P08 Epidemiology of epilepsy in early childhood and predictors of outcome: a national population-based prospective cohort study

Abstract

Objectives To calculate the incidence of early childhood–onset epilepsy To report the yield from aetiological investigations in these patients To investigate for predictors of Drug Resistant Epilepsy (DRE) and Global Developmental Delay (GDD) at 24 months after presentation Methods This was a prospective national cohort study involving all paediatric centres in Scotland. Patients presenting with epilepsy before their 3rd birthday were identified over a 3 year period (May 8th 2014 to May 7th 2017). Two independent sources were used: 1. A prospective nationwide case identification study; 2. Retrospective case note review of all children attending for EEG investigation. Capture-recapture analysis was used to estimate missing cases. Clinical follow-up data were obtained 24 months after first presentation with seizures, including presence of DRE and/or GDD. Logistic regression was used to identify predictors of DRE and GDD. Patients all had brain MRI and received genetic testing (104 gene epilepsy panel and chromosomal microarray). Those negative on gene panel and microarray underwent Whole Genome Sequencing. Results Population statistics for Scotland were: Total 390 patients with epilepsy were identified. Using capture-recapture the estimated total was 406. The incidence of epilepsy 211 (54%) patients had an aetiology identified, of which 72 were primarily structural and 133 were primarily genetic. Of the genetic diagnoses 7 were trisomies, 24 were chromosomal microdeletions/duplications, and 102 were single gene variants. At 24 month follow-up 139 patients (36%) had DRE, and 193 (49%) had GDD. Early age of presentation ( Conclusion One in 400 children develops epilepsy before their third birthday. The previous estimate in this age group from Rochester Minnesota was 1 per 614. One third of these children develops DRE and half have GDD. Aetiology can be identified in 54%. Identification of aetiology is associated with DRE and GDD.