Electroencephalography and clinical neurophysiology
-
Electroencephalogr Clin Neurophysiol · May 1987
Changes in the VEP in preterm neonates with arousal states, as assessed by EEG monitoring.
The effect of sleep state on the visual evoked potentials (VEPs) in neonates was investigated in 7 preterm infants. Polygraphic monitoring including EEG, EOG, ECG, respirogram and submental EMG for the purpose of sleep staging was carried out on all infants simultaneously with VEP testing. Awake-sleep stages were classified into 4 states: awake, transitional or atypical, quiet sleep and active sleep. ⋯ The P200, present in the older infants, disappeared in both active and quiet sleep states; the P400 was typically variable but reliably present in the awake or atypical states. When a distinction is made between quiet sleep and other arousal states, consistent and significant differences emerge. Our results emphasize the need to test infants in the same arousal states in studies of VEPs in order to make valid comparisons of latency or amplitude changes, particularly with longitudinal or follow-up studies.