Pseudotumor Cerebri (Benign Intracranial Hypertension)

Sourced from Mayo Clinic

Pseudotumor cerebri 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 symptoms may include
- Moderate to severe headaches that may originate behind your eyes, wake you from sleep and worsen with eye movement
- Ringing in the ears that pulses in time with your heartbeat
- Nausea, vomiting or dizziness
- Blurred or dimmed vision
- Brief episodes of blindness, lasting only a few seconds and affecting one or both eyes
- Difficulty seeing to the side
- Double vision

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 typically increases your intracranial pressure because there's no room for it. The same thing happens if your brain swells or if you have too much cerebrospinal fluid.

The following factors have been associated with pseudotumor cerebri
Obesity. Pseudotumor cerebri occurs in about one person per 100,000 in the general public. Obese women under the age of 44 are nearly 20 times more likely to develop the disorder.

Medications. Substances that have been linked to pseudotumor cerebri include:
- Lithium
- Oral contraceptives
- Tetracycline
- Steroids or discontinuation of steroids
- Excess vitamin A

Health problems. The following conditions and diseases have been linked to pseudotumor cerebri
- Head injury
- Kidney disease
- Lupus
- Lyme disease
- Mononucleosis
- Underactive parathyroid glands

As many as 10 percent of the people with pseudotumor cerebri experience progressively worsening vision and may eventually become blind. Even if your symptoms have resolved, a recurrence can occur — months or even years later.

While you might first discuss your symptoms with your family doctor, he or she may refer you to a neurologist or an eye specialist for further evaluation.

What you can do
Because appointments can be brief, plan ahead and write a list that includes:
- Detailed descriptions of your symptoms
- All the medications and dietary supplements you take
- Questions you want to ask the doctor
- What to expect from your doctor

In addition to a physical exam, your doctor may also check your neurological health by testing your:
- Reflexes
- Muscle strength
- Muscle tone
- Senses of touch and sight
- Coordination
- Balance

Eye exams
If pseudotumor cerebri is suspected, a doctor specializing in eye disorders will look for a distinctive type of swelling — called papilledema — in the back of your eye. You will also undergo a visual fields test to see if there are any blind spots in your vision.

Brain imaging
CT or MRI scans can rule out other problems that can cause similar symptoms, such as brain tumors and blood clots.

Spinal tap (lumbar puncture)
A lumbar puncture — which involves inserting a needle between two vertebrae in your lower back — can determine how high the pressure is inside your skull.

Pseudotumor cerebri treatment typically begins with medications to control the symptoms. Weight loss is recommended for obese individuals. If your vision worsens, surgery to reduce the pressure around your optic nerve or to decrease the intracranial pressure may be necessary.

Medications
- Glaucoma drugs. One of the first drugs usually tried is acetazolamide (Diamox), a glaucoma drug that reduces the production of cerebrospinal fluid by at least 50 percent. 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, a potent diuretic that reduces fluid retention by increasing urine output.

- Migraine medications. Medications typically prescribed to relieve migraines can sometimes ease the severe headaches that often accompany pseudotumor cerebri.

Surgery
- Optic nerve sheath fenestration. This procedure cuts a window into the membrane that surrounds the optic nerve. This allows excess cerebrospinal fluid to escape. Vision stabilizes or improves in more than 85 percent of 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. Another type of surgery inserts a long, thin tube — called a 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 improve for more than 80 percent of the people who undergo this procedure. But shunts can become clogged and often require additional surgeries to keep them working properly.

Complications can include low-pressure headaches and infections.