title: The central auditory conduction at term date and three months after birth. I. Composite group averages of brainstem (ABR), middle latency (MLR) and auditory cortical responses (ACR).
abstract: We are investigating the maturation of auditory evoked responses, as a potential diagnostic tool for the neurological examination of premature infants at the Intensive Care Unit for Prematures. In this communication we report the group composite averages of the BMC-ARs in a group of 25 mature and healthy newborns with a follow-up at 3 months of age. The ABRs showed a remarkable variability in wave I latency, with a relatively stable I-V central conduction time (CCT) of the brainstem. The ipsilateral II-V CCT does not differ appreciably from the contralateral II-V CCT. The MLR components NoPoNa and Nb, Nc, Nd are easy to identify in the group averages. Voltage asymmetry between stimulated versus non-stimulated side is slight but persistent in the newborn period as well as at 3 months of age. The group averaged ACRs, show an early complex within the latency reach of 100 ms and a slow W-shaped late complex, most distinct at 3 months. The results indicate that the protocol as applied constitutes a tool for the testing of conduction function of the auditory afference in newborns, even beyond the level of the brainstem. Group averaging offers a method to determine the intragroup stability of evoked potentials under investigation.
mesh_terms: D000161:Acoustic Stimulation; D001303:Auditory Cortex / Q000502:physiology*; D001306:Auditory Pathways / Q000502:physiology; D001933:Brain Stem / Q000502:physiology*; D002657:Child Development; D004292:Dominance, Cerebral / Q000502:physiology; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011930:Reaction Time / Q000502:physiology*; D012016:Reference Values; D009435:Synaptic Transmission