Cerebral vasomotor reactivity and carotid occlusive disease

Cerebral autoregulation is a mechanism that enables relatively constant cerebral blood flow during variations of cerebral perfusion pressure. The differences between cerebral blood flow at rest and after administration of a potent vasodilatory stimulus test such as hypercapnia reflect cerebral vasomotor reactivity defined as the vasodilation capacity of cerebral arterioles to external stimuli, providing important information about the cerebral hemodynamic status. Cerebral vasomotor reactivity provides important information about the cerebral hemodynamic status. In this article, cerebral vasomotor reactivity assessment tests are presented, with emphasis on transcranial Doppler, as well as the use of transcranial Doppler in assessing cerebral vasomotor reactivity in carotid stenosis, occlusion, and the importance of cerebral vasomotor reactivity for carotid surgery.