title: An update on idiopathic intracranial hypertension.
abstract: Idiopathic intracranial hypertension (IIH) is still a grey area in the knowledge of the aetiology, diagnosis and management of neurosurgical diseases. The definition of IIH has been reviewed over time and many hypotheses have been expressed as cause of the disease. The literature supplies very little evidence-based information to guide our decision-making process when it comes to treat the disease. In this review we sum up the latest information regarding the aetiology and therapy of IIH. Additionally, we make an attempt to unify the diagnostic criteria of Dandy, Friedman and Wall established from 1937 to date.
  
  
  
  In this narrative review, we attempt to update the current standpoint to IIH, evaluate the input until now and consider future directions for research. The vast majority of the literature consisted of cohort studies, case control studies, systematic reviews and other narrative reviews.
  
  
  
  Pathophysiology: The incidence of IIH is steadily increasing. Several pathophysiological theories have been proposed in the literature based on the flow of cerebrospinal fluid.
  
  
  
  We attempt to fuse all the three diagnostic approaches published in the literature that detect IIH, while preserving the individual characteristics of each approach.
  
  
  
  Based on evidence-based trials, the current use of acetazolamide in comparison with placebo or with topiramate has been evaluated. In the interventions' field, there seems to be a consonance about the alarming symptoms and what the most suitable operation is in each case. There is some disagreement about the indications for venous sinus transversus stenting and its risk/benefit ratio.
  
  
  
  Until now there is no class I guideline to which our decision-making can be based on for the management of IIH. A lack of systematic reviews and randomised control trials has been noted. If we focused our research on that, we could develop a standardised treatment protocol.
authors.affiliation: Department of Neurosurgery, Queen Elizabeth University Hospital, Glasgow, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Portelli
authors.affiliation: Department of Neurointensive Care Unit, Southampton University Hospital, Tremona Road, SO16 6YD, Southampton, UK. panagiotis.papageorgiou@uhs.nhs.uk.
authors.forename: Panagiotis N
authors.initials: PN
authors.lastname: Papageorgiou
mesh_terms: D006801:Humans; D011559:Pseudotumor Cerebri / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology / Q000601:surgery
keywords: Carbonic anhydrase inhibitors; Idiopathic intracranial hypertension; Topiramate; Ventriculoperitoneal shunt