engleski

Analysis of Mean Blood Flow Velocities in Posterior Cerebral Arteries by Transcranial Doppler - During Visual Stimulation

Changes of mean blood flow velocities (MBFV) in the posterior cerebral arteries (PCA) during visual stimulation were recorded in a group of 51 healthy, right-handed volunteers. There were 27 (52.9%) males and 24 (47.1%) females aged from 20 to 59 (mean age 36.98) years. Measurements were performed with a hand-held 2 MHz transcranial Doppler (.I.CD) probe through temporal window, while the subjects had their eyes open, closed, and when looking at white light. In half of the subjects, the right PCA was insonated first and then the left PCA, while in the other half a reverse procedure was used. Statistical analysis was performed using Wilcoxon.s matched-pair signed-rank test. In the left PCA, MBFV was 41.2&#177; 8.6 cm/s (mean &#177; SD) with eyes open, 27.8&#177; 8.5 cm/s with eyes closed, and 42.3&#177; 9.1 cm/s while looking at white light. In the right PCA, MBFV was 41.7&#177; 8.9 cm/s with eyes open, 28.2&#177; 9.1 cm/s with eyes closed, and 42.4&#177; 8.8 cm/s while looking at white light. In the left PCA, differences between eyes open and closed, and between eyes open and while looking at white light were statistically significant (p<0.001, z=-6.2146, and p<0.001, z=-3.4836, respectively). In the right PCA, a statistically significant difference was found between eyes open and closed (p<0.001, z=-6.2146 and p<0.001, z=-3.6928), but not between eyes open and looking at white light (p=0.03, z=-2.1693). Study results demonstrated that straightforward visual stimulation had an effect on blood flow velocities in PCA and that it could be measured with TCD.

Cerebrovascular circulation - physiology; Cerebrovascular disorders - ultrasonography; Blood flow velocity - physiology; Brain physiology

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