[Aneurysmal subarachnoid hemorrhage in the Yaeyama Islands, Japan, from 1989 to 2002].

The aim of this study was to analyze epidemiological and clinical data of patients with aneurysmal subarachnoid hemorrhage (SAH) in the Yaeyama islands, an isolated subtropical region of Japan. A total of 94 patients (31 men and 63 women, mean age 57.3 years) were diagnosed as having non-traumatic SAH during a 13-year period from 1989 to 2002. The age-and sex-adjusted annual incidence rate of SAH was 17.4 per 100,000 population. The incidence of SAH was the highest in August. Seventy-nine patients were hospitalized within 24 hours after onset of SAH. Seventeen patients were transferred by helicopter. The Hunt and Kosnik grade was I in 29 patients (30.9%). The CT Fisher group was 3 in 42 patients (44.7%). Ruptured aneurysm was detected in 78 patients (saccular type in 70 patients, small size in 49 patients, and internal carotid artery in 28 patients). Rebleeding occurred in 20 patients (21.3%). Symptomatic vasospasm occurred in 26 patients (27.7%). Acute and chronic hydrocephalus occurred in 25 (26.6%) and 22 (23.4%) patients respectively. A total of 120 neurosurgical operations were performed in 70 patients (operation for ruptured aneurysm in 62, early operation in 39). A total of 42 operative complications occurred in 29 patients. Fifty-one patients (54.3%) had a good outcome. The number of full-time neurosurgeons did not influence the performance of neurosurgical operation and outcome. In conclusion, epidemiologically, the high incidence of SAH in August is unusual. Patients with aneurysmal SAH in the Yaeyama islands have common clinical characteristics and undergo standard neurosurgical treatment.