An electrodiagnostic consultation is best interpreted within the context of a specific clinical question.
Clear identification of the clinical question allows the electromyographer to design the appropriate electrical tests. Most EMG reports should include various sections: chief complaint, history, physical examination, nerve conductions, needle EMG, summary of findings, and impression.
Likewise it is important to understand the limitations of electrodiagnostic testing. NCs and EMG display a limited repertoire of abnormalities that include loss of myelinated motor or sensory nerve fibers, or both, abnormalities in myelin that affect conduction properties and membrane characteristics, compensatory changes associated with reinnervation of muscle fibers, and changes that are consistent with acute or chronic lesions (Krarup, 2003). Routine nerve conductions only assess the large myelinated fibers usually in their more distal distribution. Symptoms that are as a result of pathology of the small myelinated or unmyelinated fibers require alternative methods of evaluation.
The timing of the electrodiagnostic evaluation is important, as there is an orderly sequence of elec-trophysiologic changes that follow nerve injury. Knowledge of these changes is necessary for proper interpretation of results.
Was this article helpful?