An Obese, 30-year-old woman is brought to the ED with a generalized persistent refractory headache over the past several days. Her headache is accompanied by severe nausea and vomiting, blurry vision, and papilledema on examination. There are no focal neurologic findings present. A non-contrast brain CT has been reported normal, while an LP revealed no abnormalities except an opening pressure of 300mm. She acknowledges improvement of symptoms after LP was performed. What test needs to be done before a diagnosis of Idiopathic Intracranial Hypertension can be made?

About the Author: Anton Helman

Dr. Anton Helman is an Emergency Physician at North York General in Toronto. He is an Assistant Professor at the University of Toronto, Division of Emergency Medicine and the Education Innovation Lead at the Schwartz-Reisman Emergency Medicine Instititute. He is the founder, editor-in-chief and host of Emergency Medicine Cases.