Subarachnoid hemorrhage, which occur between the arachnoid and pia meningeal layers, like intraparenchymal hemorrhage, can result either from trauma or from ruptures of aneurysms or arteriovenous malformations.

Simple tests for genetic risk factors would permit the identification of individuals at high risk for development and rupture of aneurysms, consequently allowing diagnostic effort to be concentrated on a smaller group that is at higher risk.

Calling his findings statistically significant, lead author Satish Krishnamurthy, MD, tells WebMD, "While I don't think you can say that smoking definitely causes rupture of aneurysms, it's definitely a factor very closely related.