Hemisensory impairment in patients with complex regional pain syndrome

The purpose of the present study was to investigate the extent and quality of sensory impairment and their relation to pain characteristics and moveme nt disorders in patients suffering from complex regional pain syndrome (CRP S) type I. Neurological testing was performed independently by two examiner s in 24 patients with CRPS type I. In eight patients (33%), a hemisensory i mpairment with decreased temperature and pinprick sensation ipsilateral to the limb affected by CRPS could be observed. In four patients (17%), a sens ory deficit in the upper quadrant of the body could be demonstrated and in eight patients (33%), sensory impairment was limited to the limb affected b y CRPS. Mechanical allodynia and mechanical hyperalgesia could be observed in a higher percentage of patients with hemisensory deficit or sensory impa irment in the upper quadrant (92%), than in those patients with sensory imp airment limited to the affected limb (17%) (P < 0.005). Tn patients with le ft-sided CRPS, sensory abnormalities in the upper quadrant or hemisensory i mpairment were more frequently demonstrated (77%) than in patients with rig ht-sided CRPS (18%) (P < 0.005). There was a high correlation (92%) for the sensory findings between the two examiners, and hemisensory abnormalities were stable over a period of 3-6 months in all six patients with repeated e xaminations. Motor impairment (contractures, weakness, tremor or difficulti es in initiating movement) could be observed in a higher percentage in pati ents with sensory abnormalities in the upper quadrant or hemisensory impair ment (83%) than in patients with sensory impairment limited to the affected limb (42%) (P < 0.05) and was significantly correlated with allodynia/hype ralgesia (P < 0.005). The results demonstrated that sensory deficits in pat ients with CRPS, frequently extend past the painful area of the affected li mb. The increased frequency of mechanical allodynia and movement disorders in patients with hemisensory impairment or sensory deficits in the upper qu adrant, might indicate that central mechanisms are involved in the pathogen esis of CRPS in these patients. (C) 1999 International Association for the Study of Pain. Published by Elsevier Science B.V.