Effects of Brain Computer Interface-Robot System on upper limb function recovery in stroke patients: A Protocol Study for a Randomized Controlled Trial

Abstract Background /ObjectiveWe developed a Brain Computer Interface(BCI) robot system for movement recovery of upper limb motor function in post-stroke patients with severe hemiplegia. We designed and performed a randomized controlled clinical trial (RCT) to explore our hypothesis that motor functional recovery using this BCI robot system could be improved in a greater level in severe hemiparesis compared to that of hand robot rehabilitation. And we also focus on the neuroplastic changes between the primary motor cortices(M1) and frontal cortices before and after BCI intervention.Methods We will conduct a single blind, parallel-group trial and recruit subacute or chronic poststroke patients with severe hemiparesis more than 90 days after onset (N=50). Participants are randomly allocated to 2 intervention groups(1:1)by a computer-generated assignment: the BCI-assisted hand robot training(the BCI group,BG,n=25) and a hand robot training not supported by BCI(the robot group,RG, n=25).Both interventions will be delivered 5 sessions per-week for totally 4 weeks as add-on therapies to conventional rehabilitation. Motor functions of the paretic hands will be measured at 4 points: pre- (baseline), mid-(after 10 sessions), post-(after 20 sessions) and one month follow-up(4 weeks after the intervention).All investigators assessing outcomes will be masked to treatment assignment. Improvement in Wolf Motor Function Test (WMFT) will be used as the primary outcome,while Fugl-Meyer Assessment (FMA), its wrist and hand（FMA-WH）sub-score and its shoulder and elbow (FMA-SE) sub-score will be served as secondary outcome measures. Neuroplastic changes will be measured by functional near-infrared spectroscopy (fNIRS) at baseline and one-month follow up after 20 sessions BCI training. Pearson correlation analysis is used to evaluate functional connectivity(FC) across time points.Discussion We expect the BCI-based rewarding of hand robot practice to promote the motor recovery in upper limb motor outcome and also, this clinical improvement to be sustained by a long-lasting neuroplasticity changes promote by the BCI-based intervention.Recruitment started in June 2021. This trial is currently in the data correcting phase. This RCT is expected to be completed by June 30, 2023.Trial registration: Name of registry: Study on the Mechanism of Hand Motor Function Rehabilitation after Stroke. Trial registration number: ChiCTR2100046301; registration date on www.chictr.org.cn: May, 12/2021.