Botulinum toxin is a protein. It can stop some of the chemical messages that are sent from nerves. These messages tell the muscles to contract in spasms (to tighten up). Botulinum toxin is used to stop muscle spasms because it blocks these messages.
Botulinum toxin is made by the same bacterium that causes food poisoning. A high dose of botulinum toxin could be fatal, just as food poisoning can be fatal. However, the dose given in injections is so small that it's unlikely you'll have any harmful effects from the toxin. Botulinum toxin has been used safely in thousands of people. It has been used for more than 10 years.
Your doctor may be considering botulinum toxin injections to treat certain muscle spasms on your face or eyelids. The injections can also be used for some eye movement disorders, such as a lazy eye. Botulinum toxin is a standard treatment for spasmodic torticollis, a muscle spasm that causes the head and neck to pull in one direction. Your doctor may use the botulinum toxin injections to treat other problems as well. Botulinum toxin has proven to be useful in the treatment of many forms of dystonia, including the following:
- chronic migraines - more than 15 headache days per month
- blepharospasm — forceful involuntary closure of the eyelids
- strabismus — misalignment of the eyes
- hemifacial spasm — sudden contraction of the muscles on one side of the face
- spasmodic torticollis, or cervical dystonia — muscle
spasm in the neck that
causes the head to turn to one side, and sometimes forward or backward
dystonia — continuous spasms of the face, jaw, neck,
larynx, and in severe cases, the respiratory system
- urinary retention — severe inability to urinate that requires catheterization
- spasmodic dysphonica — spasm
of the vocal cords that causes sudden disruption
- stuttering — repetitions of parts of words and whole words, long pauses, elongated sounds
- voice tremor — quavering vocalization
Neurons generate new nerve endings that reactivate the dystonia, so improvement is not long lasting, and treatment is usually repeated every 3 to 4 months. Physical or occupational therapy usually is undertaken to stretch and restore normal muscle function. Some patients develop antibodies to the toxin over time, rendering the treatment ineffective.
Botulinum toxin is mixed with saline (salt water) and injected into the
muscle with a tiny needle. You may receive 5 to 10 injections.
You might have some soreness at the injection sites. If your injection sites get sore, you can take acetaminophen (one brand name: Tylenol) or ibuprofen (one brand name: Motrin). You can also put an ice pack on the painful area.
You might have weakness in the muscles that were injected, muscle soreness that may affect your whole body, difficulty swallowing or a red rash that lasts several days after the injections. Some people have severe weakness in the muscles that were injected. All side effects go away quickly. The most frequently reported adverse reactions in patients with cervical dystonia are dysphagia (19%), upper respiratory infection (12%), neck pain (11%), and headache (11%). The most frequently reported adverse reactions in patients with blepharospasm are drooping of the eyelid (21%), superficial punctate keratitis (6%), and eye dryness (6%). Patients with neuromuscular disorders may be at increased risk of clinically significant systemic effects including severe dysphagia and respiratory compromise from typical doses of Botulinum.