A case of NMO seropositive for aquaporin-4 antibody more than 10 years before onset

Neuromyelitis optica (NMO) is characterized by severe optic neuritis and longitudinally extended transverse myelitis (LETM). The clinical and laboratory features of NMO are different from multiple sclerosis (MS).1 An autoantibody to aquaporin-4 (AQP4) has been detected exclusively in the NMO sera.1 Moreover, we demonstrated an extensive loss of AQP4 and glial fibrillary acidic protein immunoreactivities in the perivascular regions with complement and immunoglobulin deposition in NMO that suggests astrocytic impairment. However, when AQP4 antibody is produced in patients with NMO is unknown, and thus it remains unresolved whether there are long-term asymptomatic AQP4 antibody–positive carriers, whether AQP4 antibody alone can be pathogenic, and whether AQP4 antibody is produced secondarily as a result of tissue destruction in attacks of NMO. We herein report a case of NMO in which AQP4 antibody was detected years before the NMO onset. ### Case report. A 34-year-old healthy woman without previous history of inflammatory or neurologic diseases noticed temporary skin eruptions on her chest and shoulders in June 2007. A dermatologist made the diagnosis of eczema. Three weeks later, when the skin eruptions subsided, she noted progressive paresthesia in the chest and toes. Within a few days, she could not walk well due to right leg weakness, and then she was hospitalized. Neurologic examination on …