Ninety percent of these 120 patients with BIH were women and were obese. Headache was present in almost all patients and visual symptoms occurred in 35%. There was no neurologic abnormality other than visual loss in these patients followed up to 10 years. Twenty-five percent spontaneously remitted after the initial LP and the others required repeated LP, steroids, or surgical procedures. Thirteen of 15 patients who did not remit spontaneously or respond to repeated LP improved dramatically in 3 to 4 days on prednisone or dexamethasone. Complications of BIH include recurrence of the syndrome, visual impairment and development of the empty sells syndrome. Recurrence rate was 10% and relapses always occurred in the first 12 months. Visual acuity impairment or inferior nasal quadrant field defect occurred in 2% of patients. In only two patients was there a sudden decrease in visual acuity which did not improve with any therapy. There was no way to predict subsequent visual impairment.