Respiratory-Gated Vagal Nerve Stimulation for Chronic Pain
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 19
- 试验地点
- 1
- 主要终点
- Mechanical Temporal Summation
研究概览
简要总结
Vagus Nerve Stimulation (VNS) is a validated and FDA-approved therapy that has improved the lives of many individuals with epilepsy and depression and has shown promise for treating chronic pain. However, there is moderate morbidity associated with the surgical procedure and maintenance of VNS. The study team has developed a novel, non-invasive procedure based on the neurobiology of VNS treatment which is termed Respiratory-gated Auricular Vagal Afferent Nerve Stimulation (RAVANS). The investigators hope to maximize efficacy and better understand applicability of RAVANS by applying this to chronic pain patients with a range of psychiatric and psychological comorbidity. This high-distress subpopulation of chronic pain patients has been notoriously difficult to treat and is in need of new, innovative therapies. The investigators propose applying electrical stimulation of the somatosensory vagal afferent receptors in the ear using transcutaneous-VNS (t-VNS) during the exhalation phase of breathing in order to augment the clinical efficacy of t-VNS.
This proposal includes a single blinded, controlled design for testing the impact of RAVANS therapy on pain and mood fro chronic pain. Patients will complete 2 in-person visits, one with RAVANS therapy and one with non-RAVANS stimulation. During each session, participants will complete questionnaires, quantitative sensory testing (QST), and receive either real or sham RAVANS stimulation.
详细描述
Testing will occur over the course of 2 2-3 hour study visits. After completing consent forms, participants will complete questionnaires and undergo baseline Quantitative Sensory Testing (QST). After baseline sensory testing and completion of measures, participants will complete a 30-minute rest period during which time they are instructed to relax and regulate their breathing. After the rest, they will receive a 30-minute RAVANS or non-RAVANS stimulation. Following the RAVANS stimulation, participants will again undergo QST testing. Throughout the session, subjects will rate pain and mood using numeric rating scales and physiological monitoring will occur as described below.
RAVANS stimulation Electrodes will be placed in the auricle of the left ear. Electrical stimulation to these electrodes will be provided by a current-constant stimulator (Urostim, Schwa-Medico). Stimulation will be gated, with 1-second delay, after peak inhalation (i.e. during exhalation). Respiratory gating for stimulation will require real-time evaluation of the respiratory cycle. The study will use a belt system constructed in-house, and similar to the system used in several previous studies. A pneumatic belt will be placed around the subject's lower thorax. Once electrodes are set up, subjects will be asked to rate stimulation intensity on a NRS of 0 to 10 (0: no sensation, 10: pain detection threshold). Current intensity will be set to achieve moderate to strong (but not painful) sensation, and this current intensity will be used on subsequent stimulation runs.
Non-RAVANS stimulation For sessions randomized to sham stimulation, the electrodes in the ear will remain as described above, but the leads will be disconnected from the stimulator. Subjects will be instructed that for this session they may or may not feel pulsing in their ear, and that the goal is to ensure that the stimulus was not painful.
Physiological Monitoring In addition to respiration, which by necessity will be monitored with the pneumatic belt as part of the RAVANS procedure, the investigators will also collect ECG data. The ECG signal will also be acquired by a laptop device system, temporally locked to the respiratory signal. The ECG can be used to quantify heart rate and heart rate variability.
Sensory Tests to be Completed at Baseline and After Experimental Condition:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 21 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •chronic pain lasting for more than 6 months as the primary complaint.
- •typical pain ratings ≥ 3/10 on a visual analogue scale.
- •able to speak and understand English.
排除标准
- •evidence of delirium, dementia, psychosis, or other cognitive impairment preventing completion of study procedures.
- •history of cardiac or nervous system disease that, in the investigator's judgment, precludes participation in the study because of a heightened potential for adverse outcome.
- •current peripheral neuropathy.
- •current pregnancy, or intention to become pregnant during the study.
研究组 & 干预措施
RAVANS
Electrodes will be placed in the auricle of the left ear. Electrical stimulation to these electrodes will be provided by a current-constant stimulator (Urostim, Schwa-Medico). Stimulation will be gated, with 1-second delay, after peak inhalation (i.e. during exhalation). Respiratory gating for stimulation will require real-time evaluation of the respiratory cycle. The study will use a belt system constructed in-house, and similar to the system used in several previous studies. A pneumatic belt will be placed around the subject's lower thorax. Once electrodes are set up, subjects will be asked to rate stimulation intensity on a NRS of 0 to 10 (0: no sensation, 10: pain detection threshold). Current intensity will be set to achieve moderate to strong (but not painful) sensation, and this current intensity will be used on subsequent stimulation runs.
干预措施: RAVANS (Device)
non-RAVANS
For sessions randomized to sham stimulation, the electrodes in the ear will remain as described above, but the leads will be disconnected from the stimulator. Subjects will be instructed that for this session they may or may not feel pulsing in their ear, and that the goal is to ensure that the stimulus was not painful.
干预措施: RAVANS (Device)
结局指标
主要结局
Mechanical Temporal Summation
时间窗: immediately post-RAVANS stimulation
Increases in pain with repeated mechanical stimulation
Pressure Pain Sensitivity
时间窗: immediately post-RAVANS stimulation
Thresholds for pressure pain assessed at several body sites
次要结局
- Pain Severity(immediately post-RAVANS)
研究者
Robert Edwards
Clinical Psychologist
Brigham and Women's Hospital