The relationship between median nerve somatosensory evoked potential latencies and age and growth parameters in young children.

Median nerve somatosensory evoked potentials (SEPs) were recorded in a group of 35 normal children aged 6-36 months and related to body length, body weight and head circumference. Recordings were made while the child was awake using the following derivations: ipsilateral clavicle--Fpz; seventh cervical vertebra (CV7)--Fpz; contralateral C'--Fpz. The clavicular-Fpz response was bilobed in 77% of the recordings, the initial negativity being designated CL1 and the following negativity, CL2. Early negativities, coincident in latency with CL1 and CL2, were often present in CV7-Fpz recordings, however, a negativity longer in latency than CL2 was always present, was designated CVN, and preceded a prominent positivity. A scalp-recorded early negativity (N1) and a following positivity (P1) were well defined in all recordings. The latency of CL1, CL2 and CVN increased with an increase in age and stature. In contrast, significant negative correlations were found between the latency of N1, P1, age and stature. The CL1-CVN interpeak latency did not correlate significantly with age, while the central conduction time (CVN-N1) declined significantly with an increase in age and stature. These findings confirmed the complexity of SEP absolute and interpeak latency changes with an increase in age and stature in young children.