Objective:

To report an unusual clinical pattern of Neuromyelitis Optica Spectrum Disorder (NMOSD) presenting as a pontine stroke mimic 

Background:

A 58-year-old Hispanic woman presented to an outside hospital with right-sided numbness, blurry vision, and gait instability. Findings on brain MR imaging were thought to reflect acute pontine stroke; the patient commenced dual antiplatelet therapy. Three weeks later, she presented to our hospital with right-sided hemiparesis. Stroke workup was unrevealing for specific pathophysiology. She was readmitted about two weeks later with a new-onset right cranial nerve VI palsy with ipsilateral facial droop and tinnitus. Brain MRI demonstrated foci of diffusion restriction on DWI in the periventricular white matter and brainstem region suggesting rhombencephalitis of inflammatory or autoimmune origin. Despite IVIG infusion, the patient’s condition deteriorated and she was intubated for airway protection. Serological assays were positive for AQP4 and negative for all other autoantibodies, including anti-Gq1b. She was treated with methylprednisolone pulse dosing and plasmapheresis, followed by rituximab, with significant neurological improvement.

Design/Methods:

In addition to the case report, a systematic literature review was performed to identify NMOSD cases initially diagnosed as stroke. Publications were selected and curated in accordance with PRISMA guidelines. 

Results:

Six NMOSD patients were initially thought to represent acute stroke. However, the persistence, progression, or recurrence of symptoms with additional history, follow-up neuroimaging, and further serological immune assays facilitated the accurate diagnosis of NMOSD. Notably, the age of onset in all cases was significantly more advanced than patients normally presenting with NMOSD (median age 32-41). 

Conclusions:

NMOSD diagnosis should be considered in individuals presenting with atypical stroke-like symptoms, particularly in those greater than or equal to 41 years of age. This is important as early recognition and treatment with immune therapies can improve functional outcome.