A Patient with Tuberous Sclerosis with Hemimegalencephaly Presenting with Intractable Epilepsy in the Early Neonatal Period: A Case Report

Abstract

Hemimegalencephaly (HME) is a rare disease characterized by partial or complete hypertrophy of one cerebral hemisphere. It is associated with intractable seizures, developmental delay, hemiparesis, and other neurological symptoms. Tuberous sclerosis (TSC) is a neurocutaneous syndrome that affects various organs, including the heart, brain, skin, kidney, and eyes, and is caused by mutations in TSC1 and TSC2 genes. Herein, we report the case of a patient with TSC and HME who required early neurosurgical treatment during the neonatal period. A full-term girl was suspected to have TSC prenatally because of left ventriculomegaly and cardiac masses on fetal ultrasonography. HME was confirmed by postnatal neuroimaging studies. Multiple rhabdomyomas and renal cysts were compatible with TSC. Serially performed electroencephalography (EEG) showed intractable electrical seizures in the left hemisphere with secondary generalization, despite rare clinical convulsions. As anti-epileptic drugs did not improve electrical seizures, corpus callosotomy was performed at 39 days of age. Postoperatively, the frequency of secondary generalization of seizures was significantly reduced on EEG. A novel frameshift mutation in c. 1743_1744insCAAGG (p. Thr582GlnfsTer49) in the TSC1 gene was confirmed using targeted next-generation sequencing.