Off-Label Use of Botox for Headache Common but Controversial

NEW ORLEANS—Although reports on the use of botulinum toxin type A (Botox) for refractory headache and a host of other conditions are suggestive and enticing, there is scant proper, evidence-based support for such off-label use, and the little that does exist is “shaky,” said Mark Stillman, MD, at the American Academy of Pain Medicine (AAPM) annual meeting.

Despite the scarcity of randomized controlled trials, some physicians are prescribing this product for the treatment of acute or chronic tension-type headaches, cervicogenic headaches, and chronic migraine headaches, said Dr Stillman, director of the Center for Headache and Pain at the Cleveland Clinic Foundation. Botox is also becoming a popular treatment for myofascial pain syndromes.

Dr Stillman cited 5 randomized, double-blind, placebo-controlled studies that have evaluated the use of botulinum toxin type A for chronic tension-type headaches, showing they produced contradictory results. In one study of 59 patients, no difference was found between injecting 20 units of this agent or placebo into frontal and temporal muscles in patients with chronic tension-type headache.

In another study of 41 patients who received injections into the pericranial muscles, 50 units of botulinum toxin did not decrease pain compared with placebo. Additional studies using larger doses reported mixed results for reductions in pain intensity and frequency. Dr Stillman said the body of literature on acute, tension-type headache is even smaller and more controversial.

Headache

But the use of these injections for migraine headache has been more rigorously studied. The strongest study of 123 patients (. 2000; 40:445-450) showed that a 25-unit dose of botulinum toxin was more effective than either a 75-unit dose or placebo in reducing migraine headache frequency and intensity.

However, Dr Stillman said that it is still unknown why the smaller dose was more beneficial. “More research is warranted,” he said.

Targeting Nerves Instead of Muscles

In another study presented at the meeting, Cleveland Clinic investigators presented data on a series of 6 patients with severe occipital neuralgia, which often produces severe headaches that are difficult to treat with either conservative or surgical approaches.

None of the 6 patients had responded to conservative therapies, such as antidepressants, membrane stabilizers, opiates, and traditional occipital nerve blocks. The patients underwent occipital nerve blocks using 50 units of botulinum toxin type A for each block (100 units if bilateral).

Significant improvements in visual analogue scale (VAS) and Pain Disability Index (PDI) scores were reported in 5 of the patients. Lead investigator Leonardo Kapural, MD, PhD, associate professor of anesthesiology in the Department of Pain Management, said the mean VAS score dropped from 8 to 2 (on a scale of 1 to 10), and the PDI improved from a mean of 51 to a mean of 19. The average duration of pain relief was 16.3 weeks.

IMWR

“We went after the nerve instead of the muscle,” Dr Kapural told . “Previously, the treatments for headaches placed the botulinum toxin diffusely over the back of the head for pain relief. What we did was go down to the nerve itself. We found that this could produce temporary pain relief for up to 4 months.”

Frederick Burgess, MD, PhD, president of the AAPM, and clinical associate professor of surgery at Brown University, Providence, RI, said that even though botulinum toxin type A is now being used for headaches at many facilities, no strong evidence shows long-term efficacy with any of the current approaches. He noted that one study showed that botulinum toxin injections were no better than saline solution injections (placebo) in patients with migraine headache.

IMWR

“It does have potential, but I think the view is a little muddy at present. There are no clear-cut data now that are totally convincing that botulinum toxin is effective in refractory headache syndromes,” Dr Burgess told .