Systemic Literature Review of the Use of Virtual Reality for Rehabilitation in Parkinson Disease
Background: Functional rehabilitation is important when managing Parkinson disease (PD). Virtual reality (VR) therapy is a noninvasive, potential alternative or adjunct to conventional therapies used during rehabilitation.
Observations: The authors searched for articles in Google Scholar, PubMed, Physiotherapy Evidence Database Score (PEDro), and Cochrane after setting specific requirements starting in July 2019. Methodologic quality was assessed by PEDro for randomized controlled trials. Among 89 studies identified, 28 included in this review evaluated VR therapy for use during rehabilitation for PD: 7 used immersive VR and 21 used nonimmersive VR. Among the immersive VR studies, 6 showed improvement in primary outcomes after adding VR therapy. Among the nonimmersive VR studies, 5 showed improvement with VR therapy when compared with conventional therapy, 9 showed improvement with VR and conventional therapy with no between group difference, and the remaining 7 showed improvement in primary outcomes after adding VR intervention. The quality and diversity of studies was a major limitation.
Conclusion: VR therapy is a promising rehabilitation modality for PD but more studies are needed. Additional investigations of VR therapy and PD should include direct comparisons between immersive and nonimmersive VR therapies.
There were fewer immersive VR studies than nonimmersive VR studies. This could be because of the increased technological difficulty and demand to correctly execute immersive VR modalities, as well as the—until recently—substantial expense. This might be another reason why the mean PEDro scores for immersive VR RCTs were lower than the mean scores found in nonimmersive RCTs.
Limitations
This review was limited by several factors related to the included studies. A variety of rating scales were used in the immersive and nonimmersive VR studies. Although there was some general overlap with common measurements such as gait, balance, kinematics, and VR feasibility, no studies had the same primary and secondary outcomes. Such heterogeneity in protocols and outcomes limited our ability to draw conclusions from these differing studies. Additionally, the average number of participants of both immersive and nonimmersive studies were small and the statistical significance of findings should be interpreted with caution. Finally, VR devices and systems differed between studies, further limiting comparisons. Although these factors limit this systematic review, we can still identify treatment and research implications. Adequately powered future studies with standardized protocols would further improve the available evidence and support for VR as an intervention.
Conclusions
VR therapy is a promising rehabilitation modality for PD. Additional investigations of VR therapy and PD should include direct comparisons between immersive and nonimmersive VR therapies. It could be hypothesized that the greater immersion and engagement potential of immersive VR would demonstrate greater functional improvement compared with nonimmersive VR, but there is no data to support this for PD. VR therapy for PD appears to be a relatively safe alternative or adjunct to traditional therapy with a potentially positive impact on a variety of symptoms and is growing as an innovative therapeutic approach for PD patients.
