Vagus Nerve Stimulation as a Strategy to Augment Stroke Rehabilitation

Abstract

Neural plasticity supports recovery after neurological injury. Strategies that enhance adaptive neural plasticity in conjunction with rehabilitation hold promise to substantially improve recovery of motor and sensory function after neurological damage. We have developed an innovative method using brief bursts of vagus nerve stimulation (VNS) paired with rehabilitative training to enhance plasticity in motor circuits. VNS drives phasic activation of plasticity-enhancing neuromodulatory systems which augment rehabilitation-dependent plasticity. Our studies demonstrate that VNS paired with rehabilitative training improves recovery of forelimb function in multiple animal models of neurological injury, including spinal cord injury (SCI), traumatic brain injury (TBI), intracerebral hemorrhage, and ischemic stroke. Moreover, a recent pilot study in chronic stroke patients indicates that VNS paired with rehabilitation yields a significant 3-fold increase in upper arm recovery, highlighting the clinical potential of this therapy. Here, I will present our recent study demonstrating that VNS paired with rehabilitation improves recovery of complex forelimb motor function after ischemic stroke, and that these long-lasting benefits generalize to similar, unrehabilitated forelimb movements. VNS paired with rehabilitation triples the neural connectivity to forelimb muscles, indicating that VNS enhances plasticity to promote recovery. Additionally, I will describe ongoing studies to develop VNS therapy to improve motor and sensory recovery after other neurological injuries, including spinal cord injury (SCI) and peripheral neuropathy, and present findings from studies to optimize the efficacy of VNS therapy to promote successful translation to clinical practice.