Most people are unaware that the use of Botox for the prevention of migraine headaches came about purely by accident. It all happened through the use of Botox by plastic surgeons. Patients undergoing plastic surgery, who were also experiencing headaches, noticed that their injections of Botox helped with their migraine headaches.
Botox, also known as botulinum toxin, is a neurotoxin (a toxin that attacks nerve cells). It was originally approved by the FDA for use in conditions where hyperactivity of muscles was an underlying problem of related health and medical conditions. The theory is that Botox weakens or paralyzes muscles by inhibiting the release of acetylcholine. Acetylcholine is an ester of choline that is thought to play an important role in the transmission of nerve impulses at synapses and myoneural (muscle-nerve) junctions. By inhibiting the release of acetylcholine the nerves cannot cause a muscle contraction, thus relaxing the muscle. Botox is administered by being directly injected into the affected muscles.
There are differing theories as to how Botox works to eliminate migraine headaches, but the exact reasoning remains unclear. One theory is that muscle tension and spasms are a cause of migraines and eliminating the muscle tension with an injection of Botox will also eliminate the cause of the headaches. If given Botox before the headache begins it is possible to eliminate the headache before it even starts.
When muscles spasm it can irritate nerves that innervate them. When these nerves send signals to the brain in an increased amount it causes pain and possibly headaches. Botox may affect these nerve cells, inhibiting their transmission, causing a lessening of the perception of pain. Many researchers think that migraine headaches are a result of inflammation of blood vessels. However, muscle tension may also play an important role in the cause of headaches.
When researchers test a medication’s effectiveness they usually test it through a double-blind study. This means that some patients are given the medication being tested while others are given a placebo. A placebo is an inactive substance, such as sugar, that is given in place of the medication that is being evaluated. Some tests have been performed that did not involve double-blind studies, but showed that Botox could prevent migraine headaches. One double-blind study involving Botox and headaches showed only a small positive effect.
Initial studies may not have shown the full effectiveness of Botox for the prevention of headaches. The injections were not placed in the typical locations of the headache pain, but in areas normally injected during plastic surgery. In subsequent studies, using larger doses and injecting into more specific localities for the headache pain, the results were improved. These tests were concerning migraine headaches. However, with tension headaches, or muscle tension headaches, the studies have shown improved results. This is to be expected due to the weakening or paralyzing nature of Botox on the muscles that are experiencing tension.
When being injected with Botox for the prevention of headaches it may take several weeks before the injection takes effect. For this reason, it is usually necessary to have it injected no more often than once every 3 months or so. People that have Botox administered for the treatment of headaches typically need it injected every few months. If there is too long of an interval between injections the headaches may be experienced by the patient.
However, the question arises about the safety of these regular injections of neurotoxin. Since 1989, when it was first used as a headache treatment, it has appeared to be fairly safe. Most migraine headache medications are taken orally and eventually end up in the bloodstream. Because of these common symptoms of migraine headache medication will be dizziness and drowsiness among other symptoms. Since Botox is injected directly into the muscle tissue and does not get absorbed into the blood system as does the typical headache medicine there are fewer side effects. Most commonly, the only side effects of injecting this neurotoxin are pain in the area of injection for a couple of days or drooping of the eyelids for a few days.
Studies are still being performed on this medication and as yet the FDA has not approved it for the treatment of headaches. However, physicians do prescribe it to their patients and if you think you are a candidate to use it you should discuss it with your doctor. If you do not respond to other headache medications it may be something to talk with your physician about. As the studies continue the effects and safety issues involving this medication should become more clear.