Functional mobility in children and young adults with Dravet syndrome.

Abstract

This cohort study aimed to describe functional mobility in Dravet syndrome, a developmental and epileptic encephalopathy. Functional mobility was assessed in individuals (aged 3-25 years), diagnosed with Dravet syndrome, using the Functional Mobility Scale (FMS), Mobility Questionnaire 28 (MobQues28), and estimated walking distance. Secondary outcome variables were Gait Profile Score (GPS), walking velocity, age at independent walking, intellectual disability, seizure frequency, genetic variant type, and body mass index (BMI). Forty participants aged 3 years to 24 years 2 months (mean=12 years 2 months) had a median MobQues28 of 79%, median scores of 5, 5, and 4 for the FMS 5 m, 50 m, and 500 m and a median estimated walking distance of 1 km to 3 km. Most difficulties were seen in walking up and down the stairs, walking over obstacles, kicking a ball, and running. MobQues28 scores showed a significant decrease (-6.6%, p=0.016) in the age category of young adults (≥18 years). After correcting for age, MobQues28 was correlated to age at independent walking (-0.485, p=0.002), GPS (-0.460, p=0.003), and walking velocity (0.334, p=0.038). Analysis of variance showed a significant effect of intellectual disability and BMI on MobQues28 (p=0.029, p=0.049). No effect of seizure frequency or genetic variant was found (p=0.579, p=0.337). Functional mobility limitations were observed mainly in dual tasks and activities requiring stability, with limitations increasing from the age of 18 years. Age at independent walking, gait impairments, intellectual disability, and BMI can impact functional mobility in Dravet syndrome. Most limitations were seen in dual task activities and activities that required more stability. Deterioration in functional mobility occurred in young adults. The more gait impairments, the more functional mobility limitations. Age at independent walking, intellectual disability, and body mass index can impact functional mobility.