We herein report the case of a 60-year-old man showing overexpression of creatine kinase (hyperCKemia) related to initial and recurrent attacks of neuromyelitis optica (NMO). He showed reduced vision, ataxia and dysesthesia, but no symptoms originating in the muscles. Magnetic resonance imaging (MRI) revealed lesions in the optic nerve, medulla oblongata, and spinal cord similar to typical NMO patients. However, femoral MRI and whole positron emission tomography (PET) demonstrated no abnormal findings during an episode of hyperCKemia. This case suggests that hyperCKemia is partly involved in the pathogenesis of NMO in both the central nervous system and myofiber surface, which is usually difficult to detect by clinical imaging modalities alone.