The molecular and phenotypic spectrum of CLCN4-related epilepsy.

This study was undertaken to expand the phenotypic and genetic spectrum of CLCN4-related epilepsy and to investigate genotype-phenotype correlations. We systematically reviewed the phenotypic and genetic spectrum of newly diagnosed and previously reported patients with CLCN4-related epilepsy. Three novel variants identified in four patients reported in this study were evaluated through in silico prediction and functional analysis by Western blot, immunofluorescence, and electrophysiological measurements. Epilepsy was diagnosed in 54.55% (24/44) of individuals with CLCN4-related disorders and was drug-resistant in most cases. Of 24 patients, 15 had epileptic encephalopathy and four died at an early age; 69.57% of patients had seizure onset within the first year of life. Myoclonic seizures are the most common seizure type, and 56.25% of patients presented multiple seizure types. Notably, seizure outcome was favorable in individuals with only one seizure type. All patients showed intellectual disability, which was severe in 65.22% of patients. Additional common features included language delay, behavioral disorders, and dysmorphic features. Five patients benefitted from treatment with lamotrigine. Most variants, which were mainly missense (79.17%), were inherited (70.83%). Whereas frameshift, intragenic deletion, or inherited variants were associated with milder phenotypes, missense or de novo variants led to more severe phenotypes. All evaluated CLCN4 variants resulted in loss of function with reduced ClC-4 currents. Nonetheless, genotype-phenotype relationships for CLCN4-related epilepsy are not straightforward, as phenotypic variability was observed in recurrent variants and within single families. Pathogenic CLCN4 variants contribute significantly to the genetic etiology of epilepsy. The phenotypic spectrum of CLCN4-related epilepsy includes drug-resistant seizures, cognitive and language impairment, behavioral disorders, and congenital anomalies. Notably, the mutation type and the number of seizure types correlate with the severity of the phenotype, suggesting its use for clinical prognosis. Lamotrigine can be considered a therapeutic option.

Genetic Neonatal-Onset Epilepsies and Developmental/Epileptic Encephalopathies with Movement Disorders: A Systematic Review.

Despite expanding next generation sequencing technologies and increasing clinical interest into complex neurologic phenotypes associating epilepsies and developmental/epileptic encephalopathies (DE/EE) with movement disorders (MD), these monogenic conditions have been less extensively investigated in the neonatal period compared to infancy. We reviewed the medical literature in the study period 2000–2020 to report on monogenic conditions characterized by neonatal onset epilepsy and/or DE/EE and development of an MD, and described their electroclinical, genetic and neuroimaging spectra. In accordance with a PRISMA statement, we created a data collection sheet and a protocol specifying inclusion and exclusion criteria. A total of 28 different genes (from 49 papers) leading to neonatal-onset DE/EE with multiple seizure types, mainly featuring tonic and myoclonic, but also focal motor seizures and a hyperkinetic MD in 89% of conditions, with neonatal onset in 22%, were identified. Neonatal seizure semiology, or MD age of onset, were not always available. The rate of hypokinetic MD was low, and was described from the neonatal period only, with WW domain containing oxidoreductase (WWOX) pathogenic variants. The outcome is characterized by high rates of associated neurodevelopmental disorders and microcephaly. Brain MRI findings are either normal or nonspecific in most conditions, but serial imaging can be necessary in order to detect progressive abnormalities. We found high genetic heterogeneity and low numbers of described patients. Neurological phenotypes are complex, reflecting the involvement of genes necessary for early brain development. Future studies should focus on accurate neonatal epileptic phenotyping, and detailed description of semiology and time-course, of the associated MD, especially for the rarest conditions.

How Can an Na+ Channel Inhibitor Ameliorate Seizures in Lennox-Gastaut Syndrome?

