An additional view

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LETTERS

TO THE

Electromyography The article by Kothari and colleagues,’ “Electromyography: Do the Diagnostic Ends Justify the Means?” presented some interesting findings. Since an astonishingly high percentage (93%) of the patients tested were willing to be retested, several aspects of the study need clarification. 1. How was each muscle sampled with the EMG needle? A detailed description of the EMG technique would be helpful. 2. A stratification of the muscles sampled in terms of (1) proximal versus distal limb muscles and (2) upper limb versus lower limb versus paraspinal muscle may help differentiate sensitivity to electromyography among the muscles tested. 3. On a less serious note, what type of “soft” music was recommended? New York

Aubrey Ku, MD Hospital-Cornell Medical Center New York, NY 10021

Reference DC, Plotkin GM, Venkatesh Logigian EL. Electromyography: do the diagnostic means? Arch Phys Med Rehabil 1995;76:947-9.

1. Kothari MJ, Preston

The authors

S, Shefner ends justify

JM, the

reply

We appreciate Dr. Ku’s comments. The EMG exam of each muscle was performed in a standard fashion with examination of the insertional activity to assess any active denervation followed by analysis of motor unit morphology and the recruitment pattern. Dr. Ku raises an important issue with her second question. We agree that examination of the paraspinal muscles is useful in the evaluation of a radiculopathy. Fibrillations in the paraspinals localize the disease process to proximal structures such as the root, but the abnormalities in the limb muscles are used for localization of the specific myotome. The appropriate level paraspinal and limb muscles were examined by EMG in all of the patients who were either referred for radiculopathy or who had evidence of root dysfunction. Concerning the music played during the studies, we chose classical music by Mozart and Bach. Milind J. Kothari, DO Milton S. Hershey Medical Center Hershey, PA 17033 Eric L. Logigian, MD Brigham and Women’s Hospital Boston, MA 02115

An Additional View I believe Kothari and associates missed the mark on the main issue today regarding electromyography. They addressed primarily whether patients found the test painful, and what diagnosis was reached. A much more critical question would be, “Did the findings change clinical decision making?” Electrodiagnostic testing has a long history of overuse and abuse, particularly in the setting of Workmens Compensation and personal injury litigation. I have reviewed EMG studies for several insurance companies and have found that the tests are frequently performed without the above critical question being addressed.

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EDITOR

A much more valuable study would be to look at whether the performance of the test changed in any way clinical decision making. It is no longer enough to do a test to confirm a clinical impression if the test is not going to add to the treatment and care of the patient. Most of us do not need to perform an electrodiagnostic test to know that a patient has a diabetic polyneuropathy or a lumbar radiculopathy. I urge Kothari and associates to retrospectively go back and examine these cases to see whether the data obtained changed in any way the treating physicians’ decisions and justified the significantly greater expense. Richard C. Senelick, MD Neurology Clinic of San Antonio San Antonio, TX 78240 From the authors We agree that the electrodiagnostic examination is sometimes overused, and that the results may or may not change the clinical management of a patient. In our study, 40 patients (39%) had a diagnosis different from that of the referring physician. For example, one patient referred for cervical radiculopathy was found to have motor neuron disease, and two patients referred for myasthenia gravis were found to have another type of myopathy (table 1 in our article). The results of the EMG likely changed clinical management in at least some of the 40 patients; but, unfortunately, we do not know if or how the clinical management might have been changed. This question could be answered through a prospective study with clinical follow-up, the results of which would be most informative. Milind J. Kothari, Eric L. Logigian,

DO MD

Lumbar-Sacral Radiculopathy According to Marion and Kahanovitz,’ “A diagnosis of synovial cyst formation at a lumbar facet joint is rare and heretofore has not been described in the rehabilitation literature. . .” I must point out that Dr. Gregg L. Singer and I published a similar case in 1993’; obviously, Drs. Marion and Kahanaovitz did not do a thorough literature search. Antonio Cocchiarella, MD Cabrini Medical Center New York, NY 10003 1. Marion PJ, Kahanovitz to intraspinal synovial 3. 2. Singer GL, Cocchiarella pain. J Back Musculoskel

References N. Lumbar-sacral

radiculopathy

secondary

cyst. Arch Phys Med Rehabil 1995;76:101

I-

A. Juxtafacet cysts as a cause of low back Rehabil 1993;3:69-73.

An author replies The authors regret the omission of Drs. Singer and Cocchiarella’s case report in our review of the literature. During several Medine searches and multiple article cross-referencing, that report was not discovered at the time of the initial preparation of our manuscript. National

Philip J. Marion, MD Rehabilitation Hospital Washington, DC 20010