Neuromodulation for Functional Recovery After Stroke

This study uses a multicenter, double-blind, randomized controlled design. Eligible participants all undergo implantation of a VNS device and are randomly assigned to an active VNS (0.8 mA) group combined with upper limb rehabilitation or a control VNS (0.0 mA) group. The study hypothesizes that vagus nerve stimulation is effective in improving upper limb motor function in patients in the subacute phase after stroke; that is, a meaningful difference in FMA-UE scores exists between the active VNS group and the control group at the end of 6 weeks of hospital treatment. All enrolled participants undergo implantation of a vagus nerve stimulation device. After preoperative assessment, patients undergo implantation of the vagus nerve stimulation device under general anesthesia. After implantation, participants are randomized 1:1 to active VNS (0.8 mA) combined with upper limb rehabilitation or control VNS (0.0 mA). This trial uses the FMA-UE score, WMFT score, and other measures to assess changes in impairment severity, with a pretreatment baseline assessment performed 1 week after implantation. Stimulation testing is performed in 0.1 mA increments in both groups to assess the level at which participants can perceive and tolerate stimulation. Hospital treatment begins on the day after baseline assessment.

Inclusion criteria

• History of unilateral supratentorial ischemic stroke and in the subacute phase (3-6 months);
• Age between 18-80 years, both male and female;
• FMA-UE score of 20-50 (inclusive);
• Ability to communicate, understand, and provide appropriate consent; participant can follow two-step commands;
• Right or left upper limb weakness;
• Active flexion/extension of the wrist or fingers;
• Informed consent signed by the patient or a family member.

Exclusion criteria

• History of hemorrhagic stroke;
• Persistent dysphagia or choking/coughing while eating or drinking;
• Medications that, at study initiation, may significantly interfere with the effects of VNS on neurotransmitter systems;
• Prior vagus nerve injury, bilateral or unilateral (e.g., injury during carotid endarterectomy);
• Severe or more severe depression (Beck Depression Inventory >29);
• Candidates unsuitable for device implantation surgery (e.g., history of adverse reaction to anesthesia, deemed unsuitable as a surgical candidate by the surgeon, etc.);
• Current use of any other stimulation device, such as a pacemaker or other neurostimulator; current use of any other investigational device or drug;
• Preexisting neurological or psychiatric disorders before stroke onset that affect assessment of the condition;
• Pregnancy, planned pregnancy, or breastfeeding during the study period;
• Severe upper limb spasticity (modified Ashworth ≥3);
• Severe sensory loss. Sensory loss will be measured using the upper extremity sensory portion of the Fugl-Meyer Assessment. The assessment involves light touch (two items) and proprioception (four items). The maximum score is 12; subjects with a score below 6 will be excluded from the study;
• Other conditions that the investigator considers unsuitable for participation or that may pose a significant risk to the patient.