Botulinum Toxin for Headache: a Comprehensive Review

Purpose of ReviewHeadache disorders are among the most prevalent disorders of mankind. They incur huge costs in terms of disability, days loss to work, and quality of life. In recent years, usage of botulinum toxin (BTX-A) has been extended to the management of various headaches. This review sets out to examine the evidence and role of BTX-A in the different headache disorders.Recent FindingsBTX-A is effective in reducing the frequency of chronic migraine days per month, with statistically significant improvement in quality of life. No difference was seen in patients with episodic migraine. The evidence of BTX-A on tension-type headache, cluster headache, and trigeminal neuralgia is emerging, but high quality large-scale studies are lacking at present. The mechanism of action of BTX-A on headaches is found to be independent of its effect on muscle contraction, where BTX-A is found to have direct anti-nociceptive effect on sensory nerves.SummaryBTX-A should be considered in the most refractory forms of chronic headaches. However, more RCTs are required in the future for higher-quality evidence and to guide injection sites and doses.