Subarachnoid Hemorrhage - Screening and Prevention

Screening and Prevention

Screening for aneurysms is not performed on a population level; because they are relatively rare, it would not be cost-effective. If someone has two or more first-degree relatives who have suffered an aneurysmal subarachnoid hemorrhage, screening may be worthwhile.

Autosomal dominant polycystic kidney disease (ADPKD), a hereditary kidney condition, is known to be associated with cerebral aneurysms in 8% of cases, but most such aneurysms are small and therefore unlikely to rupture. As a result, screening is only recommended in families with ADPKD where one family member has suffered a ruptured aneurysm.

An aneurysm may be detected incidentally on brain imaging; this presents a conundrum, as all treatments for cerebral aneurysms are associated with potential complications. The International Study of Unruptured Intracranial Aneurysms (ISUIA) provided prognostic data both in people who had previously suffered a subarachnoid hemorrhage and people who had aneurysms detected by other means. Those who had previously suffered SAH were more likely to bleed from other aneurysms. In contrast, those who had never bled and had small aneurysms (smaller than 10 mm) were very unlikely to suffer SAH and were likely to sustain harm from attempts to repair these aneurysms. On the basis of the ISUIA and other studies, it is now recommended that people are only considered for preventative treatment if they have a reasonable life expectancy and have aneurysms that are highly likely to rupture. At the same time, there is only limited evidence that endovascular treatment of unruptured aneurysms is actually beneficial.