Dr. Cooper Offers EMG Insights
The following is an article that our neurologist, Dr. Bill Cooper submitted to Pinnacol Assurance as part of Pinnacol's "Provider Pulse". Dr. Cooper is a Diplomat of the American Board of Electrodiagnostic Medicine and is Board Certified Neurologist. He began practicing with San Luis Valley Health in June.
The advantage of properly evaluating neuromuscular disorders is that an appropriate diagnosis can be determined without having to resort to more invasive studies. The most important evaluation begins with the history and a physical of a patient.
Another technique that is extremely helpful when used correctly is electromyography (EMG). Unfortunately, EMG is frequently ordered in isolation (i.e., an EMG of an arm or a leg for numbness/weakness) which may not be useful and quite costly. The best practice for ordering an EMG is to already have a diagnosis in mind and only use the EMG to confirm clinical suspicions.
Weakness can originate in the muscle, the nerve or the neuromuscular junction. It may not represent a peripheral problem. It could be on a metabolic basis or misinterpreted spasticity, such as from a myelopathy or hemiparesis. It may be a manifestation of a totally unrelated problem. For instance, I admitted a fifteen-year-old straight from the EMG lab to a psychiatric unit because her foot drop was a result of her anorexia and loss of the fat pad from marked weight loss. If the referring physician had looked at the entire patient and not just her foot drop, her treatment could have been initiated earlier.
Motor neuron disease, myopathies, and movement disorders (such as Parkinson's) are often missed by the referring doctor because these are relatively uncommon entities. In motor neuron disease, if suspected, a minimum of at least three extremities should be reviewed for acute and chronic changes in the setting of increased reflexes or multiple blocks in multifocal motor neuropathy. In myopathies, the changes can be subtle and easily missed if the proximal muscles are not studied carefully.
Entities such as inclusion body myositis can have both myopathic and neuropathic changes, simultaneously. Peripheral neuropathies cannot be reliably diagnosed if only a few nerves are studied. While radiculopathies and entrapment neuropathies can present with pain or numbness, multiple other processes such as problems in the joints, soft tissues, immune system, metabolic disorders, and even mechanical or overuse syndromes can present in a similar manner.
Limited techniques such as nerve conductions or surface EMGs have been marketed to primary care doctors, therapists and others to assist in screening for “abnormalities.” These studies have no value in untrained hands and result in unnecessary procedures which may lead to critical delays in diagnosis. Random information can be more confusing than helpful. For example, MRIs may detect multiple abnormalities and create confusion rather than point to a correct diagnosis. Often, the initial MRI is of the wrong area and the patient has to undergo yet another procedure.
In summary, EMG is useful in the evaluation of peripheral nerve and muscle disorders but only when used as a piece of the entire evaluation. An EMG that is applied appropriately can be not only clinically expedient but also cost-effective.
Dr. Cooper can be reached for an appointment by calling (719) 852-9400.