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