To describe a case of MOG antibody disorder (MOGAD) with an unusual radiographic presentation.

MOGAD is associated with diverse clinical phenotypes; however, spinal nerve root involvement in this disease has rarely been described.

A 53-year-old previously healthy man presented to our hospital with three weeks of numbness and pain involving his right arm, bilateral lower extremities, and perineum. Neurologic exam was notable for decreased sensation in his right hand and left leg, hyperreflexia in bilateral lower extremities, and an extensor plantar response on the left. MRI spine was notable for multifocal short-segment T2 hyperintense lesions consistent with demyelination. There was also contrast enhancement of the cauda equina nerve roots and focal lobular enhancement of the left S1 nerve root. MRI brain showed several small T2 hyperintense brainstem lesions.

He was started on pulse dose steroids while undergoing extensive work-up for inflammatory, infectious, and neoplastic causes. Serology was notable for mildly elevated ACE. CSF showed elevated protein. Given these laboratory and radiographic findings, an inflammatory etiology such as neurosarcoidosis was initially felt to be most likely. CT chest was negative for evidence of pulmonary sarcoid. He demonstrated clinical improvement with steroids and was discharged on a slow taper. MOG antibody in the serum resulted positive at 1:100. The patient opted for monthly IVIG maintenance therapy and has been clinically stable. Repeat MRI two months later showed stable areas of spinal nerve root enhancement and decrease in some of the cord lesions.

Our case demonstrates that MOGAD should be a diagnostic consideration when MRI shows spinal nerve root enhancement in the appropriate clinical context, especially with the additional presence of CNS lesions that are typical of demyelination. MOGAD can manifest clinically and radiographically in both the central and peripheral nervous system.