Community-based study on intracerebral hemorrhage in northern Hokkaido. Northern Hokkaido Stroke Study (NOHSS)

A survey on stroke was conducted to evaluate the incidence of intracerebral hemorrhage and the prevalence of risk factors. The subjects, comprising those patients who suffesed a stroke, were registered on the Northern Hokkaido Stroke Study between July 2002 and June 2006. The severity of their illness was rated by the National Institutes of Health Stroke Scale (NIHSS) at hospital admission, while their outcome was determined by the mortality within 3 months and the mRS (modified Rankin Scale score). Of the 1,046 registered stroke patients, 271 (25.9%) were found to suffer from cerebral hemorrhage. Their mean age was 70.3±11.7 years; male-to-female ratio, 154/117; mean NIHSS at admission, 11.8±8.1; mortality within 3 months, 19.2%; and percentage who regained independence within 3 months (mRS: ≤2), 32.5%. A history of hypertension was found in 72.6%, and 13.7% had no treatment. MRI (T2*) revealed micro-hemorrhage outside the lesions in 67.5%. Forty-seven patients (17.3%) were taking anti-platelet agents at the onset of intracerebral hemorrhage. There was no significant difference between the mortalities of the anti-platelet-agent-users and non-users but the percentage of those regaining independence within 3 months was 19.1% for the users against 37.3% for the non-users (p=0.0177), with a significantly poor outcome in the user group. In northern Hokkaido, the incidence of cerebral hemorrhage remains high, and the percentage of those with poorly controlled or uncontrolled hypertension was 30%. These findings suggest a need to educate not only the inhabitants themselves but also the physicians engaged in their care. (author)