Botulinum Toxin in Pain Management

 
Diagnosis and treatment of painful muscle syndromes can be a difficult and frustrating task for any clinician. Typically, the mainstay of therapy for such conditions is therapeutic exercise, analgesics, and a tincture of time. Unfortunately, not all patients respond to this paradigm, and, despite heroic efforts on the part of the treating clinician, some conditions are refractory to this approach.
Reports have described the purported effectiveness of using a biologic neuromuscular blocking agent, botulinum toxin, in the treatment of painful conditions associated with skeletal muscle. While incompletely understood and at times controversial, use of botulinum toxin in the treatment of conditions associated with involuntary muscle contraction, such as focal dystonia and spasticity, is supported by prospective, randomized clinical research; however, while the volume of comparable studies in pain syndromes is growing, the number of clinical randomized trials is limited. Moreover, not all such reports have demonstrated clear efficacy of the use of botulinum toxin under all circumstances. Therefore, in view of our current understanding of the nature of muscle-induced pain and the paucity of prospective research regarding neuromuscular blockade and/or inhibition of nociception in such conditions, critical and careful analysis of the data and opinions presented in this section is appropriate.
This article provides general direction and practical details for the clinician considering botulinum toxin for treatment of pain. Anatomic drawings for injection localization and dosing information are intended only as general guidelines; therapy with botulinum toxin always must be individualized, accounting for the patient's needs and the clinician's expertise. In addition, information presented should be used as a convenient reference source, not as a substitute for clinical training in the use of botulinum toxin.