Brain Computer Interface training for patients with severe upper limb paresis after stroke : A pilot RCT

Background: Brain Computer Interfaces (BCI) pair brain activity with visual and/or motor feedback. They may provide sorely needed training alternatives for patients with severely impaired upper limb after stroke, where treatment choices are limited and unsatisfactory. Objectives: To examine if BCI-based training is more effective in improving upper limb (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 stroke and severe UL paresis (< 13 on Action Research Arm Test (ARAT)) were included and randomized to either BCI training as part of their rehabilitation or conventional UL rehabilitation with a target of 12 BCI sessions. The sessions were conducted 3-4 times weekly for 3-4 weeks. Main endpoint was the ARAT at three months post stroke. Secondary outcome measures comprised Fugl-Meyer Motor Assessment UL and Functional Independence Measure. At baseline, Transcranial direct stimulation (TMS) was performed to examine CST integrity. EEG data were analyzed to see if there were changes in Event-related desynchronization (ERD) and lateralization during the course of treatment. Results: Data from 35 patients were available at three months follow-up. In general, few patients (10/35) improved above the minimally clinically important difference of 6 points on ARAT, in the BCI group 5/15, in control 5/20. An independent samples Mann-Whitney U test revealed no differences between the groups, p=0.382. CST lesion (MEP-) was a significant predictor of poor outcome, p=Conclusions Though more patients in the BCI group improved, the difference was not significant. Larger studies including only patients with some preserved CST integrity should be attempted.