Usefulness of computed tomography in predicting outcome after aneurysmal subarachnoid hemorrhage: a preliminary report of the Cooperative Aneurysm Study.

We evaluated the ability of CT performed soon after subarachnoid hemorrhage (SAH) to predict outcome. Generally, the results of CT paralleled level of consciousness in predicting mortality or good recovery. However, CT did detect some groups of patients who were at greater or lesser risk of mortality. If an alert patient had normal CT, 6-month mortality was 2.8%; if blood was detected, mortality rose to 12.3%. Intracerebral hemorrhage or local, thick, or diffuse subarachnoid deposits of blood seen on CT among alert patients were particularly related to increased mortality. CT abnormalities could be used to detect higher mortality rates among drowsy or comatose patients. CT is useful as an adjunct to the clinical examination in predicting outcome after SAH.