Does noninvasive brain stimulation combined with other therapies improve upper extremity motor impairment, functional performance, and participation in activities of daily living after stroke? A systematic review and meta-analysis of randomized controlled trial

Background Several studies have investigated the effect of noninvasive brain stimulation (NIBS) on upper limb motor function in stroke, but the evidence so far is conflicting. Objective We aimed to determine the effect of NIBS on upper limb motor impairment, functional performance, and participation in activities of daily living after stroke. Method Literature search was conducted for randomized controlled trials (RCTs) assessing the effect of "tDCS" or "rTMS" combined with other therapies on upper extremity motor recovery after stroke. The outcome measures were Fugl-Meyer Assessment of Upper Extremity (FMA-UE), Wolf Motor Function Test (WMFT), and Barthel Index (BI). The mean difference (MD) and 95%CI were estimated for motor outcomes. Cochrane risk of bias tool was used to assess the quality of evidence. Result Twenty-five RCTs involving 1102 participants were included in the review. Compared to sham stimulation, NIBS combined with other therapies has effectively improved FMA-UE (MD0.97 [95%CI, 0.09 to 1.86; p = .03]) and BI score (MD9.11 [95%CI, 2.27 to 15.95; p = .009]) in acute/sub-acute stroke (MD1.73 [95%CI, 0.61 to 2.85; p = .003]) but unable to modify FMA-UE score in chronic stroke (MD-0.31 [95%CI, -1.77 to 1.15; p = .68]). Only inhibitory (MD3.04 [95%CI, 1.76 to 4.31; I-2 = 82%, p < .001] protocol is associated with improved FMA-UE score. Twenty minutes of stimulation/session for >= 20 sessions was found to be effective in improving FMA-UE score (Stimulation time: ES0.45; p <= .001; Sessions: ES0.33; p <= .001). The NIBS did not produce any significant improvement in WMFT as compared to sham NIBS (MD0.91 [95% CI, -0.89 to 2.70; p = .32]). Conclusion Moderate to high-quality evidence suggested that NIBS combined with other therapies is effective in improving upper extremity motor impairment and participation in activities of daily living after acute/sub-acute stroke.