Long-term outcome in children with infantile epileptic spasms syndrome: a multicenter retrospective study in Korea

BACKGROUND: Infantile epileptic spasms syndrome (IESS) is a severe form of infantile epilepsy with a high lifetime morbidity burden. PURPOSE: We aimed to assess the long-term epilepsy and neurodevelopmental outcomes based on how children with IESS have been managed over the past few decades. METHODS: This retrospective multicenter study included children diagnosed with IESS between 1994 and 2021 with a minimum follow-up period of 2 years. Data on demographics, clinical features, medical history, diagnostic evaluations, and treatments used to control spasms were collected. Epilepsy and neurodevelopmental outcomes were assessed at final follow-up. RESULTS: A total of 378 infants with IESS were included. The mean age at onset of spasms was 7.3 (range, 1-24) months and mean follow-up duration was 7.9 (range, 2-28) years. Etiologies were identified in 65.1% of cases, with acquired structural etiologies being the most prevalent (29.9%). Among the genetic and genetic-structural etiologies, tuberous sclerosis complex (n=35), Down syndrome (n=8), Miller-Dieker syndrome (n=3), and 15q duplication syndrome (n=3) were the most common. Vigabatrin was prescribed to 93.9% of the patients, suggesting that it was the mainstay of treatment. At the last follow-up, 77.8% of the children remained on antiseizure medications and 29.1% had drug-resistant epilepsy. Approximately 90% had intellectual disabilities, and half of the eligible individuals had received special education. CONCLUSION: The IESS imposes a substantial burden on affected children and their families and often leads to chronic epilepsy and impaired cognitive function. Consensus diagnostic and treatment guidelines tailored to the Korean clinical practice are necessary to ensure early diagnosis and timely treatment.