Effects of dual-task mode brain-computer interface based on motor imagery and virtual reality on balance and attention in patients with stroke: a randomized controlled pilot trial.

Background: Brain-computer interface (BCI) has been shown to be beneficial in improving lower limb motility in stroke, but their effectiveness on balance and attention is unclear. In addition, current BCIs are mostly in single-task mode. The BCI system used in this study was based on a dual-task model of motor imagery (MI) and virtual reality (VR). Previous studies have demonstrated that dual-task seems to be beneficial for balance and attention. The purpose of this study was to validate the effects of MI-VR-based dual-task BCI on balance and attention in participants with stroke.

Methods: This pilot, single-blind, randomized controlled trial involved 38 stroke participants, randomized to the BCI (BCI pedaling training) or control group (conventional pedaling). Both groups trained 20 min daily, 5 days a week for 4 weeks, alongside conventional rehabilitation. Thirty participants completed the program (mean age: 56.56 years, mean disease duration: 4.48 months). Assessments were made before and after 4 weeks. The primary outcome was the Berg Balance Scale (BBS), and secondary outcomes included the Timed Up and Go Test (TUGT), Fugl-Meyer Lower Extremity Assessment (FMA-LE), Symbol Digit Modalities Test (SDMT), and average attention index.

Results: 30 participants completed the study (14 in the BCI and 16 in the control group). The retention rates were 73.68% and 84.21% respectively. No adverse events were reported in this study and participants did not report any discomfort. The changes in BBS, TUGT and SDMT values in the BCI group were significantly better than those in the control group (P < 0.05). Average attention index of the BCI group's participants grew with the number of training sessions, and there was a significant difference comparing pre- to post-treatment (p < 0.05). The value of BBS change is linearly correlated with the value of SDMT change (F = 8.778, y = 0.59x + 1.90, P < 0.001).

Conclusions: This study initially showed positive effects of dual-task mode of BCI pedalling training on balance and attention in stroke participants. However, given the preliminary nature of this study and its limitations, the results need to be treated with caution. Trial registration Chinese Clinical Trial Registry Identifier: ChiCTR2300071522. Registered on 2023/05/17.