Neurological Emergencies—Subarachnoid Hemorrhage

What is going on?

This fellow just had a subarachnoid hemorrhage, that's what is going on.

CLINICALLY, a subarachnoid hemorrhage is characterized by the INSTANTANEOUS, EXPLOSIVE onset of the worst headache of the patient's life, or the first headache which brings him to the emergency room.

Any headache which sounds like this should be considered a subarachnoid hemorrhage. So what's the big deal?

90% of nontraumatic subarachnoid hemorrhage comes from a ruptured cerebral artery aneurysm. Treatment morbidity and mortality still runs around 75% overall for this disease, so it is a very dangerous thing to have. Furthermore, about HALF of subarachnoid hemorrhages probably have a "warning leak" in the weeks preceding the big blowout, so it behooves us all to pay more attention to those headaches which have instantaneous onset.

Once you suspect a subarachnoid hemorrhage by HISTORY, you are committed to working it up. Realize that after bona fide subarachnoid hemorrhage (SAH), with blood in the CSF and a burst aneurysm in the head, patients can look like:

physical exam	Hunt & Hess post SAH grade
normal, like you and me	H&H grade 1
headache, photophobia, nausea and vomiting, generally miserable	H&H grade 2 (the "classic SAH")
sleepy, arouses to talk but then closes eyes again	H&H grade 3
comatose	H&H grade 4
moribund	H&H grade 5

So the physical examination is USELESS to exclude a subarachnoid hemorrhage. You have to go with the history.