Cerebral blood flow, oxygen utilization, and blood volume in dementia.

Patients with dementia had significant decreases in cerebral blood flow and cerebral oxygen utilization and a mild, but not significant, increase in cerebral blood volume. These studies were not useful in distinguishing patients with cerebral atrophy from patients with normal pressure hydrocephalus, as similar changes in cerebral circulation and metabolism were seen in both groups. Changes in cerebral blood flow after acute decrease in the intracranial pressure also were not helpful differentiating patients with normal pressure hydrocephalus from patients with cerebral atrophy.