1

How are patients graded after subarachnoid hemorrhage from a ruptured aneurysm?

The incidence of SAH is about 10–15 per 100,000 person-years. Angiography shows that 80%–85% of cases of SAH are due to an intracranial aneurysm. Cerebral aneurysms are most often found at bifurcations near the circle of Willis, and the risk of rupture is increased with increasing size. SAH almost always manifests with rapid onset of severe headache. The presence of other signs and symptoms is used for clinical grading of patients. The Hunt-Hess clinical grade classification is widely used ( Table 15-1 ). The World Federation of Neurologic Surgeons Grading System has also gained acceptance.

2

What are the most serious complications after subarachnoid hemorrhage from aneurysm rupture?

The most serious sequela of SAH is rebleeding. The incidence of rebleeding after aneurysm rupture is approximately 15% in the first week and about 10% in the second week. Morbidity and mortality after rebleed are great and have motivated the trend toward early intervention after aneurysm rupture.

Cerebral vasospasm is also a major cause of morbidity and mortality after SAH. Symptomatic brain ischemia from vasospasm occurs in 15%–35% of patients. Angiographic evidence of vasospasm occurs in 70% of patients. Vasospasm may lead to cerebral infarction. SAH often leads to hydrocephalus and may result in dangerously elevated intracranial pressure.