INCIDENCE OF CENTRAL POSTSTROKE PAIN

Central post-stroke pain (CPSP) is a neuropathic pain syndrome characterized by constant or intermittent pain in a body part occurring after stroke and associated with sensory abnormalities in the painful body part. This study describes CPSP prospectively during the first year after stroke and characterizes the cerebrovascular lesions and neurological signs associated with the CPSP syndrome. Two hundred and sixty-seven consecutively admitted patients younger than 81 years were examined in the first week, at 1, 6 and 12 months after stroke. Sensibility to touch (cotton wool), temperature (20 degrees C and 40 degrees C), and pinprick was studied using the contralateral face and extremity as control. A CT scan was done 8 (median) days (range: 1-34 days) after stroke. Two hundred and seven (78%) patients surviving at least 6 months who were able to communicate reliably formed the basis of the study. Abnormal sensory signs were found at least once in 87 (42%) patients. CPSP was found in 16 (8%) patients of whom all but 1 patient also had evoked dysesthesia or allodynia. Further 1 patient had persistent evoked dysesthesia but denied pain. CPSP was not related to sex or age. In patients with single acute cerebral lesions there were no relation between size or location of the lesions and the presence of CPSP. The pain was light in 6 (3%) patients and moderate to severe in 10 (5%) patients. The pain quality was usually lacerating or aching. Fifteen (94%) patients had decreased temperature, touch and pain sensibility and 9 (56%) reported allodynia to cold stimulation and another 9 (56%) patients reported this to touch. Pain onset was within 1 month after stroke in 10 (63%) patients, between 1 and 6 months in 3 (19%) patients and more than 6 months after stroke in 3 (19%) patients.