Pseudotumor cerebri (idiopathic intracranial hypertension)

Idiopathic intracranial hypertension (IIH) happens when pressure inside the skull rises without a clear cause. IIH also is called pseudotumor cerebri (SOO-doe-too-mur SER-uh-bry). The higher intracranial pressure can lead to headaches, vision changes and a whooshing sound in the ears. Healthcare professionals can confirm the diagnosis with eye exams and brain imaging. Treatment aims to lower the pressure, protect vision and ease symptoms.

Symptoms of IIH mimic those of a brain tumor. The increased intracranial pressure can cause swelling of the nerve fibers that connect the eye to the brain, known as the optic nerve. The swelling can result in vision loss. Medicines often can reduce this pressure and symptoms such as headaches. Sometimes, surgery is necessary.

IIH can occur in children and adults, but it's most common in women of childbearing age with obesity.

Idiopathic intracranial hypertension (IIH), also called pseudotumor cerebri, symptoms might include:

• Bad headaches that might begin behind the eyes.
• A whooshing sound in your head that pulses with your heartbeat.
• Nausea, vomiting or dizziness.
• Vision loss.
• Brief episodes of blindness, lasting a few seconds and affecting one or both eyes.
• Trouble seeing to the side.
• Double vision.
• Seeing light flashes.
• Neck, shoulder or back pain.

Sometimes symptoms that have resolved can return months or years later.

The cause of idiopathic intracranial hypertension is not known. If a cause is found, the condition is called secondary intracranial hypertension, rather than idiopathic.

The brain and spinal cord are surrounded by cerebrospinal fluid. The fluid cushions these vital tissues and protects them from injury. Cerebrospinal fluid is produced in the brain. It is eventually absorbed into the bloodstream at a rate that usually allows the pressure in the brain to remain constant.

When cerebrospinal fluid isn't absorbed into the bloodstream at the proper rate, pressure inside the skull increases.

Obesity, medicines and health conditions have been associated with idiopathic intracranial hypertension.

Obesity

Women who are obese and of childbearing age are more likely to develop idiopathic intracranial hypertension.

Medicines

Substances linked to secondary intracranial hypertension include:

• Growth hormone.
• A class of antibiotics called tetracyclines, particularly doxycycline and minocycline.
• A class of medicines called vitamin A derivatives, particularly isotretinoin.

Health problems

Conditions and diseases that have been linked to secondary intracranial hypertension include:

• Addison's disease.
• Anemia.
• Blood-clotting disorders.
• Kidney disease.
• Lupus.
• Polycystic ovary syndrome.
• Sleep apnea.
• Underactive parathyroid glands.

For some people with idiopathic intracranial hypertension, their vision continues to worsen, leading to visual loss.

To diagnose idiopathic intracranial hypertension (IIH), your healthcare professional reviews your symptoms and medical history. You also need a physical exam and tests.

Eye exams

A doctor trained in eye conditions, known as an ophthalmologist, conducts an eye exam. The ophthalmologist looks for a specific type of swelling affecting the optic nerve in the back of the eye.

You may be given a visual field test to see if there are blind spots in your vision. Everyone has a small blind spot in each eye where the optic nerve enters the retina. But people with IIH can have a larger blind spot and other areas of visual loss.

You also may have photos taken of your eyes. And you may need an imaging test to measure the thickness of the layers at the back of the eye called the retina. This imaging test is known as optical coherence tomography.

Brain imaging

An MRI or a CT scan can rule out other conditions that can cause similar symptoms, such as brain tumors and blood clots. You also may need a test called magnetic resonance venography (MRV) or computerized tomography venography (CTV). These tests can be used to look for a blood clot in the brain, known as cerebral venous thrombosis. This test uses a contrast material that's injected into a vein.

Spinal tap, also known as a lumbar puncture

You may need a lumbar puncture to measure the pressure inside your skull and analyze your spinal fluid. In this test, a specialist inserts a needle between two bones in your lower back. The specialist then removes a small amount of cerebrospinal fluid. The fluid is sent to a laboratory for testing.

The goal of idiopathic intracranial hypertension (IIH) treatment is to improve your symptoms and keep your eyesight from worsening.

If you have excess weight, your healthcare professional might recommend a low-sodium weight-loss diet to help improve your symptoms. You might work with a dietitian to help with your weight-loss goals. Some people benefit from weight-loss programs or gastric surgery.

