Objective: To perform a systematic review on the efficacy and safety of Transcutaneous auricular vagal stimulation on gait in patients with Parkinson’s disease.

Background: PD is a progressive and debilitating neurodegenerative disease that primarily affects movement. [1] It is characterized by motor symptoms such as bradykinesia, rigidity, tremor, and postural instability. The increasing prevalence of the disease, driven by the aging of the population, will further increase global costs [2]. taVNS has emerged as a promising noninvasive therapy [3].

Method: The search strategy included an active search in the Pubmed and Lilacs databases, where the term “taVNS” was associated with the descriptor “Parkinson’s disease” using the Boolean operator “AND”. Search filters for Randomized Clinical Trials (RCTs) published in English and Spanish, up to 10 years ago, were applied. The authors last searched the databases on March 8, 2025. The identified articles were assessed by two independent reviewers. The risk of bias of each study included in this review was defined using the Revised Cochrane Risk-of-bias Tool for Randomized Trials (RoB 2.0).

Results: Four (4) RCTs were considered eligible [Figure 1], resulting in a total of seventy-seven patients (n = 77). All studies were classified as “moderate” risk by the RoB 2.0 score [Table 1]. The study by van Midden et al. (2024) [4] showed that taVNS increased arm swing velocity (P = 0.030) and stride length (P = 0.027). Zhang et al. (2023) [5] demonstrated that they significantly improved step length (p = 0.022), stride length (p = 0.025), and stride velocity (p = 0.011) compared to baseline and also reduced step length variability (p = 0.008) compared to sham stimulation. Marano et al. (2024) [6] demonstrated that taVNS improved Time to Up and Go (TUG) (P = 0.007), walking velocity (P = 0.027), and stride variability (P = 0.035). Lench et al. (2023) [7] were the only ones who reported adverse effects, which included: insomnia (n = 2), dizziness (n = 1), fatigue (n = 1), nausea (n = 1), tinnitus (n = 1), teeth grinding (n = 1), fluid in the ear (n = 1), nervousness/anxiety (n = 1), and vertigo (n = 1).

Conclusion: taVNS has been shown to improve gait in patients with PD. Future trials with larger cohorts and standardized protocols are needed to validate these results.

PRISMA Flowchart

Risk of bias (RoB 2.0)

References: [1] Ye H, Robak LA, Yu M, Cykowski M, Shulman JM. Genetics and pathogenesis of Parkinson’s syndrome. Annu Rev Pathol Mech Dis. 2023;18:95-121. doi:10.1146/annurev-pathmechdis-031521-034145.
[2] Rezapour A, Movahed E, Jahangiri R, Vahedi S, Olyaeemanesh A. Economic burden of Parkinson’s disease: a systematic review. Parkinsonism Relat Disord. 2024;118:105442. doi:10.1016/j.parkreldis.2024.105442.
[3] Redgrave J, Moore L, Clancy J, Doulazmi M, Sant’Ana T, Saffari A, et al. Clinical application of transcutaneous auricular vagus nerve stimulation: a scoping review. Disabil Rehabil. 2024. doi:10.1080/09638288.2024.2313123.
[4] van Midden V, Simončič U, Pirtošek Z, Kojović M. The effect of taVNS at 25 Hz and 100 Hz on Parkinson’s disease gait: a randomized motion sensor study. Mov Disord. 2024 Aug;39(8):1375-85. doi:10.1002/mds.29826. Epub 2024 May 17. PMID: 38757756.
[5] Zhang H, Cao XY, Wang LN, Tong Q, Sun HM, Gan CT, et al. Transcutaneous auricular vagus nerve stimulation improves gait and cortical activity in Parkinson’s disease: a pilot randomized study. CNS Neurosci Ther. 2023 Dec;29(12):3889-900. doi:10.1111/cns.14309. Epub 2023 Jun 13. PMID: 37311693; PMCID: PMC10651956.
[6] Marano M, Anzini G, Saltarocchi L, Ricciuti R, Capone F, Tan H, et al. Left vagus stimulation modulates contralateral subthalamic β power improving gait in Parkinson’s disease. Mov Disord. 2024 Feb;39(2):424-8.
[7] Lench DH, Turner TH, McLeod C, Boger HA, Lovera L, Heidelberg L, et al. Multi-session transcutaneous auricular vagus nerve stimulation for Parkinson’s disease: evaluating feasibility, safety, and preliminary efficacy. Front Neurol. 2023;14:1210103.

« Back to 2025 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/efficacy-and-safety-of-transcutaneous-auricular-vagal-stimulation-on-gait-in-patients-with-parkinsons-disease-a-systematic-review/