Botox is a safe and effective treatment for chronic migraine and three other neurological disorders, an updated guideline from the American Academy of Neurology says.
Long used to smooth wrinkles, botulinum toxin is made by a type of bacteria. The toxin blocks the release of substances at nerve endings, reducing muscle contraction and the transmission of pain signals, the researchers explained.
The authors of the updated guideline reviewed scientific studies on the four preparations of botulinum toxin available in the United States. They concluded that the treatment is generally safe and effective for four neurological conditions: chronic migraine, spasticity in adults, cervical dystonia, and blepharospasm.
Chronic migraine is defined as having migraines 15 or more days a month, the study authors explained. Spasticity in adults is muscle tightness that interferes with movement and typically occurs after a stroke, spinal cord or other neurological injury. Cervical dystonia is a disorder of the brain that affects neck muscle control, resulting in involuntary head tilt or neck movement. Blepharospasm is a movement disorder that causes the eyes to close uncontrollably, guideline author Dr. David Simpson and colleagues said. Simpson is with the Icahn School of Medicine at Mount Sinai in New York City.
The last time the guideline was updated—in 2008—there wasn’t enough information to make a recommendation on chronic migraine. This time, the guideline authors found research that showed that botulinum toxin provides a small benefit for people with chronic migraines.
The updated guideline was published online April 18 in the journal Neurology. The new guideline is also scheduled to be presented Monday at the American Academy of Neurology’s annual meeting in Vancouver, Canada.