Clinical findings in patients with chronic complex regional pain syndrome

Abstract

What are the clinical findings in patients with chronic complex regional pain syndrome (CRPS)? Bedside examination was performed in 40 patients with CRPS and a mean illness duration of 43 months. To evaluate motor and autonomic disturbances, rating scales were developed and applied. Quantitative sensory testing (QST) was conducted in 24 patients. Clinical examination revealed sensory abnormalities in 93% of patients examined (in 56% limited to the affected limb, in 7% in the upper quadrant of the body, in 30% hemisensory impairment of the ipsilateral body side), and 60% of the patients suffered from mechanical allodynia in the affected limb. Patients with generalized sensory impairment had a significantly longer illness duration, pain intensity and significantly higher frequency of mechanical allodynia/hyperalgesia than patients with sensory deficits limited to the limb affected. In patients with generalized sensory abnormalities, QST revealed significant changes of cold, warm and touch thresholds on the ipsilateral compared to the contralateral body side. Mild/moderate motor abnormalities could be demonstrated in 45% of patients, tremor (50%), impaired joint movements, 45%, and 40% of patients revealed autonomic disturbances. In chronic CRPS, among clinical symptoms and signs, pain and sensory impairment play a major role. Mechanical allodynia reveals the highest level of subjective disability among all symptoms. With respect to hemisensory impairment, functional disturbances of central pain processing in the nucleus ventralis posterior of the thalamus are postulated.