Abstracts

Rationale: Dravet syndrome is a severe developmental and epileptic encephalopathy with reduced health related quality of life (HRQOL) caused by a mutation of the SCN1A gene. This 10-year follow-up study investigated the long-term outcomes in Dravet Syndrome and aimed to identify seizure outcomes, survival data, and specifically developmental outcome and cognition. Methods: This is a follow up of a 2009 study involving the same participants. We contacted the 141 referring clinicians for survival data on their SCN1A positive Dravet syndrome patients, 140 of which (99%) responded. Ten patients were lost to follow up and the remaining 130 previous participants were contactable and sent the four questionnaires used in the original study: Epilepsy & Learning Disabilities Quality of Life Questionnaire (ELDQOL), Impact of Pedatric Epilepsy Scale (IPES), the Pediatric Quality of Life Inventory (PedsQL), and a Strength and Difficulties Questionnaire (SDQ) to screen their behaviour. A detailed demographic questionnaire, the Adaptive Behavioural Assessment System - Third Edition (ABAS-3) and the Sleep Disturbances Scale for Children were also sent to families. Genetic information was available for each case. Results: Seven patients out of 130 (5%) with SCN1A positive Dravet syndrome died within the 10-year period. Out of 130 questionnaires sent, 70 individuals (54%) responded and were included in the study. There was no change in overall seizure severity after 10 years. 40% of those that responded indicated that they had not had a discussion with a medical professional about sudden unexpected death in epilepsy (SUDEP). A number of significant comorbidities were reported: 60% having a diagnosis of autism, 75% reporting behavioural problems, and 74% suffering from mobility problems. Carer’s health/wellbeing was negatively affected in 96% of cases, and 90% of at least one of the two carers lost their jobs due to their child’s illness. Particularly younger patient’s aged 10-15 had significantly decreased scores in PedsQL physical (p=0.002) and social (p=0.042) functioning compared to their initial assessment. The developmental quotient at follow up was significantly lower compared with the previous study (p<0.001), and over 80% of affected individuals had a severe or profound learning disability. This observation was independent of the patient’s genotype (missense vs. truncating mutation). Conclusions: This study highlights the ongoing cognitive difficulties and the significant negative effect these patient’s illness can have on their primary caretakers, and illustrates how appropriate support is essential. Despite children with Dravet syndrome having the highest SUDEP risk of any epilepsy, this study reveals that explanatory discussions do not occur in many cases and as such should become a priority in future practice. With new treatment opportunities on the horizon, early interventions appear crucial for these patients to avert the observed severe cognitive disability. Funding: No funding