Disturbances of rapid-eye-movement sleep in 3 brothers with Pelizaeus-Merzbacher disease.

The electrophysiological features of 3 brothers with the classic form of Pelizaeus-Merzbacher disease (PMD) were studied. Two consecutive overnight polygraphic sleep recordings indicated a gross distortion of rapid-eye-movement (REM) sleep for all patients. A lower than normal percentage of REM sleep in these patients was consistent with their retarded intellectual development, which supports current thinking that REM sleep may be a sensitive index of brain function integrity. Non-rapid-eye-movement (NREM) sleep, in contrast to reported findings in 1 patient with PMD, was uniformly characterized by distinct stages in which the electroencephalograms contained frequent vertex waves and spindles. Tests of peripheral nerve conduction velocity, acoustic brainstem reflexes, and visual and auditory evoked potentials did not indicate any abnormalities, nor did electroencephalograms obtained during wakefulness. One patient did have epileptiform spikes and spike waves recorded during an all-night EEG, an unusual finding in a child with cerebral white matter disease.