The anatomical basis for cervicogenic headache.

The neuroanatomical basis for cervicogenic headache is convergence in the trigeminocervical nucleus between nociceptive afferents from the field of the trigeminal nerve and the receptive fields of the first three cervical nerves. Only structures innervated by C1-C3 have been shown to be capable of causing headache. These are the muscles, joints and ligaments of the upper three cervical segments, but also include the dura mater of the spinal cord and posterior cranial fossa and the vertebral artery.