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.
All 7 studies had each participant complete tasks without VR then with the VR therapy. None of the studies compared immersive VR therapy with more conventional therapies. Robles-Garcia and colleagues compared 2 VR groups where the experimental group imitated an avatar’s finger tapping in the VR system while the control group lacked this imitation.12 The authors found that adding that imitation to the VR group lead to an increase in movement amplitude.
Among the immersive VR studies, only Janeh and colleagues commented on possible adverse effects (AEs) and found that VR was a safe method without AEs of discomfort or simulator sickness.13 The other 6 studies did not make any mention or discussion of AEs related to the training.
Nonimmersive VR
VR modalities used in nonimmersive studies included consumer video gaming systems. Nintendo Wii and Microsoft Xbox Kinect were most commonly used. Among the 21 studies, 14 compared VR therapy with a type of traditional exercise (eg, treadmill training, stretching exercises, balance training). The mean number of participants of the studies was 28.3.
Five studies showed a difference between the VR and traditional training groups.14-18 However, 9 studies showed positive improvement in both groups and found no between-group differences.19-25 Among the remaining 7 studies, all showed improvement in primary outcomes after adding VR interventional therapy. In 1 RCT, 3 groups were compared (no intervention, Nintendo Wii, and Xbox Kinect) for gait tests, anxiety levels, memory, and attention.26 The authors found that only the Nintendo Wii group showed improvement in outcomes. A prospective cohort study was the only one to compare different doses of VR therapy (10 sessions vs 15 sessions of Nintendo Wii Fit).27 The authors found that both groups demonstrated the same amount of improvement on balance performances with no group effect.
Ten studiesreported no AEs during the training, but also did not define what was considered an AE.15,16,19,22-25,27-29 Eight studies did not make any mention of AEs.14,17,21,26,27,30-32 Yen and colleagues reported no AEs during training except for the patients’ tendency to fall.20 However, therapists supervised the patients to avoid falls and no falls occurred. Nuic and colleaguesreported 3 serious AEs, unrelated to the training: severe pneumonia (n = 1) and deep-brain stimulation generator replacement (n = 2).33 During the video game training sessions no specific AEs occurred. Only Pompeu and colleagues defined an AE as any untoward medical occurrence such as convulsion, syncope, dizziness, vertigo, falls, or any medical condition that required hospitalization or disability.34 One researcher registered the occurrence of any AE; however, none occurred during the study period.
Discussion
This systematic review demonstrates that VR therapy is a promising addition to rehabilitation for PD. Evidence supporting VR therapy is limited, but is continually expanding, and current evidence has shown improvement in assessments and rehabilitative outcomes involving PD. Most nonimmersive studies have shown that VR therapy does not lead to better outcomes when compared with traditional therapy but also is not harmful and does provide similar improvement. Immersive VR studies, on the other hand, have not compared therapy with conventional training extensively, and tend to focus more on time for task completion or movement.
