How does Botox relieves migraine headaches?

Botox, or onabotulinumtoxinA was recently approved by the FDA for treatment of chronic migraine based on the results of two large studies. Botox is the only prophylactic therapy specifically approved for chronic migraine. Many patients and doctors alike wonder about the mechanism of action of Botox. We originally thought that Botox works by relaxing tight muscles around the scalp. Studies have shown that during a migraine attack, the muscles in the forehead, temples and the back of the head are in fact contracted. It is also typical for a person with a migraine to rub their temples or the neck, which provides some temporary relief. However, I have seen some patients who would report that injecting muscles around the head eliminated pain in the injected areas, but that they still had pain on the top of the head. There are no muscles on the top of the head and we usually do not inject Botox there, but in those patients who do have residual pain on the top, injecting Botox stops the pain. Recent research has shown that Botox in fact also exerts a direct analgesic (pain-relieving) effect. This is supported by my and other doctors’ observation that Botox also helps other types of pain, such as that of shingles or trigeminal neuralgia. These are so called anecdotal reports and cannot be relied on to make definitive conclusions – we need large trials can prove this. It appears that Botox helps by reducing pain messages sent to the brain from both muscles and peripheral sensory nerves. This explains why migraine, which is a brain disorder, can be helped by a procedure directed only at the peripheral nerves – with the reduction of the barrage of pain messages reaching the brain, the brain does not become more and more excitable, or “wound-up” and a migraine attack does not occur. Some patients tell me that after Botox treatment they sometimes feel that a migraine is about to start, but it does not.

13 comments
  1. Michelle says: 03/01/201212:29 pm

    Dear,
    I have chronic migraine and using zomig (only that medications helps me)to stop pain…but I wanna to plan pregnancy and was wandering if botox treatment is allowed to use in treatment again chronic migraine in pregnancy or during planing pregnancy(it stays in body for 2/3 months).
    All I find on internet is that is not allowed.
    http://www.babymed.com/lifestyle-and-beauty/botox-during-pregnancy
    Do you have women in pregnancy who are under botox treatment for chronic migraine?
    This is very important to me, because I don’t know how to handle my situation anymore and botox treatment seems like the bast options…IF IS SAFE IN PREGNANCY. Please, let me know as soon possible,
    THANK YOU
    MICHELLE

  2. Dr. Mauskop says: 03/01/20121:15 pm

    The FDA gives every drug a pregnancy category. Category A are drugs tested and approved for pregnant women, drugs in category B are considered safe, although they have not been as thoroughly tested as in Category A. Most of the drugs are in Category C, which includes drugs that have not been shown safe but have not been shown to be dangerous either and the FDA recommends that the doctor weighs potential benefits vs potential risks before prescribing such drugs. Category D can definitely cause fetal problems and should be used only in rare cases, while Category X drugs should never be used in pregnant women.
    Botox belongs to category C, just like most drugs for headaches (except for a nausea drug, Reglan or metoclopramide, which is in Category B and Topamax and Depakote, which are in Category D). However, because only a very small amount of Botox is injected (5 nanograms) and because it is not distributed throughout the body by bloodstream, it is much less likely to cause any potential problems than the drugs taken by mouth. I have treated pregnant women with Botox without any problems, but because my numbers are small, a more important fact is that during the 22 years since Botox was approved by the FDA there have been no reports of serious problems with it in pregnant women. So, your doctor has to discuss and decide together with you if the potential benefits are worth the potential risks of Botox injections.

  3. Bridget says: 05/17/20124:20 pm

    I received botox for migraine 17 days ago. I have had 9 bad headaches but my biggest complaint is severe neck pain. Is this normal? My doctor just tells me everyone is different. I cannot function at work or home.
    Please help!

  4. Dr. Mauskop says: 05/17/20125:12 pm

    Yes, Botox can cause temporary worsening of headaches and neck pain, but usually it lasts a week or two. If neck pain persists, pain killers (including our Migralex and prescription drugs) and/or muscle relaxants, such as tizanidine or Flexeril can help. This doesn’t mean that Botox is not going to help or that the next time you have it the neck pain will also occur. Although in some patients Botox works well even without neck injections, especially if headaches are mostly in the forehead and temples.

