Clinical manifestations and survival rates among patients with saccular intracranial aneurysms: Population-based study in Olmsted County, Minnesota, 1965 to 1995

OBJECTIVE: To report presenting clinical symptoms, previous medical history , and survival rates for people with saccular intracranial aneurysms (IAs), in a defined population. METHODS: The medical records of all residents of Olmsted County, Minnesota, with possible IIAs were reviewed. Clinical manifestations at the time of d iagnosis, previous medical history, demographic factors, and survival rates after diagnosis were determined. RESULTS: Of 270 people with IAs detected between 1965 and 1995, 188 exhibit ed symptoms at the time of diagnosis, including 74% of women and 63% of men (P = 0.054). Intracranial hemorrhage OCH) was the most common presenting s ymptom (60% of all patients and 86% of patients who exhibited symptoms), fo llowed by cranial nerve palsy, transient ischemic attacks, and seizures. Su rvival rates after detection (with the exclusion of cases that were first d etected during autopsies) were dependent on the occurrence of ICH; 23% of p atients who presented with ICH died by I day after diagnosis, compared with 5% of those who did not exhibit symptoms or exhibited symptoms but without ICH at presentation. At 5 years, 44.7% of patients with hemorrhage had die d, compared with 29.4% of patients with symptoms other than hemorrhage. Aft er the first 24 hours after detection, survival rates did not differ signif icantly for those presenting with or without hemorrhage. Predictors of bett er survival rates also included lower age and later calendar year of presen tation. CONCLUSION: This study provides the first data on aneurysm characteristics, clinical symptoms, and survival rates among people with IAs in a defined p opulation. During the study period, most aneurysms were detected in the con text of an aneurysm-related symptom (particularly among women), with a larg e proportion of patients presenting with ICH. After the acute phase of hemo rrhage, long-term survival rates among people with IAs were similar for tho se presenting with or without ICH.