SENSORY TESTING IN PATIENTS WITH CHRONIC MUSCULOSKELETAL PAIN SYNDROMES

点击翻译按钮获取中文摘要

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Fibromyalgia is a chronic musculoskeletal pain disorder that predominantly afflicts women. Frequently associated insomnia, cognitive abnormalities, and fatigue may lead to early disability. Neither soft tissue abnormalities nor neurological changes have been identified so far in these patients. The cause of this disorder is unknown, no effective treatment is available and the current methods of diagnosis are imprecise and unreliable. The proposed pilot study will evaluate the potential for quantitative sensory testing to improve upon diagnoses of this disorder by supplementing the current procedure of manipulating defined pressure points by hand and noting the presence or absence of pain. The quantitative methods of evaluation involve repetitive application of brief, non-injurious thermal stimulation that normally produces a moderate degree of temporal summation of sensation intensity. The patients and normal control subjects will verbally rate the magnitude of late sensations elicited by each stimulus, using a numerical scale. The theoretical foundation of this study is that chronic pain in these patients may result from exaggerated activation of central N-methyl-D-aspartate (NMDA) receptors as a result of enhanced input from unmyelinated peripheral afferent nerve fibers supplying deep tissues. If this is the case, then exaggerated temporal summation of late thermal sensations should be evident, since it is dependent upon activation of unmyelinated afferents and stimulation of NMDA receptors. Quantitative psychophysical evidence for abnormal temporal summation would provide a rationale for future pharmacological treatment of this condition by suitable administration of NMDA antagonists.