Trends in subarachnoid haemorrhage in elderly persons from Nagasaki, Japan: analysis of the Nagasaki SAH Data Bank for cerebral aneurysm, 1989-1998.

Abstract

Many industrialized countries are facing a volumetric growth of the senior population. We studied the trends in the incidence and outcome of subarachnoid haemorrhage (SAH) in patients aged >or=70 years. We retrospectively reviewed the cases of 1030 patients registered in the Nagasaki SAH Data Bank from 1989 to 1993 and 1274 patients registered from 1994 to 1998. The annual age-adjusted incidence of SAH per 100,000 increased only in women, from 15.4 in the 1989-1993 period to 19.7 in the 1994-1998 period. The average annual incidence of SAH per 100,000 women in the elderly aged >or=70 years increased significantly from 44.3 in the first period to 58.2 in the second period. In patients aged >or=70 years, the proportion of high-grade SAH (Hunt & Kosnik Grade IV and V) significantly increased from 27.2% in the first 5 years to 38.2% in the second 5 years. In patients aged<70 years, it increased slightly from 23.4% to 26.7%. The rate of favorable outcomes significantly fell from 43.9% (first period) to 30.9% (second period) in patients aged >or=70 years but was stable in patients aged<70 years. Although the incidence of elderly patients with SAH in our study is compatible with or higher than that of other reports, we believe that elderly patients (especially women) with high-grade SAH may not have all been identified. When we discuss the management of ruptured and unruptured aneurysms in the elderly, we should bear these trends of SAH in mind.