Sleep and brain malformation in the neonatal period

Polygraphic recordings of 20 neonates with brain malformations and/or chromosomal anomalies were compared with those obtained in 29 normal fullterm neonates. Seep assessment was made with different methods described in the literature. These methods of sleep scoring gave similar results in the normal newborn babies but discrepant results in many pathological neonates. Thus sleep was also studied by other approaches; assessment of cycling of the 5 parameters (EEG, REM, EMG, Motility, Respiration) and study of the discrepant parameters during a sustained period of Active sleep (AS) or Quiet Sleep (QS), defined by the most flexible method. Newborn babies with brain malformations appeared to be poor sleepers. Amount of wakefulness is higher than in normal neonates. Some babies were nearly insomniac. Correlations of sleep patterns and anatomical lesions were possible in five cases where brain anatomy was available. A good sleep organization has been seen in babies with normal brain-stems but a normal brain stem with a normal locus coeruleus has been found in a baby with absence of AS. Absence of sleep organization has been seen in babies with an abnormal brain stem; but this anomaly was not isolated as these babies also had lesions of the forebrain. The sleep of human neonates shows a greater liability in the coordination of the different parameters than the sleep of human adults or adult animals. It appears that sleep mechanisms at the pontine level present more plasticity than the rigid mono aminergic model would suggest.