重症肌無力是神經肌肉傳導疾病最常見的疾病，此外它仍是相對少見的疾病。本篇報告一名25歲女性黎患延髓↑生重症肌無力並進展至重症肌危相，這個病人由於持續數週的口咽性吞嘸困難導致非蓄意性體重喪失來到本院急診，理學檢查除了於她來到台灣一年來顯著的體重喪失達到30公斤外沒明顯異常，簡短的神經學檢查顯示吞嘸困難而無其他顯著異常。於急診病人發生進行性的換氣不足合併意識喪失，病人由於高三氧化碳↑生呼吸衰竭而插管，此外腦部影像學檢查排除顱內構造性病肚，所以神經肌肉疾病比如重症肌無力為高度懷疑並經血清學檢查證實，因此病人接受血漿置換透析後成功於住院第19天拔管然後於第31天順利出院並由口服藥物控制並且沒有留下吞嘸固態食物或液體方面的困難。假如一個病人來到急診並王訴有吞嘸困難時，需視為一個警訊並且需要立即的評估以找出明確的病因並依據之作出適當的治療，罕見的表現在少見的疾病對於急診醫師永遠是診斷上的挑戰。

Myasthenia gravis is the most common disorder of neuromuscular transmission， but bulbar symptoms as the sole presentation is relatively uncommon. Herein， we report a 25- year-old woman with bulbar myasthenia gravis that progressed to a myasthenia crisis. She visited the emergency department because of involuntary weight loss due to oropharyngeal dysphagia. The diagnosis of myas-thenia gravis was confirmed by a positive serum acetylcholine receptor antibody test. Our patient suffered from a myasthenic crisis and aspiration pneumonia， which were successfullytreated by plasmapheresis and antibiotics. Itis worth emphasizing that bulbar MG is a true neurological emergency and should be seriously considered in young women who present with dysphagia. Early specialist consultation and the initiation of appropriate treatment should be carried out.