Botulinum toxin for the treatment of musculoskeletal pain and spasm

Abstract

The impressive pain relief experienced by sufferers of dystonia and spasticity from intramuscular injections of botulinum toxin suggested that patients with other chronic, musculoskeletal pain conditions also may benefit. However, there have been relatively few placebo-controlled studies of botulinum toxin in such non-neurologic conditions as myofascial pain syndrome, chronic neck and low back pain, and fibromyalgia; the results of these studies have not been impressive. One explanation for the lack of positive findings may be the lack of clinically evident muscle spasms (overactivity), despite the presence of muscle tenderness, tightness, or trigger points. Clinical observations of pain relief from injections of botulinum toxin for dystonia and spasticity and its apparent efficacy in treating migraine suggest an anti-nociceptive action independent of its neuromuscular junction-blocking action. Evidence from animal experiments supports this notion, and other data provide plausible physiologic mechanisms in the periphery and central nervous systems. These involve modulation of the activity of the neurotransmitters glutamate, substance P, calcitonin gene-related peptide, enkephalins, and others. However, even if botulinum toxin is firmly established as an analgesic, there is insufficient clinical evidence of its efficacy in treating non-neurologic, chronic, musculoskeletal pain conditions.

Conformational sampling of the botulinum neurotoxin serotype a light chain: implications for inhibitor binding

“…1 Furthermore, as BoNTs continue to gain popularity as: (1) therapies for muscle hyperactivity and spasticity [4][5][6][7] and (2) preferred agents for a range of cosmetic applications, [8][9][10] inadvertent overdosing (requiring immediate toxin inhibition) may become problematic. More ominous is the fact that BoNTs have been weaponized in highly toxic aerosol form, and malevolent airborne release and/or food contamination pose a significant threat to both civilians and military personnel.…”

Evaluation of treatments for myofascial pain syndrome and fibromyalgia

“…Botulinum toxin is increasingly used for trigger point injection, but its efficacy is not well supported in the literature despite a number of small studies over the past several years [35,36]. Botulinum toxin may be superior to steroids in the treatment of MPS [37].…”

Updated Perspectives on Neurogenic Thoracic Outlet Syndrome

“…This toxin is produced by a bacterium known as Clostridium botulinum, which can cause severe muscle weakness, nervous system dysfunction, and respiratory distress if poisoning occurs [36]. Its therapeutic effects result from reducing muscle overactivity [37] and possibly decreasing pain and inflammation [38][39][40][41]. Approved uses of botulinum toxin include hemifacial spasm, blepharospasm, strabismus, cervical dystonia, glabellar lines, hyperhidrosis [42], and chronic migraine [43].…”