Idiopathic intracranial hypertension (IIH), often called pseudotumor cerebri or benign intracranial hypertension, is characterized by papilledema and high intracranial pressure in the absence of brain tumor or meningeal infiltration. Its main morbidity is visual loss from optic atrophy, which reaches the range of legal blindness in 9-25% of cases (Corbett et al 1982, Wall et al 1983, Orcutt et al 1984, Smith & Baker 1986). Wall & George (1987), using automated static perimetry, found that more than 75% of cases had some degree of visual loss. The long term objective of this research is to determine the optimal treatment for IIH--a treatment which will prevent visual loss from optic atrophy. Adequate treatment should either bring about rapid and lasting resolution of papilledema, or decrease the amount of optic disc swelling sufficiently to prevent attrition of axons over time. This pilot study is an initial randomized comparison of treatment with a) acetazolamide, the drug most commonly used to treat IIH, and b) digoxin, a theoretically promising drug for managing intracranial hypertension by blockade of CSF production. This study is also intended to provide pilot data for a large scale, randomized, double-masked, multicenter study of treatment using acetazolamide, corticosteroids, and, if the pilot data are promising, digoxin for treatment of IIH. Corticosteroid treatment often brings about resolution of papilledema in IIH, but it frequently rebounds as steroids are withdrawn. This form of therapy seems unlikely to provide a practical long term solution since side effects are prohibitive, and IIH may persist for years (Corbett 1982). With the larger study we intend to clarify whether or not a frequently recommended {Weisberg 1975, Ahlskog & O'Neill 1982} 3 month intensive course of corticosteroid treatment produces sustained resolution of papilledema and protection from visual loss as compared with the other forms of treatment which are usually continued for the duration of the disease.