An 18-year-old woman with a history of episodic diplopia, oral ulcers, joint pain, rash, and fatigue presented to the emergency department with acute onset of diplopia. At 9 years of age, she had an episode of diplopia, with MRI of the brain showing a small T2-hyperintense, nonenhancing area of restricted diffusion in the right midbrain (Figure, A). An extensive laboratory workup, including hypercoagulability screening, rheumatologic evaluation, infectious studies, and CSF analysis, was notable for mild lymphopenia, neutropenia, and von Willebrand Factor antigen at the upper limit of normal. Echocardiogram did not show structural deficits. She subsequently presented at 11 years of age with a second episode of diplopia. Laboratory results were again notable for lymphopenia and neutropenia. Brain MRI revealed a new left paramedian pontine area of restricted diffusion (Figure, B). Diplopia self-resolved over the course of 1 to 2 months with each event.