Miller Fisher syndrome (MFS), a variant of Guillain-Barré syndrome, is a rare 
disorder typically characterized by a triad of ataxia, areflexia, and 
ophthalmoplegia, which may have a highly variable clinical presentation. We 
report a case of MFS in a 45-year-old female presenting with sphenoid sinusitis 
and sixth nerve palsy. She underwent endoscopic sphenoid sinusotomy without 
improvement, had postoperative deterioration, was diagnosed with MFS, and was 
treated with intravenous immunoglobulin with complete response. Because of the 
potential severity of Guillain-Barré syndrome, great vigilance should be taken 
when examining sixth nerve palsies to prevent misdiagnosis and delay in 
treatment of the MFS variant of this disease.