Botulinum toxin has been used since the early 1980s for medical purposes in humans when it was first used to treat strabismus, a condition commonly seen in children that involves “crossing of the eyes.” Since then, botulinum toxins have gained worldwide recognition for their beneficial effects in a myriad of medical conditions. Given the toxin’s ability to soften wrinkles, a growing popularity in Hollywood and cosmetic medicine has obscured some of the major medical advances using botulinum toxin.
Botulinum toxin is produced by the bacteria, Clostridium Botulinum. The bacteria produces seven similar, yet serologically distinct neurotoxins labeled A, B, C1, C2, D, E, F, G). Types A and B are the only serotypes currently used for medicinal purposes. Types C and D only cause symptoms in animals. Different production and purification methods are used to make the toxin safe for medical use. Commercially available type A neurotoxin (e.g. BOTOX) is the most widely available serotype.
Botulinum toxins act directly on muscle tissue by blocking the release of acetylcholine at the presynaptic neuromuscular junction. This causes muscles to relax. Without acetylcholine, muscle fibers can’t contract. It is also thought that botulinum toxins block the release of certain inflammatory mediators in sensory pain fibers.
Today, numerous medical conditions seen in a spine and pain management setting are being treated with botulinum toxin. Some examples include: cervical dystonia, chronic headaches, chronic myofascial pain, thoracic and lumbar spine myofascial pain, post-laminectomy pain syndrome, spasticity, focal dystonias, piriformis syndrome and chronic neurogenic pain.
Botulinum toxin injections have been shown to be safe and well tolerated in many clinical settings. Side effects depend on the part of the body injected, dose and dilution used, the condition being treated and coexisting illnesses. If you are being considered for treatment with botulinum toxins, your physician will discuss potential side effects with you. In a pain management setting, these injections are usually considered after more traditional measures have failed. The exception to this is in the treatment of cervical dystonia, in which botulinum toxin injections are considered a first line treatment.