CONy 2021 | Post-traumatic headache: just migraine uncovered by trauma?

I’m currently the president of the Israeli Headache Society, and until recently I was a co-chair for CONy Headache Section with Professor Alan Rapoport. Actually, I would like to present the highlights of the Headache Session of CONy 2021, that is being held virtually as we speak, and I’ve picked up three debates that I would like to summarize. The first debate is the one that I was taking part in, post-traumatic migraine it’s just migraine uncovered by trauma. And the reason for this is that numerous factors that may contribute to the development of post-traumatic headache include axonal injury, alteration in cerebral metabolism, neuro-inflammation alterations, hemodynamics, underlying genetic disposition, psychopathology. And of course a patient’s expectation of developing headache after had injury and litigations considerations in mind. All of this make a post-traumatic headache very confusing and unclear. And interestingly, the incidence of a persistent post-traumatic headache is inversely related to the degree of traumatic brain injury. Post-traumatic headache is found in 58% of patients with mild traumatic brain injury, 12 months after the initial injury, versus only 33% of patients with moderate to severe traumatic brain injury.

Acute post-traumatic headache may last up to three months, and if longer, symptoms are termed chronic or persistent post-traumatic headache. And other typical symptoms such as sleep disturbances, motor disturbances and psychosocial stressors can influence and contribute to the persistence of headache after head injury. So I presented data that I try to convince the audience that post-traumatic migraine it’s just migraine uncovered by trauma. As most post-traumatic headaches are indistinguishable from descriptions of primary headaches, I show that military post-traumatic headache meets the criteria for migraine in the majority of cases, ranging from 60% to 97%. And that traumatic brain injury and migraine have shared pathophysiological pathways. Changes in glutamine levels, nitric oxide release, plasma levels of CGRP, Substance P, serotonergic system, and the most compelling proof is that there are many reports of successful treatment of post-traumatic headache with triptans after mild traumatic brain injury.

Triptan medications were the most frequently used medications in post-traumatic headache cases, and that 70% of post-traumatic headache subjects who used triptans reported reliable headache relief within two hours. On the other side of the debate, my colleague Håkan Ashina showed that post-traumatic headache can resemble other headache phenotypes, most often tension-type headache and rarely, cluster headache. And that there is an inherent bias when we categorize post-traumatic headache with migraine because nausea, photophobia, phonophobia are also common complications following head trauma, and they may therefore be unrelated to headache. Secondly, neural imaging data had shown that post-traumatic headache defers from migraine in terms of brain structure and function, and that hyposensitivity to CGRP is less pronounced in post-traumatic headache compared with migraine. And this is also explains, according to Håkan Ashina, why CGRP therapies are less effective in post-traumatic headache compared with migraine. So this is the debate on post-traumatic migraine.