Noninvasive Vagus Nerve Stimulation in Parkinson's Disease: A Systematic Review

While pharmacologic interventions remain the mainstay of Parkinson's disease (PD) treatment, alternative approaches such as vagus nerve stimulation (VNS) have drawn attention for their potential in managing PD symptoms.

We aimed to conduct a systematic review to comprehensively evaluate the safety and efficacy of VNS for motor and nonmotor symptoms of PD.

A systematic search was conducted across PubMed, Scopus, Cochrane Library, and Web of Science for relevant journal articles published up to October 2024. The findings were descriptively reported to evaluate the overall safety and efficacy of VNS in addressing both motor and nonmotor features of PD.

A total of 12 journal articles with data from 287 participants were included. Ten studies reported that VNS significantly improved gait characteristics. Category fluency significantly declined in one study. Additionally, nonsignificant changes were observed in gastroenteric symptoms, fatigue, and both sympathetic and parasympathetic cardiac activity, with each of these outcomes reported in a separate study.

Noninvasive VNS demonstrated favorable safety and efficacy for gait impairments in patients with PD, indicating its potential as a versatile intervention capable of addressing multiple aspects of the disease pathology. However, further research is necessary to reveal the underlying mechanisms, optimize stimulation parameters, and assess the long-term safety and efficacy of VNS as a therapeutic strategy for PD.