Short- and Long-Term Outcomes After Angiographically Negative Subarachnoid Hemorrhage

For patients with nontraumatic subarachnoid hemorrhage (SAH), the failure to identify a source of hemorrhage on a catheter angiogram (i.e., angiographically negative SAH) can create uncertainty about prognosis. Angiographically negative SAH with a perimesencephalic pattern of hemorrhage has a comparatively benign clinical course. However, when a bleeding source is not found, but the blood extends into the Sylvian or interhemispheric fissures as would otherwise be seen with aneurysmal SAH, the prognosis is less clear.

In this single-center case series, researchers reviewed clinical records between 2006 and April 2018 and identified 99 patients with nontraumatic angiographically-negative SAH (66 with perimesencephalic-pattern hemorrhage and 33…