Open Ring Sign Diagnostic of Multiple Sclerosis in the Emergency Department

A 26-year-old female presented to the emergency department with a chief complaint of dizziness. Further history revealed that she was experiencing generalized weakness and intractable vomiting for three days, without complaint of abdominal pain or lower gastrointestinal symptoms. Physical examination uncovered mild dehydration with stable vital signs and non-fatigable, horizontal nystagmus consistent with internuclear opthalmoplegia. Computed tomography of her brain was ordered and revealed an “open ring sign” as displayed in the figure. The “open ring sign,” or open ring enhancement of a lesion on neuroimaging, has been found to be highly specific for demyelinating diseases and can help differentiate them Lehigh Valley Hospital-Muhlenberg, Department of Emergency Medicine, Bethlehem, Pennsylvania