AMA Guides® Newsletter - Issue Archive

Articles

1. Evaluating Lumbar Radiculopathy

   James B. Talmage, Marjorie Eskay-Auerbach, J. Edward Blaisdell

   Pages 3–10

   DOI: 10.1001/amaguidesnewsletters.2014.MayJun01

   Abstract

   For workers’ compensation, most requests for a permanent impairment rating of low back injuries involve the diagnostic labels of nonspecific chronic low back pain or intervertebral disk herniation. Use of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, to choose the right diagnosis and class for these injuries is the first step and involves correctly choosing between “nonverifiable radicular complaints” and “residual radiculopathy.” Evaluators must be able to distinguish persisting radiculopathy, as defined in the sixth edition, from resolved radiculopathy and from nonverifiable radicular complaints and to support findings with objective clinical evidence. Clinical evidence of chronic radiculopathy might include motor weakness, muscle atrophy, impaired sharp–dull discrimination, and/or abnormal electrodiagnostic tests, provided the findings are persistent and there are reflex abnormalities. When considering radiculopathy in the appropriate spine grid of the AMA Guides, Sixth Edition, the evaluator must distinguish radicular (limb) symptoms that are continuous, intermittent, or completely resolved. Positive electromyography (EMG) studies for acute radiculopathy are a sufficient objective finding to state the person has radiculopathy on the date of the test; individuals with positive needle EMG do have persisting radiculopathy at maximum medical improvement, but this does not mean that radiculopathy must persist despite time and treatment.
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2. Electrodiagnosis of the Peripheral Nervous System: An Introduction

   Richard T. Katz

   Pages 10–14

   DOI: 10.1001/amaguidesnewsletters.2014.MayJun02

   Abstract

   This article is an introduction to electrodiagnosis of the peripheral nervous system, including electromyography, electroneurography (nerve conduction studies), and somatosensory evoked potentials. Electromyography involves the introduction of a special recording needle into a muscle body in search of spontaneous activity (electrical potentials that occur while the muscle is at rest). Three types of spontaneous activity are of greatest relevance: positive sharp waves, fibrillation potentials, and fasciculations. Electromyography can help assess the status of nerve fibers indirectly, but the integrity of large myelinated sensory and motor neurons can be evaluated directly by nerve conduction studies (NCS), also known as electroneurography. NCS involves the introduction of an electrical stimulus, either by surface electrode or needle, and recording an evoked response. NCS can assess motor neurons, sensory neurons, or mixed nerve trunks, depending on the strategy employed. Somatosensory evoked potentials (SSEP) sometimes are useful as an adjunct to EMG and NCS in the diagnosis of peripheral nervous system pathology and are obtained by stimulating a peripheral mixed nerve at a frequency of approximately 2-5 Hz. Several manufacturers have created automated, hand-held units for performing nerve conduction studies, and neuromuscular ultrasound is noninvasive and painless, and ultrasound of nerve entrapment has identified nerve enlargement just proximal to the site of entrapment. Physicians should know or learn the qualifications of the physician to whom they refer their patients for electrodiagnostic assessment.
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3. Q&A: Thoracolumbar Fusion

   Christopher R. Brigham, Gunnar B J Andersson, Lorne Direnfeld, Marjorie Eskay-Auerbach, James B. Talmage

   Pages 15–16

   DOI: 10.1001/amaguidesnewsletters.2014.MayJun03