Botulinum Toxin Injections for the Treatment of Neurological and Movement Disorders

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.

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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)

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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.