Mayo Clinic Q and A: Botox for migraines

DEAR MAYO CLINIC: I have suffered with migraines for about five years. Recently, the oral treatment I used seems to be less effective. While I know there are newer medications, a friend suggested I try Botox injections. She swears it got her chronic headaches under control. How safe are these injections and how does Botox work? What is the treatment plan and will I also need to take other medication for the headache?

ANSWER: Onabotulinum toxin A, or Botox, was approved by the Food and Drug Administration in 2010 for the treatment of chronic migraine headaches. It is not a cure. People who get Botox injections for headaches usually get the treatment about every three months.

For some, this is all they need to keep their headache under control. For others, additional medication or other headache treatment is required. The investigation is ongoing about new forms of migraine treatment.

Botox is a drug that uses a form of botulinum toxin to temporarily paralyze muscle activity. Best known for its ability to reduce the appearance of facial wrinkles, Botox has also been shown to prevent chronic migraine headaches in some people. It is mainly used for those who have headaches 15 or more days a month.

Since 2002, Mayo Clinic doctors have treated thousands of chronic migraine patients effectively and safely using Botox. The drug is usually injected into the muscles of the forehead, scalp, neck and shoulders.

The specific details of how Botox works to prevent headaches are not known. But it is possible that the injected Botox is taken up by pain receptors in the nerves of the muscles. The drug then deactivates these pain receptors and blocks the pain signals that the nerves send to the brain.

But the pain does not go away permanently. After several months, the nerves grow new pain fibers and the headaches tend to return. The Botox effect usually lasts about 2½ months. Because the injections are repeated no sooner than every three months, some people need other headache treatments for the last two weeks of a Botox cycle.

Providing Botox treatment for headaches every three months is a national standard, as recommended by the American Headache Society. The treatments are not given more often because of the small chance that if you get Botox more often, your body may make antibodies to the botulism toxin. These antibodies could theoretically prevent Botox from working with future injections.

For many people, Botox treatment alone is enough to control their chronic headaches. However, some people require more care, including additional medicines to prevent migraine attacks. These may include cardiovascular drugs such as beta blockers and calcium channel blockers. certain antidepressants; and certain anticonvulsant medications. Medicines taken during migraine may also be helpful.

The most common side effects of Botox injection include swelling or bruising at the injection site. Unusually, the medicine can spread to nearby tissues and cause problems such as a drooping eyelid, eyebrows that look out of place, dry eyes or excessive tearing. This tends to happen more in people who already have some eye droop or are more sensitive to botulinum toxin. Sometimes, changing the injections to a slightly different location can reduce this side effect.

Although rare, it is possible for the effect of botulinum toxin to spread to other parts of the body and cause symptoms such as muscle weakness, vision problems, difficulty speaking or swallowing, or difficulty breathing. Doctors generally recommend not using Botox if you are pregnant or breastfeeding because the effects of the drug on a fetus are not known.

Botox injections are expensive. They can cost several thousand dollars per set of injections. Many insurance companies will cover the injections if a patient meets the criteria for chronic migraine. For at least three months, a person must have a headache that occurs 15 or more days per month that has the characteristics of a migraine at least eight days per month. It’s best to talk to a healthcare professional about options.

Before proceeding with Botox injections, make sure you are under the care of a licensed and qualified healthcare professional. Botox can be dangerous if given incorrectly, so it’s important that these injections are given by a doctor, nurse or other specialist experienced in using them for chronic headaches. I recommend asking your primary care provider or neurologist for a referral. A qualified and properly trained healthcare professional can discuss the procedure with you in detail and help you decide if it suits your needs.