We report a 13-year-old girl diagnosed with
neuromyelitis optica (NMO). We also report that
plasma exchange could be performed early in her
clinical course as well as her good response to this treatment. At the onset, transient
numbness of both upper extremities appeared. Approximately one month thereafter, photesthesia of the left eye disappeared and she visited our hospital.
Optic neuritis and
myelitis were diagnosed based on neuroimaging of the brain and spinal MRI scans. Intravenous high-dose
methylprednisolone was administered. Subsequently, although left vision improved to 0.4,
numbness of the hands and feet appeared during
methylprednisolone therapy. Since anti-AQP-4 antibody seropositivity was confirmed after
methylprednisolone therapy, she met the NMO diagnostic criteria. Therefore,
plasma exchange was performed followed by high dose
methylprednisolone therapy, which improved left vision to 0.8 and the sensory disturbance of the hands and feet disappeared. A 0.5 mg/kg/day dose of
prednisolone was then administered prophylactically, followed by
plasma exchange, and there has been no relapse to date. In general, the rate of NMO recurrence is high and the neurological prognosis is poor. Therefore, it is important to measure serum anti-AQP4 antibody during the first attack, if NMO is suspected, because this value is useful for the diagnosis of NMO. Appropriate treatments including
plasma exchange and prophylactic
therapy should be started after confirming the diagnosis.