The purpose of this study is to standardize short latencies of dermatomal SEP stimulating T₄, T₇, T₁₀, T₁₂, L₁, L₂ and L₃ sensory dermatomes and to demonstrate the effect of height and sex difference in short latencies of dermatomal SEP.

The subjects in this study were 30 normal volunteers between 20 to 39 years of age. The mean short latencies(P1) stimulating T₄, T₇, T₁₀, T₁₂, L₁, L₂ and L₃ dermatomes were 23.1±1.81 msec, 25.0±2.04 msec, 27.6±2.19 msec, 30.4±2.45 msec, 29.6±2.50 msec, 32.3±2.81 msec, 33.7±2.53 msec, respectively.

The short latencies stimulating T₁₀, L₂ and L₃ dermatomes were significantly prolonged in male than female (T₁₀, L₃: p<0.05, L₂: p<0.005). The short latencies stimulating T₁₀, L₁, L₂ and L₃ dermatomes were correlated with height (p<0.05), but there were no significant difference in short latencies between right and left side.