Q How is pseudotumor cerebri syndrome diagnosed and treated?
DR. DEBORAH I. FRIEDMAN RESPONDS:
A Pseudotumor cerebri syndrome is a neurologic condition characterized by an increase in cerebrospinal fluid pressure that cannot be explained by a brain tumor or other detectable problem, such as a clot in the veins within the head or neck; infection; inflammation; or cancer.
The condition most commonly affects obese women of childbearing age, but it may also affect young children and occasionally occurs in men. Pseudotumor cerebri syndrome can sometimes be caused by medication use, such as excessive intake of vitamin A, tetracycline antibiotics, human growth hormone supplementation, or withdrawal from steroids. When no cause for pseudotumor cerebri is found, the condition is referred to as idiopathic intracranial hypertension (IIH).
Over 90 percent of patients with a diagnosis of pseudotumor cerebri syndrome have severe headaches that occur daily or near-daily. Some patients have prominent neck or back pain as well. Other common symptoms include episodes of visual loss in one or both eyes lasting several seconds and hearing one's pulse or a whooshing in the ear. Patients may experience double vision or visual loss, which can sometimes be permanent.
Pseudotumor cerebri syndrome is usually diagnosed by eye examinations, brain scans, and lumbar puncture (spinal tap).
In an individual with pseudotumor cerebri syndrome, an eye examination will almost always show swelling of the optic nerves (papilledema) resulting from high pressure in the brain. A complete eye exam with visual field testing is necessary in diagnosing pseudotumor cerebri syndrome because the treatment is largely determined by the patient's vision status. Common treatments include a diuretic called acetazolamide (Diamox), repeat lumbar punctures to drain cerebrospinal fluid, or changing the medications thought to be causing the problem.
A brain scan—usually magnetic resonance imaging (MRI)—of a person with pseudotumor cerebri syndrome should be normal. If a brain scan is abnormal, a different diagnosis may be considered. Often, the veins in the brain are imaged as well (using a venogram) to be sure that there is no clot in the veins within the brain or neck.
Finally, a lumbar puncture (spinal tap) will show high pressure in the cerebrospinal fluid with normal spinal fluid contents.
Because headaches are common in young women—and the headaches of pseudotumor cerebri syndrome may resemble migraines—the diagnosis may be missed initially if a careful history is not taken and the eyes are not carefully examined for swelling of the optic nerves.
The diagnosis is less straightforward when the person's headache has been present for over a year and/or swelling of the optic nerves is not present. Pseudotumor cerebri without optic nerve swelling may be a different disease process than pseudotumor cerebri with optic nerve swelling. For example, patients who experience typical symptoms of the condition, such as chronic headaches, but without swelling of the optic nerves at the time of diagnosis frequently do not improve with the treatments typically used for pseudotumor cerebri syndrome.
Treatments include medications, surgery, and addressing any secondary cause—such as high sodium, obesity, or medications known to produce high spinal fluid pressure. The main goal of treatment is to prevent or reverse visual loss.
Most individuals with pseudotumor cerebri syndrome do improve, although a small percentage of patients may experience severe and irreversible visual loss. When visual loss occurs, it generally does so at the beginning of the illness. In addition, headaches may be an ongoing problem even after the optic nerve swelling resolves. Occasionally, the condition comes back after initially successful treatment, particularly in IIH patients who have gained weight.
Once diagnosed, it is important to have regular follow-up visits with a neurologist and an ophthalmologist or a neuro-ophthalmologist.
The Idiopathic Intracranial Hypertension Treatment Trial is underway to determine the best treatment for patients with mild visual loss and to try and find the cause of IIH. Go to clinicaltrials.gov/ct2/show/NCT01003639 for more information.