Electrodiagnosis: How to Read Electromyography Reports for the Nonneurophysiologist

An electrodiagnostic evaluation is a neurodiagnostic test commonly used to evaluate neuromuscular conditions. A typical electromyography (EMG) report consists of tabular data summarizing findings from nerve conduction studies (NCS) as well as needle EMG (nEMG). A text summary of these findings is also included, followed by a clinical interpretation that evaluates the obtained NCS and nEMG in the context of the clinical presentation. For electrophysiologists and nonelectrophysiologists alike, understanding the elements of EMG report, patterns of findings in common neuromuscular conditions, and potential technical errors that can erroneously influence the clinical interpretation is vital.