Correlation between Electromyographic Findings and Radiologic Findings in Brachial Plexus Injury

J Korean Assoc EMG Electrodiagn Med 2001;3(2):69-73.
Published online May 10, 2001.

Abstract

Objectives : To identify the correlation between the electrophysiologic findings and the radiologic findings in brachial plexus injury. Methods : Authors reviewed 38 cases of electromyography (EMG) records and computed tomography (CT) myelographies from September, 1996 to April, 2001. EMG findings and CT myelographic findings were compared according to the injured spinal roots. Results : Four cases of postganglionic level, which were diagnosed by EMG, were diagnosed with preganglionic level by CT myelography. Senstivities of EMG in diagnosis of preganglioinc root level were as followed: C5 80%, C6 83.3%, C7 85.6%, C8 83.3%, T1 100%. Overall false positive rate of EMG in diagnosis of preganglionic level was 39.3%. False positive rate was higher in C5 and T1 than the other roots. Conclusion : EMG was sensitive and specific in distinguishing preganglionic root injury from postganglionic level injury. But false positive rate was somewhat high in diagnosis of preganglionic root level, so further study is needed such as correlation between EMG findings and surgical findings to define the cause of high false positive rate.

Key Words: Electromyography, Brachial Plexus, Myelography