Cerebral vasospasm is a major complication associated with subarachnoid hemorrhage (SAH). Previous publications on the diagnostic value of transcranial Doppler sonography (TCD) reported conflicting results concerning predictive capacities for evaluating vasospasm only by measuring flow velocities. And the necessity to examine other indices on TCD examinations was stressed. In this study, for the evaluation of the arterial spasms, the flow velocities and the Doppler wave-forms in TCD were analyzed in 89 consecutive patients (Grades I to III of Hunt & Kosnik grading) with ruptured intracranial aneurysms. Delayed ischemic neurological deficits (DINDs) accompanying arterial spasms were detected in 21 patients (23.6%). Twelve of these (13.5%) recovered from DINDs within 3 weeks.
The flow velocities on TCD could be classified into 3 types according to their mean blood flow velocities (MBFV). They consisted of: 1) high pattern type, in which the MBFV had increased more than 100 cm/s (42 cases, 47.2%), b) normal pattern type, in which the MBFV were measured as 50-100 cm/s (38 cases, 42.7%), c) low pattern type. in which the MBFV was less than 50 cm/s (9 cases, 10.1%).
From observation of the Doppler frequency, the sound of signals, and displayed waveforms, 7 characteristic findings were evaluated. i) Filling-in of the systolic window, ii) appearance of negative flow components (reverse flow) in the systolic phase, iii) reverse flow in the diastolic phase, iv) contour oscillation, v) high-intensity frequency (systolic spindle), vi) musical murmur, and vii) disappearance of pulsatility. From the observation of these 7 components, we made a“spasm score”on TCD records. The score was 5.3±1.5 in 21 patients with DINDs (the score was 6.0±1.6 in 9 patients with permanent DINDs, and was 4.8±1.2 in 12 patients with transient DINDs), and 1.8±1.9 in 68 patients without DINDs (p<0.005). Thirteen patients out of 15 in whom the score was 6 or more suffured DINDs, and 4 patients, in whom the score was 7, suffured prolonged DINDs. But of 36 patients in whom the score was 0 or 1, no patient suffured DINDs. Of these 7 components of Doppler findings,“reverse flow”was the most significant. It remains to be seen whether the examination of these indices can give additional information in cases of SAH and allow prediction of impending DINDs.
A significant increase in the 7 indices was found as the severity of vasospasm increased, and there was a strong relation between the indicies. The spasm score on TCD seemed to be very useful in the diagnosis and evaluation of DINDs in patients with vasospasms after SAH.
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