Acute Neurophysiological Effects of Transcutaneous Auricular Vagus Nerve Stimulation in Chronic Insomnia Disorder
Abstract
Abstract Chronic insomnia disorder is characterized by persistent cortical and network-level hyperarousal, yet the acute neurophysiological effects of transcutaneous auricular vagus nerve stimulation (taVNS) remain unclear. In this randomized, single-blind, sham-controlled trial, 54 treatment-naive adults with chronic insomnia disorder received either active taVNS (n = 29) or sham stimulation (n = 25). Resting-state EEG was recorded before and after the first stimulation session and analyzed using regional spectral power and EEG microstate metrics. Active taVNS produced immediate, region-specific spectral modulation, mainly increasing central alpha and frontal theta power, with additional theta changes in bilateral temporal regions. Canonical microstate topographies were not acutely altered; however, temporal dynamics differed between groups. Microstate organization remained relatively stable after active stimulation, whereas sham stimulation was accompanied by reduced Class C expression and altered A-to-D transition probabilities. Higher baseline insomnia severity was associated with greater Class C expression and reduced Class D expression, while higher baseline anxiety predicted a weaker frontal theta response to active taVNS. These findings suggest that acute taVNS may engage insomnia-related hyperarousal through alpha-theta oscillatory modulation rather than immediate reconfiguration of canonical microstate topographies, supporting EEG markers as candidate mechanistic…
How strong is the evidence?
Evidence Hub reads this as a randomized trial. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 29 participants or records.
Read the paper
Related studies
- Comparative effectiveness of GLP-1 receptor agonists on glycaemic control, body weight, and lipid profile for type 2 diabetes: systematic review and network meta-analysis
- Adverse effects of cyclooxygenase 2 inhibitors on renal and arrhythmia events: meta-analysis of randomized trials
- Benefits and harms of drug treatment for type 2 diabetes: systematic review and network meta-analysis of randomised controlled trials
- Comparative effectiveness and safety of statins as a class and of specific statins for primary prevention of cardiovascular disease: A systematic review, meta‐analysis, and network meta‐analysis of randomized trials with 94,283 participants
- Screen time increases overweight and obesity risk among adolescents: a systematic review and dose-response meta-analysis
- Exposure to WHO AWaRe antibiotics and isolation of multi-drug resistant bacteria: a systematic review and meta-analysis
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.