Aneurysmal Subarachnoid Hemorrhage in Honjo-Yuri District of Akita Prefecture of Japan / 日本農村医学会雑誌

ABSTRACT

Purpose: The purpose of this study was to analyze the incidence if subarachnoid hemorrhage (SAH) in residents of Honjo City and its vicinity in northen Japan with a total population of 123,000 during the 8-year period from 1995 through 2002, and to evaluated the overall management outcome of the patients with SAH. Methods: All patients suspected of having SAH are referred to our hospital, which plays a crucial role as a “core” hospital in the region. Computed tomography (CT) scan was indicated for all the patients to verify the occurrence of SAH, and subsequently three dimensional (3D) CT angiography and/or catheter angiography were performed to confirm rupture of aneurysms. Results: During the period under review a total of 327 patients were diagnosed as having aneurysmal SAH, and ruptured aneurysms were confirmed in 276 cases (84%). The cruse annual incidence was 33.0 per 100,000 population for all ages during the entire 8-year period. However, the annual incidence has gradually decreased in contrast to an increasing number of operations for unruptured aneurysms performed during the same period. The age ranged from 21 to 92 years with the mean age of 64.5, and the incidence reached a peak in the 70-79 age group. Women far exceeded men in the incidence at the ratio of 1.8 to 1. The high grade patients with severe SAH as evaluated as grade 4 and 5 according to Hunt & Kosnik’s classification consisted of 45%, and 50% of this group were the patients 70 and older. Overall management outcome was assessed 6 months after the onset of SAH with the use of Glasgow Outcome Scale, and favorable outcome such as good recovery and moderate disability was obtained in 42% of the total 327 patients and death occurred in 39%. Conclusion: The high incidence of SAH was confirmed, and it was also noted that the number of elderly patients with severe SAH has increased in this region. Preventive treatment for unruptured aneurysms may be one clue to the solution of this devastating medical problem.