Behavioural and neuroplastic effects of a double-blind randomised controlled balance exercise trial in people with Parkinson's disease

Abstract

Balance dysfunction is a disabling symptom in people with Parkinson's disease (PD). Evidence suggests that exercise can improve balance performance and induce neuroplastic effects. We hypothesised that a 10-week balance intervention (HiBalance) would improve balance, other motor and cognitive symptoms, and alter task-evoked brain activity in people with PD. We performed a double-blind randomised controlled trial (RCT) where 95 participants with PD were randomised to either HiBalance (n = 48) or a control group (n = 47). We found no significant group by time effect on balance performance (b = 0.4 95% CI [-1, 1.9], p = 0.57) or on our secondary outcomes, including the measures of task-evoked brain activity. The findings of this well-powered, double-blind RCT contrast previous studies of the HiBalance programme but are congruent with other double-blind RCTs of physical exercise in PD. The divergent results raise important questions on how to optimise physical exercise interventions for people with PD.Preregistration clinicaltrials.gov: NCT03213873.

Fig. 1. Trial flowchart.

Details of the recruitment and study flow.

Fig. 2. Effects of the HiBalance programme.

The mean values, the standard error of the mean (error bars) as well as the b values, e.g., the unstandardised estimates of the time by group interaction, and their 95% CIs, are predicted values based on the intention to treat analyses. The participants’ point estimates, and their distributions are observed values. a Mini-BESTest (range 0–28), b Gait speed (m/s), c executive function (composite score of four tests from the Delis–Kaplan Executive Function System and the Wechsler Adult Intelligence Scale, z-scores).

Fig. 3. The difference score correlations of the Mini-BESTest and striatal activity.

rho = Spearman’s rank-order correlation coefficient. adj. p = false discovery rate adjusted p (alpha = 0.05). a The difference score correlations in the HiBalance group. b The difference score correlations in the active control group.