Vagus nerve stimulation paired with tactile training improved sensory function in a chronic stroke patient

Abstract

BACKGROUND:Recent studies indicate that vagus nerve stimulation (VNS) paired with rehabilitation can enhance neural plasticity in the primary sensory and motor cortices, improve forelimb function after stroke in animal models and improve motor function in patients with arm weakness after stroke. OBJECTIVE:To gain "first-in-man" experience of VNS paired with tactile training in a patient with severe sensory impairment after stroke. METHODS:During the long-term follow-up phase of a clinical trial of VNS paired with motor rehabilitation, a 71-year-old man who had made good motor recovery had ongoing severe sensory loss in his left hand and arm. He received VNS paired with tactile therapy in an attempt to improve his sensory function. During twenty 2-hour sessions, each passive and active tactile event was paired with a 0.5 second burst of 0.8 mA VNS. Sensory function was measured before, halfway through, and after this therapy. RESULTS:The patient did not report any side effects during or following VNS+Tactile therapy. Quantitative measures revealed lasting and clinically meaningful improvements in tactile threshold, proprioception, and stereognosis. After VNS+Tactile therapy, the patient was able to detect tactile stimulation to his affected hand that was eight times less intense, identify the joint position of his fingers in the affected hand three times more often, and identify everyday objects using his affected hand seven times more often, compared to baseline. CONCLUSIONS:Sensory function significantly improved in this man following VNS paired with tactile stimulation. This approach merits further study in controlled clinical trials.

Transcutaneous Auricular Vagus Nerve Stimulation with Upper Limb Repetitive Task Practice May Improve Sensory Recovery in Chronic Stroke

“…Subsequently, Kilgard et al reported sensory improvements in a stroke survivor who received VNS (via a surgically implanted stimulator) paired with a sensory stimulus ('tactile therapy') of the upper limb [8]. The individual was asked to localise, identify and explore a variety of everyday objects (e.g.…”

ReStore: A wireless peripheral nerve stimulation system

“…Peripheral nerve stimulation has emerged as a means to treat a variety of neurological diseases including pain, sleep apnea, urinary incontinence, stroke, and tinnitus [1][2][3][4][5][6][7][8][9][10][11]. Given the broad application of the potential therapy, there is a great deal of interest in developing improved technologies to deliver nerve stimulation.…”

Effects of Transcutaneous Electric Nerve Stimulation on Upper Extremity Proprioceptive Function

“…This finding is consistent with recent studies exploring the potential of combined VNS and physical training for stroke rehabilitation. For example, Kilgard and colleagues found that invasive VNS stimulation delivered at 30 Hz was associated with improved somatosensory function in a patient with severe sensory impairment due to stroke [14]. Similarly, a study of twelve stroke patients that received auricular VNS at 25 Hz during performance of a motor task found that most patients showed post-intervention increases in sensory function [8].…”

“…Twenty (20) subjects were randomly assigned to each of four stimulation frequency groups (30Hz, 300Hz, 3kHz, or sham). Thirty (30) Hz stimulation was chosen because frequencies in this range are associated with high degrees of cortical plasticity changes in animal experiments [13] and have been used in previous studies of stroke patients [8,14]. Higher frequencies were included based on their use in other cranial nerve studies [9,15] and observations that these frequencies Figure 2.…”