Overlap of Myasthenia Gravis and Miller Fisher Syndrome

In this case report, we describe a patient with myasthenia gravis (MG) and Miller Fisher syndrome (MFS) overlap. A 69-year-old woman presented with acute bilateral ptosis, ophthalmoplegia, ataxic gait, and areflexia. The MFS diagnosis was confirmed with by a positive anti-GQ1b IgG antibody test result. MG was diagnosed from electrophysiological, edrophonium, and serological test results. Although intravenous immunoglobulin therapy is effective for both diseases, two courses of the therapy did not improve the patient's symptoms. However, steroid therapy was effective. Although the overlap of MG and MFS is very rare, it should be considered in the differential diagnosis of neuro-ophthalmic diseases.