Pseudotumor cerebri (idiopathic intracranial hypertension)

Overview

Pseudotumor cerebri (SOO-doe-too-mur SER-uh-bry) occurs when the pressure inside your skull (intracranial pressure) increases for no obvious reason. It's also called idiopathic intracranial hypertension.

Symptoms mimic those of a brain tumor. The increased intracranial pressure can cause swelling of the optic nerve and result in vision loss. Medications often can reduce this pressure and the headache, but in some cases, surgery is necessary.

Pseudotumor cerebri can occur in children and adults, but it's most common in women of childbearing age who are obese.

Symptoms

Pseudotumor cerebri signs and symptoms might include:

• Often severe headaches that might originate behind your 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
• Difficulty seeing to the side
• Double vision
• Seeing light flashes
• Neck, shoulder or back pain

Sometimes, symptoms that have resolved can recur months or years later.

Causes

The cause of pseudotumor cerebri is unknown. If a cause is determined, the condition is called secondary intracranial hypertension, rather than idiopathic.

Your brain and spinal cord are surrounded by cerebrospinal fluid, which cushions these vital tissues from injury. This fluid is produced in the brain and eventually is absorbed into the bloodstream at a rate that usually allows the pressure in your brain to remain constant.

The increased intracranial pressure of pseudotumor cerebri might result from a problem in this absorption process.

Risk factors

The following factors have been associated with pseudotumor cerebri:

Obesity

Obese women of childbearing age are more likely to develop the disorder.

Medications

Substances linked to secondary intracranial hypertension include:

• Growth hormone
• Tetracycline
• Too much vitamin A

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

Complications

For some people with pseudotumor cerebri, their vision continues to worsen, leading to blindness.

Diagnosis

To diagnose your condition, your doctor will review your symptoms and medical history, conduct a physical examination, and order tests.

Eye exams

If pseudotumor cerebri is suspected, a doctor trained in eye conditions (ophthalmologist) will look for a distinctive type of swelling affecting the optic nerve in the back of your eye.

You'll also undergo a visual field test to see if there are any blind spots in your vision besides your so-called normal blind spot in each eye where the optic nerve enters the retina. And you'll likely have photos taken of your eyes and an imaging test to measure the thickness of the layers of your retina (optical coherence tomography).

Brain imaging

Your doctor is likely to order an MRI or CT scan. These tests can rule out other problems that can cause similar symptoms, such as brain tumors and blood clots.

Spinal tap (lumbar puncture)

Your doctor might order 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 vertebrae in your lower back and removes a small amount of cerebrospinal fluid for testing in the laboratory.

Treatment

The goal of pseudotumor cerebri treatment is to improve your symptoms and keep your eyesight from worsening.

If you're obese, your doctor 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

• Glaucoma drugs. One of the first drugs usually tried is acetazolamide, a glaucoma drug. This medication 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.

• Other diuretics. If acetazolamide alone isn't effective, it's sometimes combined with another diuretic, which reduces fluid retention by increasing urine output.
• Migraine medications. These drugs can sometimes ease the severe headaches that often accompany pseudotumor cerebri.

Surgery

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

• Optic nerve sheath fenestration. In this procedure, a surgeon cuts a window into the membrane that surrounds the optic nerve to allow excess cerebrospinal fluid to escape.

  Vision stabilizes or improves in most cases. Most people who have this procedure done on one eye notice a benefit for both eyes. However, this surgery isn't always successful and can increase vision problems.

• Spinal fluid shunt. In another type of surgery, your doctor inserts a long, thin tube (shunt) into your brain or lower spine to help drain excess cerebrospinal fluid. The tubing is burrowed under your skin to your abdomen, where the shunt releases the excess fluid.

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

• Venous sinus stenting. This relatively new procedure is rarely used. It involves placing a stent in one of the larger veins in the head to increase the blood's ability to flow. More study is needed to determine the benefits and risks of this procedure.

Once you've had pseudotumor cerebri, you'll need to have your vision checked regularly to monitor changes.

Self care

Obesity dramatically increases young women's risk of pseudotumor cerebri. Even in women who aren't obese, a moderate amount of weight gain can increase the risk.

Losing extra pounds and maintaining a healthy weight might help reduce your chances of developing this potentially sight-stealing disorder.

Preparing for your appointment

After discussing your symptoms with your family doctor, he or she might refer you to a doctor trained in brain and nervous system conditions (neurologist) or eye conditions (ophthalmologist) or both (neuro-ophthalmologist) for further evaluation.

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, and when they began
• Key personal information, including major stresses or recent life changes
• All medications, vitamins or other supplements you take, including doses
• Questions to ask your doctor

Bring with you 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 pseudotumor cerebri, questions to ask your doctor 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 doctor is likely to ask you questions, including:

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