47. Subcortical far-field components recorded to median nerve stimulation in children

Far field potentials are generated in structures remote from the surface electrodes and can be recorded from a widespread distribution over the scalp. A far field potential may be generated by abrupt constriction of the volume conductor or by a discontinuity in propagation of the action potential, where the nerve trunk bends or terminates. Here we present our laboratory normative data of the subcortically generated median nerve SEPs in normal children. The median nerve SEPs were recorded in n°48 children after sedation with chloralhydrate (50 mg/kg orally). The recording electrodes were placed on the ipsilateral Erb point (referred to Fz), cv6 (referred to anterocollis) and controlateral centroparietal (referred to ipsilateral auricolar, Erb and centroparietal points). All subjects have normal brain and cervicomedullary junction MRI. We evaluate for all subjects P9-P11-P13-P14-N18 far-field components including both latencies and interpeak latencies. In our case series we identified clearly all far field components in all subjects. Latencies and interpeak latencies will be then reported.