Cerebral vasoreactivity in unilateral carotid artery disease. A comparison of blood flow velocity and regional cerebral blood flow measurements.

Hemodynamic information obtained by assessing cerebral vasoreactivity is of clinical interest and may have prognostic significance in patients with occlusive carotid disease. The aim of this study was to compare the results of transcranial Doppler and regional cerebral blood flow studies when used to assess cerebral vasoreactivity.Blood flow velocities in both middle cerebral arteries and regional cerebral blood flow in their respective perfusion territories were compared in 52 patients with severe unilateral carotid stenosis or occlusion. The studies were first performed under basal conditions and repeated after the intravenous administration of 1 g acetazolamide.Asymmetry (normal compared with pathological side) in middle cerebral artery blood velocity increase was significantly greater than the asymmetry in cerebral blood flow increase in the perfusion territories of the arteries. A significant correlation (r = .63, P < .0001) was found between asymmetry in percent velocity increase and asymmetry in ab...