Table 1.

Examples of recent systematic reviews and meta-analyses demonstrating the effects of VR in neurorehabilitation of stroke, PD and CP.

Author and year	Study aims	Studies included and sample (n)	Study outcomes	Points of discussion
Stroke
Laver et al. (2015)	Compared the effects of virtual reality on arm function, walking speed and independence in managing daily activities after stroke versus an alternative intervention or no intervention.	37 studies (n = 1019)	12 studies found improved arm function.	Low sample size in most studies.
			4 studies found improved walking speed.	Some studies reported pain, headaches or dizziness in small number of participants, but no adverse events overall.
			8 studies found slight improvements in activities of daily living.	Low quality evidence for arm function.
				Very low quality evidence for walking ability, global motor function and independence in performing daily activities.
				The quality of the evidence for each outcome was limited due to small numbers of study participants, inconsistent results across studies and poor reporting of study details.
Corbetta et al. (2015)	Compared the effects of VR-based rehabilitation on gait, balance and mobility versus standard therapy.	15 studies (n = 341)	Significant improvements in walking speed, balance, and mobility.	Substituting some or all of a standard rehabilitation regimen with VR training provides greater benefits in walking speed, balance, and mobility.
			Significant improvements in mobility if VR training was combined with standard therapy.	Although the benefits are small, the cost of administering VR is also small particularly when patient demand is high in a clinic setting.
			Insufficient evidence to support to use of combined VR and standard therapy on balance and walking speed.
Luque-Moreno et al. (2015)	Compared the effects of VR interventions on lower extremity rehabilitation.	11 studies (n = 231)	High heterogeneity in study designs.	VR interventions (more than 10 sessions) may have a positive impact on lower limb function.
			Small sample sizes. Mean sample size of 20 per study.	Multimodal approach (i.e., a combination of VR and conventional therapy) may elicit greater results.
			Studies were ranked between 4 and 7 points (out of 10) on the PEDro scale.	Adaptability of software seemed to adapt better to patient’s requirements, allowing for individualized treatments.
Lohse et al. (2014)	Compared the effects of custom built virtual games and commercially available gaming systems.	26 studies (n = ?)	Only 4 studies used commercial games while 20 studies used custom built virtual games.	VR intervention improves outcomes compared to conventional therapies.
			Mean PEDro score for all studies was 5.42 ± 1.6 (out of 10).	Small samples and few number of studies in commercial games limits the assessment of potential benefits.
			Methodological limitations of studies include subject, experimenter and therapist blinding, small sample size, and difficulty in determining a dose-response effect.
			Significant improvements in body function and activity outcomes.
Parkinson’s disease
Harris et al. (2015)	Compared the effects of exergaming on static and dynamic balance in older adults and PD.	11 studies (n = 325 healthy older adults, 56 PD)	9 studies showed a significant improvement in static balance and postural control in healthy aging individuals.	Few studies in PD and small sample size limits the interpretation of the effectiveness of exergaming in PD.
			2 studies found a significant improvement in static balance and postural control people with PD.	Evidence found in this meta-analysis supports the use of exergaming as an adjunctive tool to improve balance and postural control.
			Studies were ranked between 4 and 8 points (out of 10) on the PEDro scale.
Barry et al. (2014)	Examined the safety, feasibility and effectiveness of exergaming in people with PD.	7 studies (n = 110)	Only 2 studies addressed patient safety. No objective measures (such as falls or near falls) or subjective measures (patient’s perception) were recorded in any studies.	While the effectiveness and feasibility are often measured, more research is required to establish the safety, particularly in home-based VR therapy.
			Only 1 study recorded gameplay experience. Good levels of motivation during game play were reported although difficulties with the fast pace and cognitive complexity of some games were raised.	The use of commercial games may be too difficult for some people with PD, and exergames that tailor specifically to the needs and capabilities of patients may be more effective.
			Exergaming was found to be just as effective as standard physical therapy for improving clinical measures of balance and cognition even up to 60 days post-intervention.
Cerebral Palsy
Dewar et al. (2015)	Systematic review of various interventions to improve postural control in children with CP	45 studies (n = ?)	4 studies investigated the use of VR on postural control.	The systematic review provided conflicting evidence of VR on postural control and gait.
			2 studies were rated weak in study conduct while 2 had a strong study design.	Due to the preliminary nature of these studies, it is difficult to truly ascertain if indeed the use of VR had any effects on postural control and gait.
			3 studies showed improvements in balance, while 2 study showed improvements in walking capacity.
Chen et al. (2014)	Examined the effects of virtual gaming on upper extremity function in children with CP	14 studies (n = 122)	3 RCTs, 2 cohort studies, 7 case studies and 2 single-subject design studies.	The use of VR may be highly applicable in a pediatric population.
			For 3 RCTs, no difference was found between VR therapy and conventional therapy.	Small sample size and the lack of large RCT is a limiting factor in interpreting the results.
			Overall upper extremity function was significantly improved after VR therapy.
			Strongest effects of VR was shown in younger children, custom-built systems in the home or laboratory setting.

PEDro, physiotherapy evidence database (PEDro); RCT, Randomized controlled trials; PD, parkinson’s disease; CP, cerebral palsy; VR, virtual reality.