Uses of Botulinum Toxin Injection in Medicine Today

USES OF BOTULINUM TOXIN INJECTION IN MEDICINE TODAY 

Botulinum neurotoxin is produced by me anaerobic bacterium Clostridium botulinum. It is me 

Serotype A is the only one commercially available for clinical use, although experience is emerging with serotypes B, C, and F. Two preparations exist Dysport, which is most widely used in the U.K., and Botox, which is used in the U.S. and elsewhere. 

Strains of C. botulinum produce seven antigenetically distinct neurotoxins designated as serotypes A through G. All seven serotypes have a similar structure and molecular weight, consisting of a heavy (H) chain and a light (L) chain joined by a disulfide bond. They all interfere with neural transmission by blocking the release of ACh (see Chapter 14), which is the principal neurotransmitter at the neuromuscular junction. 

After synaptic transmission is blocked by botulinum toxin, the muscles become clinically weak and atrophic. The affected nerve terminals do not degenerate, but the blockage of neurotransmitter release is irreversible. Function can be recovered by the sprouting of nerve terminals and formation of new synaptic contacts this usually takes 2 to 3 months. 

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