A case of anti-myelin-oligodendrocyte glycoprotein (MOG) antibody-associated disease without abnormal findings on spinal MRI and cerebrospinal fluid examination

A75-year-old man presented with recurrent episodes of myelopathy since youth, previously responsive well to steroid therapy. n Beginning at age of 72, he developed repeated episodes of gait disturbance suggestive of myelitis. Although spinal MRI and cerebrospinal fluid (CSF) analysis were normal, somatosensory-evoked potentials (SEP) were absent in both lower extremities. He showed a favorable response to steroid pulse therapy and tested positive for anti-myelin oligodendrocyte glycoprotein (MOG) antibodies. Additional treatment with double filtration plasmapheresis improved his mobility, enabling ambulation with a cane. Myelitis without detectable abnormalities on spinal MRI or CSF examination may still indicate anti-MOG antibody-associated disease; therefore, assessment with SEP and anti-MOG antibody testing can be useful for diagnostic tools.