Risk of Harboring an Unruptured Intracranial Aneurysm

Abstract

Background and Purpose-The purpose of the present study was to calculate the prevalence and relative risk of unruptured incidental intracranial aneurysms (IAs) among families with IA case(s) compared with the general population in one geographically defined area in East Finland and to identify the risk group that could benefit most from screening for IAs. We compared these results with our earlier study results of familial IA (FIA) cases, with two or more known IA cases in the same family. Methods-The study groups were collected from the catchment area of the University Hospital of Kuopio in East Finland. The inclusion criteria were age 30 to 70 years and unruptured incidental IAs Ն3 mm. Patients with previous subarachnoid hemorrhage or in whom a ruptured IA was found to be the cause of death were excluded from all study groups. During routine forensic autopsies the circle of Willis was studied for IAs to estimate the number of IAs in the general population. In the families with one known IA case and in FIA families, MR angiography was used as a preliminary screening method for IAs, followed by intra-arterial angiography to verify suspected IAs. Study populations were age and sex adjusted for the statistical calculations. Results-The relative risk for IAs among first-degree relatives in FIA families was 4.2 (95% confidence interval, 2.2 to 8.0) and among first-degree relatives in families with only one affected family member was 1.8 (95% confidence interval, 0.7 to 4.8) compared with the general population in East Finland. Conclusions-First-degree relatives in FIA families constitute a high-risk group for incidental IAs, and this group would benefit from screening studies for IAs. Screening for IAs in families with only one affected member or in the general population is not recommended. (Stroke. 1998;29:359-362.)

Impact of LIMK1, MMP2 and TNF-α variations for intracranial aneurysm in Japanese population

“…[3][4][5] Furthermore, several studies suggested an increased occurrence of IA and SAH in first-and second-degree relatives of SAH, with the incidence rate of 6-10%. [6][7][8][9] Several Mendelian disorders, such as autosomal-dominant polycystic kidney disease and Ehlers-Danlos syndrome type IV are associated with an increased risk of IA formation. 10,11 All these evidence fortified the roles of genetic factors in the pathogenesis of IA.…”

Genome-Wide Scan for Japanese Familial Intracranial Aneurysms

“…1,2 The risk of ruptured IAs in first-degree relatives of patients with aneurysmal SAH is Ϸ4 times higher than that in the general population. 2 Genetic and environmental factors play important roles in the pathogenesis of IA, and recent progress in molecular genetics enables the genetic determinants to be approached directly.…”

Treatment Strategy for Patients with Unruptured Intracranial Aneurysms.

“…23) Autopsy studies have reported an overall prevalence between 0.1% and 9.9% (mean frequency 5%). 24,27,32,33,41) Angiographic studies report a prevalence between 0.2% and 15%. 24,27,32,41) In Japan, using MR angiography as part of thè`b rain screening program,'' unruptured-asymptomatic intracranial aneurysms are found in more than 2% of the patients.…”