Auditory brainstem responses in pervasive developmental disorders

Several studies have reported prolonged neural transmission times on auditory brainstem responses (ABRs) measured in autistic children, a finding which implicates CNS dysfunction at the level of the brainstem in autistic conditions. This study measured ABRs in 25 children and adults with pervasive developmental disorders (PDDs), including autism, and 25 age- and sex-matched normal controls. Subjects were carefully evaluated audiometrically and neurologically and artifact was controlled to produce highly reliable measures. Prolonged transmission times were seen in only one PDD subject and in one normal control, while shortened transmission times were seen in four PDD subjects. The majority of PDD subjects showed normal ABRs. Previous reports of a significant incidence of prolonged transmission times among autistic and autisticlike subjects, thus, were not replicated. Possible reasons for this discrepancy are discussed.