Outcome after subarachnoid hemorrhage from a very small aneurysm: a case-control series.

Object: A case-control analysis of patients with SAH was performed to compare risk factors and outcomes at 6 months posthemorrhage in patients with a very small aneurysm compared with those with a larger aneurysm.

Methods: All patients with SAH who were treated between January 1998 and December 1999 were studied. A very small aneurysm was defined as "equal to or less than 5 mm in diameter.