Background and purpose: The outcome of subarachnoid hemorrhage in patients with familial occurrence of subarachnoid hemorrhage (familial SAH) is an important but neglected factor in balancing the risks of screening for asymptomatic aneurysms and repairing these in unaffected members of such families.
Methods: We studied the outcome of familial SAH in a prospective, hospital-based series of patients with at least one first-degree relative with SAH and compared it with the outcome in a prospectively collected hospital series of patients selected for the absence of SAH in first- and second-degree relatives. Outcome was graded in three categories: independence, dependence, or death. Poor outcome was defined as death or dependence.
Results: Of 29 patients with familial SAH, 52% had a poor outcome, whereas only 37% of 125 patients with sporadic SAH had a poor outcome. The crude relative risk for poor outcome in familial SAH was 1.4 (95% confidence interval [CI], 0.9 to 2.1; P = .14); the odds ratio adjusted for age and sex was 2.5 (95% CI, 1.0 to 6.0; P = .04). This risk is probably an underestimation due to our strict patient selection criteria.
Conclusions: Patients with familial SAH have a greater risk of poor outcome than patients with sporadic SAH. This adds to the factors in favor of screening unaffected first-degree relatives of patients with familial SAH.