brain injury is caused by intrinsic or extrinsic factors and it can result in various 
 disabilities such as motor , sensory , behavioral , or cognitive dysfunction depending on the 
 area of the brain lesion1 . cognitive 
 impairment due to brain injury is an important factor affecting patients independent 
 functions and participation in activities2 , interfering with their return to daily living and work3 . it can also influence motivation and the 
 ability to participate in rehabilitation programs and interfere with a return to the 
 community . therefore , for successful rehabilitation , accurate and comprehensive cognitive 
 assessment and treatment are required4 . for cognitive rehabilitation of patients with brain injury , traditional treatment and 
 computer - based cognitive therapy ( vr ) technology is 
 gaining recognition as a useful tool for cognitive research , evaluation , and 
 rehabilitation5 . vr systems allow users 
 to interact in various sensory environments and to obtain real - time feedback on their 
 performance using computer technology6 . the virtual environment offered via vr technology makes it possible for patients to 
 participate in activities in settings and environments similar to those encountered in real 
 life7 , 8 . in addition , vr tools can be used to record accurate measurements 
 of the subject s performance9 and to 
 deliver greater therapeutic stimulation to users5 . vr has been used as a 
 tool to diagnose cognitive impairment and as a vehicle to provide new treatments5 . although the use of vr in cognitive 
 rehabilitation has been increasing , few systematic reviews have investigated the use of vr 
 programs in cognitive rehabilitation and the overall effect of these programs on cognition . 
 therefore , this systematic review investigated the different types of vr programs used for 
 cognitive evaluation and interventions for patients with brain injury . studies using vr 
 programs for cognitive intervention were reviewed according to pico ( patient , intervention , 
 comparison , and outcome ) methods . ( virtual reality or virtual or game based virtual reality or computer based virtual 
 reality ) and ( stroke or cerebral vascular accident or hemiplegia or brain injury or 
 traumatic brain injury ) and ( cognition or cognitive or memory or attention or executive 
 function ) . inclusion criteria were : ( 1 ) subjects over the age of 19  years with brain 
 injury ; ( 2 ) articles written in english ; and ( 3 ) studies that used vr in cognitive 
 rehabilitation . exclusion criteria were : ( 1 ) subjects who were animals or children ; ( 2 ) 
 review articles ; and ( 3 ) 2d computer - based cognitive rehabilitation . randomized controlled trials ( rcts ) and crossover studies were scored on the physiotherapy 
 evidence database ( pedro ) scale12 . two 
 authors independently assessed the methodological quality of the included studies , and 
 disagreements were resolved by reaching consensus . memory 
 assessment was the most common study topic , followed by assessments of executive function 
 and attention . a variety of vr programs were used ( table 1table 1.analysis of studies of cognitive assessment using vrauthor , yearassessment areatype of vrbrooks et al . three were rcts24,25,26 , one was a crossover 
 study27 , and one was a case report28 . excepting the case report , four studies 
 were assessed using the pedro scale . two studies24 , 
 25 scored 4 , and the remaining two 
 studies scored 326 and 127 , respectively . table 2table 2.analysis of studies with cognitive interventions using vrstudypatientinterventioncomparisonoutcomenmean agetype of vrintensityoutcome measure(s)findingsakinwuntan et al . , 20102469eg 55 cg 54stisim drive system60  min / day , 3 times / week , total 5 weeksnon - computer based cognitive therapyufov testsignificant within group improvements but no significant 
 difference between two groupscaglio et al . , 201228124midtown madness 290  min / day , 3 times / week , total 5 weeks - fdst , bdst , ravlt - ir , dr , rbmt - ir , dr , corsi s block tapping 
 test , corsi s supraspan test - ir , dr , tmt - a , b , phonemic fluency mmse , adassignificant improvements in ravlt - ir and corsis supraspan - ir , 
 drgrealy et al . , 1999271332.38nonimm - ersive vr exercise bicycle25  min / day , 3 times / week , total 4 weeksno treatmentfdst , bdst , digit symbol test , tmt - a & b , auditory learning 
 test , velt , vilt , logical memory , complex figure testeg showed significant improvements in digit symbol test , velt , 
 vilt compared to cgjacoby et al . , 20132512eg 27.83 cg 30.67irex45  min / day , 34 times / week , total 3 weeksconventional otmet - sv , efpteg showed significant improvements in all outcome measures 
 compared to the cgkim et al . , 20112628eg 66.5 cg 62.0irex30  min / day , 5 times / week , total 4 weekscomputer based cognitive therapyk - mmse , tol , vcpt , acpt , word - color test , fdst , bdst , fvst , bvst , 
 vilt , velt , tmt - asignificant difference between experimental group and control 
 group in vcpt and bvsteg : experimental group , cg : control group , met - sv : multiple errands test - simplified 
 version , efpt : executive function performance test , fdst : forward digit span test , 
 bdst : backward digit span test , tmt - a : trail making test - type a , tmt - b : trail making 
 test - type b , velt : verbal learning test , vilt : visual learning test , ufov : useful 
