Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)
|What is Idiopathic Intracranial Hypertension (IIH)? |
Cerebrospinal fluid is the fluid that bathes the brain and spinal cord. IIH (also known as Pseudotumor Cerebri) is a condition of elevated cerebrospinal fluid pressure in the absence of a mass in the brain. If untreated, IIH can cause visual loss and even blindness.
What causes Idiopathic Intracranial Hypertension?
There are many reasons why a person can have elevated cerebrospinal fluid pressure (brain mass, medications, infections, etc.). These possible causes for elevated cerebrospinal fluid pressure must be excluded prior to diagnosing IIH. The cause of the elevation of cerebrospinal fluid pressure in IIH is not known ("idiopathic").
Who gets Idiopathic Intracranial Hypertension?
It is most common in overweight females of child-bearing age. It can occur in children and men, but this is less common.
What are the common signs and symptoms of Idiopathic Intracranial Hypertension?
Most patients with IIH experience headache. The headache may be aggravated by changes in position. There may be a ringing or a "whooshing" sound in the ear. A patient may experience double vision.
In this disorder, it is common to have momentary loss of vision known as "transient obscurations of vision". Other visual symptoms are a central blind spot, blurred vision, or loss of peripheral vision in one or both eyes. The visual loss may be mild to severe. If severe and untreated, it can result in blindness. The optic nerves are usually swollen in appearance.
How is it diagnosed?
First, imaging studies of the patient's head (via magnetic resonance imaging or computed tomography) must be normal. Next, the cerebrospinal fluid pressure is measured by a lumbar puncture ("spinal tap") and the pressure must be elevated. Laboratory studies on the cerebrospinal fluid must be normal. All of the above criteria must be met in ORDER to diagnose IIH.
How is it treated?
Most patients are treated with medications to lower the cerebrospinal fluid pressure. The most commonly used medication is acetazolamide 500 mg taken twice a day. Overweight patients should begin a diet and exercise regimen. Patients must have frequent eye exams to monitor for visual loss. Visual acuity and visual field checks are done at each visit. If visual loss progresses despite medical treatment, surgical treatment may be recommended.
The surgery performed to protect vision is called an optic nerve sheath fenestration. This involves the creation of a window in the sheath-like covering of the optic nerve. This creates an outlet for escape of cerebrospinal fluid in the region of the nerve which supplies vision.
Another type of surgery sometimes recommended is a lumboperitoneal shunt. This device diverts cerebrospinal fluid FROM around the lower spinal cord INTO the abdomen. Both types of surgeries have their own risks and benefits. The optic nerve sheath fenestration is the preferred method to protect against further loss of vision.
How do I get more information?
Neuro-Ophthalmologists are the eye-care specialists who typically treat patients with IIH. To arrange for an appointment in the New England area with a neuro-ophthalmologist, you can call the Neuro-ophthalmology Unit of the Massachusetts Eye and Ear Infirmary at (617) 573-3412.
The information and recommendations appearing on these pages are informational only and is not intended to be a basis for diagnosis, treatment or any other clinical application. For specific information concerning your personal medical condition, the DJO suggests that you consult your physician.