Healthy young woman presents with headaches, blurry vision

An 18-year-old healthy woman was referred because of 2 months of headaches associated with blurring of vision worse in side gaze.Three weeks before presentation, she began to have horizontal binocular diplopia and decreased peripheral vision. She was seen by a neurologist who found visual acuity of 20/200 in both eyes, constricted visual fields in both eyes, bilateral cranial nerve VI palsies and bilateral optic nerve swelling. She was admitted to an outside hospital and had an MRI and venography scan of her head, which demonstrated no space-occupying lesion, dural venous sinus thrombosis or other suspicious lesion. A lumbar puncture showed an opening pressure of 360 mm H2O with no evidence of infection, inflammation or neoplasm. After the spinal tap, she experienced dramatic improvement of her vision and headaches, along with resolution of her diplopia. She was started on oral acetazolamide.