Background: Myasthenia gravis (MG) is a rare neuromuscular disorder resulting from the destruction of acetylcholine receptors at the neuromuscular junction by IgG antibodies. Although dysphagia is a common symptom in generalized form of MG, it is rarely reported as a sole manifestation of the disease, specifically in younger patients. Herein, we report a middle-aged adult patient with dysphagia as the sole manifestation of MG.
Case presentation: A 49-year-old male complaining of severe dysphagia underwent an extensive clinical and paraclinical examination. Oropharyngeal dysphagia was confirmed by an experienced speech-language pathologist using the water swallowing test. Unilateral right paresis of the soft palate and vocal fold was confirmed using laryngeal video stroboscopy. Chest computerized tomography (CT) scan, brain Magnetic resonance imaging (MRI), and routine blood, urine, and thyroid tests were normal. In electromyography, slow repetitive nerve stimulation (RNS) showed a decremental response in the right nasalis muscle. The diagnostic neostigmine test with 1.5 mg of intramuscular neostigmine led to significant recovery of laryngeal and pharyngeal motor dysfunction and dysphagia within 12 hours, so the MG diagnosis was confirmed. The patient was treated with plasmapheresis, pyridostigmine, and prednisolone, which followed an improving course and led to better swallowing of solid and liquid foods.
Conclusion: MG should be considered as a diagnosis in middle-aged adults with complaints of dysphagia.