A 20-year-old woman comes to the office with a history of persistent headaches occurring daily for one month. She describes the headache as a pulsating type that is especially bothersome at night and associated with nausea and vomiting. Ibuprofen provides some relief. She has no history of prior head trauma, weakness, photophobia, or sensory abnormalities. However, she complains of blurry vision. The patient has no chronic medical conditions and does not take any medications. She does not use tobacco, alcohol, or other illicit drugs. Her body mass index is 33kg/m2. Temperature is 36.7 C (98.1 F), blood pressure is 130/80 mm of Hg, the pulse is 80/min, and respirations are 16/min. Neurological examination is unremarkable. Fundoscopy reveals optic disc edema. CT scan of the head without contrast is normal.