Botulinum Relieves Chronic Back Pain

Injected into a localized area in extremely low concentrations, the toxin blunts the nerve endings responsible for muscle spasms.

In a study of 19 patients, in which nine received two injections of botulinum toxin into both sides of the lower back and 10 received no treatment, researchers found that the botulinum group had significant reductions in pain, improvements in ability to function, and fewer muscle spasms. The nontreatment group reported an increase in pain and no improvement in muscle spasms. The botulinum injections begin working in two to three days, but their effects can last for months, say the researchers.

"Unlike acute back pain, which tends to resolve on its own, chronic back pain tends to worsen over time due to a vicious, self-perpetuating cycle of muscle spasms,” said Randall C. Cork, M.D., professor and chair of anesthesiology at Louisiana State University Health Sciences Center (Shreveport, USA), where the research was conducted. One drawback is the medication's tendency to become less and less effective with repeated injections as the body builds up antibodies to the toxin. "But most patients never need another injection,” said Dr. Cork.