A randomized feasibility study of a 12-week community-based exercise program for people with Huntington's disease.

BACKGROUND AND PURPOSE: The beneficial role of exercise as a treatment approach in Huntington's disease (HD) has support from both preclinical work and small-scale studies; however, there have been no controlled studies of gym-based exercise in people with HD. This phase 2 randomized trial (ISRCTN 59910670) assessed feasibility, safety, acceptability, and benefit of a structured exercise program. METHODS: Thirty-one participants (16 men; mean [SD] age = 50.4 [11.4] years) were randomly allocated to intervention (n = 16) or control group (usual care; n = 15). The intervention entailed a weekly supervised gym session of stationary cycling and resistance exercises, and a twice weekly independent home-based walking program. Retention and adherence rates and adverse events were recorded. Acceptability was determined from subjective reports of tolerability and physiological measures recorded during the gym sessions. Assessment of benefit included measures of physical abilities, disease severity, and quality of life (36-Item Short Form Health Survey). Analysis of covariance was used to test outcomes of interest. RESULTS: The retention rate was 81% (9 of the 11 individuals who started the intervention completed it) and of the 9 who completed the program, 7 attended more than 75% (9/12) of the gym sessions. There were no related adverse events and the intervention was well tolerated by most participants. The between-group effect estimate for the Mental Component Summary score of the 36-Item Short Form Health Survey (n = 9; intervention, n = 13; control) was 7 (95% CI: 0.4-13.7) Moderate effect sizes for cognitive outcomes and measures of walking were also observed. DISCUSSION AND CONCLUSIONS: Observed effect sizes for clinical outcomes suggest the structured exercise program has benefit for persons with HD; larger scale trials are warranted.Video Abstract available (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A60) for more insights from the authors.

Insights into gait disorders: walking variability using phase plot analysis, Huntington's disease.

Huntington's disease (HD) is a progressive inherited neurodegenerative disorder. Identifying sensitive methodologies to quantitatively measure early motor changes have been difficult to develop. This exploratory observational study investigated gait variability and symmetry in HD using phase plot analysis. We measured the walking of 22 controls and 35 HD gene carriers (7 premanifest (PreHD)), 16 early/mid (HD1) and 12 late stage (HD2) in Oxford and Cardiff, UK. The unified Huntington's disease rating scale-total motor scores (UHDRS-TMS) and disease burden scores (DBS) were used to quantify disease severity. Data was collected during a clinical walk test (8.8 or 10 m) using an inertial measurement unit attached to the trunk. The 6 middle strides were used to calculate gait variability determined by spatiotemporal parameters (co-efficient of variation (CoV)) and phase plot analysis. Phase plots considered the variability in consecutive wave forms from vertical movement and were quantified by SDA (spatiotemporal variability), SDB (temporal variability), ratio ∀ (ratio SDA:SDB) and Δangleß (symmetry). Step time CoV was greater in manifest HD (p<0.01, both manifest groups) than controls, as was stride length CoV for HD2 (p<0.01). No differences were found in spatiotemporal variability between PreHD and controls (p>0.05). Phase plot analysis identified differences between manifest HD and controls for SDB, Ratio ∀ and Δangle (all p<0.01, both manifest groups). Furthermore Ratio ∀ was smaller in PreHD compared with controls (p<0.01). Ratio ∀ also produced the strongest correlation with UHDRS-TMS (r=-0.61, p<0.01) and was correlated with DBS (r=-0.42, p=0.02). Phase plot analysis may be a sensitive method of detecting gait changes in HD and can be performed quickly during clinical walking tests.

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 disease (HD). OBJECTIVE: The aim of this study was to assess the 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 randomly assigned to control (usual care) and intervention groups. SETTING: This multisite study was conducted in 6 sites in the United Kingdom. PATIENTS: Thirty individuals with mid-stage HD (13 men, 17 women; mean age=57.0 years, SD=10.1) were enrolled and randomly assigned to study groups. INTERVENTION: Task-specific training was conducted by physical therapists in participants' homes, focusing on walking, sit-to-stand transfers, and standing, twice a week for 8 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 (n=2); adherence in the intervention group was excellent (96.9%). Ninety-two percent of goals were achieved at the end of the intervention; 46% of the participants achieved much better than expected outcomes. Effect sizes on all measures were small. LIMITATIONS: Measurements of walking endurance were lacking. CONCLUSIONS: The safety of and excellent adherence to a home-based, task-specific training program, in which most participants exceeded goal expectations, are 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. Thus, a larger-scale trial of this specific intervention does not seem warranted.