 field of view test , k - mmse : korean version of the mini - mental status examination , tol : 
 tower of london test , vcpt : visual continuous performance test , acpt : auditory 
 continuous performance test , fvst : forward visual span test , bvst : backward visual 
 span test , ravlt : rey auditory verbal learning test , ir : immediate recall , dr : delayed 
 recall , rbmt - the rivermead behavioural memory test , adas : alzheimer s disease 
 assessment scale presents the characteristics of the five studies . flowchart of the article search and study selection eg : experimental group , cg : control group , met - sv : multiple errands test - simplified 
 version , efpt : executive function performance test , fdst : forward digit span test , 
 bdst : backward digit span test , tmt - a : trail making test - type a , tmt - b : trail making 
 test - type b , velt : verbal learning test , vilt : visual learning test , ufov : useful 
 field of view test , k - mmse : korean version of the mini - mental status examination , tol : 
 tower of london test , vcpt : visual continuous performance test , acpt : auditory 
 continuous performance test , fvst : forward visual span test , bvst : backward visual 
 span test , ravlt : rey auditory verbal learning test , ir : immediate recall , dr : delayed 
 recall , rbmt - the rivermead behavioural memory test , adas : alzheimer s disease 
 assessment scale in this review , the types of vr programs that have been used in cognitive evaluations of 
 patients with brain injury were identified and studies of cognitive interventions were 
 reviewed according to pico methods . in the included studies , the vr programs could 
 distinguish the cognitive disability of patients in comparisons with healthy subjects . thus , 
 vr could be used as a new assessment method of the cognitive function of patients with brain 
 injury . therefore , in contrast to conventional cognitive 
 assessments , vr programs can provide consistently accurate measurements of cognitive 
 function . however , some methodological problems were found in the reviewed articles . in most 
 of the studies , the vr tool used was not compared with a standardized assessment tool , and 
 the inter - rater reliability was not measured . the five studies of cognitive therapy using vr all reported positive effects . in the 
 assessment of cognitive function , the vr interventions resulted in improvements in the areas 
 of memory and attention but not executive function . ben - yishay et al.29 stated that to effectively raise cognitive function , 
 normal attention is needed . if the ability to concentrate on external information is 
 impaired , memory , problem - solving skills , and appropriate behavior may be difficult . thus , 
 they suggested that the impairment of attention due to brain injury may interfere with the 
 recovery of other cognitive functions , such as memory , executive function , and planning . the 
 results of this systematic review indicate that the cognitive improvement of attention using 
 vr programs will have a positive impact on the recovery of general cognitive function . the 
 advantage of cognitive rehabilitation using vr is that it provides a variety of environments 
 similar to those encountered in real life30 . the results of this review suggest that patients are more 
 motivated in virtual environments than they are in conventional settings . therefore , vr 
 programs can be expected to lead to an improvement in cognitive function . in vr 
 interventions , patients can be treated in a safe environment compared to real settings . in 
 addition , vr programs can be tailored to the type of injury and easily adjusted to the level 
 of cognitive disability , the complexity of a task , the reaction conditions , and the 
 characteristics and patterns of feedback30 . as vr systems are constantly evolving and becoming smaller and 
 more easily adjustable , they can be expected to provide specialized therapy in new settings , 
 such as patients homes or clinics . these advantages of vr systems can benefit patients who 
 find it difficult to visit health care organizations5 . the results of this systematic review suggest that vr is an effective cognitive therapy for 
 patients with brain injury compared to control therapy . , there was a 
 significant risk of bias with regard to allocation concealment and blinding . given the 
 heterogeneity of the included studies , the ability to draw conclusions is limited . well - designed rcts and blind studies will be needed to provide evidence of the benefits of 
 vr on cognitive function .
[ purpose ] the purpose of this review was to investigate various types of vr programs and 
 their use in cognitive evaluations and interventions for patients with brain injury . 
 [ subjects and methods ] pubmed , cochrane , and otseeker electronic databases were searched 
 with the search terms . at of 350 titles and abstracts 
 were retrieved , and 17 articles were 
 selected for this review . selected articles were assessed on the level of evidence using 
 the physiotherapy evidence database ( pedro ) scale . 
 [ results ] articles assessing the impact 
 of cognitive impairments in memory were most commonly found , and vr interventions elicited 
 positive effects in patients with brain injury . [ conclusion ] vr can be considered a new 
 tool for cognitive rehabilitation after brain injury . 
 vr interventions also have a number 
 of advantages , e.g. cost - effectiveness , compared to other interventions .