Brain Computer Interface training for patients with severe upper limb paresis after stroke - A randomized controlled pilot trial

Abstract

Abstract Background Restorative Brain-Computer Interfaces (BCI) combined with visual feedback and functional electrical stimulation may provide sorely needed treatment alternatives for patients with severely impaired upper limb (UL) function after stroke. Objectives This study aimed to examine if BCI-based training is more effective in improving UL motor function than conventional therapy in the subacute phase after stroke and if patients with preserved cortical-spinal tract (CST) integrity benefit more from BCI training. Methods Forty patients with severe UL paresis (< 13 on Action Research Arm Test (ARAT) were randomized to either a 12-session BCI training as part of their rehabilitation or conventional UL rehabilitation. BCI sessions were conducted 3–4 times weekly for 3–4 weeks. At baseline, Transcranial Magnetic Stimulation (TMS) was performed to examine CST integrity. Main endpoint was the ARAT at 3 months post-stroke. A binominal logistic regression was conducted to examine the effect of treatment group and CST integrity on achieving meaningful improvement. In the BCI group, EEG data were analyzed to investigate if there were changes in Event-related desynchronization (ERD) and lateralization. Results Data from 35 patients (15 in the BCI group and 20 in the control group) were analyzed at 3-month follow-up. Few patients (10/35) improved above the minimally clinically important difference of 6 points on ARAT, 5/15 in the BCI group, 5/20 in control. An independent-samples Mann-Whitney U test revealed no differences between the two groups, p = 0.382. In the logistic regression only CST integrity was a significant predictor for improving UL motor function, p = 0.007. Conclusion Though more patients in the BCI group improved relative to the group size, the difference between the groups was not significant. In the present study, preserved CTS integrity was much more vital for UL improvement than which type of intervention the patients received. Larger studies including only patients with some preserved CST integrity should be attempted.