EXPRESS: Assessment of Pain-Related Biomarkers in Migraine and Tension Headache Patients Pre- and Post-Botulinum Toxin Therapy.

This study aimed to evaluate the therapeutic impact of Onabotulinumtoxin A (botulinum toxin) injections in patients suffering from chronic migraine and chronic tension-type headache, while assessing changes in salivary pain biomarkers-calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP). A total of 45 subjects were recruited: 25 diagnosed with chronic migraine and 20 with chronic tension-type headache, based on criteria from the International Classification of Headache Disorders (ICHD-3 and ICHD-2 revisions, respectively). Diagnosis confirmation was supported by MRI or CT imaging to exclude other etiologies. Salivary CGRP and PACAP levels were measured before and after botulinum toxin administration using enzyme-linked immunosorbent assay (ELISA). In this open-label, uncontrolled design, results showed a statistically significant reduction (p < 0.05) in both biomarkers post-treatment across both patient groups. Onabotulinumtoxin A demonstrated apparent effectiveness as a prophylactic therapy, contributing to notable improvement in headache symptoms. Among all clinical parameters evaluated, orofacial pain showed the highest responsiveness to treatment.