Background and Purpose--Patients with a perimesencephalic nonaneurysmal subarachnoid hemorrhage are not at risk for rebleeding in the initial years after the hemorrhage. Nevertheless, uncertainty remains on the long-term prognosis after perimesencephalic hemorrhage, and former patients are often considered high-risk cases for health insurance or are denied life insurance. We performed a very long-term follow-up study of a large consecutive series of such patients and compared mortality in this cohort with that in the general population.

Methods--All patients with a perimesencephalic hemorrhage (defined by pattern of hemorrhage on computed tomography within 72 hours after onset and absence of aneurysm) admitted between 1983 and 2005 to our service were followed-up by telephone. For patients who had died, we retrieved age and cause of death. We compared the age- and sex-specific mortality of this cohort with that of the general population by means of standardized mortality ratios with corresponding 95% confidence intervals.

Results--The cohort consisted of 160 patients, with a total number of patient-years of 1213. No new episodes of subarachnoid hemorrhage had occurred. During follow-up 11 patients had died; the expected number of deaths based on mortality rates in the general population (adjusted for age and gender) was 18.1. The standardized mortality ratio was 0.61 (95% confidence interval, 0.34 to 1.1).

Conclusions--Patients with perimesencephalic hemorrhage have a normal life expectancy and are not at risk for rebleeding. No restrictions should be imposed on these patients by physicians or health or life insurance companies.