NMES and Myasthenia Gravis

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Answer

No, I would not recommend the use of NMES for a person with swallowing disorders associated with myasthenia gravis. Myasthenia gravis is an autoimmune disease associated with disorders of the thymus gland that affects the neuromuscular junction i.e. the synapse between nerves and muscle fibers. In individuals with the disease, antibodies destroy or block receptor sites along the muscle fibers that receive the neurotransmitter acetylcholine. It is the reception of acetylcholine that triggers muscle contraction by the lower motor neuron. When the number of receptors receiving activation is reduced, the muscle contractions become weaker. The result is rapid fatigue and weakness with continued activity, but improvement in muscle contraction strength with rest. Direct exercise as in oral motor therapy is contraindicated in these cases as continued contraction of the muscles of swallowing actually makes the symptoms worse. While it is my understanding that NMES causes contraction of the muscles through electrical stimulation rather than neurotransmitter activation and might not trigger the blockage or destruction of the receptor sites, this treatment does not actually target the underlying etiology of the swallowing problem and therefore would not produce functional change i.e. return to more normal swallow. Though I am not trained in NMES, my understanding of the technique is that it is typically coupled with an active swallow attempt by the patient and may help strengthen muscles that are atrophied from disuse. While the person may experience an improved swallow while using NMES because of the direct muscle stimulation, they would still exhibit the progressive fatigue when stimulation was not used. Most sources recommend medical treatment for the underlying disorder coupled with compensatory strategies for swallowing management. Logemann recommends diet consistency changes and eating more frequent but smaller meals throughout the day to avoid the muscle fatigue associated with repeated contraction. Conventional wisdom is to avoid active exercise.

Dr. Nancye Roussel is an Associate Professor and Head of the Dept. of Communicative Disorders at the University of Louisiana, Lafayette. She is a certified speech-language pathologist and has practiced in both hospital and school settings prior to her employment at the University. Dr. Roussel has taught a graduate course in dysphagia for the past 12 years. In addition, she teaches graduate courses focusing on motor speech disorders in adults and children, voice disorders, and speech science.