Thoracodorsal Nerve Conduction Study of Healthy Korean Adults: Reference Value

Abstract

Objectives: To establish the thoracodorsal nerve conduction study and to determine the reference value in healthy Korean adults.

Methods: Eighty extremities in forty healthy adults (mean age, 23.67±2.59 years) were evaluated with the thoracodorsal nerve conduction study. Subjects were laid in the supine position with their arms abducted to 90 degrees. The thoracodorsal nerve was stimulated at the axilla and Erb’s point with recording over the latissimus dorsi muscle. The recording electrode was placed at the intersection of a horizontal line drawing from inferior angle of the scapula and the posterior axillary line. The reference electrode was placed on the ipsilateral flank and the ground electrode was placed in the lateral chest wall.

Results: The latency and amplitude for the axillary stimulation were 1.93±0.24 (range, 1.30-2.42) msec and 4.42±2.30 mV. The latency and amplitude for Erb’s stimulation were 3.31±0.31 (range, 2.72-4.32) msec and 8.23±2.83 mV. The conduction velocity was 88.08±11.64 m/sec.

Conclusions: The CMAP of thoracodorsal nerve was readily obtained in all subjects. The thoracodorsal nerve conduction technique used in this study and the reference values may help to assess isolated thoracodorsal

nerve neuropathy and brachial plexopathy.