That Botox erases wrinkles is well known, but the medication is also widely used to address a host of conditions
By Jacqueline Simoneau
Contrary to what you may think, cosmetics is not the primary use of botulinum toxin, marketed in Canada under the names Botox, Xeomin, and Dysport. At first, it was used to treat certain conditions related to muscle hyperactivity.
It was only by chance that Canadian ophthalmologist Jean Carruthers noticed that her patients who were treated for blepharospasm (involuntary movements of the eyelids) had fewer wrinkles around their eyes than other patients. In turn, the aesthetic use of the toxin also showed a positive effect on migraines. That is how, through observation, medical indications grew.
Today, doctors use it to treat more than a hundred medical conditions— and researchers are still discovering new possibilities.
Purified and Diluted
Medical applications of Botox employ botulinum toxin type A, a protein produced by the bacterium Clostridium botulinum—the beast that causes botulism (when the toxin attacks the body’s nerves). The toxin is purified many times and then diluted in a lab to make it safe for use, and it’s given at a low dose.
The toxin acts by blocking the release of acetylcholine, a neurotransmitter that causes muscle contractions. When the transmission of the nerve impulse is interrupted, the muscles relax, which reduces or even stops the debilitating symptoms. The result varies from one person to another depending on the area injected, the dosage, and the technique.
The effects are generally visible one to two weeks after the injection, but they aren’t permanent: the body eventually eliminates the toxin. Treatment must therefore be repeated at regular intervals, about every three months. After a few sessions, it’s sometimes possible to increase the interval between treatments.
Injections of botulinum toxin are usually well tolerated. However, they are contraindicated for people who have inflammation or an infection near the injection site, a hypersensitivity to the toxin, or a neuromuscular disease such as myasthenia gravis. Side effects are generally limited to mild pain and swelling at the injection site, though as with any medical procedure, a more serious reaction is always possible, but this is rare and, above all, reversible in most cases.
Medical Uses
Since the early 1980s, the use of botulinum toxin has revolutionized many areas of medicine and improved the quality of life of many patients. Here are a few medical fields that make good use of it.
In Neurology
According to Dr. Sylvain Chouinard, a neurologist at the Centre hospitalier de l’Université de Montréal (CHUM) and a professor at the Université de Montréal, it’s probably in neurology that botulinum toxin has the most applications. It’s used to treat certain movement disorders, muscular hypertonia (excess muscle tone), and involuntary muscle contractions.
Among the most common conditions are cervical dystonia, hemifacial spasm, spasticity, hypersalivation, and chronic migraine. It can also be used to relax certain muscles following facial paralysis or a stroke or in people with multiple sclerosis. “Botulinum toxin is injected, sometimes with the help of ultrasound or an electromyogram, directly into the muscles concerned, in a few different places,” Chouinard explains.
“In several of these conditions, it’s the treatment of choice to lessen muscle contractions, which can be painful.” The effects generally last three months.
In Urology
Injections of botulinum toxin are part of the therapeutic tool box for treating overactive bladder with or without urge incontinence. The treatment reduces bladder contractions and therefore the symptoms: urinary frequency and a sudden and overwhelming urge to urinate.
“Botulinum toxin leads to significant improvements in around 70 percent of patients who respond poorly or not at all to classic treatments,” says Montreal urologist Andrew Steinberg.
“The treatment is done under local anaesthetic. First we put in a probe, and then we insert a cystoscope through the urethra to see inside the bladder. The product is then delivered by several injections into the muscle concerned.” The treatment some- times causes mild pain and bleeding, increases the risk for infection, and occasionally causes retention of urine, but these problems are treatable and temporary. The effects of the treatment last on average eight to 12 months.
Other uses include treating spastic bladder (caused by, for example, multiple sclerosis, stroke, or Parkinson’s), interstitial cystitis in women, chronic pelvic pain in men, and, more recently, erectile dysfunction.
In Ophthalmology
While botulinum toxin is rarely used to treat strabismus (a disorder in which the eyes are not aligned properly), it’s the first option for treating essential blepharospasm (uncontrolled blinking and closing of the eyelids), a condition caused by involuntary contractions of the orbicularis oculi muscle. “The treatment consists of injecting the toxin into the hyperactive muscles of the lower and upper eyelids, and sometimes up to the eyebrows, to relax them,” explains Dr. Erika Massicotte, an oculoplastic surgeon at CHUM. “The results are generally excellent.”
After the treatment, there may be some bruising around the eyes (ecchymosis) and eye dryness. Rare complications can also arise, such as lagophthalmos (difficulty closing the eyes completely), ptosis (droopy upper eyelid), and ectropion (the lower eyelid turns out- ward). But according to Massicotte, it’s easy to prevent these problems by starting with a low dose and gradually increasing it.
Finally, botulinum toxin is also used in cases of refractory epiphora, or watery eyes.
In Gastroenterology
In this area, the toxin is used with people who have achalasia (a swallowing disorder), gastroparesis (delayed emptying of the stomach), or anal fissures. “Achalasia, a hypertonicity [stiffness] of the lower esophageal sphincter, is the most common condition treated,” says Dr. Alexandre Généreux, head of gastroenterology at CHU de Québec–Université Laval.
“For these three health conditions, treatment involves injecting the toxin by endoscopy into the sphincter muscle— the esophagus, the stomach, or the anus, depending on the problem—to relax it and, in the case of achalasia, make swallowing easier. Botulinum toxin is not, however, the first treatment given for these conditions.” The effect is quick and lasts three to six months. According to Généreux, side effects are rare.
In Dermatology
To prevent excessive sweating in the armpits, topical preparations made with aluminum chloride can temporarily block the sweat glands, but if that doesn’t work, botulinum toxin is the next step for treating hyperhidrosis. “The neurotoxin inhibits sweat production in the areas treated,” says dermatologist Émilie Bourgeault. “We do about 50 injections per armpit to cover the whole area. It’s very effective. Besides bruising and a little discomfort, side effects are rare.” The treatment’s effect lasts about six months.
The toxin can also be used for excessive sweating in the hands and feet. In addition, Bourgeault says that recent studies have shown that botulinum toxin can in some cases help to reduce hyperpigmentation and rosacea.
Myths About Botox
Much has been written about botulinum toxin, especially in the field of cosmetics, that has given rise to various myths about its use. The many botched transformations of Hollywood personalities and hearsay have contributed to stoking fears. Chouinard sees this regularly. “In my practice, I spend a lot of time trying to convince patients that the toxin is safe when used in a medical setting,” he says.
“There are people who deprive themselves of the benefits of the treatment because they’re afraid of its effects. In reality, it’s not the product that’s dangerous but people who give the injections without the appropriate training. When the toxin is given at the correct dose and injected properly, there’s no danger. The body eliminates it after a while.”
According to Steinberg, people need to remember that botulinum toxin type A has been studied and tested for decades for various applications. Since its discovery, millions of people have received injections without complications. The important thing is to be sure you choose a qualified professional.
