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Idiopathic Intracranial Hypertension

(Benign Intracranial Hypertension; Intracranial Venous Hypertension; Pseudotumor Cerebri)


Stephen D. Silberstein

, MD, Sidney Kimmel Medical College at Thomas Jefferson University

Last full review/revision Apr 2020| Content last modified Apr 2020

Idiopathic intracranial hypertension causes increased intracranial pressure without a mass lesion or hydrocephalus, probably by obstructing venous drainage; cerebrospinal fluid composition is normal.

(See also Approach to the Patient With Headache.)

Idiopathic intracranial hypertension typically occurs in women of childbearing age. Incidence is 1/100,000 in normal-weight women but 20/100,000 in obese women. Intracranial pressure (ICP) is elevated (> 250 mm H2O); the cause is unknown but probably involves obstruction of cerebral venous outflow, possibly because venous sinuses are smaller than normal.

In children, this disorder sometimes develops after corticosteroids are stopped or after growth hormone is used. Idiopathic intracranial hypertension may also develop after tetracyclines or large amounts of vitamin A are taken.

Symptoms and Signs

Almost all patients have a daily or near daily generalized headache of fluctuating intensity, at times with nausea. They may also have transient obscuration of vision, diplopia (due to 6th cranial nerve dysfunction), and pulsatile intracranial tinnitus. Vision loss begins peripherally and may not be noticed by patients until late in the course. Permanent vision loss is the most serious consequence. Once vision is lost, it usually does not return, even if ICP is reduced.

Bilateral papilledema is common; a few patients have unilateral or no papilledema. In some asymptomatic patients, papilledema is discovered during routine ophthalmoscopic examination. Neurologic examination may detect partial 6th cranial nerve palsy but is otherwise unremarkable.

Pearls & Pitfalls

  • If clinical findings suggest idiopathic intracranial hypertension, check visual fields and optic fundi, even when patients have no visual symptoms.


  • MRI with magnetic resonance venography
  • Lumbar puncture

If clinical findings suggest idiopathic intracranial hypertension, clinicians should check visual fields and optic fundi, even in patients with no visual symptoms.

Diagnosis of idiopathic intracranial hypertension is suspected clinically and established by brain imaging (preferably MRI with magnetic resonance venography) that has normal results (except for narrowing of the venous transverse sinus), followed, if not contraindicated, by lumbar puncture with cerebrospinal fluid (CSF) testing that indicates elevated opening pressure and normal CSF composition.

Use of certain drugs and certain disorders can produce a clinical picture resembling idiopathic intracranial hypertension and should be excluded (see table Conditions Associated With Papilledema and Resembling Idiopathic Intracranial Hypertension).

Conditions Associated With Papilledema and Resembling Idiopathic Intracranial Hypertension



Obstruction of cerebral venous drainage

Cerebral venous sinus thrombosis

Jugular vein thrombosis


Addison disease

Chronic obstructive pulmonary disease


Iron deficiency anemia if severe

Obesity (usually in young women)

Polycystic ovary syndrome

Renal failure

Right ventricular heart failure with pulmonary hypertension

Sleep apnea


Anabolic steroids

Corticosteroid withdrawal after prolonged use

Growth hormone in patients with a deficiency

Nalidixic acid


Tetracycline and its derivatives

Vitamin A toxicity


  • Acetazolamide
  • Weight loss
  • Drugs used for migraine, especially topiramate
  • Sometimes surgery

Idiopathic intracranial hypertension occasionally resolves without treatment.

Treatment of idiopathic intracranial hypertension is aimed at the following:

  • Reducing pressure
  • Preserving vision
  • Relieving symptoms

The carbonic anhydrase inhibitor acetazolamide (250 mg orally 4 times a day) is used.

Obese patients are encouraged to lose weight, which may help reduce intracranial pressure.

Serial lumbar punctures are controversial but are sometimes used, particularly if, while waiting for definitive treatment, vision is threatened. (Definitive treatment includes optic nerve sheath fenestration, shunting, and venous sinus stenting.)

Any potential causes (disorders or drugs) are corrected or eliminated if possible.

Drugs used for migraine (particularly topiramate, which also inhibits carbonic anhydrase) may relieve headache. Nonsteroidal anti-inflammatory drugs (NSAIDs) can be used as needed.

Frequent ophthalmologic assessment (including quantitative visual fields) is required to monitor response to treatment; testing visual acuity is not sensitive enough to warn of impending vision loss.

If vision deteriorates despite treatment, one of the following may be indicated:

  • Optic nerve sheath fenestration
  • Shunting (lumboperitoneal or ventriculoperitoneal)
  • Endovascular venous stenting

Bariatric surgery with sustained weight loss may cure the disorder in obese patients who were otherwise unable to lose weight.

Key Points

  • Consider idiopathic intracranial hypertension if patients, particularly overweight women, have a daily generalized headache with or without visual symptoms; check visual fields and optic fundi.
  • Diagnose based on results of brain imaging (preferably MRI with venography) and, if not contraindicated, lumbar puncture.
  • Advise weight loss if needed, and treat with acetazolamide.
  • Do frequent ophthalmologic assessments (including quantitative visual fields) to monitor response to treatment.
  • If vision deteriorates despite treatment, consider optic nerve sheath fenestration, shunting, or endovascular venous stenting.

Drugs Mentioned In This Article

Drug Name Select Trade
Acetazolamide DIAMOX
Tetracycline ACHROMYCIN V
topiramate TOPAMAX

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