[Evoked somatosensory cerebral potentials from the lower limb in newborn infants and infants]

In 26 babies, from 1 day to 3 months old, the somatosensory scalp potentials (SEPs) were evoked by electrical stimulation of the tibialis posterior nerve. No reproducible response in any location was obtained in 6 cases. In the other 20 cases, the initial wave was positive in 18 cases, with a peak latency at about 35 msec (P36) but the initial latency differed according to the location of the electrodes on the midline and to the baby. In a systematic topographical study, P36 was found to be variable in its distribution and its latency without correlation, whether with the baby's age, size, physiological state or intensity of stimulation. Our results are compared with SEPs obtained from the lower limb in adults and from the upper limb in children.