Aanem Practice Topic Utility of Electrodiagnostic Testing in Evaluating Patients with Lumbosacral Radiculopathy: an Evidence-based Review

This is an evidence-based review of electrodiagnostic (EDX) testing of patients with suspected lumbosacral radiculopathy to determine its utility in diagnosis and prognosis. Literature searches were performed to identify articles applying EDX techniques to patients with suspected lumbosacral radiculopathy. From the 355 articles initially discovered, 119 articles describing nerve conduction studies, electromyography (EMG), or evoked potentials in adequate detail were reviewed further. Fifty-three studies met inclusion criteria and were graded using predetermined criteria for classification of evidence for diagnostic studies. Two class II, 7 class III, and 34 class IV studies described the diagnostic use of EDX. One class II and three class III articles described H-reflexes with acceptable statistical significance for use in the diagnosis and confirmation of suspected S1 lumbosacral radiculopathy. Two class II and two class III studies demonstrated a range of sensitivities for use of muscle paraspinal mapping. Two class II studies demonstrated the utility of peripheral myotomal limb electromyography in radiculopathies. Muscle Nerve 42: 276–282, 2010 The diagnosis of lumbosacral radiculopathy is based on clinical history and examination, imaging studies, and electrodiagnostic (EDX) testing. Converging lines of evidence localize the lesion, establish the diagnostic certainty, and assist with prognostication. In those cases with negative imaging findings or atypical clinical presentations, EDX is especially useful; whereas, in those with abnormal imaging findings, it serves a complementary diagnostic role. A correct diagnosis of lumbosacral radiculopathy is important for implementation of timely and appropriate treatments. The primary difficulty in this systematic review was the lack of an established reference standard for the diagnosis of lumbosacral radiculopathy. This lack of a standard makes comparison of reported sensitivity and specificity impossible. Structural abnormalities by imaging modalities had high rates of false positives, and occasional false negatives. Surgical visualization also did not consistently translate into clinical symptoms or physiological changes. In addition, the clinical presentation itself may be inconclusive. For example, injuries affecting the sacroiliac and zygapophysial joints, ligaments, muscles, and the peripheral disk annulus may cause referred pain suggestive of radiculopathy. The Lumbosacral Radiculopathy Task Force was charged by the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) to perform a systematic review of the available literature to evaluate the utility of EDX studies in the diagnosis of lumbosacral radiculopathies. Task force members were selected on the basis of their EDX and methodological expertise. This practice parameter describes the results and recommendations of this systematic review.