Neonatal Brainstem Function and 4‐Month Arousal‐Modulated Attention Are Jointly Associated With Autism

Lay Abstract A stronger preference for high rates of stimulation when tested after feeding at four months of age has been reported in Neonatal Intensive Care Unit (NICU) graduates who later were diagnosed with autism relative to those who were not. This visual preference is typical of newborns, is likely mediated by arousal systems in the brainstem, and should no longer be present by four months. The fact that it was so persistent in babies who later developed autism suggested they may have had atypical brainstem development or functioning. There exists a group of newborns who initially fail Auditory Brainstem Response screens (ABRs; a measure of the integrity of their brainstem auditory pathways) but eventually recover by hospital discharge suggesting they have atypical brainstem development. We therefore examined the extent to which this problem with ABR functioning along with four-month-olds’ preference for high rates of stimulation predicts the later occurrence of autism in toddlers and preschoolers. We found that preference for higher rates of stimulation at four months was highly associated with later measures of autism severity and with language development problems but only in those who had initially abnormal ABRs. It was concluded that the joint occurrence of initially abnormal neonatal ABRs and preference for more stimulation at four months, both indices of early brainstem dysfunction, may be a marker for the development of autism.