Cerebral aneurysms > 5-7 mm are most likely to rupture. Approximately 1%-3% of patients visiting the emergency department for a headache are subsequently found to have a SAH. Trauma is the most common cause of SAH; however, nontraumatic SAH is found to result from a ruptured saccular aneurysm in 80% of cases. Patients with SAH require close monitoring and often require intensive care unit admission.
Approximately 10%-15% of patients die before reaching medical care. Even with appropriate care, the mortality rate from SAH is approximately 25%-50%. About one-half of patients who survive have significant morbidity.
Related topic: drug-induced stroke
I60.9 – Nontraumatic subarachnoid hemorrhage, unspecified
21454007 – Subarachnoid intracranial hemorrhage
Differential Diagnosis & Pitfalls