Idiopathic intracranial hypertension (IIH), also called pseudotumor cerebri, is a condition in which there is high pressure in the fluid surrounding your brain, spinal cord and optic nerves. This can cause headaches and problems with vision. Although the cause(s) of the condition is not fully understood (the definition of “idiopathic”), we know much about the condition itself.
Patients with pseudotumor cerebri do not have a tumor. A brain tumor may also cause increased intracranial pressure, which is why this condition is called “pseudotumor”: it can cause symptoms like a real tumor, but the tests do not show any tumors (pseudo- means “false,” so pseudotumor means “false tumor”).
IIH can affect anyone, but is more common in women (90%) than men. It is more common in teenagers and young women but can affect people of any age. It is much more common in those who are overweight, obese or who have had a recent substantial weight gain. Children who have not yet reached puberty can rarely get IIH. In these children, IIH occurs nearly equally in boys and girls and occurs in those who are not overweight.
We do not know what causes IIH. However, there is a clear association with being overweight or obese. Certainly, not all overweight or obese people develop this condition. This likely means that there are unique features that predispose some people to develop IIH that we have yet to discover. Medical studies have shown that recent weight gain can cause IIH, and that weight loss alone can achieve remission in most cases. There is ongoing research into the cause/causes of IIH. Certain medications increase a person’s chance of having IIH. These mostly include tetracycline antibiotics (e.g., minocycline, doxycycline), high doses of vitamin A and retinoids, so these should be discontinued and avoided in the future by people with this diagnosis. Growth hormone can rarely lead to IIH. Hormonal contraceptives (oral and implants) have not been convincingly shown to cause IIH and should not necessarily be discontinued in IIH patients.
Not everyone will develop all the symptoms of IIH. The most common symptoms of IIH include:
Less common symptoms include:
In severe cases, IIH can cause severe peripheral vision loss and blurred central vision. If severe cases are left untreated, there is a high risk of permanent disabling loss of vision.
There are three important steps that must be completed in order to diagnose IIH:
Courtesy of Dr. Valerie Biousse, M.D.
Normal optic nerve (left) and papilledema (right). The normal optic nerve looks like a flat pink-orange-yellow disc. In papilledema, the edges of the disc become blurred and fuzzy, and the entire disc eventually swells.
Most people with IIH are treated with medications and weight loss. Less than 1 out of 10 people (< 10%) with IIH will require surgical treatment.
Relatively few people become blind from IIH and most people recover if they are treated early. Surgery is needed if medical treatment and weight loss do not stop the visual loss. In very rare cases, blindness may occur even with correctly administered medications and surgery.
Do I need treatment?
If you do not have significant headaches or vision loss, no treatment may be necessary, although weight reduction is always a good idea to prevent the disease from worsening. The decision to treat or not treat is based on the clarity of your vision (visual acuity), peripheral vision (visual fields), presence of papilledema, and whether or not you have headaches or other symptoms.
Weight loss is hard to do. How much weight do I need to lose?
Weight loss can be a sensitive issue for both the doctor and the patient. Weight loss is difficult to achieve and maintaining a lower weight long-term is challenging. Almost all people with IIH are overweight, and weight loss can be a very effective component of treatment. Weight reduction programs that include increasing physical activity and a diet low in sodium have been shown to be effective in treating IIH. A good initial goal is losing 6-10% of your starting weight; for example, someone with a starting weight of 250 lbs (113 kg) would have an initial target weight loss of 16-25 lbs (7.3-11.3 kg). In some cases, weight management (bariatric) surgery may be helpful.
What medications are used for treating IIH?
Acetazolamide (Diamox) is the most common medication used for treating IIH. It is thought to lower pressure inside the skull by reducing fluid (CSF) production. Research shows that acetazolamide significantly improves vision, papilledema, quality of life and CSF pressure.
