Early evoked pain or dysesthesia is a predictor of central poststroke pain

Central poststroke pain (CPSP) is a central neuropathic pain condition caused by a cerebrovascular lesion affecting the central somatosensory nervous system. Once developed, CPSP is difficult to treat, so there is an interest in identifying stroke patients at risk for the development of CPSP. This study examined if sensory abnormalities, including evoked dysesthesia, allodynia, or hyperalgesia to static and dynamic touch, cold, and pinprick, at stroke onset are a predictor for the development of CPSP. Consecutive stroke patients were recruited from a large prospective study of poststroke pain in Aarhus, Denmark, between 2007 and 2008. Patients underwent a structured pain interview and a standardized sensory examination within 4 days of admission, and a structured telephone interview was conducted after 3 and 6months. Patients who developed poststroke pain in the affected side without any other plausible cause were classified as having possible CPSP. A total of 275 stroke patients completed the study, and 29 patients (10.5%) were classified as having possible CPSP. The diagnosis was confirmed by a clinical examination in 15 of 17 patients, corresponding to a prevalence of 8.3%. The presence of allodynia, hyperalgesia, or dysesthesia in response to the sensory examination at stroke onset increased the odds for CPSP at 6months by 4.6 (odds ratio; 95% confidence interval 1.5-13.9). The combination of reduced or absent sensation to pinprick or cold and early evoked pain or dysesthesia at onset increased odds by 8.0 (odds ratio; 95% confidence interval 2.6-24.8). In conclusion, early evoked pain or dysesthesia is a predictor for CPSP.