Botulinum toxin
Injections are focal treatments administered directly into the spastic muscle. Drugs used include: Botulinum toxin (BTX), phenol, alcohol, and lidocaine. Phenol and alcohol cause local muscle damage by denaturing protein, and thus relaxing the muscle. Botulinum toxin is a neurotoxin and it relaxes the muscle by preventing the release of a neurotransmitter (acetylcholine). Many studies have shown the benefits of BTX and it has also been demonstrated that repeat injections of BTX show unchanged effectiveness.