The most common cause of nontraumatic subarachnoid hemorrhage is aneurysmal rupture, and the vast majority of aneurysmal formation occurs in the anterior circulation.

The typical presentation is the "worst headache of my life," which may also be accompanied by signs of meningism due to dural irritation or cranial nerve palsies, depending on the location.

Up to one-fifth of patients have more than one aneurysm, and management is invasive in cases accompanied by subarachnoid hemorrhage.

This patient was managed by endovascular coiling of the aneurysm.