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Cerebral ischemia from vasospasm is a major cause of death and disability following aneurysmal subarachnoid hemorrhage (SAH). This study examines and compares the relative utility of the initial neurologic examination and early CT in predicting cerebral ischemia after SAH. The influence of antifibrinolytic drugs (AFD) in the development of cerebral ischemia was also studied. AFD increased the risk of cerebral ischemia regardless of the admitting neurologic condition or the findings of CT. Among patients given AFD, impaired orientation or alertness was associated with a higher risk of ischemia. Other neurologic signs were not predictive of ischemia. Clinical features were not predictive of ischemia among patients not given AFD. Focal, thick collections of blood on CT were highly predictive of ischemia, whether or not patients received AFD. Admitting CT is the best prognostic indicator for the development of cerebral ischemia after SAH. It should be used to supplement the clinical examination in selecting patients best suited for therapy to prevent vasospasm.

Computed tomography was performed on 1,378 patients admitted within 3 days of subarachnoid hemorrhage (SAH) at 71 centers in a cooperative study. CT on the day of SAH (day 0) was abnormal in 95.8%. Intracranial blood was detected in 95.3% of patients on day 0, 90.5% on the first day after SAH (day 1), and 73.8% on day 3. CT was normal in only 1 of 284 patients in stupor or coma but was normal in 14.6% of 638 alert patients. In the first few days after SAH, CT is highly accurate, often obviating the need of CSF examinations. The interval from SAH until CT and the seriousness of the patient's condition are two factors that influence the results of CT.

Vasospasm is the leading cause of death and disability in patients with aneurysmal subarachnoid hemorrhage (SAH). Transcranial Doppler ultrasonography (TCD) can detect the arterial narrowing noninvasively, but the sensitivity and specificity of this technique have not been reported in a population of patients with a high frequency of angiographic vasospasm. In this study, 34 consecutive patients with SAH undergoing angiography during the period of risk for vasospasm had technically adequate TCD examinations within 24 hours of the angiogram. Using a mean flow velocity of 120 cm/sec and above as indicative of vasospasm, TCD correctly detected angiographic vasospasm in 17 patients; there were no false positives. It correctly determined that 5 patients did not have vasospasm, whereas there were 12 false negatives. False negatives were frequently due to angiographic vasospasm involving vessels not assessable by TCD. The correlation between mean flow velocity and the angiographic residual lumen diameter of the middle cerebral artery was statistically significant. These data suggest that TCD is a highly specific (100%), but less sensitive (58.6%) test for the detection of angiographic vasospasm following SAH. Confirmatory angiography may be avoided if the TCD study is positive, but additional studies may be necessary if the clinical picture is suspicious and the TCD study is negative.

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.