Evaluation of functional goal outcomes using the Canadian Occupational Performance Measure (COPM) following Deep Brain Stimulation (DBS) in childhood dystonia.

PURPOSE: To evaluate the functional goal-directed outcomes of Deep Brain Stimulation (DBS) in childhood dystonia according to aetiology and to explore relationship with a traditional impairment-based measure.
METHOD: This is a prospective case series study involving thirty children with dystonia with a 1-year follow-up post-DBS. The Canadian Occupational Performance Measure (COPM) and Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) were used as primary outcome measures. Results were analysed based on aetiology in 3 groups: 1. primary/primary plus dystonia; 2. secondary dystonia-cerebral palsy (CP); 3. secondary dystonia-non-CP group. Correlation between functional outcome using COPM and dystonia improvement as captured by BFMDRS was measured.
RESULTS: All groups demonstrated significant improvement in individualised goal attainment, measured with the COPM, at 1-year post-DBS. The secondary dystonia-CP group also achieved significant improvement at 6 months for performance and satisfaction scores. In the majority of secondary dystonias, the BFMDRS failed to demonstrate significant improvement. A linear correlation between change in BFMDRS and COPM scores was observed when the entire cohort was analysed. INTERPRETATION/
CONCLUSIONS: DBS improved functional performance, independently of the dystonic phenotype. Improvements in individualized COPM functional goal areas were seen in the absence of significant changes in BFMDRS scores, highlighting the relative insensitivity of impairment scales in this patient group.