Age is an important factor correlated with stroke prevalence and independently influences stroke outcome especially in Japanese longevity society. To re-evaluate the characteristics of acute ischemic stroke in the old-old, analyses of clinical data on 426 patients registered at a Japanese tertiary emergency hospital were performed under appropriate statistical methods. Clinical features, stroke subtypes, current-known risk factors for stroke, time from onset to arrival, the National Institute of Health Stroke scale (NIHSS) score on admission, length of hospital stay, modified Rankin Scale (mRS) at discharge were compared between two stratified groups by age-at-onset (≧75 and < 75 years old). Significant differences were demonstrated in categories of sex, NIHSS score, length of hospital stay and m-RS. Current-known risk factors for stroke except atrial fibrillation were not prominent in the elderly group. Our study revealed that clinical phenotype and outcome in stroke patients would have been modified and re-evaluation of risk factors is necessary for prevention of ischemic stroke in Japanese longevity society
