electrodiagnostic examination of the lateral antebrachial cutaneous nerve(LACN) that is the sensory branch the musculocutaneous nerve is useful to screen the upper trunk, lateral cord in brachial plexus and C5/C6 roots. But its clinical usability is relatively poor at now and normal values of the musculocutaneous SEP are not gotten yet in Korean. In this study, we tried to get the SEPs of LACN in 52 healthy Korean aged from 20 to 29 years old.

Stimulation were performed at the elbow where it penetrates the fascia to become the cutaneous nerve and recording at C3 or C4 of 10~20 EEG recording system. We performed together its sensory nerve conduction & superficial radial nerve SEP as the basic data for the inter or intra-nerve comparision at the same time and aquired their normal values.

Results are followings(mean⁑1SD).

1) The distal latency, the peak to peak amplitude, conduction velocity in LACN peripheral conduction were 1.84 ⁑ 0.14 msec, 28.9 ⁑ 10.7 ㎶, 65.4 ⁑ 5.07 m/sec respectively.

2) The peak latencies of the LACN SEP were 15.1 ⁑ 0.80, 21.3 ⁑ 1.29, 30.4 ⁑ 1.39 and 40.8 ⁑ 1.191 msec in order of N1, P1, N2, P2 respectively.

3) The peak latencies of the superfical radial nerve SEP were 17.6 ⁑ 0.91, 23.4 ⁑ 2.58, 32.7⁑ 1.46 and 42.7 ⁑ 2.06 msec in order of N1, P1, N2, P2 respectively.

4) There is no significant difference between right and left sides, male and female in peripheral conduction and SEP study statistically.

5) There was significant correlation between the initial negative peak(N1) latency of SEP and height of the subject.

Keywords :Musculocutaneous nerve, Lateral antebrachial cutaneous nerve, Somatosensory evoked potential, Sensory nerve conduction