A separate category is that of lacerations, which require emergency surgery.

Preoperative Evaluation

Because these patients often present with multiple injuries, the diagnosis of brachial plexus lesion may not be readily made. In an emergency situation in which the patient presents with cranial, thoracic, and other lesions, it is difficult to conduct the type of examination that would demonstrate a lesion of the brachial plexus. It may take a few days or even a few weeks before a valid evaluation is possible. To be accurate, the evaluation must not be hampered by other osteoarticular lesions of the upper limb.

The study of sensitivity and motoricity allows assessment of the level of the lesion. After 3 weeks, when Wallerian degeneration is completed, the first electromyographic examination can be made. The purpose of this electromyographic study is to assess the nature of the lesions and to determine their severity according to Sunderland's classification.26 Expanding on Seddon's classification in three grades,5 Sunderland proposed the notion of integrity of basic lamina structures in nerve tissue regeneration and differentiated five grades.26

Grade I is neuropraxis, i.e., a conduction block that resolves itself spontaneously.

Grade II involves axonal rupture (axonotmesis) without interruption of the basil lamina tubes. The prognosis of this lesion is favorable because axonal regrowth will be guided by the basal lamina structures.

Grade III involves rupture of both axons and basal lamina tubes. In this case, axonal regrowth is possible but will be chaotic, which explains the uncertainty of results and especially the misrouting.

In Grade IV, in addition to the rupture of nerve fibers there is rupture of the perineurium; regrowth becomes difficult through the dense fibrous scar, and spontaneous results are poor.

Grade V is the complete interruption of the nerve structures.

Only through repeated electromyographic assessments over a period of several months is it possible to differentiate total interruptions from partial lesions. The danger would be to remain surgically inactive because of a spontaneous partial regeneration of the brachial plexus and thus neglect attendant complete interruption, which would benefit from early treatment by fascicular grafting.

next page...