Lennox-Gastaut syndrome (LGS) is an epileptic encephalopathy frequently associated with multiple types of seizures. The classical Na+ channel inhibitors are in general ineffective against the seizures in LGS. Rufinamide is a new Na+ channel inhibitor, but approved for the treatment of LGS. This is not consistent with a choice of antiseizure drugs (ASDs) according to simplistic categorical grouping. The effect of rufinamide on the Na+ channel, cellular discharges, and seizure behaviors was quantitatively characterized in native neurons and mammalian models of epilepsy, and compared with the other Na+ channel inhibitors. With a much faster binding rate to the inactivated Na+ channel than phenytoin, rufinamide is distinctively effective if the seizure discharges chiefly involve short bursts interspersed with hyperpolarized interburst intervals, exemplified by spike and wave discharges (SWDs) on electroencephalograms. Consistently, rufinamide, but not phenytoin, suppresses SWD-associated seizures in pentylenetetrazol or AY-9944 models, which recapitulate the major electrophysiological and behavioral manifestations in typical and atypical absence seizures, including LGS. Na+ channel inhibitors shall have sufficiently fast binding to exert an action during the short bursts and then suppress SWDs, in which cases rufinamide is superior. For the epileptiform discharges where the interburst intervals are not so hyperpolarized, phenytoin could be better because of the higher affinity. Na+ channel inhibitors with different binding kinetics and affinity to the inactivated channels may have different antiseizure scope. A rational choice of ASDs according to in-depth molecular pharmacology and the attributes of ictal discharges is advisable. ANN NEUROL 2021;89:1099-1113.

Seizures in Sotos syndrome: Phenotyping in 49 patients.

We aimed to describe the phenotypic spectrum of seizures in Sotos syndrome, a genetic condition involving overgrowth, macrocephaly, dysmorphic features, and learning disability, in which 60%‐90% have NSD1 pathogenic variants. Patients were recruited from clinics and referral from support groups. Those with seizures and a clinical diagnosis of Sotos syndrome were included. Phenotyping data were collected via structured clinical interview and chart review. Forty‐nine patients were included. Twenty had NSD1 testing results available; of these, 15 (75%) had NSD1 pathogenic variants. Seizure onset age ranged from 3 months to 12 years. Staring spells (absence or focal impaired awareness seizure) were the most frequently reported semiology (33/49; 67%), followed by febrile seizures (25/49; 51%) and afebrile bilateral tonic‐clonic seizures (25/49; 51%). Most patients (33/49; 67%) had multiple seizure types. The majority (33/49; 67%) had seizures controlled on a single antiseizure medication or no medication. Nine (18%) had drug‐resistant epilepsy. Epilepsy syndromes included febrile seizures plus, Lennox‐Gastaut syndrome, childhood absence epilepsy, and generalized tonic‐clonic seizures alone. The seizure phenotype in Sotos syndrome most commonly involves staring spells, afebrile tonic‐clonic seizures or febrile convulsions; however, other seizure types may occur. Seizures are typically well‐controlled with medication, but drug‐resistant epilepsy occurs in a minority.

Non-invasive wearable seizure detection using long–short-term memory networks with transfer learning

Objective. The detection of seizures using wearable devices would improve epilepsy management, but reliable detection of seizures in an ambulatory environment remains challenging, and current studies lack concurrent validation of seizures using electroencephalography (EEG) data. Approach. An adaptively trained long–short-term memory deep neural network was developed and trained using a modest number of seizure data sets from wrist-worn devices. Transfer learning was used to adapt a classifier that was initially trained on intracranial electroencephalography (iEEG) signals to facilitate classification of non-EEG physiological datasets comprising accelerometry, blood volume pulse, skin electrodermal activity, heart rate, and temperature signals. The algorithm’s performance was assessed with and without pre-training on iEEG signals and transfer learning. To assess the performance of the seizure detection classifier using long-term ambulatory data, wearable devices were used for multiple months with an implanted neurostimulator capable of recording iEEG signals, which provided independent electrographic seizure detections that were reviewed by a board-certified epileptologist. Main results. For 19 motor seizures from 10 in-hospital patients, the algorithm yielded a mean area under curve (AUC), a sensitivity, and an false alarm rate per day (FAR/day) of 0.98, 0.93, and 2.3, respectively. Additionally, for eight seizures with probable motor semiology from two ambulatory patients, the classifier achieved a mean AUC of 0.97 and an FAR of 2.45 events/day at a sensitivity of 0.9. For all seizure types in the ambulatory setting, the classifier had a mean AUC of 0.82 with a sensitivity of 0.47 and an FAR of 7.2 events/day. Significance. The performance of the algorithm was evaluated using motor and non-motor seizures during in-hospital and ambulatory use. The classifier was able to detect multiple types of motor and non-motor seizures, but performed significantly better on motor seizures.

Anti-seizure medications for Lennox-Gastaut syndrome.

Anti-seizure medications for Lennox-Gastaut syndrome.