Left Vagus Stimulation Modulates Contralateral Subthalamic Power Improving the Gait in Parkinson's Disease

Background: Transcutaneous vagus nerve stimulation (VNS) showed early evidence of efficacy for the gait treatment of Parkinson's disease (PD).Objectives: Providing data on neurophysiological and clinical effects of transauricular VNS (taVNS).Methods: Ten patients with recording deep brain stimulation (DBS) have been enrolled in a within participant design pilot study, double-blind crossover sham-controlled trial of taVNS. Subthalamic local field potentials (beta band power), Unified Parkinson's Disease Rating Scales (UPDRS), and a digital timed-up-and-go test (TUG) were measured and compared with real versus sham taVNS during medication-off/DBS-OFF condition.Results: The left taVNS induced a reduction of the total beta power in the contralateral (ie, right) subthalamic nucleus and an improvement of TUG time, speed, and variability. The taVNS-induced beta reduction correlated with the improvement of gait speed. No major clinical changes were observed at UPDRS.Conclusions: taVNS is a promising strategy for the management of PD gait, deserving prospective trials of chronic neuromodulation.