Neuromyelitis optica spectrum disorders (NMOSDs) are a set of demyelinating disorders that primarily target the optic nerves and the spinal cord. Previously thought to be a subset of multiple sclerosis (MS), now is recognized as a distinct entity. We present a 59-year-old female patient who was admitted for acute upper and lower extremity weakness. The patient had woken up from sleep with sudden onset of weakness. Patient was initially diagnosed with a right hemispheric stroke; however, magnetic resonance imaging of the cervical spine later performed showed abnormal enhancement from C2-C4, representing transverse myelitis. Cerebrospinal fluid was negative for organisms and inflammatory biomarkers. An anti-aquaporin-4 receptor antibody titer was found to be elevated with titers >80 units/mL. The patient was treated with high-dose steroids and plasmapheresis. The NMOSD is a rare entity and, here, we present a rare presentation of the disease. Since its description in 1870, it was confused with MS for years. The advent of anti-aquaporin-4 antibody has been instrumental in differentiating the disease process from MS. This distinction is important, in terms of agents used for treatment and prognostication. The NMOSD is a set of debilitating disease, which requires prompt recognition and appropriate treatment, to avoid the disabling sequelae. Future prospects of the disease include development of novel biological treatment modalities which focus on restoring the loss of immune tolerance which is key to the pathogenesis of the disease.
Keywords: NMOSD; anti-aquaporin 4 antibody; neuromyelitis optica spectrum disorder; transverse myelitis.