Seasonality of stroke in Finland

Abstract

All major stroke subtypes occurred most commonly in autumn and most infrequently in summer. Seasonality of in-hospital mortality and length of hospital stay appears to vary by stroke subtype. The seasonal pattern of ischemic stroke occurrence appears to have changed during the past decades. Key messages All major stroke subtypes (ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage) occurred most frequently in autumn and least frequently in summer. Seasonal patterns of in-hospital mortality and length of stay differed markedly by stroke subtype. The seasonal pattern of ischemic stroke occurrence in Finland seems to have changed compared to 1982-1992.