[Use of botulinum toxin the the treatment of muscle pain].

The analgesic effects of botulinum toxin (BTX) have been discussed controversially due to substantial placebo effects and flaws in the study designs used. Additionally, pathophysiological concepts of pain and the specific analgesic mechanisms of BTX remain largely unclear. Apart from pain reduction through the well-documented effects of BTX at the neuromuscular endplate, additional analgesic mechanisms, including other synaptic and local effects, have been suggested. Currently, BTX can be recommended for pain treatment in dystonia and spasticity. In myofascial pain syndromes, pain relief by BTX injections has been reported, but definite proof according to evidence-based medicinal criteria is still lacking. In fibromyalgia, there seems to be no analgesic effect. The role of BTX in pain therapy is likely to increase in the future.