Home Training for Cerebellar Ataxias: A Randomized Clinical Trial.

Importance: Clinical practice guidelines advise balance training for cerebellar ataxia, but little is known regarding high-intensity aerobic exercise. Objective: To compare home high-intensity aerobic training to home balance training on improvements of ataxia symptoms using the Scale for the Assessment and Rating of Ataxia (SARA). Design, Setting, and Participants: This assessor-masked randomized clinical trial was conducted between January 1, 2021, and September 1, 2024, through home training, with in-person assessments at a single ataxia care center in a large urban US city. Individuals with various cerebellar ataxia types were eligible for inclusion. Data analysis was performed from November 2024 to February 2025. Interventions: Individuals in the aerobic group trained for 30 minutes/session, 5 times/week, at up to 85% predicted maximum heart rate. Individuals in the balance group performed 30 minutes of balance exercises of varying difficulty 5 times/week. Participants were given study support of biweekly phone calls for only the first 6 months of this 12-month study. Main Outcomes and Measures: The primary outcome was SARA score to measure ataxia symptoms (range, 0-40 points, with higher scores indicating more ataxia). Secondary outcomes included number of adverse events, training adherence, balance measures, gait speed, quality of life, fatigue, and fitness levels (assessed via V̇o2max). Assessments were conducted at baseline and at 6, 9, and 12 months. Results: A total of 114 individuals with various cerebellar ataxia types were approached: 52 individuals declined participation or did not meet inclusion criteria, while 62 individuals were enrolled. The 62 participants included 29 women (46.8%), with a mean (SD) age of 54.4 (12.9) years and mean (SD) SARA score of 12.1 (4.1) points. Linear mixed-effects model analysis revealed that the home aerobic group had significantly larger improvement in outcomes than the balance group, particularly for SARA score (β, -1.53; 95% CI, -2.44 to -0.61; P = .001), fatigue (β, -9.38; 95% CI, -15.1 to -3.7; P = .001), and Vo2max (β, 4.26; 95% CI, 2.1-6.4; P < .001). At 6 months, the aerobic and balance groups had changes in SARA scores of -2.4 points (95% CI, -3.1 to -1.80) and -0.9 points (95% CI, -1.5 to -0.2), respectively. For the aerobic group, individuals who continued training maintained benefits in SARA score (change from baseline, -3.81 points; 95% CI, -2.2 to -5.4), whereas those who limited or stopped training had benefits trend back to baseline levels (change from baseline, 0.4 points; 95% CI, -0.4 to 1.2) at 1 year. Conclusions and Relevance: In this randomized clinical trial, home high-intensity aerobic training improved ataxia symptoms, fatigue, and aerobic fitness more than dose-matched home balance training among individuals with cerebellar ataxias. Individuals in the aerobic group who continued to train regularly maintained benefits at 1 year. Trial Registration: ClinicalTrials.gov Identifier: NCT05002218.