Brain Activation During Accommodation to Painful Stimulation With Functional Imaging of Pain
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 15
- 试验地点
- 1
- 主要终点
- To determine the areas of brain activity from a 2 minute long painful stimulation
研究概览
简要总结
Blood oxygen level dependant (BOLD) functional magnetic resonance imaging (FMRI) investigations of pain have provided substantial insight into the workings of the human brain. To date, however, the vast majority of studies have dealt with short painful stimulations. This work will expand the investigators knowledge of how longer stimulations are processed by comparing the activation pattern from a two minute painful stimulation with that of an 30-second painful stimulus. The investigators hypothesis that accommodation to the longer stimulation will be evident by either decreases in signal intensity in brain areas known to process pain, or by increasing activity in brain areas thought to be responsible for the modulation of painful perception.
详细描述
Background: Over the past 14 years, BOLD FMRI studies have non-invasively shown that pain activates a matrix of areas, but that this activation decays during stimulation, possibly reflecting the body's ability to "accommodate" to the stimulation. The majority of these use short applications of pain lasting 1 to 30 seconds. However, investigators are now using stimulations much longer than the periods that were typical a few years ago. The effect of signal decay on the activation maps generated by these longer tasks is not known. Because the signal change in many of the subcortical areas involved in pain processing is low, errors in analysis due to neglecting the signal decay may induce significant artifact.
Materials and Methods
Using transcutaneous electrical nerve stimulation, 20 healthy volunteers will experience two different painful stimulations: a repeating 30-second long stimulation and a constant 2 minute stimulation. The brain activity for each will be determined and compared. In addition, the signal decay during each painful stimulation will be quantified and compared.
Significance: Investigators are using longer stimulations periods in an attempt to understand how the brain processes "real- life" pain instead of the artificial on-off pattern of earlier studies. However, significant attention has not been paid to the possible effect of accommodation on the stimulus and how this may impact the activity pattern found. In addition, proof of activation of pain-control areas like the periaquaductal gray while inverse changes are occurring in pain-perceiving areas has not been sought. This study will address both of these issues with a single BOLD FMRI experiment.
研究设计
- 研究类型
- Observational
- 观察模型
- Case Only
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age 18 to 50
- •Right-handed
- •Male or female
- •Healthy individuals not taking any medication.
排除标准
- •Pregnancy
- •Diagnosed with any treated or untreated medical or neurological conditions
- •Using any prescription drugs, including antidepressants, pain medications, sedative medications, blood pressure medications, seizure medications, or antipsychotics. Oral contraceptives are permitted
- •Using any over-the-counter medications including aspirin, Tylenol, or herbal supplements
- •Using any illicit substances
- •Contraindications to magnetic resonance imaging.
结局指标
主要结局
To determine the areas of brain activity from a 2 minute long painful stimulation
时间窗: After a 2 minute long painful stimulation
次要结局
未报告次要终点
研究者
Jim Ibinson
Clinical Instructor
University of Pittsburgh