Effect of transcranial direct current stimulation combined with virtual reality on lower-limb function and balance in patients during convalescent stroke recovery

<title>Abstract</title> <p>Objective: To evaluate the effects of transcranial direct current stimulation (tDCS) combined with virtual reality (VR) training on lower-extremity motor function and balance in patients recovering from stroke and to explore the underlying neurophysiological mechanisms. Methods: In this randomized, double-blind, sham-controlled trial, 60 patients recovering from stroke were allocated in a 1:1 ratio to an experimental group receiving tDCS, VR training, and conventional rehabilitation or a control group receiving sham tDCS, VR training, and conventional rehabilitation. Each group initially included 30 patients; one patient in the experimental group withdrew, leaving 59 patients who completed the study. The intervention was administered once daily, 5 days per week, for 4 weeks. The primary outcome was the Fugl-Meyer Assessment of the Lower Extremity (FMA-LE). Secondary outcomes included the Berg Balance Scale (BBS), Timed Up and Go Test (TUGT), 6-Minute Walk Test (6MWT), Modified Barthel Index (MBI), and central motor conduction time (CMCT) assessed using motor-evoked potentials. Results: After the intervention, FMA-LE, BBS, 6MWT, and MBI scores increased significantly in both groups (all P &lt; 0.001), whereas TUGT time and CMCT decreased significantly (P &lt; 0.05). Improvements were significantly greater in the experimental group than in the control group, with post-intervention values of 26.17 ± 1.69 versus 23.07 ± 1.86 for FMA-LE, 38.21 ± 4.16 versus 33.13 ± 5.69 for BBS, 14.03 ± 2.34 versus 15.83 ± 2.42 for TUGT, 248.07 ± 49.99 m versus 188.20 ± 87.35 m for 6MWT, 70.62 ± 5.07 versus 63.43 ± 5.64 for MBI, and 7.18 ± 1.37 ms versus 8.30 ± 2.05 ms for CMCT (all P &lt; 0.05). In addition, the change in FMA-LE score was negatively correlated with the change in CMCT in the experimental group (r =-0.143, P &lt; 0.05). Conclusion: tDCS combined with VR training may further improve lower-extremity motor function, balance, and activities of daily living in patients recovering from stroke by enhancing cortical excitability and shortening central motor conduction time. This combined intervention was more effective than VR training alone.</p>