Does Botox Work For Chronic Migraine?

Does Botox Work For Chronic Migraine?

OnabotulinumtoxinA, or as it is colloquially known in the world, Botox, is a famous dermatology, beauty assisting, facial line erasing drug which also works for chronic migraine headache and has an indication from the FDA for migraine prevention for patients with chronic migraine (15 headache days a month, 8 of which have migraine features).  Botox doesn’t work for episodic migraine (14 or less headache days a month) or for Tension type headache.

Botox is a neurotoxic protein produced by the bacterium Clostridium botulinum.  It prevents the release of the neurotransmitter acetylcholine at the neuromuscular junction.  This can result in paralysis of striated muscle found in the eye muscles, diaphragm, arms and legs.  Human infection with the bacterium causes the disease, botulism.  Marketed in the U.S. Botox is used commercially in medicine and cosmetics.

Botulism is a rare illness but is one of the most serious of all illnesses.  Clostridium botulinum is an anaerobic, gram-positive, spore-forming rod commonly found on plants, in soil, water, and the intestinal tracts of animals. Humans ingest it through food like bulging, unopened canned foods which allow the bacteria to grow, or through contact with an open wound, or contaminated soil.

Since it is an extremely rare disorder, botulism may cause limb and breathing paralysis, sometimes resulting in death.  Botulinum toxin is a potential biological weapon, so the U.S. military is interested in finding an anti-toxin or blocking molecule to protect soldiers.  The exact structure of the link between the toxin and nerve cell is now known, hopefully making it easier to find this blocking molecule.

1 gram of botulinum toxin could kill over 1 million people. Two kilograms could kill the entire human population of Earth.

Clostridium botulinum bacterium

Clostridium botulinum bacterium

Botulinum toxin acts at the neuromuscular junction to cause muscle paralysis by inhibiting the release of acetylcholine from presynaptic motor neurons. Botulinum toxins act at four different sites in the body:

1.the neuromuscular junction

2.autonomic ganglia

3.postganglionic parasympathetic nerve endings

4.postganglionic sympathetic nerve endings

Botulinum toxin induces weakness of striated muscles by inhibiting transmission of alpha motor neurons at the neuromuscular junction.  This has led to its use in conditions with muscular overactivity, such as dystonia.  Transmission is also inhibited at gamma neurons in muscle spindles, which may alter reflex overactivity.  The toxin also inhibits release of acetylcholine in all parasympathetic and cholinergic postganglionic sympathetic neurons.  This has generated interest in its use as a treatment for overactive smooth muscles (for example, in achalasia) or abnormal activity of glands (for example, hyperhidrosis).

 Botulinum toxin requires 24-72 hours to disrupt the nerve/muscle process. In very rare circumstances, some individuals may require as many as five days for the full effect to be observed. Peaking at about 10 days, the effect of botulinum toxin lasts nearly 8-12 weeks.

Does Botox Work For Chronic Migraine?  Onabotulinumtoxin A (trade name Botox) received FDA approval for treatment of chronic migraine on October 15, 2010.  The toxin is injected into the head and neck to treat chronic migraine.  Approval followed evidence presented to the FDA from two studies funded by Allergan showing a very slight improvement in incidence of chronic migraines for migraine sufferers undergoing the Botox treatment.

OnabotulinumtoxinA significantly reduced the number of headache days per 28-day cycle relative to placebo at week 24 (change from baseline: -8.4 days for onabotulinumtoxinA versus -6.6 days for placebo; P < 0.001, pooled data).  OnabotulinumtoxinA improved health-related quality of life and had an acceptable safety profile.

Related Questions

What is the dose of Botox for chronic migraine?


The chronic migraine dose is 155 units IM divided into 31 sites, given every 12 weeks.

