Johns Hopkins researchers have found that patients with a painful and debilitating nerve compression disorder called thoracic outlet syndrome (TOS), which studies suggest may occur in up to 8% of the population, reported a significant reduction in short-term pain after receiving a single, low-dose injection of Botox in a muscle located in the neck.
Though the study, published in the April issue of the journal Pain Medicine, was small, researchers say it suggests Botox is a safe, noninvasive alternative to the syndrome’s treatment of last resort: surgery to remove the first rib and sever one of the muscles in the neck.
“There have not been many alternatives to the use of surgery to treat this syndrome,” says Paul J Christo. “Botox seems to be an effective treatment that avoids surgery’s obvious drawbacks, such as its invasive nature and long recovery time.”
Christo says his latest work significantly improves on previous studies in which TOS sufferers received several Botox injections or injections were made more blindly, without the aid of a CT scan.
Christo and his colleagues evaluated 27 patients who were candidates for surgery to treat their TOS and for whom physical therapy and anti-inflammatory medications failed to help. Each was given a 20-unit injection of Botox, a brand-name drug that contains botulinum toxin. Christo used a CT scanner to guide the placement of the needle in the patient’s anterior scalene muscle in the neck. Each session lasted around one minute, requiring minimal radiation, he says.
Patients experienced a significant decrease in pain in each of the first two months after the injection. At three months, patients still felt a 29% decrease in their TOS-related pain as measured on a scientific pain scale.
“This modest amount of pain reduction can have a significant impact on a patient’s life,” says Christo, a pain medicine specialist. “For many, it allows them to do what they could not do before, brush their hair, brush their teeth, and hold their child.”
Christo says the Botox works to temporarily relieve the pain of TOS in many patients because its paralysing function decreases the tension and spasms of the muscle, relieving pressure on the nerves as more room is made for them to pass through the thoracic outlet. He says the drug may also decrease pain by reducing the number of neurotransmitters that notify the brain that the body is in pain. Though the study just looked at pain, Christo says some patients appeared to also have increased arm and shoulder function as a result of the Botox injections.
The effects of the drug begin to wear off in a few months, as they do when Botox is injected into facial wrinkles. Christo says patients should be able to receive repeated injections of Botox into the muscle over time, though some could develop antibodies to the compound with excessive use, which would mean the toxin would no longer block pain. In the study, 48% of patients went on to have surgery.