Related Experiment Video
Updated: Jul 17, 2026
Transauricular Vagus Nerve Stimulation and Electroencephalographic Assessment in Disorders of Consciousness
Published on: July 11, 2025
Transcutaneous auricular vagus nerve stimulation for prevention of postoperative cognitive dysfunction in older
Li Ma1, Jianhua Xia1, Xiangsheng Li1
1Department of Anesthesiology, Shanghai Pudong New Area People's Hospital, Shanghai 201299, China.
Introduction:
Postoperative cognitive dysfunction (POCD) is common in the perioperative period among older adults and has been linked to inflammatory responses, neural injury-related biomarkers, and mood changes. Evidence for safe, feasible, and effective non-pharmacological interventions remains limited. This prospective, double-blind, randomized controlled trial evaluated the association between transcutaneous auricular vagus nerve stimulation (taVNS) and postoperative cognitive test performance, and examined concomitant changes in inflammatory and neural injury-related biomarkers and mood.
Materials And Methods:
A total of 103 older adults scheduled for elective laparoscopic gastrointestinal tumor resection were consecutively enrolled and randomly assigned to taVNS or sham stimulation; 99 participants completed follow-up and were included in the primary analysis. Cognitive function was assessed preoperatively and at postoperative day 1, day 7, month 1, and month 3 using the Montreal Cognitive Assessment (MoCA). Serum interleukin-1β (IL-1β) and S100β were measured preoperatively and on postoperative day 7. Mood was assessed preoperatively and on postoperative day 7 using the 24-item Hamilton Depression Scale (HAMD-24).
Results:
From postoperative day 7 onward, MoCA scores were higher in the taVNS group than in the sham group (p = 0.01), with differences maintained at postoperative months 1 and 3 (absolute between-group differences of 2.06 and 2.97 points, respectively; both p < 0.01). RM ANOVA and ANCOVA indicated significant main effects of time and a significant group × time interaction. On postoperative day 7, the taVNS group showed lower postoperative IL-1β and S100β levels than the control group (both p < 0.001) and a smaller worsening in HAMD-24 scores. ΔMoCA was negatively correlated with ΔIL-1β (r = -0.425), ΔS100β (r = -0.248), and ΔHAMD-24 (r = -0.234). Exploratory stratified analyses showed broadly consistent effect directions across subgroups. Adverse event rates were similar between groups (approximately 4.1% in each), and events were mild local reactions.
Discussion:
In this exploratory randomized controlled trial, perioperative taVNS was associated with a more favorable MoCA trajectory after laparoscopic gastrointestinal tumor surgery in older adults, with between-group differences in IL-1β, S100β, and HAMD-24 on postoperative day 7. Clinical significance and generalizability require confirmation in larger studies.
