Pseudotumor cerebri (SOO-doe-too-mur SER-uh-bry) occurs when the pressure inside your skull (intracranial pressure) increases for no obvious reason.

Symptoms mimic those of a brain tumor, but no tumor is present. Pseudotumor cerebri can occur in children and adults, but it's most common in obese women of childbearing age.

When no underlying cause for the increased intracranial pressure can be discovered, pseudotumor cerebri may also be called idiopathic intracranial hypertension.

The increased intracranial pressure associated with pseudotumor cerebri can cause swelling of the optic nerve and result in vision loss. Medications often can reduce this pressure, but in some cases, surgery is necessary.

Pseudotumor cerebri signs and symptoms may include:

  • Moderate to severe headaches that may originate behind your eyes and worsen with eye movement
  • Ringing in the ears that pulses in time with your heartbeat (pulsatile tinnitus)
  • Nausea, vomiting or dizziness
  • Blurred or dimmed vision
  • Brief episodes of blindness, lasting only a few seconds and affecting one or both eyes (visual obscurations)
  • Difficulty seeing to the side
  • Double vision (diplopia)
  • Seeing light flashes (photopsia)
  • Neck, shoulder or back pain

The exact cause of pseudotumor cerebri in most individuals is unknown, but it may be linked to an excess amount of cerebrospinal fluid within the bony confines of your skull.

Your brain and spinal cord are surrounded by cerebrospinal fluid, which acts like a cushion to protect these vital tissues from injury. This fluid is produced in the brain and eventually is absorbed into the bloodstream. The increased intracranial pressure of pseudotumor cerebri may be a result of a problem in this absorption process.

In general, your intracranial pressure increases when the contents of your skull exceed its capacity. For example, a brain tumor generally increases your intracranial pressure because there's no room for the tumor. The same thing happens if your brain swells or if you have too much cerebrospinal fluid.

Several studies indicate that many people with pseudotumor cerebri have a narrowing (stenosis) in two large sinuses in the brain (transverse sinuses). Studies are determining whether this is an effect or a cause of the condition.

The following factors have been associated with pseudotumor cerebri:

Obesity

Obesity has been associated with pseudotumor cerebri, which occurs in 1 to 2 people in 100,000. About 4 to 21 obese women in 100,000 develop the condition. Obese women under the age of 44 are more likely to develop the disorder.

Medications

Substances that have been linked to pseudotumor cerebri include:

  • Growth hormone
  • Tetracycline
  • Excess vitamin A

Other medications may be associated with pseudotumor cerebri, but further research is needed.

Health problems

The following conditions and diseases have been linked to pseudotumor cerebri:

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

Some people with pseudotumor cerebri experience progressively worsening vision and may eventually become blind.

Even if your symptoms have resolved, they can recur months or even years later.

Though you might first discuss your symptoms with your family doctor, he or she may refer you to a doctor trained in brain and nervous system conditions (neurologist) or eye conditions (ophthalmologist) for further evaluation.

To get the most from your appointment, it's a good idea to prepare. Here's some information to help you.

What you can do

  • Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Write down key personal information, including any major stresses or recent life changes.
  • Make a list of all medications, vitamins or supplements you're taking.
  • Take a family member or friend along, if possible. Sometimes it can be difficult to soak up all the information you get during an appointment. Someone who accompanies you may remember something that you missed or forgot.
  • Write down questions to ask your doctor.

Preparing a list of questions to ask your doctor will help you make the most of your time together. For pseudotumor cerebri, some questions to ask your doctor include:

  • What is likely causing my symptoms or condition?
  • Other than the most likely cause, what are other possible causes for my symptoms or condition?
  • What kinds of tests do I need?
  • Is my condition likely temporary or chronic?
  • What is the best course of action?
  • What are the alternatives to the primary approach you're suggesting?
  • Would losing weight help my condition?
  • I have these other health conditions. How can I best manage them together?
  • Are there any restrictions I need to follow?
  • Should I see a specialist?
  • Is there a generic alternative to the medicine you're prescribing?
  • Are there any brochures or other printed material that I can take home with me? What websites do you recommend?

Don't hesitate to ask any other questions that arise during your appointment.

What to expect from your doctor

Your doctor is likely to ask you a number of questions, including:

  • When did you begin experiencing symptoms?
  • 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?

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

Eye exams

A doctor trained in eye conditions (ophthalmologist) may conduct an eye examination.

If pseudotumor cerebri is suspected, your eye doctor will look for a distinctive type of swelling affecting the optic nerve, called papilledema, in the back of your eye.

You'll also undergo a visual fields 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.

Brain imaging

Your doctor may 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 may order a lumbar puncture to measure the pressure inside your skull, as well as your glucose and protein levels.

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.

The goal of pseudotumor cerebri treatment is to improve your symptoms and keep your eyesight from worsening. Your doctor may prescribe medications to control your symptoms.

If you're obese, your doctor will recommend weight loss. You may work with a dietitian to help with your weight-loss goals. Losing weight may improve your symptoms. Some people who are morbidly obese may benefit from weight-loss programs or gastric surgery to lose weight.

If your vision worsens, surgery to reduce the pressure around your optic nerve or to decrease the intracranial pressure may be necessary. Once you've had pseudotumor cerebri, you should have your vision checked regularly.

Medications

  • Glaucoma drugs. One of the first drugs usually tried is acetazolamide (Diamox), a glaucoma drug. This medication may reduce the production of cerebrospinal fluid. Also, it has been shown to improve symptoms in 47 to 67 percent of people.

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

  • Diuretics. If acetazolamide alone isn't effective, it's sometimes combined with furosemide (Lasix), a potent diuretic that reduces fluid retention by increasing urine output.
  • Migraine medications. Medications usually prescribed to relieve migraines can sometimes ease the severe headaches that often accompany pseudotumor cerebri.

Surgery

  • 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.

    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 may even 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 away excess cerebrospinal fluid.

    The tubing is burrowed under your skin to your abdomen, where the shunt discharges the excess fluid. Symptoms may improve for some people who undergo this procedure.

    However, shunts can become clogged and often require additional surgeries to keep them working properly. Complications can include low-pressure headaches and infections.

    This procedure is generally only a treatment option if other treatments haven't relieved your condition.

Obesity dramatically increases a young woman's risk of pseudotumor cerebri. In fact, even in women who aren't obese a moderate amount of weight gain may increase the risk.

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

Feb. 01, 2014