Acute Myasthenia Crisis: A Critical Emergency Department Differential

Myasthenia gravis (MG) is the most common autoimmune disorder of the neuromuscular junction (NMJ). It is caused by autoantibodies blocking acetylcholine receptors (AChRs) or structural receptors of the NMJ: agrin, LRP4, and MuSK. These antibodies can block, change, or destroy AChRs or structural proteins of the NMJ, preventing the binding of ACh and therefore, muscle contractions. This molecular dysfunction can manifest as any of the following symptoms: ptosis, diplopia, bulbar dysfunction, or impaired vision in bright light. Symptoms fluctuate in severity throughout the day and with prolonged use of respective muscles. Typical treatment for mild cases is acetylcholinesterase inhibition combined with an immunosuppressor. Myasthenia crisis results from the exacerbation of the aforementioned symptoms and requires intubation for respiratory support. Intensive care along with intensified immunosuppressive treatments and constant monitoring are recommended. We present the case of a 76-year-old man arriving to the emergency department (ED) with symptoms of fatigue and dysphagia, diagnosed as acute myasthenia crisis. Here, we highlight the symptoms of MG, acute myasthenia crisis, and the critical measures that need to be taken.