Chapter 58 - Visual evoked responses to LED photostimulation in newborn infants

Abstract

This chapter discusses a study to elaborate the visual evoked responses (VER) to led photostimulation in newborn infants. VERs were obtained on 16 healthy, full-term infants aged 2 to 9 days in whom delivery and the perinatal period had been uneventful, and in whom neurological examination had been normal. A total of 70 infants on the Special Care Baby Unit at the Hammersmith Hospital were also studied. Gestational ages at birth ranged from 27 to 35 weeks and birthweights from 800 to 2690 g. Clinical diagnoses included asphyxia, respiratory distress requiring ventilatory support and sepsis. Infants with convulsions, meningitis, or congenital structural brain anomaly were excluded. It is found that when the VER waveform was compared in the four groups, a significant difference was noted in the incidence of the positive component in the neurologically normal and abnormal infants. The proportion of VER records in which the positive component is present is shown for each group of subjects at each postmenstrual age. It can be seen that 38% of Group 1 had developed positivity by 32 weeks' PMA compared with none in Groups 2, 3 and, the delay in the VER maturation was also compared to the presence of ventricular dilatation.