Measurement of cerebral blood flow by ultrasonic doppler technique. Quantitative detection of cerebral arteriosclerosis

The effect of a cerebral vasodilator, vinpocetine, on cerebral vascular resistance evaluated by the Doppler ultrasonic technique in patients with cerebrovascular diseases

Changes in cerebral vascular resistance were examined in patients with cerebral circulatory diseases by the Doppler ultrasonic technique after administration of a cerebral vasodilator, vinpocetine, for two months. Continuous index (CI) and pulsatility index (PI) of the blood flow pattern in the internal carotid artery were used as objective parameters for changes in cerebral vascular resistance. 1. The CI and PI changed significantly after administration of the drug; ie, the CI increased while the PI decreased. 2. An inverse correlation was noted between the rate of change of the CI (delta CI) and that of the PI (delta PI). 3. The results suggest that measurement of the CI and PI by the Doppler ultrasonic technique is useful in investigating the effect of drugs on the cerebral circulation.

Changes in internal carotid artery flow velocities with cerebral vasodilation and constriction

Non-invasive Doppler-shift ultrasound, together with spectral analysis, have been used to study the changes in internal carotid artery flow velocity patterns that occur with cerebral vasoconstriction and vasodilation provoked by over-breathing and breath-holding. Significantly different waveform shapes, characteristic for each vessel, were demonstrated from the internal and external carotid arteries, making identification of the internal carotid certain. In 5 healthy subjects over-breathing for 3 minutes significantly lowered the mean height of the internal carotid waveform by an average of 32% (p less than 0.001). Breath-holding for 40-60 seconds raised the mean height by an average of 31% (p less than 0.001). The pulsatility index of the waveforms varied inversely to mean height. These results show that the effects of cerebral dilation or constriction are easily detected by flow-velocity changes in the internal carotid artery.

Differentiation of the dementias of old age by ultrasonic doppler flowmetry: a pilot study

At the Bel-Air Psychiatric Clinic, Geneva, Switzerland, the technique of ultrasonic Doppler flowmetry was used to examine the internal carotid arteries of 30 aged patients - 10 with cerebral degenerative dementia, 10 with cerebrovascular dementia, and 10 without dementia. An index of cerebrovascular resistance was calculated. Apparently this index can distinguish a group of vascular dementias from a group of degenerative dementias.