MOG antibody-associated disease (MOGAD) is an inflammatory and demyelinating disease of the central nervous system. Brainstem and cerebellar involvement in MOGAD is relatively common and typically occurs in conjunction with lesions in other parts of the central nervous system such as the optic nerve, supratentorial white matter, or spine. Isolated attacks of the brainstem and cerebellum are rare – especially in a relapsing form.

We present the case of a 60 year-old female who developed new onset weakness and incoordination of her left arm and leg. Her brain MRI revealed restricted diffusion and edema involving the left cerebellar peduncle. She was diagnosed with a stroke and discharged home on anti-platelet therapy. One month later, she developed a left facial droop and was diagnosed with a Bell’s palsy. She received oral steroids and had improvement of her facial droop, though it returned a few weeks after completion of her oral steroids. A repeat brain MRI at that time revealed enlargement of the left cerebellar lesion with extension into the left pons. She was again treated with oral steroids and her symptoms improved. She presented again 3 months later with dysarthria and pseudobulbar affect with her brain MRI revealing diffuse T2/FLAIR hyperintensities and edema throughout the bilateral pons and cerebellar peduncles. She received 3 days of high-dose IV methylprednisolone with marked improvement. She ultimately had serum MOG antibody testing performed which returned positive (titer of 1:1000). She was initiated on rituximab, and was clinically stable for over 24 months.

Although brainstem involvement in MOGAD usually occurs in conjunction with other lesions, our case demonstrates that relapsing attacks isolated to the brainstem and cerebellum are within the clinical spectrum of MOGAD.