Different Frequency Applications of Transcutaneous Auricular Vagus Nerve Stimulation in Healthy Individuals

Официальное название

Investigation of the Acute Effects of Different Frequency Applications of Transcutaneous Auricular Vagus Nerve Stimulation on Autonomic Physiological Responses in Healthy Individuals

Обзор

This randomized, participant-blinded, sham-controlled crossover study aims to investigate the acute effects of different frequency applications of transcutaneous auricular vagus nerve stimulation (taVNS) on autonomic physiological responses in healthy adults. Participants will receive sham (0 Hz), 10 Hz, 25 Hz, 50 Hz, and 100 Hz taVNS in separate sessions with washout periods between visits. Heart rate variability, blood pressure, pulse rate, respiratory rate, and subjective discomfort will be assessed before and after each intervention session.

Подробное описание

The vagus nerve is a major regulator of the parasympathetic branch of the autonomic nervous system. Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation technique applied to auricular regions innervated by the auricular branch of the vagus nerve. Although taVNS has been reported to modulate autonomic function, the acute physiological effects of different stimulation frequencies remain insufficiently characterized.

This study is designed as a randomized, participant-blinded, sham-controlled crossover trial in healthy adults aged 18 to 40 years. Each participant will undergo five intervention conditions in randomized order: sham (0 Hz), 10 Hz, 25 Hz, 50 Hz, and 100 Hz taVNS. Sessions will be separated by 48 to 72 hours to minimize carryover effects. Each stimulation session will last 10 minutes.

Primary autonomic outcomes will be derived from heart rate variability parameters obtained using a Polar H10 chest strap and analyzed with Kubios HRV software. Secondary physiological outcomes will include systolic and diastolic blood pressure, pulse rate, respiratory rate, and subjective discomfort measured using a visual analog scale. The study aims to identify frequency-specific autonomic response profiles and to evaluate whether respiratory rate influences heart rate variability changes associated with taVNS.

Вмешательства

• Устройство Sham taVNS
  Sham stimulation is delivered under conditions similar to active taVNS without meaningful vagal stimulation.
• Устройство taVNS 10 Hz
  Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 10 Hz.
• Устройство taVNS 25 Hz
  Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 25 Hz.
• Устройство taVNS 50 Hz
  Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 50 Hz.
• Устройство taVNS 100 Hz
  Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 100 Hz.

Первичные конечные точки

• Change in Root Mean Square of Successive Differences (RMSSD) [Срок оценки: Immediately before and immediately after each 10-minute intervention session]
• Change in High-Frequency Heart Rate Variability (HF-HRV) [Срок оценки: Immediately before and immediately after each 10-minute intervention session]

Вторичные конечные точки (8)

• Change in Standard Deviation of Normal-to-Normal RR Intervals (SDNN) [Срок оценки: Immediately before and immediately after each 10-minute intervention session]
• Change in Low-Frequency (LF) Power [Срок оценки: Immediately before and immediately after each 10-minute intervention session]
• Change in LF/HF Ratio [Срок оценки: Immediately before and immediately after each 10-minute intervention session]
• Change in Systolic Blood Pressure [Срок оценки: Immediately before and immediately after each 10-minute intervention session]
• Change in Diastolic Blood Pressure [Срок оценки: Immediately before and immediately after each 10-minute intervention session]
• Change in Pulse Rate [Срок оценки: Immediately before and immediately after each 10-minute intervention session]
• Change in Respiratory Rate [Срок оценки: Immediately before and immediately after each 10-minute intervention session]
• Change in Subjective Discomfort Assessed by Visual Analog Scale (VAS) [Срок оценки: Immediately before and immediately after each 10-minute intervention session]

Критерии участия

Критерии включения

• Healthy adults aged 18 to 40 years
• No known neurological, cardiovascular, respiratory, or metabolic disease
• Able to understand study procedures and provide written informed consent
• No active infection, open wound, or dermatological lesion in the ear region that would interfere with taVNS application
• Willing and able to attend all study visits

Критерии исключения

• History of cardiac arrhythmia, pacemaker, or any implanted electronic medical device History of hypertension, diabetes, chronic pulmonary disease, epilepsy, or systemic disease affecting autonomic nervous system function
• Regular use of medications that may affect autonomic function (e.g., beta-blockers, antidepressants, antiarrhythmics)
• Intense physical exercise within the previous 24 hours
• High caffeine or alcohol intake within 12 hours prior to assessment
• Active smoking on the assessment day
• Pregnancy or suspected pregnancy
• Severe discomfort during stimulation (VAS >= 7), dizziness, nausea, or unwillingness to continue
• Any condition judged by the investigators to make participation unsuitable'

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Да

Дизайн исследования

Распределение

Рандомизированное

Модель

Перекрёстный дизайн

Маскирование

Простое слепое

Основная цель

Фундаментальное исследование

Центры проведения

Turkey (Türkiye) · 1 центр

• Artvin Coruh University, Artvin Vocational School, Disabled Care and Rehabilitation Labora — Artvin

Публикации

• Shaffer F, Ginsberg JP. An Overview of Heart Rate Variability Metrics and Norms. Front Public Health. 2017 Sep 28;5:258. doi: 10.3389/fpubh.2017.00258. eCollection 2017. PMID 29034226
• Yakunina N, Kim SS, Nam EC. Optimization of Transcutaneous Vagus Nerve Stimulation Using Functional MRI. Neuromodulation. 2017 Apr;20(3):290-300. doi: 10.1111/ner.12541. Epub 2016 Nov 29. PMID 27898202
• Peuker ET, Filler TJ. The nerve supply of the human auricle. Clin Anat. 2002 Jan;15(1):35-7. doi: 10.1002/ca.1089. PMID 11835542
• Frangos E, Ellrich J, Komisaruk BR. Non-invasive Access to the Vagus Nerve Central Projections via Electrical Stimulation of the External Ear: fMRI Evidence in Humans. Brain Stimul. 2015 May-Jun;8(3):624-36. doi: 10.1016/j.brs.2014.11.018. Epub 2014 Dec 6. PMID 25573069

Идентификаторы

NCT: NCT07526402 · TAVNS4

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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