Effects of virtual reality intervention dosage on gait performance in Parkinson's disease: a systematic review and...

Gait impairment is a prevalent and disabling feature of Parkinson's disease (PD) that is often insufficiently improved by conventional rehabilitation approaches. Virtual reality (VR)-based training has emerged as a novel therapeutic strategy; however, the overall efficacy of VR interventions on gait outcomes in PD remains inconclusive. This systematic review and meta-analysis aimed to (1) quantify the effects of VR-based rehabilitation on gait performance in individuals with PD, and (2) investigate whether treatment outcomes are moderated by intervention dosage parameters-such as training frequency, session duration, and total intervention period-as well as patient-related factors like disease duration and age.

Seven databases (Embase, Web of Science, PubMed, Cochrane Library, Wanfang Data, VIP, and CNKI) were searched from inception to December 2024. Randomized controlled trials (RCTs) investigating VR training for gait in PD were independently screened by two reviewers. Study quality was assessed using the PEDro scale. Meta-analyses were conducted with RevMan 5.4.1, and publication bias was examined using Stata 17.0. Effect sizes were calculated using standardized mean differences with 95% confidence intervals. The certainty of evidence was graded using the GRADE approach.

A total of 13 RCTs, involving 541 patients with Parkinson's disease, met the inclusion criteria. VR-based interventions demonstrated significant effects in improving composite gait function (SMD = 0.56; 95% CI [0.36-0.77]; P < 0.00001), indicating a moderate and clinically meaningful benefit. Gait function was evaluated using a range of clinical scales and spatiotemporal parameters, encompassing multiple dimensions such as dynamic stability, walking efficiency, and functional mobility. Subgroup analyses revealed greater improvements among patients with disease duration ≤8 years (SMD = 0.65), shorter intervention periods (≤4 weeks, SMD = 0.86), and shorter session durations (≤30 minutes, SMD = 0.83). The intervention effects were generally consistent across different age groups (SMD = 0.48-0.74). The average PEDro score was 6.77, indicating moderate to high methodological quality, although allocation concealment and blinding were frequently absent. No significant publication bias was detected, and the overall certainty of evidence was rated as high.

VR-based training yields statistically robust and clinically relevant improvements in gait among individuals with PD. These benefits are moderated by disease stage and intervention parameters, supporting the integration of VR into personalized, early-phase rehabilitation strategies.