Transcutaneous Auricular Vagus Nerve Stimulation Modulates Autonomic Dynamics During Exercise and Recovery in Chronic Spinal Cord Injury
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 35
- 试验地点
- 1
- 主要终点
- DFA α2
研究概览
简要总结
This study investigates the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on autonomic cardiovascular regulation during exercise and recovery in individuals with chronic spinal cord injury (SCI). Participants undergo two experimental conditions (active taVNS and sham stimulation) in a randomized crossover design while performing a standardized exercise protocol.
Heart rate variability (HRV) is used as a non-invasive biomarker to assess autonomic nervous system dynamics across different phases (baseline, exercise, and recovery). The aim is to characterize physiological responses to neuromodulation and explore whether taVNS modulates autonomic adaptability in this population.
This is a mechanistic physiological study designed to improve the understanding of autonomic regulation in SCI and to explore potential biomarkers of response to neuromodulation.
详细描述
Spinal cord injury (SCI) is associated with significant impairments in autonomic nervous system function, particularly affecting cardiovascular regulation. These alterations reduce physiological adaptability to internal and external stressors and may contribute to increased cardiovascular risk.
Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation technique that has been proposed as a potential tool to influence autonomic function. However, its effects on dynamic autonomic regulation during physiological stress, such as exercise, remain insufficiently characterized in individuals with SCI.
The present study is a randomized, controlled, crossover experimental protocol designed to investigate the acute effects of taVNS on autonomic cardiovascular dynamics during a structured exercise and recovery paradigm. Participants with chronic SCI are exposed to two conditions: active taVNS and sham stimulation, applied in a randomized order.
Each experimental session includes three phases: baseline (rest), exercise (submaximal effort), and recovery. Continuous electrocardiographic recordings are obtained to derive heart rate variability (HRV) metrics. Both linear (time and frequency domain) and non-linear analyses are performed to characterize autonomic regulation and system dynamics.
The primary objective is to evaluate whether taVNS modulates autonomic responsiveness and adaptability across different physiological states. Secondary objectives include the exploration of HRV-derived biomarkers that may reflect autonomic complexity and the identification of response patterns to neuromodulation.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Single (Participant)
盲法说明
Participants are blinded to the stimulation condition (active taVNS vs sham), while investigators are aware of the assigned condition.
入排标准
- 年龄范围
- 18 Years 至 70 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adults (≥18 years) with chronic spinal cord injury
- •Medically stable condition
- •Ability to perform the exercise protocol
- •Ability to provide informed consent
排除标准
- •Acute spinal cord injury
- •Severe cardiovascular or respiratory instability
- •Use of medications significantly affecting autonomic function
- •Skin lesions or contraindications to transcutaneous stimulation
- •Cognitive impairment preventing protocol compliance
研究组 & 干预措施
Active taVNS
Transcutaneous auricular vagus nerve stimulation applied during the experimental protocol.
干预措施: Transcutaneous Auricular Vagus Nerve Stimulation (Device)
Sham Stimulation
Sham stimulation applied under identical experimental conditions without effective vagus nerve activation.
干预措施: Sham Stimulation (Device)
结局指标
主要结局
DFA α2
时间窗: Baseline (last 5 minutes of rest), 10, 15, 20, 25, 30, 35, and 40 minutes.
Detrended fluctuation analysis (α2) derived from RR intervals to assess long-term fractal scaling properties of heart rate variability. RR intervals are recorded continuously and analyzed offline. Data are processed using 5-minute overlapping windows. The value reported at each specific time point represents the calculation for the preceding 5-minute window to characterize autonomic regulation across the session.
次要结局
- RMSSD (ms)(Baseline (last 5 minutes of rest), 10, 15, 20, 25, 30, 35, and 40 minutes.)
- HF power (ms²)(Baseline (last 5 minutes of rest), 10, 15, 20, 25, 30, 35, and 40 minutes.)
- LF power (ms²)(Baseline (last 5 minutes of rest), 10, 15, 20, 25, 30, 35, and 40 minutes.)
- SD1 (ms)(Baseline (last 5 minutes of rest), 10, 15, 20, 25, 30, 35, and 40 minutes.)
研究者
Maria Cristina Nicolau Llobera
Researcher
University of the Balearic Islands