<LEAP> highlights the findings and application of Cochrane reviews and other evidence pertinent to the practice of physical therapy. The Cochrane Library is a respected source of reliable evidence related to health care. Cochrane systematic reviews explore the evidence for and against the effectiveness and appropriateness of interventions—medications, surgery, education, nutrition, exercises—and the evidence for and against the use of diagnostic tests for specific conditions. Cochrane reviews are designed to facilitate the decisions of clinicians, patients, and others in health care by providing a careful review and interpretation of research studies published in the scientific literature.1 Each article in this PTJ series will summarize a Cochrane review or other scientific evidence resource on a single topic and will present clinical scenarios based on real patients to illustrate how the results of the review can be used to directly inform clinical decisions. This article focuses on the effectiveness of virtual reality for stroke rehabilitation. Can virtual reality systems be incorporated as part of or instead of usual rehabilitation programs for a person after stroke?
Stroke is the second leading cause of death around the world and one of the main causes of years living with disability in adults.2,3 A stroke is caused by a disruption of the blood supply to the brain because an artery to the brain is either blocked (ischaemic stroke) or bursts (hemorrhagic stroke), causing damage to the brain tissue.4 After a stroke, physical impairments such as weakness and loss of coordination are common.5,6 These impairments cause limitations in mobility and upper limb activities, restricting the person with stroke from returning to his or her everyday activities.7,8
Several treatment options are available for patients after stroke, with varied evidence to support them.9,10 Repetitive task-specific training is commonly prescribed in stroke rehabilitation10 and has been shown to be effective for improving walking and upper limb function, especially when higher doses are used.10,12 However, providing a high dose of therapy in rehabilitation is challenging due to a number of factors, including limitations in staffing and reducing hospital length of stay. Thus, alternative and innovative strategies for delivering a high dose of training are needed.
Virtual reality is an emerging treatment option, which may have the capacity to provide a high dose of repetitive task-specific training.13 Virtual reality has been defined as the “use of interactive simulations created with computer hardware and software to present users with opportunities to engage in environments that appear and feel similar to real-world objects and events.”14 In addition to providing a high dose of therapy, virtual reality interventions also appear to be well suited for stroke rehabilitation, as they provide concurrent feedback, can be tailored to match the person's ability,15 and can engage and motivate the person with stroke to achieve his or her therapy goals.13 Laver et al16 recently performed a Cochrane systematic review on virtual reality for stroke rehabilitation with the primary objective of determining the effects of virtual reality on upper limb function and activity compared with an alternative intervention or no intervention. The review also evaluated the effects of virtual reality on a number of other outcomes, including gait and balance activity, motor and cognitive function, activity limitation, and participation restriction. This review included randomized controlled trials and quasi-randomized controlled trials and participants 18 years or older with the diagnosis of stroke of any type, severity, or time poststroke. The electronic searches were conducted up to November 2013.
Take-Home Message
The Table summarizes the results of the systematic review.16 In this review, 37 randomized controlled trials were included, with a total of 1,019 participants with stroke. The study sample sizes varied from 10 to 83 participants, with 59% of the studies having fewer than 25 participants. The risk of bias was unclear for most of the studies due to poor reporting and lack of information. Based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, the quality of evidence was considered “low” (further research is very likely to have an important impact on our confidence in the estimate of effect) or “very low” (very little confidence in the effect estimate) for all comparisons included.17 The studies included both male and female participants with mean ages of 46 to 75 years, any type of stroke and at any time poststroke, and all levels of severity. For studies that evaluated upper limb function, participants with a range of severities (including severe impairment) were included, and for studies that evaluated walking, participants were independent walkers.
Results of the Cochrane Reviewa
The review included any form of low-immersive or immersive virtual reality intervention. The term “immersion” refers to the degree to which the user senses that he or she is in the virtual environment rather than the real world.14 The included studies used commercially available low-immersive recreational gaming systems (eg, Nintendo Wii, Foxconn, Taipei, Taiwan), commercially available rehabilitation systems (eg, GestureTek IREX, Silicon Valley, California), and customized immersive virtual reality systems. The interventions were delivered in outpatient or inpatient settings in the majority of studies and in the participant's own home in 2 studies. The total dose of therapy ranged from less than 5 hours to more than 21 hours. Most studies compared virtual reality with the same amount of an alternative intervention, usually conventional therapy. Twelve studies investigated virtual reality as an adjunct to conventional therapy (the control group received conventional therapy) or compared virtual reality with no intervention.
