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

Abstract

Background-Sensory impairment is associated with reduced functional recovery in stroke survivors. Invasive vagus nerve stimulation (VNS) paired with rehabilitative interventions improves motor recovery in chronic stroke. Non-invasive approaches e.g. transcutaneous auricular VNS (taVNS) are safe, well-tolerated and may also improve motor function in those with residual weakness. We report the impact of taVNS paired with a motor intervention, repetitive task practice, on sensory recovery in a cohort of patients with chronic stroke. Methods-Twelve participants who were > 3 months post-ischaemic stroke with residual upper limb weakness received 18 x 1 hour sessions over 6 weeks with an average of at least 300 repetitions of functional arm movements per session concurrently with taVNS at maximum tolerated intensity. Light touch and proprioception were scored as part of the Upper Limb Fugl-Meyer (UFM) assessment at baseline and post-intervention (score range for sensation 0-12). Results-11 participants (92%) had sensory impairment at baseline of whom 7 (64%) regained some sensation (proprioception n = 6 participants, light touch n = 2, both modalities n =1) post intervention. The maximal increase in UFM sensation score (3 points) was seen in the patient with the greatest improvement in motor function. Conclusions-taVNS paired with motor rehabilitation may improve sensory recovery in chronic stroke patients. The relative contribution of motor and sensory rehabilitation to overall functional recovery in chronic stroke needs further characterisation in a larger, phase 2 study.

Autonomic balance determines the severity of COVID-19 courses

“…We know direct electrical efferent and afferent VNS. Moreover, several transcutaneous VNS (Baig et al 2019 ) approaches are also in use (Johnston and Webster 2009 ). Recently, Staats et al (Staats et al 2020 ) reported distinct symptom relief (fatigue, low appetite, and coughing bouts such as dyspnea and chest pressure/tightness) in two SARS-CoV-2 positive tested patients under the usage of noninvasive vagal nerve stimulation (nVNS).…”

Effect and Safety of Transcutaneous Auricular Vagus Nerve Stimulation on Recovery of Upper Limb Motor Function in Subacute Ischemic Stroke Patients: A Randomized Pilot Study

“…Recent clinical trials show that VNS can improve upper extremity motor function in stroke patients with upper extremity motor dysfunction [ 6 , 7 ]. Transcutaneous auricular vagus nerve stimulation (taVNS) is a noninvasive method of VNS via transcutaneous stimulation of the peripheral auricular branch of the vagus nerve [ 8 ] and regarded as a potentially safer, better-tolerated method for sensory and motor recovery in chronic stroke [ 9 , 10 ]. Previously, one study has reported that taVNS improves neurobehavioral recovery in acute stroke rats [ 11 ].…”

Effects of Transcutaneous Electric Nerve Stimulation on Upper Extremity Proprioceptive Function

“…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.…”

“…For example, TENS of the trigeminal, vagal, and other craniocervical nerves has been shown to safely induce plasticity in healthy humans and provide therapeutic benefits for the treatment of epilepsy, depression, PTSD, and other disorders [5][6][7]. In the sensorimotor domain, a recent study suggests that TENS of the auricular branch of the vagus nerve combined with standard rehabilitation can improve proprioceptive and motor function following stroke [8]. This is thought to occur through activation of brainstem circuits responsible for arousal and endogenous neuromodulation of the cortex.…”