Q. My primary-care physician recommended a second opinion for problems with exercise intolerance because of leg pain. The doctor ordered an EMG. I didn’t understand what the test was, nor was I able to understand his interpretation of the results, which did not include treatment recommendations. I have trouble standing and walking because of muscle pain and heaviness in my legs, which gets progressively worse with exertion.
A. “The exertional pain in your legs suggests that there is something wrong with your leg muscles, the nerves supplying those muscles, or the blood supply feeding them,” says Jason Sobel, MD, the senior medical director of Capital Caring, a hospice and palliative care organization that serves southeast Maryland, northern Virginia, and the District of Columbia. “An ElectroMyoGram (EMG) measures the electrical activity of muscles. Generally speaking, different muscle and neurological diseases present with different abnormal electrical patterns. Your physician is looking for a telltale electrical pattern that would highlight the culprit causing your distressing symptoms. Unfortunately, the test may not be sensitive enough to pick up the telltale electrical pattern or be specific enough to identify one culprit out of several possibilities. That’s why it is critical to work with a physician (usually a neurologist or physiatrist) who does many EMGs and can discuss the findings with you to your satisfaction.
“Remember that EMG testing is strictly diagnostic and does not provide information pertaining to treatment. If the EMG doesn’t show anything unusual, then your physician may suggest an ultrasound (Doppler study) of the arteries supplying your leg muscles to ascertain whether poor circulation is causing your exertional pain. Once the culprit has been confidently identified, then your physician can discuss potential treatment options with you.”
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