SATURDAY, Oct. 13 (HealthDay News) -- Botox injections, long used to smooth away wrinkles, might also soothe chronic neck and shoulder muscle pain, new research suggests.

This type of persistent pain "is a common disorder that potentially may cause functional impairment in our patients," explained one expert not connected to the study, Dr. Robert Duarte. "In addition, neck pain may provoke headaches," said Duarte, who directs the Pain Center at the Cushing Neuroscience Institute, part of the North Shore-LIJ Health System in Great Neck, NY.

In the study, 118 patients with pain lasting more than two months who had already tried other pain medications were given injections of either botox (botulinum toxin type A) or a placebo.

Those who received botox had a much greater reduction in pain scores than those who received the placebo, according to a team from the University of California, Los Angeles.

The patients who received the botox injections also had a significant reduction in the number of headaches per week, and their headaches were less severe. They also had an overall improved quality of life because pain was less likely to interfere with general activity, sleep and enjoyment.

The study was scheduled for presentation Saturday at the annual meeting of the American Society of Anesthesiologists (ASA).

The researchers said their findings suggest that botox may be an option for people with chronic neck and shoulder pain (myofascial pain syndrome) that hasn't been relieved with traditional therapies, such as anti-inflammatory drugs, steroids and muscle relaxants, physical therapy and behavioral modification.

"At best, long-term benefit with traditional therapies is transient and unpredictable. Even with these treatments, some people with myofascial pain syndrome get incomplete benefit or no benefit at all," study author Dr. Andrea Nicol, director of research at the UCLA Pain Management Center, said in an ASA news release.

Along with its use to smooth out frown lines and wrinkles, botox is being tested as a treatment for other conditions, including bladder leakage, or urinary incontinence. Researchers are also using botox to treat a number of painful conditions, including migraine headaches.

"Botox is in a class of medications called neurotoxins and when injected into muscles, blocks the nerve signals that cause the tightening of muscle, leading to muscle relaxation. Thus, botox may offer advantages over traditional therapies for myofascial pain syndrome due to its prolonged and sustained effects," Nicol said.

Duarte said that "in patients complaining of persistent neck pain who have failed these therapies, botox may prove to be helpful. In my own practice, I have seen patients respond to such a treatment. More studies, however, are needed."

Another expert agreed. "Botox injections may play a role for those patients who have failed more traditional treatment protocols," said Dr. Victor Khabie, chief of the department of surgery and co-director of the Orthopedic and Spine Institute at Northern Westchester Hospital in Mount Kisco, N.Y. "Although the preliminary data looks promising, more studies are needed to investigate the efficacy and safety of botox injections in patients with chronic cervical conditions," he added.

Findings presented at medical meetings are typically considered preliminary until published in a peer-reviewed journal.

More information

The American Academy of Physical Rehabilitation and Medicine has more about neck pain.