Auditory brainstem response findings in Rett syndrome.

The ABR findings for 11 subjects with Rett syndrome were compared with two normal control groups, one female and the other male. Measurements were made for ipsilateral and contralateral recorded responses. Significant findings were noted for the latency of Wave V and for the III-V interval between the Rett subjects and the normal female controls on ipsilateral recording and between the Rett group and both control groups for the difference obtained between ipsilateral and contralateral recorded III-V intervals. While the basis for these observations is not clear, the findings provide evidence for some degree of involvement within the auditory brainstem pathway of this group and further support for the rather diffuse nature of the CNS pathology within the syndrome. Suggestions are made for further ABR study of this clinical entity.

Auditory brainstem evoked responses in autistic children.

Previous studies have implicated a brainstem dysfunction in the syndrome of autism. This study matched six autistic children with six normal children by age and sex to evaluate brainstem evoked response (BSER) to auditory stimuli. An evaluation of pure tone audiometric threshold showed no evidence of impairment; however, the electrophysiologic responses differed for the autistic and control groups. The BSER of the autistic children was remarkable for showing increased latency and markedly increased variability. The findings from this study add additional evidence of a brainstem dysfunction in autistic children, while the electrophysiologic variability supports the hypothesis of perceptual inconstancy.