A case of Miller Fisher syndrome during preoperative chemotherapy for breast cancer.

A 53-year-old woman with breast cancer received FEC treatment (5FU: 500 mg/m(2), epirubicin: 100 mg/m(2), and cyclophosphamide: 500 mg/m(2)) every 3 weeks as preoperative chemotherapy. Fifteen days after her third cycle of FEC, she developed a cold. Diplopia occurred 4 days after developing the cold, and progressive paresthesia of the hands and weakness of the limbs occurred. She had ophthalmoplegia, ataxia, and are flexia and was diagnosed with Miller Fisher Syndrome (MFS). The cause of MFS during chemotherapy is believed to be caused by an immunological response to infection, or drug neurotoxicity. In our case, since the patient underwent an antecedent upper respiratory infection in the period of myelosuppression, her MFS was probably induced by the immunoreaction associated with this infection. Our patient underwent intravenous immunoglobulin therapy. After initiation of the treatment, her neurological symptoms improved, then, she received a fourth cycle of FEC and her remaining neurological symptoms did not worsen. Thus, we report a rare case of MFS developed in immunosuppression by chemotherapy and remind physicians of the alarming triad of MFS symptoms.