Case Study: Use of Electrodiagnostic Evaluation to Assess Lumbar Radiculopathy

Abstract

The electrodiagnostic examination is an important diagnostic tool that defines the location, pathophysiology, severity, and chronicity of a wide array of neuromuscular disorders. The test comprises two parts, a nerve conduction study (NCS) and needle electromyography (EMG), and is an extension of the neuromuscular portion of the physical examination. Together, NCS and EMG provide complementary information about the integrity of the peripheral nervous system. The article presents a case example that is evaluated using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition. The case describes a 52-year-old woman who had a back injury that was managed conservatively for fifteen months and then underwent a three-level lumbosacral instrumented posterolateral fusion (the rationale is unclear from the records). Her pain persisted and treatment has included chronic narcotics; she reported multiple physical and psychological complaints and difficulties, and illness behavior and unreliable self-reports failed to corroborate her reports. Needle EMG must be performed on the patient's paraspinal muscles for proper evaluation of radiculopathy, and in this case there was no evidence of involvement of any ventral ramus and thus no evidence was documented of nerve root abnormality involving two or more limb muscles that receive innervation from the same nerve root. For this individual, the changes seen in paraspinal EMGs were unlikely to be due to a true lumbar radiculopathy, which was not convincingly established.