Voltage-gated sodium channel epilepsies in a tertiary care center: Phenotypic spectrum with correlation to predicted functional effects.

BACKGROUND: Variants in sodium channel genes (SCN) are strongly associated with epilepsy phenotypes. Our aim in this study to evaluate the genotype and phenotype correlation of patients with SCN variants in our tertiary care center. METHODS: In this retrospective study, patients with SCN variants and epilepsy who were followed up at our clinic between 2018 and 2022 were evaluated. Our study discussed the demographics of the patients, the seizure types, the age of seizure onset, the SCN variants, the domains and the functions of the variants, the magnetic resonance imaging findings, the motor, cognitive, and psychiatric comorbidities, and the response to anti-seizure medication. Genetic testing was conducted using a next-generation sequencing gene panel (epilepsy panel) or a whole-exome sequencing. For evaluating variant function, we used a prediction tool (https://funnc.shinyapps.io/shinyappweb/ site). To assess protein domains, we used the PER viewer (http://per.broadinstitute.org/). RESULTS: Twenty-three patients with SCN variants and epilepsy have been identified. Sixteen patients had variants in the SCN1A, six patients had variants in the SCN2A, and one patient had a variant in the SCN3A. Two novel SCN1A variants and two novel SCN2A variants were identified. The analysis revealed 14/23 missense, 6/23 nonsense, 2/23 frameshift, and 1/23 splice site variants in the SCN. There are seven variants predicted to be gain-of-function and 13 predicted to be loss-of-function. Among 23 patients; 11 had Dravet Syndrome, 6 had early infantile developmental and epileptic encephalopathy, three had genetic epilepsy with febrile seizures plus spectrum disorder, one had self-limited familial neonatal-infantile epilepsy, one had self-limited infantile epilepsy and one had infantile childhood development epileptic encephalopathy. CONCLUSION: Our cohort consists of mainly SCN1 variants, most of them were predicted to be loss of function. Dravet syndrome was the most common phenotype. The prediction tool used in our study demonstrated overall compatibility with clinical findings. Due to the diverse clinical manifestations of variant functions, it may assist in guiding medication selection and predicting outcomes. We believe that such a tool will help the clinician in both prognosis prediction and solving therapeutic challenges in this group where refractory seizures are common.

Evaluation of the prognostic factors in school age children who experienced neonatal seizures.

BACKGROUND: This prospective study aimed to evaluate long-term neurodevelopmental outcomes and risk factors of the previously reported cohort, at their school age. METHOD: We included neonates whose seizures were directly observed by the child neurologist or neonatologist based on clinical observations. They were assessed for cognitive and neurological outcomes at the age of 9-11 years. The test battery included a neurological examination, the Wechsler Intelligence Scale for Children-Revised (WISC-R) test, and patients with the diagnosis of cerebral palsy (CP) were graded according to the Gross Motor Function Classification System (GMFCS). The primary outcome of this study was to determine risk factors for the long-term prognosis of neonatal seizures. RESULTS: For the long-term follow-up, 97 out of 112 patients of the initial cohort were available (86.6%). We found that 40 patients (41%) have the normal prognosis, 22 patients (22.7%) have the diagnosis of CP, and 30 patients (30.9%) were diagnosed as having epilepsy. Twelve out of 22 patients with CP had the diagnosis of epilepsy. The WISC-R full-scale IQ scores were <55 points in 27 patients (27.8%) and were >85 points in 40 patients (41.2%). According to GMFCS, 10 patients were classified as levels 1-2, and 12 patients were classified as levels 3-5. In multivariate regression analyses, 5-min APGAR score <6 was found to be an independent risk factor for CP, and 5-min APGAR score <6 and neonatal status epilepticus were independent risk factors for epilepsy. CONCLUSIONS: This prospective cohort study reveals that abnormal school age outcome after neonatal seizures are significantly related to 5-min APGAR score <6 and neonatal status epilepticus.

Epileptic spasm and other forms of epilepsy in presumed perinatal arterial ischemic stroke in Turkey after more than 10 years follow-up: A single centre study.

PURPOSE: To identify the frequency of epilepsy and whether the association of epilepsy with clinical and neuroimaging findings in children with presumed perinatal arterial ischemic stroke (PPAIS). METHODS: We performed a retrospective analysis of 37 children with PPAIS followed-up at a tertiary referral center between January 1, 2000, and October 31, 2016. Clinical data including demographic features, age at onset of symptoms and seizures, initial clinical presentation, epilepsy features, used antiepileptic drugs, and thrombophilia screening results were abstracted from medical records. Brain magnetic resonance imaging scans were assessed for infarct laterality, location and affected brain regions. RESULTS: The median age of the patients was 12 years (range 2-17.9 years) at last assessment. The initial symptom of PPAIS was early hand preference in 33 children (89%) and seizure in 4 children (11%). A total of 20 children (54%) developed epilepsy at a median age of 0.9 years. There were two peaks of epilepsy onset in infancy and adolescence. Fifteen children (41%) had focal epilepsy and 5 children (14%) had epileptic spasms. Twelve out of 20 children (60%) with epilepsy had drug resistant epilepsy. Cortical involvement was a statistically significant predictor of epilepsy (p = 0.021, relative risk 4.4, 95% confidence interval 0.7-27.7). CONCLUSION: More than half of the children with PPAIS suffered from epilepsy during childhood, of whom developed drug resistant epilepsy in majority. Children with cortical lesion may have a higher risk to develop epilepsy.

Aggravation of atonic seizures by rufinamide: A case report.

BACKGROUND: Rufinamide is a novel antiepileptic drug used as adjunctive therapy in patients with Lennox-Gastaut syndrome and provides seizure control especially in tonic and atonic seizures. Rufinamide is expected to be effective in intractable epilepsy when atonic and tonic seizures exist. However, rufinamide induced seizure aggravation has been reported in a few patients, which was not associated with a specific type of seizure. CASE: A 12-year-old boy with intractable epilepsy had tonic and atonic seizures despite treatment with valproic acid (3000mg/day), levetiracetam (3000mg/day) and clobazam (40mg/day). Rufinamide was administered as adjuvant therapy. After 2weeks on rufinamide, he experienced atonic seizure worsening, and the frequency of epileptic discharges increased. The deterioration in seizure frequency and epileptiform discharges resolved when rufinamide was discontinued. CONCLUSION: Rufinamide may aggravate atonic seizures in patients with intractable epilepsy.