When many people hear the words Botulinum Toxin, the first thing they think of is botulism, an often fatal form of food poisoning. Botulism is caused by some strains of Clostridium botulinum, bacteria that is generally found in badly canned foods. In recent years, however, scientists have discovered that a certain strain of Clostridium botulinum can safely be used as a drug to prevent migraine attacks. According to the Physician's Desk Reference:
"BOTOX® (Botulinum Toxin Type A) Purified Neurotoxin Complex is a sterile, vacuum-dried form of purified botulinum toxin type A, produced from a culture of the Hall strain of Clostridium botulinum grown in a medium containing N-Z amine and yeast extract. It is purified from the culture solution by a series of acid precipitations to a crystalline complex consisting of the active high molecular weight toxin protein and an associated hemagglutinin protein. The crystalline complex is re-dissolved in a solution containing saline and albumin and sterile filtered (0.2 microns) prior to vacuum-drying. BOTOX® is to be reconstituted with sterile non-preserved saline prior to intramuscular injection. When injected intramuscularly at therapeutic doses, BOTOX® produces a localized chemical denervation muscle paralysis."
A clinical study, Botulinum Toxin Type A as a Migraine Preventive Treatment, was conducted by Stephen Silberstein, MD, of the Thomas Jefferson University School of Medicine; Ninan Mathew, MD, of the Houston Headache Clinic; Joel Saper, MD, of the Michigan Head Pain & Neurological Institute; and Stephen Jenkins, MD, of Allergan, Inc. for the BOTOX Migraine Clinical Research Group. The objective of the study was "to assess the safety and efficacy of botulinum toxin type A (BOTOX; Allergan, Inc) in the prevention of migraine."
Prior to this study, Botox had been used in clinical practice to treat several disorders believed to be due to overactive striated or smooth muscles. Positive results had also been reported in using Botox to inhibit overactive nonmotor as well as motor peripheral acetylcholine neurons. Not only was it effective in reducing muscle hyperactivity and spasm, Botox treatment often reduce the pain associated with cervical dystonia, achalasia, and rectal fissures. In addition, there was preliminary evidence that it could be effective in the treatment of chronic low back pain associated with muscle spasm. There had also been a noncontrolled study of Botox used as a migraine preventive. This study by Silberstein, et al, was performed to confirm the findings of the uncontrolled study, "by examining the safety and efficacy of BTX-A in the prevention of migraine, using a double-blind, vehicle-controlled design."
Design and Methods of the Study:
"This was a double-blind, vehicle-controlled study of 123 subjects with a history of two to eight moderate-to-severe migraine attacks per month, with or without aura. Participants were randomized to receive single administrations of vehicle or botulinum toxin type A, 25 U or 75 U, injected into multiple sites of pericranial muscles at the same visit. During a 1-month baseline period and for 3 months following injection, subjects kept daily diaries in which they recorded migraine frequency, migraine severity, and the occurrence of migraine-associated symptoms." Click HERE for a photo with the injection sites indicated by red dots.
Compared with subjects who received placebo injections, the subjects in the Botox treatment group experienced:
- significantly fewer migraine attacks per month
- reduced severity of migraine attacks
- fewer days using abortive/rescue medications
- fewer episodes of vomiting
"Pericranial injection of botulinum toxin type A, 25 U, was found to be a safe treatment that significantly reduced migraine frequency, migraine severity, acute medication usage, and associated vomiting."
Obviously, no therapy will work for all migraineurs, but this study definitely gives hope that Botox injections are helpful as a preventive for a significant percentage of migraineurs. A word of caution - if you are considering Botox injections, please be sure that the doctor administering the treatment is experienced in its use. It's your health. Don't hesitate to ask how many times the doctor has administered Botox and the rate of success achieved.
Based on the information from this study, if you haven't found the
right medication or combination of medications to keep your migraine attacks
down to a manageable number, you may want to consider giving them a bit of
Silberstein, Mathew, Saper, and Jenkins. "Botulinum Toxin Type A as a Migraine Preventive Treatment." Headache: The Journal of Head and Face Pain 40 (6), 445-450