[Auditory brain stem responses in Down's syndrome].

Auditory brain-stem responses (ABR) to click stimuli were recorded from 81 children and 20 young adults of Down's syndrome with normal hearing. Comparisons were made to groups of normal control subjects matched by age and sex. I - V interpeak interval in infants younger than 18 months was significantly shorter, while that in children over 18 months and young adults with Down's syndrome was not shortened, compared with that of each control group. Previous studies have emphasised that, regardless of age, the I - V interpeak interval in Down's syndrome is significantly shorter than in the control group. However our study suggests that cases of Down's syndrome with normal hearing have normal central conduction times after CNS maturation. And the shortened central conduction times in infants of Down's syndrome were not lesser than that of normal adults. Our results suggest that the shortened central conduction time in Down-syndrome infants is associated with earlier neurological maturation in Down's syndrome.