The primary outcomes were upper limb function and activity, incorporating arm and hand function and activity. Secondary outcomes were walking and balance activity, global motor function, cognitive function, activity limitation, participation restriction and quality of life, brain imaging, and adverse events.
For the primary outcomes, there is low-quality evidence that virtual reality is better than the same amount of conventional therapy for upper limb function and activity, with a small effect size (standardized mean difference [SMD]=0.29; 95% confidence interval [CI]=0.09, 0.49; which means an improvement of about 4.96 points out of 66; 95% CI=1.54, 8.38), based on 12 studies (397 participants). Subgroup analysis revealed a greater significant benefit for trials recruiting participants within 6 months of their stroke (SMD=0.78; 95% CI=0.28, 1.29) compared with more than 6 months after stroke (SMD=0.21; 95% CI=0.04, 0.46; χ2=3.90, df=1, P=.05). Nine trials (190 participants) either investigated virtual reality as an adjunct to conventional therapy or compared virtual reality with no intervention for upper limb function, and there was a significant effect in favor of the addition of virtual reality to conventional therapy (SMD=0.44; 95% CI=0.15, 0.73; which means an improvement of about 7.52 points out of 66; 95% CI=2.57, 12.48). Furthermore, 2 trials (44 participants) evaluated the effect of virtual reality versus conventional therapy on hand function (grip strength), and 3 trials (60 participants) either investigated virtual reality as an adjunct to conventional therapy or compared virtual reality with no intervention on hand function (coordination), but for both comparisons, there was no significant difference in grip strength (in kilograms) between the groups (mean difference [MD]=3.55; 95% CI=−0.20, 7.30; and SMD=0.25; 95% CI=−0.27, 0.77, respectively).
For the secondary outcomes, there is very low-quality evidence that there is no significant difference between virtual reality and conventional therapy for walking speed (m/s), based on 3 studies (MD=0.07; 95% CI=−0.09, 0.23; n=58). Two studies evaluated the effects of virtual reality versus conventional therapy for global motor function, and there was no significant difference, with very low-quality evidence (not included in the meta-analysis). Two studies also compared virtual reality as an adjunct to conventional therapy versus conventional therapy alone for global motor function and did not find significant differences (SMD=0.14; 95% CI=−0.63, 0.90; n=27). There is very low-quality evidence that virtual reality was better than the same amount of conventional therapy for activities of daily living, with a medium effect size, based on 8 studies (SMD=0.43; 95% CI=0.18, 0.69; n=253). Similarly, low-quality evidence also showed that virtual reality provided in addition to conventional therapy was significantly better than conventional therapy alone for activities of daily living, with a medium effect size, based on 8 studies (SMD=0.44; 95% CI=0.11, 0.76; n=153). Twelve studies evaluated adverse events, with 2 participants reporting transient dizziness and headaches in the virtual reality group in one study and 2 participants in the virtual reality group and 3 participants in the control group reporting pain caused by the intervention in another study. The other secondary outcomes were not included in the meta-analysis, and no evidence of effect was reported.
Case #28: Applying Evidence to a Patient With Stroke
Can virtual reality help this patient?
Mr Silva is a 72-year-old man who had a stroke due to a middle cerebral artery territory infarct. Prior to his stroke, he was retired, lived independently with his wife in the community, and walked unaided. He was admitted to an inpatient stroke rehabilitation unit 2 weeks after his stroke, and at that time he scored 25/30 on the Mini-Mental State Examination,18 indicating normal cognitive function.
On physical examination, Mr Silva had right-sided weakness. To measure his upper limb function, his physical therapist used the Fugl-Meyer Scale19 and the Box and Block Test.20 On the Fugl-Meyer Scale (upper limb section), he scored 41/66 points, indicating moderate motor impairment.17 On the Box and Block Test, he moved 23 blocks in 60 seconds, indicating moderate limitation in hand function.21–24 The normative value (average performance) on the Box and Block Test for a man aged 72 years using his right hand is 68 blocks (SD=8).25
On assessment of his walking at this time, Mr Silva was able to walk short distances indoors with standby supervision of one person and was unable to walk outdoors. To measure his mobility, his physical therapist conducted the Short Physical Performance Battery,26 on which he scored 2/12. For the balance subscale, he scored 0/4. He was able to stand in side-by-side stance unassisted, but only for 8 seconds; thus, semi-tandem and tandem stance were not attempted. For the walking subscale, he scored 1/4 and was able to walk 4 m in 21 seconds (0.19 m/s). For the sit-to-stand subscale, he scored 1/4 and was able to stand up without using his hands 5 times in 17.5 seconds.
