[Myasthenia Gravis Treated with Zilucoplan Prior to Extended Transsternal Thymectomy for the Prevention of Myasthenic Crisis: A Case Report].

A 50year-old female was diagnosed with myasthenia gravis (MG) following aspiration pneumonia. Despite treatment with prednisolone (5mg/day) and intravenous immunoglobulin (IVIg), the bulbar palsy persisted. Additionally, chest CT revealed findings suggestive of invasive thymoma or thymic carcinoma, leading to a planned thymectomy with median sternotomy. This case presents a high-risk of myasthenic crisis due to thymoma-associated MG, persistent bulbar palsy, and the need for highly invasive surgery. Therefore, enhanced immunotherapy was required to prevent this crisis, and zilucoplan was chosen because of its rapid onset of action and compatibility with IVIg. Following the initiation of zilucoplan, there was prompt improvement in the symptoms of MG. Effective preoperative control of MG led to a good clinical course, with no significant postoperative myasthenic crisis or exacerbation of symptoms. This is the first report on the use of zilucoplan for the prevention of perioperative myasthenic crisis. (Received April 14, 2025; Accepted June 3, 2025, Published August 1, 2025).