A 45-year-old female was positive for anti-aquaporin-4 antibody with disturbance of consciousness, respiratory failure, and ophthalmoplegia associated with extensive brain stem involvement with intractable hiccup and nausea as an initial manifestation. Her level of consciousness and state of respiration worsened approximately one month later. There was no abnormality in the cerebrospinal fluid examination. A lesion was found in the medullary tegmentum on brain MRI. The patient received steroid pulse therapy and her level of consciousness improved the next day. However, her state of respiration worsened, and she had extensively clinical involvement of the brain stem. Her symptoms gradually improved with intravenous administration of prednisolone and intravenous immunoglobulin therapy (IVIg). The patient had almost completely recovered, but she relapsed with cervical myelitis extending over 3 vertebral segments approximately 10 months later. She underwent steroid pulse therapy, oral prednisolone, and IVIg again and improved.