Maturation of near-field and far-field somatosensory evoked potentials after median nerve stimulation in children under 4 years of age

Objectives: The maturation of subcortical SEPs in young children. Methods: Median nerve SEPs were recorded during sleep in 42 subjects aged 0-48 months. Active electrodes were at the ipsilateral Erb's point, the lower and upper dorsal neck, and the frontal and contralateral centroparietal scalp; reference electrodes were at the contralateral Erb's point, the ipsilateral earlobe and the frontal scalp; bandpass was 10-3000 Hz. The peaks were labelled by their latencies in adults. Results: The peak latencies of N9 (brachial plexus potential) decreased exponentially with age during the first year, but increased with height thereafter. The interpeak latencies (IPLs N9-N11, which measure conduction between brachial plexus and dorsal column, decreased with age (linear regression). The IPLs N11-P13 and N11-N13b, which measure conduction between the dorsal column and approximately the cervico-medullary junction, did not change across this age range. The IPLs N13a-N20, N13b-N20 and P13-N20, which measure central conduction, showed negative exponential regressions with rapidly decreasing latencies during the first year of life and slowly decreasing latencies thereafter. Conclusions: Maturation of the peripheral segments of the somatosensory pathway progresses more rapidly than that of the central segments. The maturation of central conduction is not completed within the first 4 years of age. Our maturational data may serve as a reference source for subsequent developmental and clinical studies. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.