Anti-MOG and Anti-AQP4 positive neuromyelitis optica spectrum disorder in a patient with myasthenia gravis.

Aquaporin 4 antibody (anti-AQP4) positive neuromyelitis optica spectrum disorder (NMOSD) is known to occur in the setting of myasthenia gravis (MG). However, comorbid MG with myelin oligodendrocyte glycoprotein antibody (anti-MOG) positive NMOSD has not been reported. We present a case of anti-MOG and anti-AQP4 positive NMOSD in a patient with long-standing MG. The patient presented with acute right-sided weakness with MRI demonstrating extensive spinal cord edema extending from T2 to the medulla with associated contrast enhancement. To our knowledge, this is the first reported case of anti-MOG and anti-AQP4 positive NMOSD in a patient with known MG.