The long-term prognosis in untreated cerebral aneurysms: II. Late morbidity and mortality.

Three hundred sixty-four patients who suffered a subarachnoid hemorrhage from an aneurysm at either the anterior (ACA) or posterior (PCA) communicating artery location and who were not surgically treated have been followed for up to 21 years in order to study the late morbidity and mortality. For patients surviving six months: (1) little improvement in morbidity was noted during the many years of subsequent follow-up; (2) in general, ACA patients fared better than PCA patients; (3) the neurological state on original admission was strongly correlated with the degree of morbidity; (4) other factors measured at time of original hemorrhage which adversely affected morbidity included the level of blood pressure or the presence of clot or spasm; (5) if deaths from late hemorrhage are excluded, cardiovascular causes account for the majority of subsequent deaths; and (6) the risk of dying from all causes is increased when compared to a population matched by age and sex.