Age dependence of the flow velocity in the basal cerebral arteries--a transcranial Doppler ultrasound study.

The age dependence of the blood flow velocities of the middle, anterior, and posterior cerebral arteries measured by the transcranial Doppler method is discussed and compared with the velocity values in the internal carotid artery. A number of 535 patients without neurological deficits but with a previous neurological event were examined. Flow velocities decrease in all examined vessels with increasing age. This is in accordance with cerebral blood flow measurements by Xenon inhalation techniques. The reasons of the decrease and its consequences on the vasospasm in patients suffering from subarachnoidal hemorrhage are discussed.