Biological sciences related to headache

Headache can occur as a result of activation of pain-sensitive cranial structures, such as the dura mater, vasculature, and the cranial and cervical muscles and ligaments, which are innervated by primary afferent neurons originating from the trigeminal and dorsal root ganglia of the upper cervical spinal nerves. Similar to general nociceptive sensation, C fibers and Aδ fibers are known to play an important role in headache perception. Findings from nerve stimulation studies indicate that C fibers transmit aching, throbbing, or burning pain that builds up slowly, whereas the Aδ fibers conduct sharper initial pain sensation. These primary afferent nerve fibers transmit nociceptive information from the pain-sensitive endings in the cranial structures through the trigeminal and first and second spinal dorsal root ganglia to the brainstem at the pontine level. The nociceptive fibers then project to the central pain-conducting pathways at the spinal trigeminal nucleus. In this chapter, we discuss the anatomy in relation to headache, including the meninges, dural sinuses, blood vessels, sensory ganglia, cranial and neck muscles, and the central pain-conducting pathways.