Botulinum toxin prevents the release of acetylcholine form the presynaptic terminals, therefore prevents muscle contraction. Its effect usually last 3 months. More frequent injections may lead to development of resistance due to formation of antibodies against this protein.
The sites of injections and the dosage depend on the targeted muscles. Responsive disorders include:
- Hemifacial spasm
- Cervical dystonia
- Severe spasticity
- Intractable tremor