Interpreting Electrodiagnostic Studies for the Management of Nerve Injury

Abstract

Nerve injuries are common after trauma and can be life-altering for patients. Electrodiagnostic studies are the gold standard for diagnosing and prognosticating nerve injuries. However, most surgeons are not trained in the interpretation of these studies; rather, they rely on the interpretation provided by the electrodiagnostician, who in turn is unlikely to be trained in nerve reconstruction. This discrepancy between the interpretation of these studies and the management of nerve injuries can lead to suboptimal surgical planning and patient outcomes. This review aims to provide a framework for surgeons to take a more active role in collaborating with their colleagues in electrodiagnostic medicine in the interpretation of these studies, with an ultimate goal of improved patient care. The basics of nerve conduction studies, electromyography, and relevant terminology are reviewed. The relationship between the concepts of demyelination, axon loss, Wallerian degeneration, nerve regeneration, collateral sprouting, and clinical function are explained within the framework of the Seddon and Sunderland nerve injury classification system. The natural evolution of each degree of nerve injury over time is illustrated, and management strategies are suggested.

Keywords: Electrodiagnostics; electromyography; nerve conduction; nerve injury; nerve transfer.