Low plasma levels of calcitonin gene-related peptide in persistent post-traumatic headache attributed to mild traumatic brain injury
Håkan Ashina, Haidar M. Al‐Khazali, Afrim Iljazi, Sait Ashina, Niklas Rye Jørgensen, Faisal Mohammad Amin, Messoud Ashina, Henrik Winther Schytz
Abstract
Objective To investigate the role of calcitonin gene-related peptide (CGRP) in persistent post-traumatic headache (PTH) attributed to mild traumatic brain injury (TBI). Methods A total of 100 individuals with persistent PTH attributed to mild TBI and 100 age- and gender-matched healthy controls were enrolled between July 2018 and June 2019. Blood was drawn from the antecubital vein and subsequently analyzed using a validated radioimmunoassay for human CGRP. Measurements were performed on coded samples by a board-certified laboratory technician who was blind to clinical information. Results CGRP plasma levels were lower in subjects with persistent PTH (mean, 75.8 pmol/L; SD, 26.4 pmol/L), compared with age- and gender-matched healthy controls (mean, 88.0 pmol/L; SD, 34.1 pmol/L) ( p = 0.04). No correlation was found of CGRP plasma levels with monthly headache days ( r = −0.11; p = 0.27), monthly migraine-like days ( r = 0.15; p = 0.13), headache quality ( r = −0.14; p = 0.15), or a chronic migraine-like headache phenotype ( r = −0.02; p = 0.85). Conclusions CGRP plasma measurements are unlikely a feasible blood-based biomarker of persistent PTH. Future studies should assess whether CGRP plasma measurements can be used to predict development of persistent PTH.