[Botulinum toxin in specific pain therapy]

Botulinum toxin has been used for therapeutic purposes in medicine for more than 20 years. Its effective use now covers more than 50 conditions in a wide variety of areas. Its medicinal use was initially based on its blockade of neuromuscular and neurosecretory transfers. Its use for conditions in the field of specific pain therapy is currently authorized in Germany for spastic torticollis, blepharospasm, hemifacial spasm, spastic equine gait in cases of idiopathic cerebral paresis, and spasticity of the arm following stroke. New publications suggest that it can usefully be employed for numerous other painful conditions. The modes of action known today are not confined to the blockade of cholinergic innervation.Indeed, there is also evidence that therapeutic effects are mediated through a normalization of muscle spindle activity, retrograde intake into the CNS with modulation of the central neuropeptide function, inhibition of sterile neurogenic inflammation, and normalization of endplate dysfunction. In view of the methodological peculiarities of studies in the field of pain therapy, such as injection techniques, injection sites, blind study techniques, dosage etc., the scientific evidence for its use in a wide variety of pain syndromes is still patchy in many areas. For this reason the use of botulinum toxin for these syndromes is only justified after full use has been made of standard therapeutic methods and evaluation in specialized centers. The possibility of considering botulinum toxin in specific pain therapy contexts is a new option for patients and doctors.However, its use calls for detailed knowledge of functional neuroanatomy and extensive practical experience and expertise.