Botox dosing by muscle for Chronic migraine

Frontalis--20 units in 4 sites

Corrugator--units in 2 sites

Procerus--5 units in 1 site

Occipitalis--30 units in 6 sites

Temporalis--40 units in 8 sites

Cervical Paraspinal--20 units in 4 sites

How does Botox work?  Botox is botulinum toxin, a neurotoxin produced by the bacteria that causes botulism.  The toxin is purified and used in tiny doses in specific areas to block motor muscle contractions.  It wears off after about 3 months.  It is common knowledge that plastic surgeons in Hollywood inject movie stars with Botox and in that circumstance the toxin paralyzes the facial muscles and eliminates frowns and lines.  So, it has been known that the Botox toxin would block efferent (motor) nerve transmission but how it helped migraine has not been understood.  Recent articles have discussed that Botox will block the release of a common neurotoxin, generated during the migraine process, CGRP, and this helps migraine.  

What do Botox injections feel like?  Patients describe the injections as like tiny pin pricks as the needle is going a shallow distance into muscles in the face, jaw, and back of head.  The drug works best if given in the protocol as described above.  Sometimes no migraine relief works on the first try, so it is recommended that the patient try it twice.

31 needles every 3 months?

31 needles every 3 months?


What are the side effects of Botox?  There may be problems swallowing, speaking, or breathing.  The toxin effects may appear in areas away from the injection site and may cause all over muscle weakness, double vision, blurred vision, drooped eyelids, hoarseness, change or loss of voice, or unclear speech.

Left lid ptosis from Botox injection

Left lid ptosis from Botox injection


What does Botox cost?  Most insurance companies cover most of Botox therapy.  Patients should talk to an insurance supervisor about coverage.

Celebrity Botox Babe

Celebrity Botox Babe

What is the effectiveness of Botox?  Allergan, the maker of Botox, says that “some patients in company sponsored trials experienced a 50% reduction or more in headache days per month after two cycles of Botox, and more than 2 out of 3 patients showed some improvement.”  Nobody else has achieved these results.

An April 24, 2012 article in the Journal of the American Medical Association headlined that Botox injections are only modestly effective for preventing migraines in the most frequent suffers.  The researchers looked at 27 trials comparing Botox to placebo and four other studies comparing Botox to other migraine treatments.  Botox treatment given to patients with chronic migraine or at least 15 headaches a month prevented 1.8 headaches a month more than placebo.  The researchers felt that Botox was no more effective than commonly used migraine preventive drugs, didn’t work for Chronic Tension Type Headache, nor for patients with episodic migraine or less than 14 migraines a month.  There also is a high placebo response with Botox use.

Satnam Niijar MD, a headache specialist at Johns Hopkins University School of Medicine said “the research analysis will surprise few clinicians working in the field.  This review emphasizes that most patients experience modest benefits, but we already knew that."

What are other problems using Botox for chronic migraine?  80-90% of patients with chronic migraine are overtreating with over the counter analgesics, caffeine, opioids, or butalbital.  That causes chronic migraine due to medication overuse headache.  This syndrome used to be called “rebound headache.”  See the articles at overuse headache.

When I see these patients for a second opinion, and they are already on Botox, but they're not doing well, I discover that they many have not been educated regarding how taking too much medication can cause headache

Chronic right sided migraine headache

Chronic right sided migraine headache

The International Classification of Headache criteria for medication overuse headache are:

Triptans or Ergotamine intake >10 days/month (like sumatriptan)

Non-opioid simple analgesics >15days/month (like Tylenol, caffeine, or Advil)

Opioids or Analgesics combined with barbiturates >10days/month

A recent patient I saw was getting Botox and taking hydrocodone from the same doctor.  In my opinion patients should be educated about medication overuse headache and detoxed before Botox is ever considered.  Most of these patients pass right on into episodic headache and do well.

For good migraine treatment consider:

Do the migraine lifestyle.  No caffeine, three meals a day, aerobic exercise 3-4 days a week for 20-30 minutes, set your sleep cycle to be the same, don’t nap or oversleep, deal with stress, and don’t overtreat with over the counters, NSAIDs, caffeine, or triptans more than 2 days a week.  Don’t use opioid narcotics or butalbital at all.

Get on a migraine preventive drug.  For Chronic or episodic migraine-the new CGRP antibody drugs—Aimovig, Ajovy, or Emgality.

Limit all headache medication to no more than 2 days a week, except maybe DHE or timolol eye drops. Again, don't take opioid narcotics or butalbital.

Good luck with this.

 Britt Talley Daniel MD