title: Neuropeptides as a Marker for Chronic Headache.
abstract: OBJECTIVE
  The purpose of this review is to revise current evidence on trigemino-vascular system (TVS) neuropeptides as potential biomarkers for chronic primary headaches, mainly for chronic migraine (CM).
  
  
  RESULTS
  Within sensory neuropeptides, released by an activated trigeminal nerve, calcitonin gene-related peptide (CGRP) levels seem to be a good biomarker of acute migraine and somewhat sensitive and specific for CM. CGRP, however, is not increased in 20-30% of CM patients, which suggests that CGRP is not the only neuropeptide involved in migraine pain generation and maintenance. Data for other sensory neuropeptides are inconsistent (neurokinin, substance P) or absent (amylin and cholecystokinin-8). Among parasympathetic neuropeptides, vasoactive intestinal polypeptide (VIP) is increased interictally in CM, and in at least some migraine cases ictally, pituitary adenylate cyclase-activating peptide (PACAP) has been shown to be increased ictally in jugular blood, but interictal, peripheral data do not indicate such an increase, and there are no data for other parasympathetic peptides. Finally, S100B, as a potential marker of glial TVS activation, has been studied with inconsistent results in migraine patients. Current data on TVS neuropeptides as potential migraine biomarkers must be taken with caution, even for the promising case of CGRP. We do not know with certainty whether increased levels are the reflection of TVS activation, the reliability and homogeneity of the different laboratory tests, or what is the influence on these measurements of the short half-life of many of these peptides or of preventive treatments. One further limitation would be whether the described increases in levels of some neuropeptides such as CGRP are specific for migraine versus other headaches.
authors.affiliation: Service of Neurology, University Hospital Central de Asturias, Oviedo, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Riesco
authors.affiliation: Service of Neurology, University Hospital Central de Asturias, Oviedo, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Cernuda-Morollón
authors.affiliation: Service of Neurology, University Hospital Marqués de Valdecilla and IDIVAL, Av. Valdecilla s/n, 39008, Santander, Spain. juliopascual@telefonica.net.
authors.forename: Julio
authors.initials: J
authors.lastname: Pascual
mesh_terms: D015415:Biomarkers / Q000097:blood*; D020773:Headache Disorders / Q000097:blood*; D006801:Humans; D009479:Neuropeptides / Q000097:blood*
chemical_list: D015415:Biomarkers; D009479:Neuropeptides
keywords: CGRP; Chronic migraine; Episodic migraine; PACAP; S100B; VIP