A treatment commonly used by dermatologists to get rid of facial wrinkles may also help migraine sufferers, a UCSF researcher has reported.
In a presentation at the American Society of Dermatologic Surgery meeting (held November 2-5), Richard Glogau, MD, UCSF professor of dermatology, reported that 75 percent of patients in his case study experienced four to six months of migraine relief following injections of Botox® (botulinum toxin A derived from bacteria) to muscles of the face and head. Glogau's small study of 24 patients adds weight to previous reports that botulinum toxin A can relieve headaches.
Since 1992, Botox®, the same bacteria that causes deadly food poisoning, has been used in purified and diluted form to temporarily paralyze the muscles that bring the eye brows together, thereby eliminating wrinkles in this region. Since then, it has also been used to mitigate wrinkles in the forehead and near the eyes and mouth. Patients in Glogau's dermatology practice injected with botulinum toxin A in the upper third of the face for treatment of cosmetic frown lines (who coincidentally suffered from migraine headaches) have reported the added benefit of headache relief, he said.
Following this serendipitous discovery, Glogau and other researchers began to evaluate injection points and dosages that could alleviate headaches. Glogau's results indicate that botulinum toxin A injected into the muscles of the brow, eyes, forehead, side of the head and back of the head near the neck (a point that earlier investigators have neglected) induce sometimes immediate headache relief and provide benefit for up to six months, he said. Botox® dosage in his case studies averaged 80 units per patient.
Though the mechanism for migraine relief is not known, Botox® injections paralyze the muscles in the face and head. Botulinum toxin A may stop the expression of pain by stopping muscle contractions that lead to spasm, he explained, or it may inhibit nerves that transfer pain responses to the brain and spinal chord. In all likelihood, it does both, he said.
There are no published, randomized, double-blind trials that show the safety and efficacy of Botox® for treatment of migraines, Glogau said. In fact, most of the data consists of case reports and meeting abstracts. Two previous studies were presented at the 1999 meeting of the American Association for the Study of Headache. In the first study, reported by researchers at the Michigan Head Pain and Neurological Institute in Ann Arbor and Michigan State University, a one-time dose of 25 units of botulinum toxin A injected into the muscles of the brow, forehead and side of the head, reduced the frequency of migraines, the severity of pain, vomiting, and the use of pain medications for up to three months. A 75-unit treatment yielded headache relief, but also side effects like eyelid drooping. In another study, reported by researchers at the University of California, Los Angeles, 51 percent of 96 patients reported complete improvement of their migraine pain.
"It doesn't work on everyone and it doesn't work on all headaches," said Glogau. However, when physicians start with injections into the eye brow area (the same method used by dermatologists to treat wrinkles) and work toward the back of the head, the response rate appears to be higher, he explained.
Glogau also noted that higher dosages of botulinum toxin A administered with increasingly improved technique may be critical to migraine relief. "Too much drug in one spot and too close to the eye rim affects muscles of the eye, causing drooping," he explained.
Patients successfully treated in Glogau's case studies had long-standing diagnoses of migraines, had all seen neurologists, and were taking standard migraine medications, including sumatriptan (Imitrex). Some required narcotic medication to relieve the pain of their frequent headaches. Most suffered migraines on a minimum of once a week and several suffered on a daily basis.
In addition to use in prevention of wrinkles, Botox® has been used to treat uncontrolled eye twitching, crossed eyes, muscle spasms and, most recently, excessive underarm sweating (reported by Glogau in the September, 1998 issue of Dermatologic Surgery).
One limitation for botulinum toxin's use in treating migraines is cost. Unlike other treatments for migraines, such as the prescription drug Imitrex and nasal sprays, Botox® injections are not covered by insurance and cost about $350 for each targeted area.
Glogau is a consultant to Allergan, the Irvine, California company that manufactures Botox®. He does not own stock in the company.
Materials provided by University Of California, San Francisco. Note: Content may be edited for style and length.
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