A case of myasthenia gravis occurring in the period of remission of chronic inflammatory demyelinating polyradiculoneuropathy]

A 31-year-old woman noticed progressive muscular weakness in the limbs and paresthesia in the fingers in February 1989. Paresthesia worsened and improved 4 times during 2 months. Intravenous edrophonium chloride failed to improve her muscular weakness. She had high antiacetylcholine receptor antibody titer in serum. We made a diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) because of slow nerve conduction velocity (NCV), increased CSF protein, and the clinical course. Treatment with prednisolone improved muscular weakness and the slow NCV. Two years later she acutely had dyspnea, dysphagia, and muscular weakness after upper respiratory infection. Intravenous edrophonium chloride dramatically improved her symptoms. The diagnosis was made as myasthenia gravis (MG). After thymectomy her weakness was getting better without any medications. There may exist an autoimmune mechanism common, at least in part, to both CIDP and MG in our patient.