Epidemiology and outcome of subarachnoid hemorrhage

Abstract

The incidence of subarachnoid hemorrhage（SAH）is declining worldwide, and is also declining in Japan, although the incidence in Japan is the highest in the world. On the other hand, the incidence of SAH in elderly women is high, and estrogen depletion is thought to be a factor. The treatment of SAH in Japan has shifted from surgical clipping to endovascular coil embolization. In a study on the relationship between SAH and unruptured cerebral aneurysm（UCA）, the treatment rate of UCA was low, and the effect of reducing the incidence of SAH was considered to be small. The incidence of SAH in Japan has been declining due to improvements in lifestyle habits such as hypertension and smoking, suggesting the significance of lifestyle guidance provided by brain docks. The epidemiology and outcome of SAH are discussed in this report.