Transcutaneous Auricular Vagus Nerve Stimulation for Persistent Post-concussion Symptoms

PPCS occur in 30-50% of individuals following a concussion and can persist for months, causing somatic complaints (e.g., headaches and dizziness), cognitive impairments (e.g., memory and concentration issues), emotional disturbances (e.g., anxiety and depression), and sleep disorders. Despite their long-term consequences, effective treatments for PPCS remain scarce. Transcutaneous auricular vagus nerve stimulation (taVNS) is a promising non-invasive technique that stimulates the auricular branch of the vagus nerve to induce bottom-up effects on brain activity, potentially alleviating PPCS.

This randomized, controlled, double-blind clinical trial will evaluate the cumulative and direct neurophysiological and clinical effects of taVNS (tVNS Technologies GmbH, Germany) in 48 patients aged 18 to 65 years who experienced a diagnosed concussion between 4 weeks and 1 year prior to enrollment and suffer from PPCS. Participants will be randomized to either an active taVNS group or a sham stimulation group.

Patients will undergo a total of 15 taVNS sessions over two weeks, including two visits at the University Hospital of Liège (first and last session) and 13 self-administered sessions at home. Symptom severity, including headaches, depression, anxiety, sleep disturbances, and overall quality of life, will be measured using validated questionnaires, while cognitive function (i.e., attention, working memory, executive functions) will be assessed through neuropsychological tests. Additionally, electroencephalographic (EEG) and electrocardiogram (ECG) recordings will be used to measure changes in brain activity and heart rate, respectively, focusing on alterations in power spectral density and functional connectivity patterns that may correlate with clinical improvements.

Follow-up assessments will occur one-month post-intervention via a phone call to collect questionnaires assessing symptom severity and quality of life.

This protocol aims to provide robust evidence on the efficacy and mechanisms of taVNS for PPCS while advancing our understanding of the neurophysiological changes associated with this therapeutic approach.

Interim analyses will be conducted after the inclusion of 24 patients to evaluate preliminary data. These analyses will also allow for adjustments to the sample size, if necessary, to maintain the study's statistical power.

Patients who did not complete 80% of the sessions (12 sessions) will be excluded from the study.

• Effects of taVNS on cognitive functions in patients with PPCS [Срок оценки: From enrollment to the end of the treatment at 2 weeks.]
• Effects of taVNS on verbal memory in patients with PPCS [Срок оценки: From enrollement to the end of the treatment at 2 weeks.]
• Effects of taVNS on heart rate variability in patients with PPCS [Срок оценки: From enrollment to the end of the treatment at 2 weeks.]
• Effects of taVNS on headaches in patients with PPCS [Срок оценки: From enrollment to the end of the study at 6 weeks (including follow-up).]
• Effect of taVNS on sleep quality in patients with PPCS [Срок оценки: From enrollment to the end of the study at 6 weeks (including follow-up).]
• Effects of taVNS on daytime sleepiness in patients with PPCS [Срок оценки: From enrollment to the end of the study at 6 weeks (including follow-up).]
• Effects of taVNS on sleep changes in patients with PPCS [Срок оценки: From enrollment to the end of the study at 6 weeks (including follow-up).]
• Effects of taVNS on depressive symptoms in patients with PPCS [Срок оценки: From enrollment to the end of the study at 6 weeks (including follow-up).]
• Effects of taVNS on anxiety symptoms in patients with PPCS [Срок оценки: From enrollment to the end of the study at 6 weeks (including follow-up).]
• Effects of taVNS on quality of life in patients with PPCS [Срок оценки: From enrollment to the end of the study at 6 weeks (including follow-up).]