TRANSCRANIAL DOPPLER ULTRASOUND IN HYPERTENSIVE VERSUS NORMOTENSIVE PATIENTS AFTER ANEURYSMAL SUBARACHNOID HEMORRHAGE

Background and Purpose Arterial hypertension is a negative prognostic risk factor after aneurysmal subarachnoid hemorrhage (SAH). Transcranial Doppler ultrasound is commonly used for measuring blood flow velocities to predict cerebral ischemia due to vasospasm after SAH. Our purpose was to evaluate the influence of arterial hypertension on blood flow velocities in the cerebral circulation after aneurysmal SAH. Methods With transcranial Doppler ultrasound we compared the brood flow velocities in matched groups of hypertensive and normotensive patients with aneurysmal SAH. Twenty-four patients with arterial hypertension were examined daily during a 2-week period. As controls, 24 normotensive patients, also with SAH, were matched by age, sex, neurological status, and clinical outcome. Results Minimum, mean and maximum flow velocities in the middle cerebral artery in the hypertensive patients were significantly lower than in the normotensive individuals, with P=.02 for minimum, P=.02 for mean, and P=.02 for maximum. There was no statistical significance for pulsatility index differences in these groups (P=.45). Diastolic notch was noted in two of the hypertensive and in six of the normotensive patients. Conclusions The results indicate that even moderately increased flow velocities in hypertensive patients may represent significant vasospasm.