A 50-year-old gentleman, with no previous comorbidities, presented with difficulty in neck holding, double vision, and ptosis of 2½ year duration. Repetitive nerve stimulation (RNS) and neostigmine test were suggestive of MG. Anti-AChR was negative. The patient was started on steroids, pyridostigmine, and azathioprine. Contrast-enhanced computed tomography (CECT) scan of the chest was normal. He improved symptomatically but never had complete remission. After 1½ years, he had worsening of symptoms associated with difficulty in chewing and swallowing, slurring of speech, and breathing difficulty. A diagnosis of myasthenic crisis was made, and the patient was given five cycles of plasma exchange with no improvement in symptoms. Anti-MuSK antibody was positive. He was started on intravenous (IV) rituximab (375 mg/m2) weekly for 4 weeks, and the symptoms gradually improved. After 2 weeks of initiation of treatment, the breathing difficulty resolved, and ptosis, diplopia, and neck holding improved after the next 2 months. Steroids and azathioprine were tapered and stopped. He is doing well currently at 24 months of follow-up after three cycles of rituximab and is planned for another cycle.
A 49-year-old lady with MuSK-positive MG, diagnosed outside and treated with steroids, presented with fever, cough, and breathlessness for 2 weeks. Keeping a possibility of community-acquired pneumonia, she was managed with IV antibiotics with which her fever improved, but her dyspnea continued. Myasthenia crisis was considered, and a cycle of IVIG (2 g/kg) followed by IV cyclophosphamide was given with mild improvement. She was continuing monthly IV cyclophosphamide but never attained remission. She was then started on IV rituximab (375 mg/m2 weekly for 4 weeks), to which she responded remarkably with complete resolution of respiratory difficulty and other symptoms.