The Indications and Importance of Obtaining Electrical Studies

Abstract

The use of electromyography (EMG) and nerve conduction studies (NCS) in the evaluation of carpal tunnel syndrome (CTS) has evolved over the last few decades. Its use has been debated when patients undergoing carpal tunnel release in light of normal EMG findings had significant relief of their symptoms (Grundberg, J Hand Surg 8:348–349, 1983). Currently, however, the use of EMG and nerve conduction studies in the evaluation of compression neuropathies is accepted as a common practice. A recent survey of ASSH members showed 90% of surgeons used electrodiagnostic studies preoperatively at least occasionally, and that number was as high as 96% among younger surgeons (Munns and Awan, J Hand Surg Am 40:767–771, 2015). This more recent near-universal use of electrodiagnostic studies most likely is multifactorial, and can be at least partly related to defensive medicine in light of current published guidelines for the treatment of CTS, which recommend NCS/EMG (Keith et al., J Am Acad Orthop Surg 17:389–396, 2009; Keith et al., J Am Acad Orthop Surg 17:397–405, 2009). Given the prevalence and importance of electrodiagnostic testing in the management of carpal tunnel syndrome, the treating surgeon should have a basic understanding in its use and interpretation.