Clinical application of evoked electroencephalographic responses in newborn infants. I: Perinatal asphyxia.

Evoked electroencephalographic responses are useful for the study of cerebral maturation in full-term and pre-term newborn infants. In an attempt to achieve wider clinical application, 57 newborn infants with differing degrees of perinatal asphyxia were examined. Altogether 154 examinations were performed. In all of them photostimulation was used, and in 72 investigations somatosensory evoked responses were also recorded. The following results were obtained: (1) Visual evoked responses were affected in 85 per cent of the cases. Somatosensory evoked responses were affected less often - in 65 per cent of the newborn babies examined. The incidence and degree of deviations were related to the degree of asphyxia. (2) The most characteristic features of the evoked responses in asphyxiated infants were abnormal response patterns, increase of latency and poor photic driving. (3) On the basis of all alterations observed, a scoring system was developed which enabled quantitative evaluation. The evoked response risk-score correlated well with the degree of asphyxia. (4) Repeated observations were important: a permanently high risk-score at repeated investigations was a serious prognostic sign.