Fifteen studies (145 participants) were included: four RCTs, two controlled clinical trials (CCTs), one single group pre-post study, six case series and two case studies. Internal validity scores for the six RCTs/CCTs ranged from 2 to 5 out of a possible 8 points. Evidence of allocation concealment, blinding of participants and intention-to-treat analysis was lacking. Five of the six studies scored 2 out of a possible 2 points for statistical reporting.
Considerable between-study heterogeneity was identified in terms of design, patients, interventions and outcomes.
Mental practice was found to have a positive effect on upper-limb recovery in terms of impairment (supported by three RCTs, two CCTs, and nine studies that used less reliable designs) and activity limitations (supported by three RCTs, one CCT and six studies that used less reliable designs). Seven studies showed statistically significant effects; these included five RCTs and CCTs. Five trials showed that mental practice plus physical therapy was better than physical therapy alone or conventional therapy.