A Trial of Rehabilitation Paired with VNS for Motor Function in Patients with Stroke (Repair Study)

The goal of this clinical trial is to investigate the efficacy and safety of vagus nerve stimulation (VNS) paired with rehabilitation for enhancing upper extremity motor function after ischemic stroke. Researchers will compare the outcomes of active VNS paired with rehabilitation against sham VNS (the actual intensity is 0 mA) also paired with rehabilitation, in order to assess improvements in arm motor function post-stroke. Participants in this study will undergo a surgical procedure to implant the VNS system and will subsequently recieve a 6 weeks in-clinic therapy, followed by an additional 6 weeks home exercise. During the final 6 weeks, participants will either recieve in-clinic therapy or maintain their home exercise, depending on their assigned group.

There are 6 follow-up timepoints in this trial: 1. Screening follow-up timepoint (V1): All participants will sign the informed consent form and receive pre-implant evaluation, including physical examination, brain magnetic resonance imaging, FMA-UE, WMFT, modified Ashworth sacle, BDI, ect. 2. Surgery follow-up timepoint (V2):All participants will be implanted with the VNS system, including the G115R IPG and L312 lead. 3. Baseline follow-up timepoint (V3): There is a baseline evaluation 7 to 14 days after the surgery, then participants will be randomly assigned to VNS group or Control group. The randomization will be stratified by baseline FMA-UE (20 to 35, 36 to 50), age (\<50, ≥50) and research center (south centers, north centers). 4. Clinic rehabilitation follow-up timepoint (V4): Participants will receive standard clinic rehabilitation 3 days per week and lasting 6 weeks. Active VNS (VNS group) or sham VNS (Control group) will be paired with rehabilitation. Participants will be evaluated at the last day of this follow-up timepoint. 5. Home exercise follow-up timepoint (V5): Participants will take standard home exercise everyday in 6 weeks. Active VNS (VNS group) or sham VNS (Control group) will be paired with rehabilitation. At the last day, after evaluating, group assignment is unblinded. 6. Unmasking follow-up timepoint (V6): In this 6 weeks, all participants will receive active VNS. Participants in VNS group will still take standard home exercise, and participants in Control group will receive standard clinic rehabilitation again. Participants will be also evaluated at the last day of this follow-up timepoint.