Intracranial pressure and rapid eye movement sleep in hydrocephalus.

Intracranial pressure (ICP) was monitored for 24 h in 30 hydrocephalic patients (21 infants, 9 children) representing borderline cases. The need for surgery was uncertain because their hydrocephalus seemed to be more or less arrested. In 13 cases an electroencephalogram, an electro-oculogram, an electromyogram and an actogram were simultaneously recorded. During sleep related to a period of rapid eye movement (REM) fairly regular steep-rising waves of raised ICP recurred every 50-75 min, decreasing slowly to previous levels in 25-40 min. No concomitant clinical symptoms were exhibited. The cerebral pulse wave amplitude increase during REM sleep, but might vary during one period of REM sleep. The relationship between these raised ICP waves and an increase in cerebral blood flow occurring during REM sleep is studied.