Task-specific training in Huntington disease: a randomized controlled feasibility trial

Background Task-specific training may be a suitable intervention to address mobility limitations in people with Huntington's disease (HD). Objective We aimed to assess feasibility and safety of goal-directed, task-specific mobility training for individuals with mid-stage HD. Design This study was a randomized, blinded, feasibility trial; participants were randomized into control (usual care) or intervention groups. Setting This multi-site study was conducted in 6 U.K. sites. Patients Thirty individuals with mid-stage HD (13 male; mean (SD) age: 57.0 (10.1) years) were enrolled and randomized. Intervention Task-specific training was conducted by physical therapists in participant's homes, focusing on walking, sit-to-stand and standing, twice a week for eight weeks. Goal attainment scaling was used to individualize the intervention and monitor achievement of personal goals. Measurements Adherence and adverse events were recorded. Adjusted between-group comparisons on standardized outcome measures were conducted at 8 and 16 weeks to determine effect sizes. Results Loss to follow up was minimal (2); adherence in the intervention group was excellent (96.9%). Ninety-two percent (92%) of goals were achieved at the end of the intervention; 46% achieved much better than expected outcome. Effect sizes on all measures were small. Limitations Measurements of walking endurance were lacking. Conclusions The safety and excellent adherence to a home-based, task-specific training program, in which most participants exceeded goal expectation is encouraging given the range of motivational, behavioral and mobility issues in people with HD. The design of the intervention, in terms of frequency (dose), intensity (aerobic versus anaerobic) and specificity (focused training on individual tasks) may not have been sufficient to elicit any systematic effects, and thus a larger scale trial of this specific intervention does not seem warranted