Botox for the prevention of chronic migraine
Well known for smoothing facial wrinkles, you may not be aware that UK health authorities have approved Botox as a preventive treatment for chronic migraine.
The throbbing pain of chronic migraine can’t be overlooked or ignored, and migraine is a genuine public health issue, estimated to affect some 700,000 people in the UK. Though the launch of triptans in the 1990s truly revolutionized migraine treatment, the side effects, including renal, hepatic and gastric toxicity, has somewhat limited their use.
Botox, or botulinum toxin type A, on the other hand, provokes no known side effects and therefore seems a highly promising therapeutic alternative. Doctissimo gives you an overview of Botox in relation to migraine, which may soon change the lives of millions of people suffering from chronic migraine.
Botox: a poison with proven therapeutic virtues
Botulinum toxin is a dangerous poison produced by a bacterium called Clostridium botulinum found, for instance, in poorly sterilized canned food and rotting cooked meats. It blocks transmission between nerves and muscles, which causes respiratory and motor paralysis and can even result in death.
The therapeutic virtues of this neurotoxin started receiving some attention as early as the 19th century. Since then, it has been extensively used, with applications ranging from the treatment of neurological diseases causing excessive muscle activity (contractions and abnormal movements, cramps, spasticity and dystonia) to abnormally increased perspiration (hyperhidrosis), wrinkle-smoothing treatments and, now, chronic migraine.
Chronic migraine is an under-diagnosed condition characterised by a particularly high frequency of headache attacks (at least 15 days a month over 3 months, including 8 days of migraine). Women are three times as likely to be affected as men (18% vs. 6%), while an estimated 5% of children experience chronic headache. To date, no preventive treatment is available against chronic migraine, which can be highly disabling on professional, relationship, emotional and family levels.
The potential of Botox in treating migraine was discovered in the 1990s in patients who’d been using the product to smooth out wrinkles. Women who were regular migraine sufferers said their headaches had “miraculously” disappeared. Based on these observations, researchers began to investigate this mysterious phenomenon. Hundreds of migraine patients for whom conventional therapy had failed participated in a series of studies and were successfully relieved of their headaches. In 2003, preliminary studies were conducted and provided further support for this hypothesis with encouraging results recently confirmed by larger-scale studies1,2,3,4.
Botox: reducing migraine frequency and intensity
In order to assess the efficacy, safety and tolerance of Botox as a preventive treatment for chronic migraine, the study authors compared two groups of chronic headache patients unresponsive to conventional treatments. The first group received two botulinum toxin injections in specific head and neck muscles at a 12-week interval, while the second group got a placebo.
According to Marc Schwob, a French neurologist and chairman of the French Association for Migraine Treatment, the results speak for themselves: “The authors noted positive effects on migraine frequency; a 24% drop in the number of migraine days and decreased severity in half of the participants, going from severe to mild; a 75% fall in the number of hours of headache; and considerable improvement in quality of life”. Another compelling argument in favour of botulinum toxin is its cost: “Botox is very cheap compared to other approved migraine medications such as triptans,” Dr Schwob said.
However, the study didn’t show any improvement in medication-overuse headache (MOH) patients. MOH is caused by excessive consumption of pain-relieving drugs by patients seeking to get rid of headaches. Because analgesic drugs don’t work, patients raise their consumption, which paradoxically produces the opposite of the desired effect. By doing what they think is right, MOH patients actually make their headaches more frequent and more resistant to conventional treatments.
This condition, though unfamiliar to the general public, is fairly common, says neurologist Eric Bozzolo and can be blamed on the fact that participants don’t limit their analgesic drug consumption, which is what causes their chronic headaches. Therefore, Dr Bozzolo recommends performing thorough neurologic exams prior to starting any treatment, as this is the only way to accurately pinpoint the causes of migraine and thus to offer patients relevant treatment options.
Convinced by the study results, British authorities have approved Botox® as a preventive treatment for chronic migraine. So if you suffer from chronic headaches or migraines have a word to your GP about Botox as a possible solution.
1. "OnabotulinumtoxinA for treatment of chronic migraine: Results from the double-blind, randomized, placebo-controlled phase of the PREEMPT 2 trial," Cephalalgia July 2010 30: 804-814, March 2010
2. "OnabotulinumtoxinA for treatment of chronic migraine: Results from the double-blind, randomized, placebo-controlled phase of the PREEMPT 1 trial," Cephalalgia July 2010 30: 793-803, March 2010
3. "Botulinum toxin in headache treatment: Finally a promising path?" Cephalalgia July 2010 30: 771-773
4. "OnabotulinumtoxinA for Treatment of Chronic Migraine: Pooled Results From the Double-Blind, Randomized, Placebo-Controlled Phases of the PREEMPT Clinical Program," Headache: The Journal of Head and Face Pain, Volume 50 Issue 6, p. 921-936
Copyright © 2010 Doctissimo
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