New Data on Botulinum Toxin as Treatment for Nerve Pain

According to a study recently published in the journal Anesthesia & Analegesia, botulinum toxin could serve as an effective new treatment for two forms of neuropathy. The study shows differing effects of local versus spinal injection of botulinum toxin and offers new insight into the molecular-level explanations for how “Botox” works to affect pain processing. Building on previous mouse-model studies, the researchers performed experiments in mice to evaluate the effects of botulinum toxin type B (BoNT-B) on exaggerated pain responses to touch (allodynia) in one or both hind paws after nerve injury. Mononeuropathy (single nerve injury) was induced by cutting a single spinal nerve and polyneuropathy (multiple nerve injury) by giving the chemotherapy drug cisplatin. For both types of neuropathy, the study evaluated the effects of injecting BoNT-B directly into the affected paw or into the spine. In mononeuropathy, injecting BoNT-B into the affected paw significantly reduced abnormal pain responses. In polyneuropathy, local BoNT-B injection reduced allodynia in the injected paw only. The reduction in allodynia after local BoNT-B injection lasted about two weeks before wearing off. That’s consistent with the temporary effect of botulinum toxin used for other purposes — the injections must be repeated to sustain the beneficial effects. “Further work focusing on transport and uptake of these and other BoNT serotypes will likely provide important insights into the mechanisms whereby these toxins exert their effects upon nociceptive [pain] processing.” To read more about this study, click here.