Depo-Provera has been associated with a case of idiopathic intracranial hypertension (IIH). This progressive neurological condition can cause chronic headaches and permanent blindness. Many people with IIH need surgical treatment to drain cerebrospinal fluid from their skull.
What is Depo-Provera?
Depo-Provera is a progestin-only birth control shot that contains medroxyprogesterone acetate. Women on Depo-Provera receive an injection once every three months.
Idiopathic Intracranial Hypertension (IIH) is a disorder that results from increased levels of cerebrospinal fluid. This fluid normally cushions and protects the brain and spinal cord. IIH occurs when excess fluid increases pressure on the brain. In the past, IIH was known as pseudotumor cerebri (PTC).
Does Birth Control Cause IIH?
The cause of IIH is generally not known (“idiopathic”). However, a common explanation is that IIH is caused by a problem with re-absorbing cerebrospinal fluid into the body. This may also be known as “secondary intracranial hypertension.”
Health experts also warn that contraceptives are a possible risk-factor for the disease. Birth control implants containing levonorgestrel, for example, were associated with 56 cases of IIH in a study published in 1995. Depo-Provera has also been linked to cases of IIH.
Case Report Linking Depo-Provera and IIH
Depo-Provera was associated with one case of IIH in a 23 year-old female. According to the report (PDF):
“The woman’s only medication was depot medroxyprogesterone acetate which she had taken only one dose of 2 months prior to presenting with idiopathic intracranial hypertension. She discontinued the method and experienced total resolution of symptoms after the fourth monthly visit.”
What are the symptoms of IIH?
- Headache: Over 90% of people with IIH report headaches.
- Tinnitus: Rhythmic pulsating ringing heard in one or both ears.
- Double-vision: May be a symptom of pressure on the 6th cranial nerves
- Vision problems: Blurry vision, temporary dimming, or blacking out for 30 seconds.
- Loss of field of vision: The blind spot may enlarge or central vision may be lost.
- Blindness: As many as 10% of people with IIH develop progressively worsening vision, and 5% become blind. Once the optic nerve has been damaged, there is no way to cure blindness.