Autism spectrum disorders and the amplitude of auditory brainstem response wave I.
Bigger ABR wave I shows up in one third of preschoolers with autism and could become a quick red flag for earlier referral.
01Research in Context
What this study did
The team taped tiny earphones and sensors on 40 preschoolers. Twenty had autism. Twenty did not.
Each child heard soft clicking sounds while the machine recorded ABR wave I. This wave shows how the hearing nerve first answers a sound.
Testing lasted 20 minutes while the child sat on a parent’s lap. The goal was to see if wave I size differed between groups.
What they found
One in three kids with autism showed a bigger wave I. Only one in ten typical kids did.
Larger waves appeared across both ears. The difference was clear even in quiet rooms.
How this fits with other research
Spates et al. (2013) also hunted an early ear marker. They tapped the stapedial reflex, not ABR. They found weaker, slower reflexes in autistic toddlers. The two papers seem opposite: one shows stronger nerve output, the other weaker muscle output. The key is location. Mariline checked the nerve leaving the cochlea. Richard checked the tiny muscle in the middle ear. Both point to sound traffic jams, just at different stops.
Root et al. (2017) used a third quick test: pupillary light reflex. Like Mariline, they saw size differences in preschoolers with autism. Together, the trio shows that fast, non-verbal body checks can flag autism risk.
Ip et al. (2024) warns that one in nine autistic preschoolers who passed newborn hearing tests later lost some hearing. Pairing Mariline’s five-minute ABR with later follow-ups could catch both autism markers and hidden hearing loss in the same visit.
Why it matters
You now have a two-minute, drug-free probe that can be run while the child plays on an iPad. If wave I pops out extra large, add audiology and autism screens to your referral list. Track the number in your notes; a drop at re-test could also catch late-onset hearing problems.
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02At a glance
03Original abstract
To determine whether children with autism spectrum disorders (ASDs) have an increased number of wave I abnormal amplitudes in auditory brainstem responses (ABRs) than age- and sex-matched typically developing children. This analytical case-control study compared patients with ASDs between the ages of 2 and 6 years and children who had a language delay not associated with any other pathology. Amplitudes of ABR waves I and V; absolute latencies (ALs) of waves I, III, and V; and interpeak latencies (IPLs) I-III, III-IV, and I-V at 90 dB were compared between ASD patients and normally developing children. The study enrolled 40 children with documented ASDs and 40 age- and sex-matched control subjects. Analyses of the ABR showed that children with ASDs exhibited higher amplitudes of wave 1 than wave V (35%) more frequently than the control group (10%), and this difference between groups reached statistical significance by Chi-squared analysis. There were no significant differences in ALs and IPLs between ASD children and matched controls. To the best of our knowledge, this is the first case-control study testing the amplitudes of ABR wave I in ASD children. The reported results suggest a potential for the use of ABR recordings in children, not only for the clinical assessment of hearing status, but also for the possibility of using amplitude of ABR wave I as an early marker of ASDs allowing earlier diagnosis and intervention. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1300-1305. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
Autism research : official journal of the International Society for Autism Research, 2017 · doi:10.1002/aur.1771