Neuromyelitis Optica Spectrum Disorder (NMOSD) Misdiagnosed as Spinal Cord Infarction (5394)

Objective: NA Background: Neuromyelitis Optica Spectrum Disorder (NMOSD) is an inflammatory disorder characterized by immune-mediated demyelination, and axonal damage targeting the optic nerves and spinal cord. NMOSD typically presents with longitudinally extensive transverse myelitis, involving three or more levels. Similarly, spinal cord infarctions can present the same way and hence diagnosis, especially in the initial encounter, can be challenging. Design/Methods: Case report Results: 63-year-old female with history of hypertension, diabetes mellitus, and Sjogren syndrome presented with one day of left leg numbness. On exam, there was absent pinprick, vibration and proprioception sensation on the left lower extremity up to the level of below the chest. Magnetic resonance imaging (MRI) showed an abnormal signal in the central cord involving the grey matter extending from T1 to T7. Brain MRI showed multiple small areas of restricted diffusion with corresponding ADC signal dropout in the right corona radiata, right parietal lobe and left parietal lobe. A CSF panel was normal. Patient was diagnosed with cryptogenic spinal cord infraction, and was discharged home with a loop cardiac monitoring. Three weeks later, she presented with right leg weakness. On exam, the patient was plegic on her right leg. There was loss of pinprick, vibration and proprioception sensations on the lower extremities up to the chest. Repeat MRI of the spinal cord showed extended signal intensity from T1 to T9. Repeat CSF analysis revealed lymphocytic pleocytosis and elevated CSF protein, myelin basic protein, and IgG synthesis rate. Serum and CSF came back positive for anti-aquaporin-4 IgG antibodies. The patient was started on high dose IV methylprednisolone followed by plasmapheresis. Patient’s symptoms started improving, and she was discharged to acute rehabilitation. Conclusions: NMOSD can present without any clear inflammatory markers. It can be misdiagnosed as spinal cord infarction, especially in the setting of similar imaging findings. Disclosure: Dr. Abdalla has nothing to disclose. Dr. Lopez has nothing to disclose. Dr. Siraj has nothing to disclose. Dr. Ahmed has nothing to disclose. Dr. McGraw has nothing to disclose.