Objective To test the hypothesis that perinatal brain injury affects cortical auditory processing.
Methods Auditory event-related potentials (AERP) were assessed in preterm infants (n = 9, median gestational age 27.9 weeks, range 23.9–30.0) and term infants (n = 5, median gestational age 40.3 weeks, range 37.4–42.3) with perinatal intracerebral haemorrhage (ICH), and term infants with perinatal asphyxia (n = 4, median gestational age 39.4 weeks, range 37.9–40.3). Two control groups were used, preterm infants without cerebral abnormality (n = 9) and healthy term infants (n = 22). An oddball paradigm was used with a harmonic tone of 500 Hz frequency as the standard and of 750 Hz frequency as the deviant stimulus. The preterm infants were studied at term, 6 and 12 months of corrected age, and the full-term infants within 17 days after birth, and at 6 and 12 months of age. Mean AERP amplitudes were calculated over the 150–250 and 250–350 ms periods, separately to standard tones preceding deviants and to the deviant tones. The neurological outcome was followed to 2 years of age.
Results Term infants with asphyxia and ICH showed smaller responses than controls. Both the term and preterm ICH group showed more negative responses than controls. AERP alterations did not predict gross motor abnormalities at 2 years of age.
Conclusions Altered AERP may indicate that perinatal cerebral insults affect cortical auditory processing. Whether altered AERP predict cognitive dysfunction needs to be assessed in a study with extended follow-up.