[Intracerebral steal after acetazolamide administration].

Occlusion or high grade stenosis of the internal carotid artery may be asymptomatic depending on the collateral patterns in the circle of Willis and the reserve capacity of the microvascular (arteriolar) system. The distensibility of the cerebral arterioles may be described quantitatively by the vasomotor reactivity. We present three patients with severe stenosis of an internal carotid artery associated with more severe stenosis or occlusion of the contralateral internal carotid artery.