ABSTRACT
A 75-year-old Japanese woman developed myelitis 3years prior to her admission. She was diagnosed with HTLV-1-related myelitis and had taken prednisolone. Her myelitis relapsed several times, and serum aquaporin-4 was positive in an ELISA. She developed a sudden headache, consciousness disturbance, dysarthria, and left limb paralysis, and was admitted to our hospital. The CSF analysis revealed pleocytosis dominated by morphonuclear cells and hypoglycorrhachia. Magnetic resonance imaging revealed abnormalities in the corpus callosum, bilateral thalamus, and corticospinal tracts. We initially suspected a relapse of neuromyelitis optica spectrum disorder (NMOSD) and infection. We treated the patient with methylprednisolone pulse and antibacterial and antiviral treatment, which were not effective. Plasmapheresis was performed five times, and she gradually improved. Immunosuppressive treatment was added. It is rare for NMOSD to cause hypoglycorrhachia. This case suggests that infection may trigger an autoimmune response in NMOSD. (Received February 13, 2018; Accepted July 12, 2018; Published October 1, 2018).