Inhibition of trigeminal nociception may be impaired in individuals with migraine, according to a study published in Pain Medicine.
The study included adults with or without a history of migraine (n=23 and n=32, respectively) who underwent 4 electrocutaneous stimulations of the supraorbital branch of the left trigeminal nerve, which were delivered at 150% of individually determined pain thresholds. Conditioned pain modulation was evaluated by applying a noxious counterstimulus (ie, forearm ischemia) and delivering 4 additional electrocutaneous stimulations. Pain and the nociceptive blink reflex were assessed after each stimulation. In addition, depression and pain catastrophizing were evaluated to control for their possible influence on pain modulation.
Participants with and without migraine had comparable pain responsivity at baseline, with no significant differences in pain report or in nociceptive blink reflexes. Conditioned pain modulation was found to inhibit the pain report in individuals with and without migraine. Participants with migraine did not show an inhibition of nociceptive blink reflexes during the ischemia task, whereas participants without migraine did. The effect remained significant after controlling for pain catastrophizing and depression.
“This deficiency may be closely tied to the development of migraine headaches and may represent a risk factor for development of migraines,” noted the researchers.
Williams AE, Miller MM, Bartley EJ, McCabe KM, Kerr KL, Rhudy JL. Impairment of inhibition of trigeminal nociception via conditioned pain modulation in persons with migraine headaches [published online January 25, 2019]. Pain Med. doi:10.1093/pm/pny305