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

The cause for the condition is unknown.

The following factors increase the risk:

• Obesity
• Non-steroidal anti-inflammatory drugs (NSAIDs), tetracycline, nitrofurantoin, isotretinoin, tamoxifen, naladixic acid, lithium, and the starting or stopping of steroids
• Vitamin A (too much or too little)
• Cushing’s disease
• Hypoparathyroidism
• Hypothyroidism
• Chronic renal failure
• Anemia

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

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

• Headache
• Buzzing sound in the ears (tinnitus)
• Dizziness
• Nausea
• Double vision (diplopia)
• Parial or permanent loss of vision. Patients often complain of blurred vision.
• Symptoms may get worse during physical activity, especially with the contraction of abdominal muscles.

Papilledema -- swelling of a small region in the back of the eye -- is an important sign of pseudotumor cerebri. Other signs include an increased head size and bulging anterior fontanelle (only in babies in which the cranial sutures are not yet closed.)

Despite the increased pressure in the skull, there is no altered consciousness.

Tests that help with diagnosis include:

• A CT Scan and MRI (will not show tumor)
• A lumbar puncture, or spinal tap (usually confirms an elevated intracranial pressure)
• Formal visual field testing (detects early vision loss)

Treatment must be directed at the condition causing the pseudotumor. An initial lumbar puncture is both diagnostic and therapeutic. Repeated lumbar punctures may be done to decrease the intracranial pressure and to help prevent progressive papilledema and visual loss. Other treatments may include:

• Fluid or salt restriction.
• Medications such as corticosteroids, glycerol, acetazolamide, and furosemide.
• Shunting procedures to relieve pressure due to spinal fluid retention.
• Incision of the optic nerve sheath for relief of the papilledema, and to prevent further deterioration of vision.
• Weight loss.
• Close monitoring of vision, since there is potential for progressive and sometimes permanent visual loss.
• Follow-up MRI or CT scan to exclude hidden malignancy (cancer).

The outcome varies, and sometimes the condition disappears on its own within 6 months. About 10-20% of the people diagnosed with pseudotumor cerebri experience recurrences, and there is a small percentage who become progressively worse and may eventually become blind.

Complications may occur in connection with some of the procedures used for treatment or from side effects of the various medications. Vision loss is the main serious complication of this condition.

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