Spinal Botox reduces pain in mice

Seoul, South Korea - Botulinum neurotoxin type A (BoNT/A; onabotulinumtoxinA, Botox, Allergan) reduces responses to an inflammation-related pain stimulus when injected into the spinal canal in mice, according to a new study reported by Newswise.com.

Researchers from Seoul National University injected formalin into the paws of mice to produce a predictable, two-phase inflammatory pain response. Some mice received spinal BoNT/A; others did not. Pain behaviors were monitored for up to four weeks in both groups.

Even a single BoNT/A spinal injection produced significantly fewer pain behaviors in the injected mice, particularly during the second phase of the pain response. These effects were not accompanied by any movement abnormalities, which suggests that BoNT/A had no adverse effects on spinal-cord function.

The pain-reducing effect of a single BoNT/A injection peaked at 10 days, then decreased up to 14 days. BoNT/A-injected mice also experienced significant reductions in certain neurotransmitters involved in various types of pain conditions.

Newswise.com quotes lead author Won-Ho Lee, M.S.D., Ph.D., as saying, “BoNT/A, with its long-lasting antinociceptive effect, may be a useful analgesic in inflammatory pain.”

Investigators say more research will be needed to further explore the effects of such injections and the potential uses of spinal Botulinum neurotoxin injections for specific types of pain in humans.

The study appears in the January issue of Anesthesia & Analgesia, the official journal of the International Anesthesia Research Society (IARS).