How did the results of the Cochrane review apply to Mr Silva?
During the initial rehabilitation assessment, Mr Silva expressed motivation for additional exercise and an interest in technology. The physical therapist, therefore, considered whether Mr Silva would benefit from the addition of virtual reality as an adjunct to usual therapy to improve his upper limb function and mobility. She, therefore, posed the clinical question: In a 72-year-old man who is 2 weeks poststroke, will virtual reality (in addition to conventional therapy) improve upper limb function and mobility? Thus, the review by Laver et al16 was identified and provided useful information for this patient.
The review16 included studies with both male and female participants with a range of upper limb severities (for studies evaluating the upper limb) and independent walkers (for studies evaluating mobility), with study mean ages of 46 to 75 years. The majority of studies recruited participants who were more than 6 months poststroke; however, some studies recruited participants earlier poststroke, and subgroup analysis showed greater benefit in upper limb function for studies recruiting participants within 6 months of stroke compared with more than 6 months. Mr Silva was a 72-year-old man 2 weeks after stroke with moderate upper limb limitations who could walk indoors with supervision, which is similar to the population included in the review.
The virtual reality intervention in the review16 was composed of different gaming systems (eg, Nintendo Wii, GestureTek IREX), of which included studies focused on different training aspects of rehabilitation (eg, reaching and manipulation, standing and walking). The physical therapist working with Mr Silva opted to use the Nintendo Wii gaming console (Nintendo Wii Seventh generation, RVL-001, Foxconn), as this device was easy to access, there were suitable games to target upper limb and hand function and overall mobility, and the Cochrane review showed no significant difference between commercially available systems and more expensive custom-made systems. The intervention was applied in a private room of the hospital, without any distractions. As most studies included in the review16 provided between 11 and 20 hours of therapy (range=>5 hours to >21 hours), the physical therapist decided to deliver a program of 1 hour of supervised virtual reality sessions, 5 times per week for 3 weeks (15 hours total). The games selected were from the Wii Sports, Wii Fit, and Cooking Mama software. Games were selected to address activity limitations (eg, Penguin slide game from Wii Fit to improve loading the right leg for standing and walking) and were modified where necessary to better tailor the game to suit Mr Silva's current abilities (eg, Tightrope game from Wii Fit changed to a step-touch exercise to a block). The therapist used about 4 to 6 different games per session, with Mr Silva playing each game between 3 to 6 times depending on the length and difficulty of the game. Before commencing the training, the physical therapist introduced Mr Silva to the virtual reality system and instructed him on how to move his body to control the movements of the avatar within the games. The physical therapist also assisted Mr Silva in holding the controls (Wiimote and Nunchuk) and directed the correct movements of his arm and hand when necessary.
The virtual reality therapy was accompanied with 1 to 2 hours of conventional physical therapy (usual care) 5 times per week (prior to the virtual reality sessions) and with other rehabilitation provided by the multidisciplinary team. Conventional physical therapy included exercises to address physical impairments (eg, strength training to address weakness) and task-specific practice to address activity limitations, delivered in a combination of one-on-one, semisupervised and group therapy sessions.
A number of different outcome measures were reported in the Cochrane review, most likely due to the diverse interventions addressing different activity limitations (eg, hand function versus walking). For our case study (Mr Silva), the aim of therapy was to improve upper limb function and mobility. We, therefore, chose the same (Fugl-Meyer Scale and Box and Block Test) or similar (Short Physical Performance Battery) outcome measures as reported in the review.16
How well do the outcomes of the treatment provided to the patient match those suggested in the review?
