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 lowe r and upper dorsal neck, and the frontal and contralateral centroparietal s calp; reference electrodes were at the contralateral Erb's point, the ipsil ateral earlobe and the frontal scalp; bandpass was 10-3000 Hz. The peaks we re labelled by their latencies in adults. Results: The peak latencies of N9 (brachial plexus potential) decreased exp onentially with age during the first year, but increased with height therea fter. The interpeak latencies (IPLs N9-N11, which measure conduction betwee n brachial plexus and dorsal column, decreased with age (linear regression) . The IPLs N11-P13 and N11-N13b, which measure conduction between the dorsa l column and approximately the cervico-medullary junction, did not change a cross this age range. The IPLs N13a-N20, N13b-N20 and P13-N20, which measur e central conduction, showed negative exponential regressions with rapidly decreasing latencies during the first year of life and slowly decreasing la tencies thereafter. Conclusions: Maturation of the peripheral segments of the somatosensory pat hway progresses more rapidly than that of the central segments. The maturat ion of central conduction is not completed within the first 4 years of age. Our maturational data may serve as a reference source for subsequent devel opmental and clinical studies. (C) 2000 Elsevier Science Ireland Ltd. All r ights reserved.