Botulinum toxin injection for cervicogenic headache.

We report a 28-year-old woman with a 5-year history of cervicogenic headache following a whiplash injury. Her unilateral neck pain, if aggravated by exertion, would create a predictable sequence of events leading to a hemicephalgia. She proved medically refractory to usual therapies, but had a striking response to a single botulinum toxin Injection in her symptomatic trapezius muscle. Repeated Injections every 3 months have been required to maintain this benefit. The Implications of this observation are discussed.