Cerebral blood flow and sleep state in the normal newborn infant.

The cerebral blood flow (CBF) index measured by venous occlusion plethysmography in 12 normal newborn infants was found to vary significantly with sleep state. Criteria for definition of sleep state are described. The cerebral blood flow index in active sleep was 23% higher than in quiet sleep, and there were smaller, but consistent and significant, differences between intermediate and active or quiet sleep.