Age, sex and mental retardation related changes of brainstem auditory evoked potentials in Down's syndrome.

Brainstem auditory evoked potentials (BAEPs) were recorded in 51 Down's syndrome (DS) subjects and compared with those of 38 normal controls; the correlations between the BAEP measures and age, sex, and degree of mental retardation were then evaluated. The DS patients showed a significant reduction in wave V latency and amplitude and in I-III, III-V, and I-V interpeak intervals. An age-related shortening of the I-V interpeak interval found in DS patients was interpreted as being a result of changes in central inhibitory/excitatory mechanisms. In both groups, female subjects presented an I-V interval shorter than that of males but this difference was greater in the DS subjects than in the normal population. The DS patients with severe mental retardation showed significantly longer I-V interpeak intervals than those with moderate retardation; this could be due to the presence of additional central nervous system abnormalities.