How 'Botox' may offer new effective nerve pain therapy

A new study has revealed that botulinum toxin can offer an effective new treatment for two forms of neuropathy, pain caused by different types of nerve injury.

University of California's experimental study found that treatment with botulinum toxin type B (BoNT-B) produces lasting reduction in abnormal pain responses caused by physical nerve injury or chemotherapy-related nerve damage in mice.

The study shows differing effects of local versus spinal injection of botulinum toxin and lends new insights into the molecular-level explanations for how "Botox" works to affect pain processing.

Botulinum toxin is most familiar from the use of BoNT-A, commonly known by the trade name Botox, for cosmetic plastic surgery. Both BoNT-A and BoNT-B are used for treatment of various neuromuscular disorders.

Over the past decade, BoNT-A has been successfully used to treat certain chronic pain syndromes. Since botulinum toxin causes temporary muscle paralysis, the pain-reducing effects have been attributed to muscle relaxation. However, recent studies have suggested that other analgesic mechanisms may be operating as well.

Cellular-level studies showed that the two types of BoNT-B injection had differing effects in the pain-processing centers of the spinal cord. The results provided new insights into the specific molecular targets involved in local and intrathecal injection.

The study is published in Anesthesia & Analgesia.