EMG/NCV in the evaluation of spine trauma with radicular symptoms.

Andrew J. Haig, MD, University of Michigan, Ann Arbor; John C. Kincaid, MD, Indiana University, Indianapolis; Timothy Dillingham, MD, MS, University of Pennsylvania, Philadelphia; Peter Grant, MD, private practice, Medford, OR: A recent article by Charles and Souayah concludes that electrodiagnostic testing for spinal disorders is of little value. As neurologists and physiatrist subspecialists in the field, we disagree. Much of the evidence presented is incorrect, incomplete, or outdated, leading to faulty conclusions. This short letter can only highlight a few problems. The authors claim that no practice guidelines are available when these are readily available from the American Association of Neuromuscular and Electrodiagnostic Medicine and others. The article cites early unmasked studies to claim that paraspinal EMG has such a high false-positive rate that it is useless. This contrasts with the modern literature. For example, a masked, double-controlled study using validated reproducible techniques and established norms found that abnormal paraspinal EMG was 100% specific, in great contrast to the low specificity of diagnostic imaging. In addition to positively diagnosing spinal nerve disorders, EMG has also been shown in various situations to detect diseases that mimic spinal disorders, localize pathology for surgical and injection treatments, establish the duration of symptoms, establish the severity of disease, and predict or validate outcomes from certain spinal treatments. The literature, in contrast to this article, shows that electrodiagnosis is a useful and validated test for spinal disorders. A more detailed response can be found at www.aanem.org/defending-edx.