Benign intracranial hypertension

Definition

Pseudotumor cerebri is a reversible process affecting the brain that appears to be -- but is not -- a tumor.

Alternative Names

Causes

The cause for the condition is unknown.

Certain medicines can increase your risk for this condition. These medicines include:

• Non-steroidal anti-inflammatory drugs (NSAIDs)
• Tetracycline
• Nitrofurantoin
• Isotretinoin
• Minocycline
• Tamoxifen
• Nalidixic acid
• Lithium
• Steroids (starting or stopping them)

The following factors also increase your risk:

• Obesity
• Vitamin A (too much or too little)
• Cushing's disease
• Hypoparathyroidism
• Hypothyroidism
• Chronic kidney failure
• Anemia

The condition occurs more frequently in women than men, particularly in premenopausal obese women. It is rare in infants.

Symptoms

The major symptom is increased pressure within the skull (increased intracranial pressure). There is no evidence of tumor, infection, blocked drainage of the fluid surrounding the brain, or any other cause.

Symptoms include:

• Headache
• Buzzing sound in the ears (tinnitus)
• Dizziness
• Nausea
• Double vision (diplopia)
• Partial or permanent loss of vision. Patients often complain of blurred vision.

Symptoms may get worse during physical activity, especially when tightening the stomach muscles.

Exams and Tests

The doctor will perform a physical exam. Signs of this condition include:

• Swelling of a small area in the back of the eye (papilledema)
• Increased head size
• Bulging anterior fontanelle in babies whose cranial sutures are not yet closed

Despite the increased pressure in the skull, there is no change in alertness.

Tests that may be done include:

• CT Scan
• MRI
• Lumbar puncture (spinal tap)
• Eye exam, including formal visual field testing

The diagnosis is made when other health conditions are ruled out. Several conditions may cause increased intracranial pressure, including venous sinus thrombosis, hydrocephalus, and an intracranial mass (such as a tumor).

Treatment

Treatment must be directed at the specific cause of the pseudotumor.

A lumbar puncture can help relieve pressure within the brain and prevent vision problems.

Other treatments may include:

• Fluid or salt restrictions
• Medications such as corticosteroids, glycerol, acetazolamide, and furosemide
• Shunting procedures to relieve pressure due to spinal fluid retention
• Surgery to relieve pressure on the optic nerve
• Weight loss

The patient will need their vision closely monitored, since there is potential for progressive and sometimes permanent visual loss. Follow-up MRI or CT scans may be done to rule out hidden cancer.

Outlook (Prognosis)

Sometimes the condition disappears on its own within 6 months. About 10-20% of persons have their symptoms return. A small number of patients have symptoms that slowly get worse and lead to blindness.

Possible Complications

Vision loss is a serious complication of this condition.

When to Contact a Medical Professional

Call your health care provider if you or your child experience the symptoms listed above.

Jonnalagadda J. Lithium, minocycline, and pseudotumor cerebri. J Am Acad Child Adolesc Psychiatry. March 1, 2005; 44(3): 209.

Behrman RE. Nelson Textbook of Pediatrics. 17th ed. Philadelphia, Pa: WB Saunders; 2004; 2048-2049.

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