After the 3-week program of virtual reality and conventional therapy, Mr Silva completed 14 sessions (93%), missing 1 session due to feeling too fatigued, and showed excellent adherence to the intervention. He showed improvement in upper limb function, with his Fugl-Meyer Upper Extremity Scale score increasing from 41 to 46 points. This improvement aligns with the Cochrane review,16 and the increase was greater than the 4-point change considered to reflect a clinically important difference for individuals with stroke.27 Mr Silva also demonstrated improvement in hand function, with his posttraining Box and Block Test score increasing from 23 to 26 blocks. This improvement is in accordance with the Cochrane review,16 but it is lower than the 5.5-point change considered to reflect a clinically important difference for individuals with stroke.23
Mr Silva also improved his mobility after the 3-week training, as demonstrated by his Short Physical Performance Battery score increasing from 2 to 8 points. For the balance subscale scale, he scored 4/4, as he was now able to stand with his feet side-by-side, semitandem, and tandem stance for 10 seconds each. For the walking subscale, he still scored 1/4 but was now able to walk 4 m in 11 seconds (0.36 m/s). For the sit-to-stand subscale, he scored 3/4 and was able to stand up without using his hands 5 times in 11.3 seconds. The minimal detectable change on the Short Physical Performance Battery is 2.9 points for elderly people,28 although it is not clear whether it is the same for patients with stroke. This mobility improvement exceeded the systematic review findings, which did not show a difference between groups. This discrepancy may be explained by the very low quality of evidence for this comparison, which represents uncertainty about the effect estimate and a lack of studies investigating the effects on walking of virtual reality early after stroke.
Can you apply the results of the review to your own patient?
The systematic review results applied well to Mr Silva, who exhibited limitations in reaching and manipulating, standing, and walking. The studies included in the Cochrane review by Laver et al16 included relatively young people after stroke and often excluded people with cognitive impairment, aphasia, apraxia, and visual impairments; thus, the results may not generalize to this subset of people after stroke.
The studies included in the review focused on different training aspects of rehabilitation, including upper limb, activity, lower limb, and balance and walking; global motor function; and visual perceptual retraining. The strongest evidence was in improving upper limb function, particularly in people within 6 months of stroke. The evidence, however, is only of low quality due to small sample sizes and unclear bias within the study designs, which means that further research is very likely to change the effect estimates and that we lack confidence in the effect estimate. For other aspects of rehabilitation (eg, walking, mobility), the evidence from the review was less clear, with very little confidence in the effect estimates provided by the very low-quality evidence. However, a more recent systematic review,29 which incorporated 6 new studies30–35 published after the Cochrane review search, was conducted and reported improvements in walking speed, balance, and mobility when virtual reality was compared with standard rehabilitation. The evidence, however, was less clear when virtual reality was used as an adjunct to standard rehabilitation.
The virtual reality systems used in the studies included in the review ranged from inexpensive commercially available recreational gaming systems to more expensive, commercially available rehabilitation systems to expensive customized virtual reality systems that are not readily available. Subgroup analysis in the review did not show any differences in upper limb function when comparing different types of virtual reality systems. These analyses, however, were limited by the number of studies using the different systems, suggesting that further research is warranted to understand key features important in virtual reality systems. As such, as we demonstrated in our case study that due to the limited quality of evidence available, the use of commercially available recreational gaming systems appears to be reasonable at this time as an affordable way to provide virtual reality as part of rehabilitation.
What can be advised based on the results of this systematic review?
The Cochrane systematic review16 showed low- to very low-quality evidence that virtual reality can be benefical for people after stroke with activity limitations in reaching and manipulation; the benefits on standing and walking are less clear. In addition, minimal adverse events were reported and considered minor (eg, transient dizziness). The rehabilitation program proposed in this case study consisted of virtual reality used in addition to usual care. Mr Silva improved his upper limb function, walking, and balance, which may or may not have been due to the addition of virtual reality to his usual care and taking into account the natural recovery after stroke. It is possible that people after stroke, like Mr Silva, can benefit from virtual reality as an adjunct to usual care.
Further research is needed, as virtual reality is still a new addition to physical therapy treatment options and the low and very low quality of the evidence means there is still uncertainty in the benefits. Trials including cost-effectiveness analysis and studies evaluating the acceptibility and feasibility of virtual reality are needed to guide the implementation of these systems into clinical practice. The current evidence does not support clinical services investing and utilizing expensive virtual reality systems or replacing current evidence-based rehabilitation interventions. However, it would appear reasonable and safe to incorporate accessible virtual reality systems as part of the rehabilitation program for a person after stroke, taking into account the person's preferences for this type of intervention.
Footnotes
All authors provided concept/idea/project design and writing. Dr Hassett provided data analysis. Dr J. Pompeu provided project management. Ms Yamato provided consultation (including review of manuscript before submission).
The case study was developed from data collected as part of an Australian National Health and Medical Research Council project grant: APP1063751. Ms Yamato is supported by CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior), Brazil.
- Received September 22, 2015.
- Accepted March 31, 2016.
- © 2016 American Physical Therapy Association