Posterior antebrachial cutaneous nerve conduction study technique

Purpose: This paper describes an improved electrodiagnostic methodology for posterior antebrachial cutaneous nerve (PABC) neuropathy based on retrospective analysis. Methods: Results of PABC nerve conduction studies in 14 control patients and 3 patients with left PABC neuropathy are included. Stimulation was performed 0.5 to 2.0 cm above the lateral epicondyle, and the recordings were acquired at 12 cm, 15 cm and 20 cm distally. Data was evaluated using the mean ± standard deviation, calculated for descriptive analysis of continuous variables whereas frequencies and percentages were determined for categorical variables. Abnormal cutoff values including side-side comparison values were established so that all normal control values would fall within the normal range. Results: PABC conduction studies with 20 cm recording distance demonstrated abnormal electrodiagnostic findings in all 3 patients, while more proximal recordings failed to document the neuropathy. Conclusion: The recording of PABC responses at 12 cm, 15 cm and 20 cm distal to the stimulating electrode offers a more comprehensive evaluation and may be a more sensitive test for evaluation of suspected PABC neuropathy, in comparison to traditional 12 cm recording.