Dose-Response Relationship of Virtual Reality Training in Parkinson's Disease: A Meta-Analysis of Overall Motor Function, Functional Mobility, and Balance Confidence.

OBJECTIVE

To investigate the dose-response relationship of virtual reality training (VRT) on overall motor function (Unified Parkinson's Disease Rating Scale Part III [UPDRS-III]), functional mobility (timed Up and Go [TUG]), and balance confidence (Activities-specific Balance Confidence [ABC] Scale) in individuals with Parkinson's disease (PD) to optimize rehabilitation protocols.

DATA SOURCES: A comprehensive literature search was conducted across 6 electronic databases-PubMed, Embase, Cochrane Library, Web of Science, EBSCOhost, and China National Knowledge Infrastructure -from inception to August 3, 2025.

STUDY SELECTION: A systematic search identified 31 randomized controlled trials (n=1110) evaluating the effects of VRT on balance capabilities and functional gait in patients with PD.

DATA EXTRACTION: Data were organized into 3 categories: bibliographic details, participant characteristics, and intervention specifics, along with quantitative data on TUG, UPDRS-III, and ABC scores. Data extraction was independently conducted by 2 reviewers, followed by cross-verification and adjudication.

DATA SYNTHESIS: Weighted mean differences (WMDs) and univariate meta-regression were analyzed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. VRT significantly improved TUG (WMD=-3.69) and ABC scores (WMD=11.80), both of which met the minimal clinically important difference (MCID). VRT alone improved TUG but did not meet the MCID. No significant improvement was observed overall for UPDRS-III. Optimal TUG parameters were identified as 21-40 min/session and 4-7 sessions/wk for 6-8 weeks. High-frequency training (≥4 sessions/wk) was required for UPDRS-III benefits. Commercial and specialized platforms showed comparable efficacy.

CONCLUSIONS

VRT significantly enhances TUG and ABC, particularly achieving clinical utility (MCID) when combined with physical therapy. While UPDRS-III effects are limited, high-frequency protocols show potential. A frequency of 4-7 sessions/wk was associated with clinically important improvements in TUG. Additionally, patients aged ≥70 years showed no statistical heterogeneity in their response to the intervention (I²=0%). However, this finding should be interpreted cautiously, as it is based on a small number of studies and may reflect limited statistical power rather than true clinical predictability.