Virtual Reality Therapy for Adults Post-Stroke: A Systematic Review and Meta-Analysis Exploring Virtual Environments and Commercial Games in Therapy Keith R. Lohse 1,2 *, Courtney G. E. Hilderman 3 , Katharine L. Cheung 3 , Sandy Tatla 4 , H. F. Machiel Van der Loos 5 1 School of Kinesiology, Auburn University, Auburn, Alabama, United States of America, 2 School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada, 3 Department of Physical Therapy, University of British Columbia, Vancouver, British Columbia, Canada, 4 Department of Occupational Science and Occupational Therapy, University of British Columbia, Vancouver, British Columbia, Canada, 5 Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, Canada Abstract Background: The objective of this analysis was to systematically review the evidence for virtual reality (VR) therapy in an adult post-stroke population in both custom built virtual environments (VE) and commercially available gaming systems (CG). Methods: MEDLINE, CINAHL, EMBASE, ERIC, PSYCInfo, DARE, PEDro, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews were systematically searched from the earliest available date until April 4, 2013. Controlled trials that compared VR to conventional therapy were included. Population criteria included adults (.18) post- stroke, excluding children, cerebral palsy, and other neurological disorders. Included studies were reported in English. Quality of studies was assessed with the Physiotherapy Evidence Database Scale (PEDro). Results: Twenty-six studies met the inclusion criteria. For body function outcomes, there was a significant benefit of VR therapy compared to conventional therapy controls, G = 0.48, 95% CI = [0.27, 0.70], and no significant difference between VE and CG interventions (P = 0.38). For activity outcomes, there was a significant benefit of VR therapy, G = 0.58, 95% CI = [0.32, 0.85], and no significant difference between VE and CG interventions (P = 0.66). For participation outcomes, the overall effect size was G = 0.56, 95% CI = [0.02, 1.10]. All participation outcomes came from VE studies. Discussion: VR rehabilitation moderately improves outcomes compared to conventional therapy in adults post-stroke. Current CG interventions have been too few and too small to assess potential benefits of CG. Future research in this area should aim to clearly define conventional therapy, report on participation measures, consider motivational components of therapy, and investigate commercially available systems in larger RCTs. Trial Registration: Prospero CRD42013004338 Citation: Lohse KR, Hilderman CGE, Cheung KL, Tatla S, Van der Loos HFM (2014) Virtual Reality Therapy for Adults Post-Stroke: A Systematic Review and Meta- Analysis Exploring Virtual Environments and Commercial Games in Therapy. PLoS ONE 9(3): e93318. doi:10.1371/journal.pone.0093318 Editor: Terence J. Quinn, University of Glasgow, United Kingdom Received January 17, 2014; Accepted February 28, 2014; Published March 28, 2014 Copyright: ß 2014 Lohse et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This research was funded by #11-079 from the Peter Wall Solutions Initiative at the University of British Columbia awarded to H.F.M. Van der Loos. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: kelopelli@gmail.com Introduction Stroke is a leading cause of death and disability around the world, and the majority of survivors experience chronic motor deficits associated with reduced quality of life [1]. Neurophysio- logical data suggest considerable amounts of practice are required to induce neuroplastic change and functional recovery of these motor deficits [2]–[4]. This requisite high repetition is problem- atic, however, because observational data show that clients generally perform a very limited number of movement repetitions in traditional therapy sessions [5]. Furthermore, many logistical, financial, environmental, and individual barriers limit the efficacy of conventional therapy for adults post-stroke [6],[7]. Conse- quently, research is often focused on optimizing an individual’s potential amount of recovery for a given amount of time in therapy. One proposed method for optimizing the effects of therapy is the use of virtual reality (VR). VR can be defined as a type of user-computer interface that implements real-time simulation of an activity or environment allowing user interaction via multiple sensory modalities [8]. VR therapies are an appealing avenue of research because they can provide patients and therapists with additional feedback during therapy, increase patient motivation, and dynamically adjust the difficulty of therapy [9]–[11]. Increasingly, VR therapies have been compared to "usual care" or "conventional therapy" (CT) as sophisticated technologies have PLOS ONE | www.plosone.org 1 March 2014 | Volume 9 | Issue 3 | e93318