Is a carotid artery stenosis effect on cerebro vascular reactivity

ABSTRACT

To assess the effect of carotid artery stenosis on cerebrovascular reactivity. A transcranial Doppler [TCD] velocimeter was used to measure middle cerebral artery blood flow velocity [Vmca] at rest and during breath holding bilaterally in 10 controls, in 14 patients with unilateral high grade [>75%] internal carotid artery [ICA] stenosis and in 10 patients with ICA occlusion. Breath holding index [B HI], calculated as the rate increase of the Vmca during breath holding, was taken as a measure of autoregulative reserve. There was shown a highly significant difference of BFII between the control group [40 +/- 6%] and stenosis group [17 +/- 5%] [p< 0.005] as well as between the control group and occlusion group [9 +/- 6%] [p< 0.001]. With TCD breath holding test, it is possible to identify patients with carotid lesions, who have decreased auto-regulative reserve