Transcranial Doppler ultrasonography makes it possible to measure, nontraumatically and repeatedly, the changes in blood flow velocity that occur with vasospasm. The clinical material for this study consists of 67 consecutive patients with
ruptured
aneurysm who were operated on early from June 1990 through May 1991. But in 15 cases, satisfactory transcranial Doppler signals were not recorded. So in 52 cases, the mean flow velocities of middle cerebral arteries, anterior cerebral arteries
and
posterior cerebral arteries were measured with a noninvasive 3 dimensional transcranial Doppler sonography method at least every third day. Most patients followed for 1 month. To prevent symptomatic vasospasm, Nimodipine was intravenously infused
in
doses of 2mg/hour for 2 weeks.
In cases of good clinical conditions or thin subarachnoid hemorrhage, the mean flow velocities of the velocities of the MCA's increased moderately whereas, with poor clinical conditions or thick subarachnoid clots, there was a faster and higher
increase
of mean flow velocities. A steep early increase of the flow velocites of the MCA's foreboded a high chance of delayed ischemia. The ipsilateral side of ruptured aneurysm showed higher flow velocites than did the contra-lateral side. The degree of
increase of flow velocities correlated well with the severity of neurological deficits due to vasospasm. The measurement of flow velocities in the large branches of the circle of Willis on patients with aneurysmal subarchnoid hemorrhage was
thought
helpful to foresee the clinical course of patients.
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