Yohei Okada, Yuki Nishi, Naoya Hasegawa, Hiroshi Kataoka, Junji Nakamura, Taiyo Kai, Koki Ikuno, Sachio Nabeshima, Ryotaro Doko, Rina Nishimoto, Rio Fujita, Yuki Mori, Ayato Yoshinaga, Koji Shomoto
Transcutaneous auricular vagus nerve stimulation (taVNS) is a promising non-invasive neuromodulation approach for addressing gait impairments in Parkinson's disease (PD). However, evidence regarding its effects on daily-life gait remains limited. We report a case of a 67-year-old woman with PD and freezing of gait (FOG), based on the hypothesis that taVNS may enhance gait automaticity under daily-life conditions. A single-case A-B-C design was used, consisting of baseline, sham stimulation, and taVNS phases. Gait performance was assessed using wearable accelerometry in both experimental and daily-life settings. While no significant changes were observed in gait parameters during experimental assessments, daily-life walking measures-step velocity, step length, variability, and asymmetry-showed improvements during the taVNS phase. Importantly, no falls or FOG episodes were observed during the taVNS phase. These findings support the feasibility of taVNS and provide preliminary support for its potential therapeutic role in enhancing gait automaticity in daily life. Further controlled studies are warranted.