Safety, Feasibility, and Efficacy of Immersive Virtual Reality Training With a Body Weight Support System for Patients With Extrapyramidal Disorders: A Pilot Case Series Study.

Background Extrapyramidal disorders, including Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy, are commonly associated with balance disabilities and an increased risk of falls. Therefore, continuous balance training is important for maintaining quality of life. Recently, rehabilitation using virtual reality (VR) has been introduced; however, most studies have focused on non-immersive VR. In addition, there have been no reports of immersive VR (IVR) training being applied to patients with extrapyramidal disorders. Therefore, we developed a safe, task-oriented standing balance training protocol using IVR combined with a body weight support (BWS) system. The purpose of this study was to evaluate the safety, feasibility, and potential efficacy of IVR training using a BWS system for standing balance and walking speed in patients with extrapyramidal disorders. Methods This pilot case series study (a before-after trial) enrolled seven patients with extrapyramidal disorders. All participants were admitted to our rehabilitation ward to receive long-term inpatient rehabilitation. After admission, physical assessments were performed, and participants then underwent 20 minutes of IVR training for standing balance and walking speed combined with conventional physical therapy. This combined protocol was continued for 10 consecutive days (a total of 10 sessions). IVR training was designed to facilitate center-of-gravity shifts and stepping movements in a standing position by requiring participants to reach and touch virtual targets. Visual and auditory feedback were provided, and performance was quantified as a VR score based on the duration of successful target contact. Task difficulty was adjusted according to each participant's ability. A BWS system was used to ensure safety during training. Berg Balance Scale (BBS), Functional Reaching Test (FRT), and maximum walking speed during the 10-m walking test were assessed as primary outcomes before the first IVR training session and after completing all sessions. Significant differences in the outcomes were determined using the paired Student's t-test, with a significance level of <0.05. The effect size (ES) was calculated using Cohen's d. Results Among the study participants, five participants completed the 10-day protocol of IVR training, although two participants were discharged before training completion for non-study-related reasons. The total score of the Simulator Sickness Questionnaire was 5.9 ± 5.2, and no serious adverse events were observed during IVR training. No cases of falls were reported. VAS scores for satisfaction, enjoyment, and immersion were high (75.9 ± 19.6, 83.4 ± 17.0, and 81.3 ± 20.4, respectively). The 10-day IVR training promoted significant improvements in the BBS and FRT (p < 0.01). Although no significant improvement was found in maximum walking speed (p = 0.058), a moderate ES was observed (d = 0.69). Conclusions Our proposed IVR training using a BWS system could safely and feasibly improve standing balance and may contribute to improvements in walking speed among patients with extrapyramidal disorders. Further studies with larger sample sizes are needed to confirm the efficacy of this training.