A 55-year-old female with history of hypertension, hyperlipidemia, type 2 diabetes mellitus, cervical cancer, and subdural hematoma presented with 10-day history of right-sided facial numbness, ophthalmoplegia, and bilateral blurred vision. Exam revealed bilaterally impaired visual acuity to finger counting, left conjugate horizontal gaze palsy, right internuclear ophthalmoplegia (one-and-a-half syndrome), right peripheral facial nerve paresis, and diffuse hyperreflexia. LP showed a lymphocytic pleocytosis with elevated oligoclonal bands and kappa free light chains. MRI revealed multifocal contrast-enhancing periventricular, brainstem, and spinal cord lesions. MOG and aquaporin-4 antibodies were negative. She was initiated on high-dose IV steroids and an oral taper regimen with significant improvement.

One week after discharge she was readmitted for worsening visual acuity, ophthalmoplegia, dysarthria, dysphagia, and gait instability. MRI revealed progression of the prior lesions with new contrast-enhancing brainstem and periventricular lesions. Serial LPs showed persistent lymphocytic pleocytosis without evidence of malignancy. She underwent a second course of high-dose IV steroids, followed by plasmapheresis without improvement. Stereotactic brain biopsy was inconclusive. Repeat brain biopsy of a large periventricular lesion demonstrated a demyelinating lesion with relative axonal preservation and no evidence of malignancy. Based on her clinical course and pathologic findings, she was diagnosed with Marburg variant of multiple sclerosis. Monthly cyclophosphamide was initiated with gradual improvement.