  5. Bridget says: 05/17/20125:16 pm

    Thanks for the info. I do have chronic neck pain for the last 2 years and feel like 1/2 of my migraines start because of neck pain. They have not done a ct scan, just a regular x-ray and seem to ignore my saying i have neck pain. I have had migraines since i was 8 years old and now i am 22 years old. With a 2 year old son i am trying to care for also. I am trying to finish my schooling as a rad tech and have had so much pain since the botox that i have been missing my clinicals as i am in so much pain

  6. marian says: 06/03/20121:35 pm

    I too am wondering about botox and pregnancy. I had lived with debilitating migraines for years and botox was a god send. It gave me back my life. Previously because of the days upon days of vomiting, i was extremely underweight, couldn’t work and I spent a great deal of time in hospital for dehydration which in turn cause urinary tart infections and kidney stones.
    My first pregnancy was terrible, due to migraines and dehydration. I am pregnant again 15 years later and have stopped the botox but have spent the last 5 days in bed. taking pain killers and I do wonder if botox wouldn’t be a better alternative for the baby to dehydration, caffeine and pain killers? I generally get about 50 units every 3 months in my head, temples, jaw and forehead.

  7. Dr. Mauskop says: 06/03/20122:35 pm

    You are right, Botox would probably be safer, but you would have to discuss this with your obstetrician and neurologist.

  8. Wendy says: 07/30/201211:07 pm

    I put my neck out this week and have been taking 100mg of celebrex twice a day. Will this be a problem if I have 31 botox injections on Friday because it is a NSAID and the bleeding issues?

  9. Dr. Mauskop says: 08/01/201210:40 pm

    You need to ask your doctor who is administering Botox, but I do not have patients stop Celebrex or Migralex (aspirin) before Botox injections.

  10. Fenella says: 09/08/20128:12 am

    My mum had Botox in her neck a month ago. Prior to this she had chronic stiff neck and pain for about a year. She has also had a headache every night which has been happening for about 5 years. Often the headache would go if she got and moved around. She has always suffered from headaches and migraine. Whilst her neck pain has eased since the Botox she is now experiencing daily migraine type headaches, could this be because of the Botox?

  11. Dr. Mauskop says: 09/08/201211:16 am

    Your mom (this is how we call them in the US) needs to ask her doctor about getting additional Botox injections for her chronic migraine. For migraine Botox is injected in the forehead, temples, and back of the head, as well as neck

  12. Debbie says: 11/28/20129:19 pm

    i have had headaches since age 15 now at 35 i am getting very frustrated as i am placed on one “preventative” medication and it works for a short time and then stops. i am back to trying some meds from years ago…i am taking metoprolol daily and imitrex inj as needed along with zanaflex at night and then midrin or fiorocet as needed. i also use zofran for nausea. i am tired of taking pills and looking for something easier. we have no cause for them i have had labs drawn over and over to check things like hormones, i have had CT and MRI while having a migraine. i have a daily headache 4-5 times a week and then get a “migraine” 2-3 times a month. i goes for massage every 10-14 days and have tried PT and chiropractor. so i quess i need to know who to talk to about other treatments. PCP or a specialist as i do not see a neuro dr as they have told me that i have no change in complaints over 20 years and they are the same so they gave me more pain meds and sent me on my way. i am a nurse and this is the last thing i want to deal with. i seem to be always short with my family by the end of the day because i have dealt with the headache all day. please help? i have tried most of the meds listed and others that aren’t how do i know if botox is right?

  13. Dr. Mauskop says: 11/29/20129:46 am

    It sounds like you are a perfect candidate for Botox injections. Botox is approved by the FDA for chronic migraine headaches. Chronic migraine is defined as a headache occurring on 15 or more days each month and headache lasting for at least four hours. On some of those days, but not necessarily all, the headache has to have some migraine features. So, it sounds like your headaches definitely fulfill all criteria for the diagnosis of chronic migraine and Botox could potentially significantly change your life for the better. You can find a local neurologist who injects Botox for migraines at this site.

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