Idiopathic Intracranial Hypertension, also known as Pseudotumor Cerebri is a disorder of elevated spinal fluid pressure in the brain. IIH is a condition important to recognize because it may lead to progressive loss of vision over time – which may be permanent.
What are the symptoms of IIH?
IIH headaches may be dull, are often at the back of the head, and tend to be worse at night or first thing in the morning. Over time, symptoms become constant. Patients may suffer from temporary episodes of visual blurring or even blindness. If the pressure continues to build up, the nerves affecting eye movement can cause double vision or slowly deteriorating vision.
What causes IIH?
IIH tends to affect overweight individuals, especially after recent weight gain, even during pregnancy. Certain medications can also predispose individuals to the syndrome, including the antibiotic tetracycline, steroids (as they are weaned off) and vitamin A. Some people may be predisposed to IIH because of being born with a narrowed vein that drains blood from the brain; a condition that was in place since birth.
How is IIH diagnosed?
An eye exam may reveal optic nerve swelling at the back of the eye, an abnormality called papilledema. CT scan may be normal or may reveal smaller than normal pockets (ventricles) of spinal fluid. MRI scans may be normal or may show small ventricles. They may also show narrowed draining veins or indirect signs of abnormally elevated spinal fluid pressure. Because patients with this condition clearly have symptoms of elevated pressure in the head – which is also seen with large brain tumors – but have normal scans, the condition has been called pseudotumor cerebri, meaning “false brain tumor”.
Once imaging tests have ruled out any tumors or other abnormalities, the pressure of the spinal fluid needs to be measured in order to verify the diagnosis, preferably by a lumbar puncture (spinal tap). Some patients find immediate, but temporary, relief of their symptoms after drainage of the spinal fluid.
Once the diagnosis is made, a careful eye exam and testing of the visual fields will is performed to determine the risk of vision loss.
How is IIH treated?
There are several treatment options, including medications to reduce the spinal fluid pressure or repeated lumbar punctures to keep the pressure down to a safe and tolerable level. Weight loss, even a moderate amount, can cure the condition; nutritionists, medications, and weight-loss programs are often helpful. The sheath surrounding the optic nerves is sometimes surgically opened with small holes to relieve pressure and prevent deterioration of vision. In severe cases, an implantable tube (shunt) that drains the spinal fluid out of the brain needs to be surgically placed. The Headache Center has experts available for each of these options.