Aberrant lateralization of brainstem auditory evoked responses by individuals with Down syndrome.

Brainstem auditory evoked response latencies were studied in 80 males (13 with Down syndrome, 23 with developmental disability due to other causes, and 44 with no disability). Latencies for waves P3 and P5 were shorter for the Down syndrome than for the other groups, though at P5, as compared to latencies for the nondisabled group, the difference was not significant. The pattern of left versus right ear responses in the Down syndrome group differed from those of the other groups. This finding was related to research noting decreased lateralization of and decreased ability at receptive and expressive language among people with Down syndrome. Some individuals required sedation. A lateralized effect of sedation was noted.