Idiopathic Intracranial Hypertension (IIH) is a brain injury that occurs when high levels of cerebrospinal fluid inside the skull increases pressure on the brain and optic nerve, causing severe headaches, migraines, and vision problems that can lead to blindness.
What Causes IIH?
No one knows what causes Idiopathic Intracranial Hypertension (IIH). The term “idiopathic” means “of unknown cause.” However, there are a number of risk-factors that increase your chances of IIH. Women are over 3-times more likely than men to develop IIH — especially obese women. Birth control pills are another risk-factor, according to the National Institute of Health (NIH).
Birth Control and IIH
One of the first studies to link birth control and IIH was published by the New England Journal of Medicine in 1995. Researchers described 56 cases of IIH in women (average age 22) who were using a contraceptive implant called Norplanon, which contains only levonorgestrel.
Bayer, the manufacturer of the Mirena intrauterine device (IUD), has been hit with several lawsuits from women who developed IIH. They allege that experts have known about the link between levonorgestrel and IIH for decades, but warnings were never added to the Prescribing Information.
- Headache: About 94% people with IIH report headaches, including migraines. The symptoms usually include severe throbbing or pulsating pain, typically worst in the morning, nausea, and other symptoms.
- Vision problems: Over 60% of people develop vision problems, such as episodes of blurry vision lasting 30 seconds. Double-vision (diplopia) is also common.
- Hearing problems: Tinnitus (ringing in the ears).
- Papilledema: Swelling (edema) of the optic disc, which is the head of the optic nerve located in the back of the eye at the blind spot.
- Blindness: Visual field loss occurs in 90% of people with IIH, but blindness only occurs in 5% of cases. It is common for the blind spot to grow progressively larger over time.
IIH is diagnosed with a lumbar puncture (spinal tap). This painful test involves removing a small amount of cerebrospinal fluid using a needle inserted between two vertebrae in the lower back. It is also sometimes used to relieve painful headaches, but it is not a cure. Eye exams can also look for signs of papilledema.
Treatment for IIH may involve a combination of medications and surgery. In severe cases involving vision loss, IIH may need to be treated with surgery to implant a shunt (surgical tube) and drain cerebrospinal fluid from the skull.