Capsaicin-induced Muscle Pain in Humans: From Investigating Central Pain Processing to Developing Clinical Applications
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 72
- 试验地点
- 1
- 主要终点
- Intensity of shoulder pain on numeric rating scale
研究概览
简要总结
There is currently no specific diagnostic test for primary muscular pain. The present study investigates whether selective blockade of the suprascapular nerve can effectively abolish experimental pain arising from the supraspinatus muscle. Experimental muscle pain is induced by intramuscular injection of capsaicin, an alkaloid from red chili peppers. The study consists of three parts:
- to describe the development, time course and intensity of capsaicin-induced muscle pain
- to evaluate the effectiveness of suprascapular nerve block against capsaicin-induced muscle pain
- to compare suprascapular nerve block and direct intramuscular local anesthetic infiltration for their effectiveness in capsaicin-induced muscle pain
详细描述
Background
Musculoskeletal pain is one of the most common reasons for consulting a physician. Many musculoskeletal pain disorders are associated with a widespread decrease in pain thresholds, indicating a state of hyperexcitability of the central nervous system.
This central hypersensitivity can be assessed by measuring pain thresholds to different experimental stimuli, using so-called quantitative sensory tests (QST).
Several experimental pain models are being used in healthy volunteers in order to study the central mechanisms of pain processing. Injection of capsaicin is one of them, which is associated with spreading of local pain, development of referred pain and hyperalgesia to thermal, mechanical or electrical stimuli.
Intramuscular injection of capsaicin is therefore potentially interesting for investigating primary muscle pain, central hypersensitivity and endogenous pain modulation. The present research project comprises three substudies which use intramuscular capsaicin to detect changes in central pain processing and to evaluate clinical tools for the diagnosis of primary muscle pain.
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)
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age 18-80 years
- •Written informed consent
排除标准
- •Any acute pain at the moment of testing
- •Intake of analgesics 24hours before testing
- •Intake of antidepressants, anticonvulsants or benzodiazepines
- •Allergy to local anesthetic or skin disinfectant
- •Pregnancy or breast-feeding
研究组 & 干预措施
Part 1
Intramuscular injection of capsaicin for the study of pain and hyperalgesia
干预措施: Intramuscular capsaicin injection (Procedure)
Part 2
Pain arising from supraspinatus muscle vs. pain arising from trapezius muscle. Nerve block is only expected to be effective in the former.
干预措施: Suprascapular nerve block (Procedure)
Part 3
Suprascapular nerve block vs. intramuscular local anesthetic against pain arising from the supraspinatus muscle.
干预措施: Local anesthetic infiltration (Procedure)
结局指标
主要结局
Intensity of shoulder pain on numeric rating scale
时间窗: two hours
次要结局
- Pressure pain thresholds(two hours)
- Area of referred pain(two hours)