[Pathophysiological role of calcitonin gene-related peptide (CGRP) in migraine and cluster headache]

Calcitonin gene-related peptide (CGRP) is released from trigeminal afferents during migraine and cluster headache attacks and can be detected in the jugular plasma. Infusion of CGRP can induce headache attacks in migraine and cluster patients. Inhibition of the CGRP signal system is therapeutic in migraine and cluster headache. CGRP is a potent dilator of intracranial arteries but does not immediately activate the trigeminal pain system. CGRP may act as a signal molecule between different cells in the trigeminal ganglion and enhances nociceptive transmission in the spinal trigeminal nucleus. Peripheral inhibition of the CGRP system reduces these actions. Outside the trigeminovascular system, CGRP is important for maintaining the perfusion of organs in critical situations, promotes growth and repair functions and is an immunomodulatory factor. These actions should be considered when the CGRP system is suppressed for a long time.