Abstract Details

Evidence from preclinical studies has suggested the utility of vagus nerve stimulation to treat acute stroke.

The aim of this study was to evaluate the feasibility, safety, and potential efficacy of non-invasive vagus nerve stimulation (nVNS) for the acute treatment of ischemic and hemorrhagic stroke.

Enrolled subjects receiving the standard care for acute stroke were randomly assigned to receive low-dose nVNS, sham (2-minute stimulation applied to the skin overlying the vagus nerve every 10 minutes for 1 hour; 7 stimulations), or high-dose nVNS (2-minute stimulation every 10 minutes during hour 1 and hour 5; 14 stimulations) within 6 hours of stroke onset. Safety endpoints included severe bradycardia (≤50 beats/min) or significant hypotension (≥20-mm Hg reduction in arterial blood pressure) evaluated at 2 and 5 minutes after each stimulation and 30 minutes after the final stimulation. Feasibility was assessed via the proportion of eligible subjects who could initiate nVNS within 6 hours of stroke onset and complete the stimulation protocol. Efficacy measurements included objective imaging and clinical endpoints.

Sixty-eight patients with ischemic (n=60) or hemorrhagic (n=8) stroke completed the study. Baseline characteristics did not differ between the sham (n=24) and nVNS (n=44) groups. No significant bradycardia (sham, 2.9%; nVNS, 3.1%; p=0.965) or hypotension (sham, 1.1%; nVNS, 2.5%; p=0.145) occurred with nVNS. No deaths, acute coronary syndrome, symptomatic intracerebral hemorrhage, or stimulation site reactions were noted. All patients received 100% of intended stimulations. Relative infarct growth, measured by diffusion-weighted imaging, in the high-dose nVNS group (63.3%) was lower than in the sham group (185.8%; p=0.05). Clinical efficacy measures were similar between the sham and nVNS groups.

This study suggests that nVNS is safe and feasible for the acute treatment of ischemic and hemorrhagic stroke. Possible efficacy is suggested by a decrease in relative infarct growth.