Validation of an electromyography and nerve conduction study protocol for the analysis of brachial plexus lesions in 184 consecutive patients with traumatic lesions.

Objectives: To validate a concentric needle electromyography (EMG) and nerve conduction study (NCS) protocol for the preoperative analysis of brachial plexus lesions.METHODS. 184 consecutive patients with traumatic brachial plexus lesions were analyzed. The results of the neurophysiological studies were compared with the final diagnoses based on the results of computed tomography-myelography and findings during the operation.

Results: The protocol proved reliable in the analysis of these lesions in 84% of cases. Limitations were that extraforaminal lesions may mask root avulsion or central lesions; paraspinal sampling is of limited value in multiple root lesions because of the overlap in innervation; and sometimes normal sensory nerve action potentials (SNAPs) could occur in an extra foraminal lesion. Lesions outside the plexus were found in 21% of the patients, most of which would not have been expected on clinical grounds.

Conclusion: With this protocol, a reliable analysis of traumatic brachial plexus lesions can be made in 84% of the patients, even finding lesions outside the brachial plexus not expected on clinical grounds in 2l degrees of the patients.