Comorbidities and predictors of health-related quality of life in Dravet syndrome: A 10-year, prospective follow-up study

Abstract

Objective: Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy, leading to reduced health-related quality of life (HRQOL). Prospective outcome data on HRQOL are sparse, and this study investigated long-term predictors of HRQOL in DS.

Methods: One hundred thirteen families of SCN1A-positive patients with DS, who were recruited as part of our 2010 study were contacted at 10-year follow-up, of which 68 (60%) responded. The mortality was 5.8%. Detailed clinical and demographic information was available for each patient. HRQOL was evaluated with two epilepsy-specific instruments, the Impact of Pediatric Epilepsy Scale (IPES) and the Epilepsy & Learning Disabilities Quality of Life Questionnaire (ELDQOL); a generic HRQOL instrument, the Pediatric Quality of Life Inventory (PedsQL); and a behavioral screening tool, the Strength and Difficulties Questionnaire (SDQ).

Results: Twenty-eight patients were 10-15 years of age (0-5 years at baseline) and 40 were ≥16 years of age (≥6 years at baseline). Patients 0- to 5-years-old at baseline showed a significant decline in mean scores on the PedsQL total score (p = .004), physical score (p < .001), cognitive score (p = .011), social score (p = .003), and eating score (p = .030) at follow-up. On multivariate regression, lower baseline and follow-up HRQOL for the whole cohort were associated with worse epilepsy severity and a high SDQ total score (R² = 33% and 18%, respectively). In the younger patient group, younger age at first seizure and increased severity of epilepsy were associated with a lower baseline HRQOL (R² = 35%). In the older age group, worse epilepsy severity (F = 6.40, p = .016, R² = 14%) and the use of sodium-channel blockers were independently associated with a lower HRQOL at 10-year follow-up (F = 4.13, p = .05, R² = 8%).

Significance: This 10-year, prospective follow-up study highlights the significant HRQOL-associated cognitive, social, and physical decline particularly affecting younger patients with DS. Sodium channel blocker use appears to negatively impact long-term HRQOL, highlighting the importance of early diagnosis and disease-specific management in DS.

Keywords: SCN1A; Dravet syndrome; HRQOL; SMEI; comorbidity; severe myoclonic epilepsy of infancy.