Critical review, published in Epilepsia Open
Epilepsy can occur in individuals with Down syndrome (DS), with epileptic spasms representing the most frequent seizure type in this population. Epileptic spasms are brief seizures characterized by bending of the trunk and bending/extension of the limbs. These types of seizures can have devastating consequences on the development of individuals with the condition. This review sought to explore the lifetime prevalence and underlying mechanism of epileptic spasms in this population. We also aimed to review the response rate to various treatments, the relapse rate, and the development of subsequent epilepsy or autism in this population.
A comprehensive literature search was conducted for articles discussing the lifetime prevalence, diagnosis, treatment, outcomes, or underlying cause of epileptic spasms in animal models or individuals with DS. According to available literature, the global clinic-based lifetime prevalence of epilepsy in individuals with DS ranged from 1.6% to 23.1%, with epileptic spasms representing 6.7% to 66.7% of these cases.
Response rate to treatment with a specific steroid hormone was highest (81%) and has the most literature supporting its use, with other treatments, including vigabatrin (Sabril®) and other antiepileptic drugs, having lower response rates. Epileptic spasms occur more frequently in children with DS than in the general population, though more studies are needed to determine the true lifetime prevalence of epileptic spasms in this population. Generally, children with DS and epileptic spasms tend to be more responsive to treatment and have better outcomes than children with epileptic spasms of unknown cause, in terms of response and relapse rates, as well as the development of intractable epilepsy.