The Neck: A Pain Generator for the Head

Abstract

191 ISSN 1758-1869 10.2217/PMT.12.10 © 2012 Future Medicine Ltd Pain Manage. (2012) 2(3), 191–194 Headache arising from cervical spine pathologies remains one of the most debated areas in headache medicine. The absence of a clear distinction between migraine and cervicogenic headache (CEH), as well as the lack of ‘diagnostic markers’ for CEH are among the main reasons [1]. One important biological marker for migraine is a focal increase in CGRP [2]. CGRP measurements performed in patients with CEH showed no detectable trigeminovascular activation and it is most likely that CEH is biologically different from migraine and not just a migraine variant triggered by neck dysfunction [3]. The following paragraphs discuss the rationale of the neck being a valid pain generator for the head from the basis of neurophysiological pathways, topographical pain mapping experiments and treatment observations, and also highlights the important facilitatory role of the lower cervical segments. Potential nociceptive structures in the neck The weight of the head and the mobility of the neck are key factors in the susceptibility of the cervical spine to injury. Even in younger patients, the presence of degenerative changes in the cervical spine, although often asymptomatic, highlights the amount of mechanical load placed on the neck. Many structures in the neck have a rich nociceptive neural network. These include structures such as the zygapophysial joints, intervertebral discs, ligaments, muscles, as well as the overlying skin. Of these, the zygapophysial joints and the intervertebral discs appear to be the most important pain generators [1]. Furthermore, clinical studies have also revealed that the zygapophysial joints are the most likely to be injured following whiplash injuries [4]. In addition, biomechanical data also point towards an increased likelihood of injury