Virtual reality balance training to improve balance and mobility in Parkinson’s disease: a systematic review and meta-analysis

Background: In the last few years, virtual reality (VR) has been increasingly used to strengthen the effect of balance training (BT) in Parkinson’s disease (PD). Objective: We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to compare the effects of VR-BT relative to BT alone for improving balance and mobility PD subjects with balance/mobility difficulties. Methods: Four electronic databases were searched: two reviewers independently selected RCTs, extracted data, and applied the Cochrane risk-of-bias tool for randomized trials (version 2) and the GRADE framework for assessing the certainty of evidence. Primary outcomes were balanced (Berg Balance Scale-BBS), mobility (Timed Up and Go-TUG) and walking speed. Secondary outcomes were falls, walking distance and stability, spatial gait parameters, balance confidence, sensory integration ability, motor signs and quality of life. Results: We included 22 studies (901 patients). Meta-analysis on fourteen trials (430 patients) showed a mean difference (MD) of 2.09 points (95% confidence interval [CI] 0.86–3.33) on BBS favoring VR-BT compared to BT (low certainty evidence). Subgroup analyses showed higher balance improvement in most affected subjects (moderate certainty evidence) and using VR rehabilitation-specific systems vs. VR non-specific systems. Eight trials (236 patients) assessing mobility showed a MD of 1.55 s (95% CI 0.04–3.06) on TUG favoring VR-BT (very low certainty evidence). No differences were observed in walking speed. Estimated effects were not maintained for any outcome at follow-up. Conclusions: This review suggests that VR-BT is more effective than BT to improve balance in PD subjects immediately after training, particularly in individuals with higher postural instability at baseline.