Electrical Status Epilepticus during Sleep in a Male Filipino with Rare Nonsense Mutation Variant of Sotos Syndrome on Carbamazepine Monotherapy

Electrical status epilepticus during sleep (ESES) is an electrographic pattern associated with specific genetic disorders, brain malformations, and use of some antiseizure medications. This case report aims to present the management of ESES in Sotos syndrome (SoS) on carbamazepine. A nine-year-old Filipino male with clinical features suggestive of overgrowth syndrome presented with febrile seizure at one year old. Cranial imaging showed cavum septum pellucidum, corpus callosal dysgenesis, and ventriculomegaly. He was on carbamazepine monotherapy starting at three years old. A near continuous diffuse spike-wave discharges in slow wave sleep was recorded at nine years old hence shifted to valproic acid. Follow-up study showed focal epileptiform discharges during sleep with disappearance of ESES. Next generation sequencing tested positive for rare nonsense mutation of nuclear receptor binding set-domain protein 1 confirming the diagnosis of SoS. Advanced molecular genetics contributed to determination of ESES etiologies. To date, this is the first documented case of SoS developing ESES. Whether an inherent genetic predisposition or drug-induced, we recommend the avoidance of carbamazepine and use of valproic acid as first-line therapy.