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Abstract: Objectives: During visual stimulation, the elevated metabolism rate will couple with increase of blood flow velocity (BFV) in posterior cerebral artery (PCA). This study with TCD was aimed to investigate whether the coupling might change according to the different vasoneuronal conditions. Methods: Ninety-nine volunteers including 24 hypertension (HT) patients and 2 patients suffering from both HT and diabetes mellitus (DM) were enrolled in this trial. BFV and pulse indexes (PI) in P2 segments of PCA on both sides were monitored during visual stimulation. Results: In all subjects, Mean BFV increased and PI went down in response to visual stimulation. The percentages of changes (ΔV and ΔP) of both mean BFV and PI were larger in young group (<55 years old) than in old one (≥55 years old). There was significant positive correlation between ΔV and ΔP. Multivariated regression analysis did not show HT and DM, but age related to ΔV(ΔP). We did not find significant difference of ΔV(ΔP) between left and right sides. Conclusions: Blood flow velocity in PCA P2 segment increased due to decreased cerebrovascular resistance during visual stimulation and the response weakened with aging of the patient.

[1]Becker, V.U., Hansen, H.C., Brewitt, U. and Thie,A., 1996. Visually evoked cerebral blood flow velocity changes in different states of brain dysfunction. Stroke,27(3):446-449.

[2]Buedingen, H.J. and Staudacher, T., 1992. Evaluation of vertebrobasilar disease. In: Newell DW, Aaslid R, eds. Transcranial Doppler. Raven Press Publishers, New York.

[3]Corbetta, M., Miezin, F.M. and Petersen, S.E., 1990. Attentional modulation of neural processing of shape, color, and velocity in humans. Science, 248(4962):1556-1559.

[4]Diehl, B., Stodieck, S.R., Diehl, R.R. and Ringelstein, E.B., 1998. The photic driving EEG response and photoreactive cerebral blood flow in the posterior cerebral artery in controls and in patients with epilepsy. Electroencephalogr clin Neurophysiol, 107(1): 8-12.

[5]Liu, Y., Huang, Y. and Wang, B., 2001. Intracranial artery occlusive diseasesin patients with hypertension and diabetes mellitus. Zhonghua Yi Xue Za Zhi, 81(22):1387-1389(in Chinese with English abstract).

[6]Newell, D.W., Aaslid, R., Lam, A., Mayberg, T.S. and Winn, H.R., 1994. Comparison of flow and velocity during dynamic autoregulation testing in humans. Stroke, 25(4):793-797.

[7]Niehaus, L., Lehmann, R., Roricht, S. and Meyer, B.U., 2001. Age-related reduction in visually evoked cerebral blood flow responses. Neurobiology of Aging, 22(1): 35-38.

[8]Ostrow, P.T. and Miller, L.L., 1993. Pathology of small artery disease. In: Advances in Neurology(Vol. 62:): Cerebral Small Artery Disease, Raven Press Publishers, New York, p.93-123.

[9]Panczel, G., Daffertshofer, M., Ries, S., Spiegel, D. and Hennerici, M., 1999. Age and stimulation dependency of visually evoked cerebral blood flow responses. Stroke, 30(3): 619-623.

[10]Sturzenegger, M., Newell, D.W. and Aaslid, R., 1996. Visually evoked blood flow response assessed by simultaneous two-channel transcranial Doppler using flow velocity averaging. Stroke, 27(12): 2256-2261.

[11]Terry, R.D., De Teresa, R. and Hansen, L.A., 1987. Neocortical cell counts in normal human adult aging. Ann Neurol, 21(6): 530-539.

[12]Urban, P.P., Allardt, A., Tettenborn, B., Hopf, H.C., Pfennigsdorf, S. and Lieb, W., 1995. Photoreactive flow changes in the posterior cerebral artery in control subjects and patients with occipital lobe infarction. Stroke,26(10):1817-1819.