Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

Idiopathic intracranial hypertension (IIH), formerly called pseudotumor cerebri, is a condition of elevated pressure inside the skull without an identifiable cause like a tumor or blood clot. The increased pressure can damage the optic nerves and cause vision loss if untreated.

Your IIH Patient Journey

For comprehensive guidance on living with IIH—from diagnosis through long-term management, including medication tips, vision monitoring, and when surgery may be needed—see our complete patient guide: Your IIH Journey - Diagnosis to Long-Term Management.

Understanding IIH

In IIH, cerebrospinal fluid (CSF)—the fluid cushioning the brain—is produced normally but doesn't drain efficiently. This causes pressure to build up, affecting the brain and particularly the optic nerves where they enter the skull.

The condition is called:

• Idiopathic—no identified cause
• Intracranial hypertension—high pressure inside the skull
• Pseudotumor cerebri—old name meaning "false brain tumor" (mimics tumor symptoms)

Symptoms

Headache

• Most common symptom
• Often daily, throbbing
• Worse in morning
• Worse with straining, coughing, bending
• May improve after vomiting
• May be triggered by lying down

Visual Symptoms

• Transient visual obscurations—brief (seconds) dimming or graying of vision
• Often triggered by position change or straining
• Visual field loss—may be gradual and unnoticed
• Blurred vision
• Double vision—from sixth nerve palsy

Other Symptoms

• Pulsatile tinnitus—whooshing sound in ears synchronized with heartbeat
• Neck and shoulder pain
• Nausea
• Cognitive difficulties ("brain fog")

Who Gets IIH?

Classic Demographic

• Women of childbearing age (15-44 years)
• Overweight or recent weight gain
• 20 times more common in obese women
• Can occur in men and children (less common)

Associated Factors

• Obesity (most important risk factor)
• Recent weight gain
• Certain medications (tetracyclines, vitamin A/retinoids, growth hormone)
• Venous sinus stenosis (narrowing)
• Sleep apnea

Diagnosis

Fundoscopic Examination

• Papilledema—swelling of the optic discs
• Key finding that raises suspicion for IIH
• Severity correlates with risk of vision loss

Visual Field Testing

• Detects vision loss that patient may not notice
• Often shows enlarged blind spot
• May show peripheral constriction
• Essential for monitoring

Brain Imaging

• MRI brain with MRV—required to rule out other causes
• May show: empty sella, flattened back of eyeballs, enlarged optic nerve sheaths, venous sinus stenosis
• Rules out tumors, blood clots, other structural causes

Lumbar Puncture (Spinal Tap)

• Confirms elevated pressure—typically >25 cm H2O (often higher)
• CSF composition is normal
• May provide temporary relief of symptoms
• Required for diagnosis

Optical Coherence Tomography (OCT)

• Measures optic nerve fiber layer thickness
• Tracks papilledema over time
• Detects early nerve damage

Diagnostic Criteria (Modified Dandy)

1. Symptoms of elevated intracranial pressure (headache, vision symptoms)
2. Papilledema present
3. Normal neurological exam (except cranial nerve VI palsy)
4. Normal brain imaging (MRI/MRV)
5. Elevated CSF pressure on lumbar puncture
6. Normal CSF composition

Treatment

Weight Loss

• Most effective long-term treatment
• 5-10% weight loss can significantly improve symptoms
• May lead to complete resolution
• Bariatric surgery may be considered for severe obesity

Medications

Acetazolamide (Diamox)

• First-line medication
• Reduces CSF production
• Start low, increase gradually
• Side effects: tingling, carbonated drinks taste flat, kidney stones

Topiramate (Topamax)

• Alternative or addition to acetazolamide
• May help with headache
• Can cause weight loss (advantage in IIH)
• Side effects: cognitive slowing, tingling

Furosemide

• Sometimes added to acetazolamide
• Monitor potassium

Procedures

Serial lumbar punctures

• Temporary relief of pressure
• Not a long-term solution
• May be used while medications take effect

Surgery (for severe or progressive cases)

Optic nerve sheath fenestration

• Creates window in optic nerve covering
• Protects vision
• May not help headache

Shunting procedures

• Ventriculoperitoneal (VP) shunt or lumboperitoneal shunt
• Drains excess CSF
• Helps both vision and headache
• May need revision over time

Venous sinus stenting

• For patients with venous sinus stenosis
• May reduce pressure
• Specialized centers

Monitoring

Regular follow-up is essential:

• Visual field testing—every few months or more often if unstable
• OCT—tracks nerve fiber layer
• Clinical exam—checking papilledema
• Symptom assessment
• Weight monitoring

Prognosis

Good Outcomes

• Most patients have good visual outcomes with treatment
• Symptoms often improve or resolve
• Weight loss can lead to long-term remission

Concerns

• Without treatment, progressive vision loss can occur
• Vision loss may be permanent
• May recur, especially with weight regain
• Requires ongoing monitoring

Frequently Asked Questions

Is IIH the same as a brain tumor?

No. The old name "pseudotumor cerebri" meant it mimics tumor symptoms, but there's no actual tumor. IIH is caused by elevated CSF pressure without a structural cause.

Will I go blind from IIH?

Without treatment, progressive vision loss can occur. However, with proper monitoring and treatment, most people maintain good vision. This is why regular visual field testing is so important.

Do I have to lose weight?

Weight loss is the most effective long-term treatment for IIH in overweight patients. Even modest weight loss (5-10%) can significantly improve the condition. Medications can help but work best combined with weight management.

Can IIH be cured?

Many people achieve remission, especially with significant weight loss. However, the condition can recur, particularly with weight regain. Some people need long-term medication or surgery.

Why do I have double vision?

The elevated pressure can stretch the sixth cranial nerve, which controls outward eye movement. This is usually temporary and improves as pressure is controlled.

How long do I need to take medication?

It varies. Some people can taper off after weight loss and stabilization. Others need long-term treatment. Your doctor will guide tapering based on your response.

References