Dravet syndrome: Insights into seizure and speech progression from registry data

Abstract

Objective: Dravet syndrome (DS) is a rare genetic developmental and epileptic encephalopathy syndrome characterized by refractory seizures and neurodevelopmental disorders beginning in infancy. This study aims to understand the natural history of DS by utilizing longitudinal data from patient registries. Methods: We analysed data from 475 subjects across two European patient registries (RESIDRAS and Platform-RESIDRAS) from Dravet Italia Onlus, collected between 2010 and 2024. The study included only participants that were under 18 years old. Clinical characteristics such as seizure types and speech development were modelled using generalized linear mixed models and ordinal transition models. Results: Unilateral seizures predominantly occurred during infancy and early childhood, while generalized convulsive and focal to bilateral tonic-clonic seizures increased with age, showing a higher incidence in boys. Focal seizures peaked around the age of three years before declining. Speech development varied, with most participants initially having poor speech. However, a considerable number of transitions between different levels of speech impairment were observed over time. Transition models indicated that once speech is acquired, the likelihood of losing this ability is negligible. Significance: Patient registries are instrumental in modelling the disease history of DS, offering insight into its progression by means of advanced statistical modelling techniques that build on clinical expertise. Future research should focus on evaluating the effects of therapies and exploring the interrelations between different clinical characteristics. Understanding these aspects can guide better management strategies and improve patient outcomes.