Common side-effects of acetazolamide include:
If you are not able to take acetazolamide, your doctor may prescribe another medication called topiramate (Topamax) which may help the headache and also assists with weight loss. Side effects of topiramate can include mild slowing of thought processing. Furosemide and methazolamide are alternative medications that are sometimes used to treat IIH in patients who do not tolerate acetazolamide or topiramate.
What medications help for headache in IIH?
There are no medications specifically designed for IIH-related headaches, although many neurologists specifically use topiramate because it may also lower pressure inside the skull and may act as an appetite-suppressant. Over-the-counter analgesics such as non-steroidal anti-inflammatory drugs (NSAIDs) and/or migraine medications may be helpful if you have headaches even after the IIH treatment is successful in lowering the intracranial pressure and resolving the papilledema.
Using pain medications >2-3 days per week for more than a few months can make you dependent on the medications, so that when you don’t take the pain medications you get a withdrawal headache (medication-overuse headache). This is a background daily headache that may be confused with high pressure and can make the severe headaches worse. Stopping these medications is helpful. Consulting with a neurologist may be useful if headaches are a persistent concern.
Surgery is recommended when vision is getting worse from high pressure despite aggressive treatment with medications and best efforts at weight loss. Because surgery has small but potentially dangerous risks to your life and/or vision, surgery for IIH is usually not recommended when your vision is good. The goal of surgery is to release pressure around the optic nerves. There are three main types:
Shunt surgery: a neurosurgeon places one end of a flexible tube into one of the normal fluid-filled spaces in your brain (ventricle) or into your lower (lumbar) spinal canal and the other end into another part of your body, such as your abdomen (peritoneum). This allows the fluid under high pressure in the head a way to escape.
Venous stenting: A specially-trained neurovascular surgeon inserts a device that holds open a vein inside your skull that drains blood from the brain. If a patient has a vein narrowing inside the skull that is restricting blood flow, opening it more fully with a stent can lower the pressure inside the skull. It is a newer technique for lowering pressure inside the skull. Specialists are still determining when it is best to use venous sinus stent placement in the treatment of IIH. You will need to be on a blood thinner for several months after the procedure and thus venous stenting is not a good option for patients who are pregnant.
Optic nerve sheath fenestration: an orbital or neuro-ophthalmic surgeon creates a small window in the lining (sheath) around your optic nerve to allow the fluid to drain behind your eye, which lowers the pressure on the front of the optic nerve and helps optic nerve swelling improve.
IIH may resolve over months to years or it may be a lifelong medical problem. IIH can return, and is often linked to regaining weight (even just 6-10% of body weight). If you become pregnant in the future, inform your neuro-ophthalmologist, as you may require closer follow up during your pregnancy. However, IIH during pregnancy does not require a Cesarean section.
You should let your neuro-ophthalmologist know about any changes in symptoms such as worsening headache. You should report changes in vision immediately since that could indicate worsening optic nerve swelling, which could lead to permanent loss of vision if left untreated.
Generally not, unless there is a new problem or if it is unclear whether the pressure in your head is still high and a repeat measurement would change how you are treated. IIH is now only rarely treated with multiple spinal taps.
IIH rarely runs in some families (approximately 5%).
Copyright © 2023. North American Neuro-Ophthalmology Society. All rights reserved.
This information was developed collaboratively by the Patient Information Committee of the North American Neuro-Ophthalmology Society. This has been written by neuro-ophthalmologists and has been edited, updated, and peer-reviewed by multiple neuro-ophthalmologists. The views expressed in this brochure are of the contributors and not their employers or other organizations. Please note we have made every effort to ensure the content of this is correct at time of publication, but remember that information about the condition and drugs may change. Major revisions are performed on a periodic basis.
This information is produced and made available “as is” without warranty and for informational and educational purposes only and do not constitute, and should not be used as a substitute for, medical advice, diagnosis, or treatment. Patients and other members of the general public should always seek the advice of a physician or other qualified healthcare professional regarding personal health or medical conditions.
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