Botulinum toxin A injections don’t provide much relief for patients with chronic migraine headaches and chronic daily headaches, a new study shows.

And these injections were no better than placebo for preventing episodic migraine or chronic tension-type headache. The findings appear in the April 25 issue of the Journal of the American Medical Association.

Researchers led by Jeffrey L. Jackson, MD, MPH, of the Medical College of Wisconsin in Milwaukee, assessed the efficacy of botulinum toxin A for headache frequency when used for preventive treatment of migraine, tension, or chronic daily headaches in adults.

For the study, headaches were categorized as episodic (less than 15 headaches per month) or chronic migraine and episodic or chronic tension headaches. The researchers identified 27 randomized placebo-controlled trials of 5,313 study participants and 4 randomized comparisons with other medications that met study inclusion criteria.

According to pooled analyses, botulinum toxin A was associated with about two fewer headaches per month among patients with chronic daily and chronic migraine headaches.

These injections did nor reduce the number of episodic migraine or chronic tension-type headache, the study showed.

Compared with placebo, botulinum toxin A was associated with a greater frequency of blepharoptosis, skin tightness, paresthesia, neck stiffness, muscle weakness, and neck pain.

[Source: Journal of the American Medical Association]