Idiopathic intracranial hypertension

Last updated: September 6, 2023

Summarytoggle arrow icon

Idiopathic intracranial hypertension (IIH), often referred to as pseudotumor cerebri or benign intracranial hypertension, is a condition of unknown etiology that manifests with chronically elevated intracranial pressure (ICP). It predominantly affects obese women, especially such who have gained significant weight over a short period of time, but certain drugs (growth hormones, tetracyclines, excessive vitamin A) are also associated with the condition. The most common symptoms are diffuse headaches, although various visual symptoms and pulsatile tinnitus are also common. Ophthalmologic examination is crucial for confirming the diagnosis and usually reveals bilateral papilledema and possibly loss of vision. MRI is often done to rule out other causes of increased ICP. Lumbar puncture typically shows an elevated opening pressure. Acetazolamide is the first-line therapy, whereas surgery is only used as a last resort. Even with treatment, the condition often worsens over the course of months to years, and permanent symptoms are common.

Epidemiologytoggle arrow icon

  • Predominantly affects obese women aged 15–44 years [1][2]

Epidemiological data refers to the US, unless otherwise specified.

Etiologytoggle arrow icon

A female TOAD: female sex, Tetracyclines, Obesity, excessive intake of vitamin A, and Danazol are the major risk factors for pseudotumor cerebri.

Classificationtoggle arrow icon

Pathophysiologytoggle arrow icon

  • A mismatch between production and resorption of CSF (cause unknown) → ↑ ICP → damage to structures of the CNS and especially to the optical nerve fibers
  • Orthograde axoplasmic flow stasis at the optic nerve head leads to bilateral papilledema.


Clinical featurestoggle arrow icon


Diagnosticstoggle arrow icon

The following tests should always be performed: [9][10]

In communicating hydrocephalus (e.g., in IIH), there is no pressure difference between the ventricles and subarachnoid space. Therefore, a decrease in intracranial pressure poses little risk of herniation. Unlike in meningitis, papilledema and other signs of increased intracranial pressure are not a contraindication for LP in IIH.

Treatmenttoggle arrow icon


Prognosistoggle arrow icon

  • IIH typically worsens over months to years, until the condition stabilizes.
  • Even with treatment, many patients will have persistent symptoms (up to 79%). [14]
  • Severe loss of vision (or even blindness) occurs in up to 24% of patients. [15]

Referencestoggle arrow icon

  1. Radhakrishnan K, Ahlskog JE, Cross SA, Kurland LT, O'Fallon WM. Idiopathic intracranial hypertension (pseudotumor cerebri). Descriptive epidemiology in Rochester, Minn, 1976 to 1990.. Arch Neurol. 1993; 50 (1): p.78-80.doi: 10.1001/archneur.1993.00540010072020 . | Open in Read by QxMD
  2. Kesler A, Gadoth N. Epidemiology of idiopathic intracranial hypertension in Israel.. J Neuroophthalmol. 2001; 21 (1): p.12-4.doi: 10.1097/00041327-200103000-00003 . | Open in Read by QxMD
  3. Donahue SP. Recurrence of idiopathic intracranial hypertension after weight loss: the carrot craver.. Am J Ophthalmol. 2000; 130 (6): p.850-1.doi: 10.1016/s0002-9394(00)00607-3 . | Open in Read by QxMD
  4. Friedman DI. Medication-induced intracranial hypertension in dermatology.. Am J Clin Dermatol. 2005; 6 (1): p.29-37.doi: 10.2165/00128071-200506010-00004 . | Open in Read by QxMD
  5. Biousse V, Bruce BB, Newman NJ. Update on the pathophysiology and management of idiopathic intracranial hypertension. J Neurol Neurosurg Psychiatr. 2012; 83 (5): p.488-494.doi: 10.1136/jnnp-2011-302029 . | Open in Read by QxMD
  6. Hulens M, Rasschaert R, Vansant G, Stalmans I, Bruyninckx F, Dankaerts W. The link between idiopathic intracranial hypertension, fibromyalgia, and chronic fatigue syndrome: exploration of a shared pathophysiology. Journal of Pain Research. 2018; Volume 11: p.3129-3140.doi: 10.2147/jpr.s186878 . | Open in Read by QxMD
  7. Jensen RH, Radojicic A, Yri H. The diagnosis and management of idiopathic intracranial hypertension and the associated headache. Ther Adv Neurol Disord. 2016; 9 (4): p.317-326.doi: 10.1177/1756285616635987 . | Open in Read by QxMD
  8. Thurtell MJ, Wall M. Idiopathic intracranial hypertension (pseudotumor cerebri): recognition, treatment, and ongoing management. Curr Treat Options Neurol. 2013; 15 (1): p.1-12.doi: 10.1007/s11940-012-0207-4 . | Open in Read by QxMD
  9. Julayanont P, Karukote A, Ruthirago D, Panikkath D, Panikkath R. Idiopathic intracranial hypertension: ongoing clinical challenges and future prospects. J Pain Res. 2016; 9: p.87-99.doi: 10.2147/JPR.S60633 . | Open in Read by QxMD
  10. Salman M. Why does tonsillar herniation not occur in idiopathic intracranial hypertension?. Med Hypotheses. 1999; 53 (4): p.270-271.doi: 10.1054/mehy.1998.0756 . | Open in Read by QxMD
  11. Mollan SP, Markey KA, Benzimra JD, et al. A practical approach to, diagnosis, assessment and management of idiopathic intracranial hypertension. Pract Neurol. 2014; 14 (6): p.380-390.doi: 10.1136/practneurol-2014-000821 . | Open in Read by QxMD
  12. Förderreuther S, Straube A. Indomethacin reduces CSF pressure in intracranial hypertension.. Neurology. 2000; 55 (7): p.1043-5.doi: 10.1212/wnl.55.7.1043 . | Open in Read by QxMD
  13. Sinclair AJ, Kuruvath S, Sen D, Nightingale PG, Burdon MA, Flint G. Is cerebrospinal fluid shunting in idiopathic intracranial hypertension worthwhile? A 10-year review.. Cephalalgia. 2011; 31 (16): p.1627-33.doi: 10.1177/0333102411423305 . | Open in Read by QxMD
  14. Corbett JJ, Savino PJ, Thompson HS, et al. Visual loss in pseudotumor cerebri. Follow-up of 57 patients from five to 41 years and a profile of 14 patients with permanent severe visual loss.. Arch Neurol. 1982; 39 (8): p.461-74.doi: 10.1001/archneur.1982.00510200003001 . | Open in Read by QxMD
  15. Wall M. Update on Idiopathic Intracranial Hypertension.. Neurol Clin. 2017; 35 (1): p.45-57.doi: 10.1016/j.ncl.2016.08.004 . | Open in Read by QxMD

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