Abstract
Somatosensory evoked potentials (SEP) and auditory brainstem responses (ABR) were analyzed in Down syndrome children in order to search for some characteristic developmental patterns with them.
Median nerve SEP was recorded in 48 Down syndrome infants and children aged from 1 month to 7 years. Recording electrodes were applied to the 3 rd cervical spine and to the contralateral scalp C3 or C4 (international 10-20 system) against the midfrontal reference. The amplifier band-pass was set between 10Hz to 1KHz, and 512 responses were averaged. Thirty-five Down syndrome infants and children aged from 1 month to 7 years received ABR recordings. Both SEP and ABR were examined by the DISA-1500 system. The records in these patients were compared with those obtained from age-matched normal control subjects.
In SEP, the central conduction time (N20-N13) and the ratio of N20 latency to the body height (N20/Ht) became longer in Down syndrome that in the control group after 1 year of age. These data may suggest maturation delay of the somatosensory pathway in Down syndrome. SEP was also useful to detect the spinal compression in patients with the atlantoaxial dislocation.
In ABR, I-III inter-peak latencies were significantly shorter in Down syndrome than in the control group after 2 years of age. This result probably suggested the small size of brainstem in Down syndrome. In addition, in many patients with Down syndrome it was difficult to seprate III, IV and V waves. This difficulty may imply the immaturation of brainstem in Down syndrome.
