Botulinum toxin (BoNT) is a protein and neurotoxin which is extremely effective in treating certain neurological and movement disorders. BoNT injections are used to treat disabling pain, varieties of dystonia, abnormal movement disorders and autonomic nervous system. BoNT works by blocking unwanted transmissions from being sent along the nervous system by preventing an organic compound called acetylcholine from being released. This reduces the volume of transmissions passing the point where the nervous system connects with the muscle system connect and reaching the body’s pain receptors and involuntary nervous system.
The goal of the therapy is to reduce muscle spasm and pain, and restore more useful function. A very small dose of botulinum toxin is injected into a muscle to block some of the messages that are sent from the nerves to the muscles, reducing spasms. Neurons generate new nerve endings that reactivate the muscle contracture, so improvement is time limited, and treatment is usually repeated every 3 to 4 months. Physical or occupational therapy occasionally helps restore normal muscle function.
A botulinum toxin injection is usually a quick and relatively simple procedure that can be done in a doctor’s office. Firstly, the area for injection will be cleaned. There may be a little pain or pressure associated with the injection related to the needle and fluid itself, but a local anaesthetic agent is usually not required. The actual injection is just like having a vaccination shot, with a smaller amount of liquid being injected into the desired area. The effects (both the good and bad if present) can be variable but wear off in time (usually within 3-4 months) and so the injection will probably have to be repeated then.
No preparation is needed before you go to have an injection. If you are using a drug that thins the blood aside from aspirin, the clinician may wish to know.
Botulinum toxin therapy is a safe and effective treatment when given in appropriate amounts by a qualified neurologist. Some patients experience temporary weakness in the group of muscles being treated, or those nearby. For example, ptosis (drooping eyelid) can develop after treating blepharospasm. Flu-like symptoms develop in some patients, but rarely. Patients with certain other neuromuscular diseases, such as amyotrophic lateral sclerosis or myasthenia gravis, may not be appropriate candidates for botulinum toxin therapy. Infrequently, some patients develop antibodies to the medication over time, rendering the treatment ineffective.
How does Botulinum toxin actually work?
Botulinum toxin blocks the chemical signal between the nerves and the muscles that makes a muscle contract or tighten. In order for your muscles to contract, nerves have to release a neurotransmitter called acetylcholine, which attaches to receptors on your muscle cells and causes them to contract. Injecting botulinum toxin prevents the release of acetylcholine, which in turn prevents muscle cells from contract and therefore, moving. As a result, you get relief from symptoms like pain and muscle stiffness. The treatment usually starts working a few days after the injection and lasts for about three months. While its effectiveness is mainly due to paralyzing muscles, it may also alter pain signaling and reduce nerve inflammation that's causing tightness and pain.
What are some of the symptoms of neurological dysfunction?
Pain Chronic daily headaches, including chronic migraine headache or chronic tension headache Myofascial (tissues covering and connecting muscles), neck or back pain Movement disorders Blepharospasm (eyelid twitches) Hemifacial spasm (twitches on one half of the face) Oromandibular dystonia (contractions of the mouth, jaw and tongue muscles) Cervical dystonia (contractions of the neck muscles) Truncal dystonia (contractions of the torso muscles) Hand or foot dystonia Refractory tremor (persistent and uncontrollable shaking) Palatal tremor (shaking of the rear roof of the mouth) Tics, Myoclonus (brief, involuntary twitching of the muscles) Spasticity (stiff or rigid muscles) Bruxism (teeth grinding) Hyperhidrosis (excessive sweating, especially of the armpits, palms and soles) Hypersalivation or Sialorrhea (excessive production of saliva)
I thought botulinum toxin was bad. How is being used medically?
The preparations are purified forms of the toxin, and contain rather minute quantities of the toxin produced by the bacterium. When purified and injected, it can be incredibly useful in diseases where the muscles are too tight/overcontracted, or where doctors want to stop the release of acetylcholine. By making sure the injections are in just the right spot, botulinum toxin can provide very effective treatment for lots of conditions with very few side effects. Although the weakening of the muscle is felt to be important, some recent research suggests that some conditions like dystonia, which is an involuntary tightening of muscle, may be the result of abnormal incoming signals from nerves and muscle. This has led to recent thinking that the toxin may exert its beneficial effect by interrupting these incoming signals to the brain as well.