I read with interest the article by Purvin et al.1 They reported that patients with obstruction of cerebral venous outflow may present with features that can resemble pseudotumor cerebri (PTC). The diagnosis of PTC is one of exclusion and is based on the following criteria: (1) a normal neuroimaging study; (2) an elevated opening pressure on lumbar puncture, but otherwise normal cerebrospinal fluid contents; and (3) neurologic signs and symptoms only owing to increased intracranial pressure, such as headache, papilledema, or sixth nerve palsy.2
Neuroimaging studies that include computed tomography (CT) and magnetic resonance imaging (MRI) have been used to exclude mass lesions and enlarged ventricular size in patients with PTC. Unfortunately, CT is not as sensitive as MRI for the detection of cerebral venous thrombosis,3 and I have seen patients with normal CT scans who were initially misdiagnosed with PTC but were later discovered to have