[The median nerve evoked potential in normal children and youths: normal values]

The derivation of cortical somatosensory evoked potentials permits a good local and functional diagnosis of supratentorial structures and the localisation of damage in this area. The special diagnostical relevance of early cortical somatosensory evoked potentials as a sage, non-invasive examination method in pediatric neurology is given both by these characteristics and by the fact that they cannot, in principle, be influenced by sleep or by drugs affecting the central nervous system. Somatosensory evoked cortical potentials of N. medianus were investigated for 35 children (17 boys, 18 girls) between the ages of 6 and 17, for whom there were no anamnestic or clinical indications of neurological or otological diseases. Investigations demonstrate that the SEPs of the N. medianus from the P15 up to and including the N55, is in every case clearly measurable in children from preschool age up to the end of adolescence. In the evaluation of the cortical SEPs, the P15, N20 and P25 were considered to be the components most stable and those most valuable for clinical practice. These could also be presented with the smallest standard deviations and side differences. The latencies of the P15 and N20 of the N. medianus show significant dependencies on the height of the children. The later potential components, side differences, interpeak intervals and amplitudes show no correlations with height. The SEPs of N. medianus show no dependencies on gender or on physical parameters such as weight or head circumference of the experiments. In summary it can be established that, using the procedure mentioned above, the cortical somatosensory evoked potentials in children can be described well and reproducibly and within practical narrow standard limits.