ABSTRACT
Complex regional pain syndrome (CRPS) is a pain syndrome diagnosed clinically, not in the laboratory. CRPS was meant to be a descriptive term, not implying etiology or pathology. CRPS typically has pathological changes in the regulation of skin blood flow that is observed by the patient and medical attendants. Chronic CRPS has traditionally been regarded as cold. Sympathetic overactivity or supersensitivity to circulating catecholamines are the putative explanations for this phenomenon. Differential sweating between the affected and unaffected side is regarded as one of the diagnostic criteria for CRPS. Motor and movement disorders occur in as many as 95 percent of patients with CRPS and include weakness, bradykinesia, dystonia, myoclonus, and tremor. Electrophysiological evaluation of the CRPS patient may involve estimation of nerve conduction velocity, somatosensory evoked potentials, and electromyography. CRPS represents a very complicated pathophysiological disturbance, further complicated by its biopsychosocial complications.
