Idiopathic intracranial hypertension: diagnosis and management

Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, may occur at any age but is primarily a disease of obese women between the ages of 15 and 40. Diagnosis is made based on modified Dandy criteria, which include normal neuroimaging studies, elevated intracranial pressure (ICP) on lumbar puncture, signs and symptoms of elevated ICP, and a non-focal neurologic examination aside from sixth nerve paresis. Presenting symptoms include headache, pulsatile tinnitus, transient visual obscurations, diplopia, and visual field constriction. Diagnosis may be delayed because headache from other causes such as migraine is much more common, and patients may be treated for this condition without improvement before the actual diagnosis is recognized. Ophthalmologic signs may include papilledema and esotropia (from the sixth nerve palsy) as well as visual field and even visual acuity loss; the latter two signs are very ominous, as they indicate severe and potentially permanent visual damage. Medical and surgical options vary depending on the severity of the disease and are used to control headache as well as to prevent vision loss. Because most IIH is associated with obesity, weight loss is an essential element of any treatment regimen, as retrospective as well as prospective studies have shown disease resolution with as little as 6% weight reduction. Secondary causes of high ICP are being recognized in a greater number of IIH patients, and the term idiopathic likely applies to fewer patients than in the past. The underlying pathogenesis of the disorder remains elusive.