Somatosensory evoked potentials(SEPs) are useful for the evaluation of the nervous system from peripheral receptor to cerebral cortex.
SEPs were recorded from 46 normal subjects (male=28, female=18), aged 15^-70 years (mean=41.9) using TECA 42 EMG system. Both median nerves were stimulated at wrist and recording electrodes were placedon C2(active) and Fz(reference) position of the international 10-20 EEG system. Following results were obtained.
1) The mean latencies of the No, N1, P1, N2, P2 were 15.4±0.97 msec, 18.7±0.91 msec, 23.5±1.76 msec, 31.7±2.25 msec, 42.6±3.02 msec respectively on the right side.
2) The mean amplitudes, N1P1 and N2P2 on the right side were 8.06±1.61 pV and 5.85± 1.90 pV ant NP/NP was 72.5%.
3) The Np, was neglected due to irregularity and inconsistency in shape.
4) Differences between the right and left and between the male and female for the
latency and amplitude were not found, but N2P2/N1P1 of the male and -female respectively
were 79.8°o and 67.9°0 on the right side.
5) According to aging, mean latencies were increased.
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