INTRODUCTION: Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disease caused by antibodies against the postsynaptic membrane at the neuromuscular junction, leading to muscle weakness, fatigue, and respiratory failure in severe cases. Myasthenic crisis (MC) is a life-threatening condition which requires hospitalization and treatments with intravenous immunoglobulin, plasma exchange and high dose steroids. We report a case of a patient with refractory MC and anti-AChR antibodies positivity who started Eculizumab as rescue therapy, leading to a complete resolution of the acute neuromuscular condition. CASE PRESENTATION: A 72-year-old man presented with bilateral ptosis, severe weakness in all limbs, dysphonia, dysphagia and dyspnea. He was diagnosed with MG with anti-AChR positivity and refractory MC. He was unresponsive to classical rescue therapy, so he underwent Eculizumab administration which resulted in a notable improvement in symptoms. DISCUSSION: Eculizumab, a humanized monoclonal antibody that inhibits complement activation, is now approved as treatment for refractory generalized MG with anti-AChR antibodies. The use of eculizumab in refractory MC is still under investigation
however, this case report suggests that it could be a promising treatment option for patients with severe acute clinical condition.