Presently, there are few electrodiagnostic method to evaluate lesions affecting the thoracic nerve roots or spinal cord. The purpose of this study was to establish the normal value for segmental intercostal somatosensory-evoked potentials.

The subjects in this study were 30 normal volunteers between 28 to 69 years of age, Bi lateral segmental intercostal SEP's were elicited after stimulation of third intercostal nerves just lateral to the sternum anteriorly. Segmental intercostal SEPs were also elicited form the fifth, seventh, and ninth intercostal nerves along the anterior axillary line bilaterally. The mean short latencies(P1) stimulation T3, T5, T7, T9 intercostal nerves were 23.5⁑1.85 msec, 24.9⁑2.27 msec, 25.5⁑1.72 msec, 26.3⁑2.23 msec, respectively, without any significant difference between two sides. The latencies were no significant difference between height, weight, BMI and age.

From the above results, these electrodiagnostic methods can be useful technique clinically suspected thoracic radiculopathy.