title: Brain Imaging in Idiopathic Intracranial Hypertension.
abstract: BACKGROUND
  The primary role of brain imaging in idiopathic intracranial hypertension (IIH) is to exclude other pathologies causing intracranial hypertension. However, subtle radiologic findings suggestive of IIH have emerged with modern neuroimaging. This review provides a detailed description of the imaging findings reported in IIH and discusses their possible roles in the pathophysiology and the diagnosis of IIH.
  
  
  METHODS
  References were identified by searches of PubMed from 1955 to January 2015, with the terms "idiopathic intracranial hypertension," "pseudotumor cerebri," "intracranial hypertension," "benign intracranial hypertension," "magnetic resonance imaging," "magnetic resonance venography," "computed tomography (CT)," "CT venography," "imaging," and "cerebrospinal fluid (CSF) leak." Additional references were identified by hand search of relevant articles. When possible, we extracted the number of patients and control subjects from each study for each radiological finding. When at least 2 studies used the same criteria to define a radiological finding, all patients from these studies were pooled to obtain a mean sensitivity and specificity with 95% confidence interval.
  
  
  RESULTS
  Specific neuroimaging findings may suggest long-standing IIH, including empty sella, flattening of the posterior globes, optic nerve head protrusion, distention of the optic nerve sheaths, tortuosity of the optic nerve, cerebellar tonsillar herniation, meningoceles, CSF leaks, and transverse venous sinus stenosis.
  
  
  CONCLUSIONS
  Although IIH remains a diagnosis of exclusion, the most recently proposed diagnostic criteria have included neuroimaging findings to suggest IIH when major diagnostic criteria are not fulfilled. However, these findings are not diagnostic of IIH, and their presence is not required for the diagnosis of definite IIH. Their incidental discovery on brain imaging should not prompt invasive procedures, unless other signs of IIH, such as papilledema, are present.
authors.affiliation: Departments of Ophthalmology (SB, JHP, BBB, NJN, VB), Radiology and Imaging Sciences (AMS), Pediatrics (JHP), and Neurology (BBB, NJN, VB), Emory University School of Medicine, Atlanta, Georgia; Department of Epidemiology (BBB), Rollins School of Public Health, Emory University, Atlanta, Georgia; and Department of Neurological Surgery (NJN), Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Samuel
authors.initials: S
authors.lastname: Bidot
authors.forename: Amit M
authors.initials: AM
authors.lastname: Saindane
authors.forename: Jason H
authors.initials: JH
authors.lastname: Peragallo
authors.forename: Beau B
authors.initials: BB
authors.lastname: Bruce
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Newman
authors.forename: Valérie
authors.initials: V
authors.lastname: Biousse
mesh_terms: D001921:Brain / Q000473:pathology*; D065634:Cerebrospinal Fluid Leak / Q000209:etiology; D016206:Databases, Bibliographic / Q000706:statistics & numerical data; D006801:Humans; D007091:Image Processing, Computer-Assisted; D059906:Neuroimaging; D009900:Optic Nerve / Q000473:pathology; D010211:Papilledema / Q000209:etiology; D011559:Pseudotumor Cerebri / Q000473:pathology*; D012680:Sensitivity and Specificity