Effect of N-REM sleep on the cortical SEPs in early life.

Cortical and cervical somatosensory evoked potentials (SEPs) were studied by the averaging method in twenty healthy children, aged 20 days to 3 years. The stimulus was applied to the median nerve at the wrist and SEPs were recorded by electrodes placed on to the contralateral parietal scalp region as well as over the skin at the C6-7 vertebral region. The reference electrode was placed at the Fz. All subjects were studied during the awake state as well as during the N-REM sleep. The results indicate that N-REM sleep influenced the latency and the duration of SEPs, especially in children aged less than one year. This finding probably reflects a variable rate of maturation of the somatosensory pathway. The state of wakefulness must therefore be taken into account when assessing the pathological relevance of SEP recording in young children.