Medications

• The diuretic acetazolamide. Often, acetazolamide is one of the first medicines that’s tried. It’s a diuretic and glaucoma medicine. This medicine might reduce the production of cerebrospinal fluid and reduce symptoms.

  Possible side effects include stomach upset, fatigue, tingling of fingers, toes and mouth, and kidney stones.

• Topiramate. Topiramate is not a diuretic. It can be used instead of or in addition to acetazolamide if that medicine doesn't work for you. It can help you have fewer headaches and may help with weight loss, which can reduce pressure in the brain. Topiramate can cause side effects such as tingling in the fingers or toes, taste changes, trouble finding words, or kidney stones. It should not be used during pregnancy.
• Other diuretics. If acetazolamide isn't effective, other diuretics may be used. They include spironolactone (Aldactone, Carospir), methazolamide and furosemide (Furoscix, Lasix). Diuretics reduce the amount of fluid in your body by increasing urine output.
• Migraine medicines. These medicines can sometimes ease the headaches caused by IIH.
• Weight-loss medicines. Newer weight-loss medicines may be recommended to help treat IIH. Glucagon-like peptide 1 (GLP-1) receptor agonists such as semaglutide (Ozempic, Wegovy, others) can help people lose weight and may also reduce pressure in the brain.

Surgery

If your vision gets worse, surgery to reduce the pressure around your optic nerve or to decrease intracranial pressure might be necessary.

• Venous sinus stenting (VSS). This procedure involves placing a small stent in a narrowed vein in the head to keep the vein open and improve blood flow. Keeping the vein open also can help cerebrospinal fluid (CSF) drain. This lowers pressure in the brain. VSS may be used when tests show venous sinus narrowing and other treatments have not stopped vision loss or IIH symptoms. In general, healthcare professionals offer VSS only if tests show a clear pressure difference at the narrow spot compared with a nearby typical area. After the stent is placed, you need regular checkups. Rarely, the stent can narrow again or a blood clot can form.
• Optic nerve sheath fenestration. In this procedure, a surgeon cuts a window into the membrane that surrounds the optic nerve. This allows excess cerebrospinal fluid to escape.

  In most people, vision stabilizes or improves. If you have this procedure done on one eye, you may notice improvement in both eyes. However, this surgery isn't always successful and can make vision loss worse.

• Spinal fluid shunt. In another type of surgery, a long, thin tube called a shunt is inserted into the brain or lower spine. The shunt helps drain excess cerebrospinal fluid. The tubing is threaded under the skin to your stomach, where the shunt releases the fluid.

  A shunt is considered only if other treatments haven't relieved your condition. Shunts can clog. Often, other surgeries are needed to keep them working. Complications can include low-pressure headaches and infections.

Once you have had IIH, you need to have your vision checked regularly to monitor changes.

Obesity dramatically increases the risk of idiopathic intracranial hypertension (IIH) in young women. Even in women who don't carry excess weight, a moderate amount of weight gain can increase the risk.

But losing extra pounds and maintaining a healthy weight might help reduce your chances of developing this condition.

After talking about your symptoms with your healthcare professional, you may be referred to a specialist. You may see a doctor trained in brain and nervous system conditions, known as a neurologist, or in eye conditions, known as an ophthalmologist. Or you may see a doctor who specializes in the brain and nervous system and eye conditions, known as a neuro-ophthalmologist.

Here's some information to help you get ready for your appointment.

What you can do

Make a list of:

• Your symptoms, including any that may seem unrelated to the reason for which you scheduled the appointment. Include when they began.
• Key personal information, including major stresses or recent life changes.
• All medicines, vitamins or other supplements you take, including doses.
• Questions to ask your healthcare professional.

Bring to the appointment recent test results and scans of your eyes. Take a family member or friend along, if possible, to help you remember the information you receive.

For idiopathic intracranial hypertension, questions you might ask your healthcare professional include:

• What is likely causing my symptoms or condition?
• What tests do I need?
• Is my condition likely temporary or chronic?
• What is the best course of action?
• Would losing weight help my condition?
• I have these other health conditions. How can I best manage them together?
• Are there restrictions I need to follow?
• Should I see a specialist?
• Are there brochures or other printed material that I can have? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your doctor

Your healthcare professional is likely to ask you questions, including:

• When did your symptoms start?
• Have your symptoms been continuous or occasional?
• How bad are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?