Auditory Brainstem Response in Infants and Children with Autism: A Meta-Analysis

TL;DR

This meta-analysis shows that infants and children with autism have prolonged Auditory Brainstem Response (ABR), which normalizes or shortens in adulthood, indicating its potential as an early autism biomarker.

Contribution

It provides a comprehensive analysis of ABR differences across age groups in autism, highlighting its potential as an early diagnostic biomarker.

Findings

Prolonged wave V in autism during childhood

ABR normalizes or shortens in adults with autism

ABR can serve as an early autism biomarker

Abstract

Infants with autism were recently found to have prolonged Auditory Brainstem Response (ABR); however, at older ages, findings are contradictory. We compared ABR differences between participants with autism and controls with respect to age using a meta-analysis. Data sources included MEDLINE, EMBASE, Web of Science, Google Scholar, HOLLIS and ScienceDirect from their inception to June 2016. The 25 studies that were included had a total of 1349 participants (727 participants with autism and 622 controls) and an age range of 0-40 years. Prolongation of wave V in autism had a significant negative correlation with age (R2=0.23; P=.01). The 22 studies below age 18 years showed a significantly prolonged wave V in autism (Standard Mean Difference=0.6 [95% CI, 0.5 to 0.8]; P<.001). The 3 studies above 18 years of age showed a significantly shorter wave V in autism (SMD=-0.6 [95% CI, -1.0 to -0.2]; P=.004). Prolonged ABR was consistent in infants and children with autism, suggesting it can serve as an autism biomarker at infancy. As the ABR is routinely used to screen infants for hearing impairment, the opportunity for replication studies is extensive.