13/03/2024
Migraine World Summit Day 7
Inflammation & Chronic Migraine - Gretchen E. Tietjen, MD
Dr Tietjen;
"We know inflammation occurs during a migraine, but is it the cause or is it an epiphenomenon? This is being debated by Neurologists, and so it should be."
You can see both sides of the debate in my previous posts on the talks from;
Dr Robert Cowan - CGRP (part of the inflammatory process) is released in response to pain'
Prof Peter Goadsby - One of CGRP's 'roles' is it is over expressed in migraine. A finding that has not consistently been reproduced and is reflected in the low numbers having complete relief, or 75% relief with CGRP targeted medications.
Dr Tietjen;
"Neurogenic inflammation, which is often what we are talking about with migraine, you get release of neuropeptides and other inflammatory mediators, and there we're talking about things like substance P, CGRP, Neurokinin A, PACAP from the peripheral nerve endings"
A good synopsis of neurogenic inflammation - that is inflammation coming from some kind of irritation of the nerve.
It does highlight one of the key questions about the origin of increased CGRP (itself a debatable subject) which is often ascribed to the trigeminal ganglion.
CGRP and substance P are both heavily expressed from the trigeminal ganglion when irritation is induced.
In the study by Prof Goadsby that really turbo-charged the CGRP industry, substance P was not found to be elevated.
Why? This question is important, and is one that is routinely ignored as it wrecks a good story.
Goadsby, P. J., Edvinsson, L., & Ekman, R. (1990). Vasoactive peptide release in the extracerebral circulation of humans during migraine headache. Annals of Neurology, 28(2), 183–187. https://doi.org/10.1002/ana.410280213
There are many 'truths' to migraine pathogenesis. Some do have elevated CGRP, but why not substance P - what model of inflammation describes that?
Others have increased substance P and PACAP and not CGRP. Why again?
What is causing these different inflammatory cascades, and if they are epiphenomenon, targeting them is like putting water on a fire. It may help put the fire out but does not stop the next fire from starting.
So far with CGRP medications this is exactly what we see - stop taking the medications and the fire starts again.
Terhart, M., Mecklenburg, J., Neeb, L., Overeem, L. H., Siebert, A., Steinicke, M., Raffaelli, B., & Reuter, U. (2021). Deterioration of headache impact and health-related quality of life in migraine patients after cessation of preventive treatment with CGRP(-receptor) antibodies. The Journal of Headache and Pain, 22(1), 158. https://doi.org/10.1186/s10194-021-01368-7
Great that Dr Tietjen is presenting a balanced talk - there are questions. Important questions.
Dr Robert Cowan's research is;
Cowan RP, Gross NB, Sweeney MD, Sagare AP, Montagne A, Arakaki X, Fonteh AN, Zlokovic BV, Pogoda JM, Harrington MG. Evidence that blood-CSF barrier transport, but not inflammatory biomarkers, change in migraine, while CSF sVCAM1 associates with migraine frequency and CSF fibrinogen. Headache. 2021 Mar;61(3):536-545. doi: 10.1111/head.14088. Epub 2021 Mar 16. PMID: 33724462; PMCID: PMC8023403.
Dr Tietjen;
That's probably the best data set for migraine that's come out so far, and they couldn't substantiate that (i.e. didn't find elevated inflammatory markers in chronic or episodic migraine).
"That was kind of a little disconcerting."
Only if all your eggs are in the trigemino-vascular inflammation basket.
Others might view it as a great finding helping to tease out sub-groups within migraine, such as those with upper cervical pain.
Just like inflammatory conditions, some will be relevant and thers not. Discovering the true depth of the impact on upper cervical dysfunction and whether or not it is relevant to your condition relies on assessment with clinicians who have vast experience in working with migraine in all its variants and presentations.
It is a complex puzzle and rarely do simple solutions work, or last. Look for expert care to help unravel each piece of the puzzle, including the cervical spine. Contact Melbourne Headache Centre today to see if we can help unravel a piece of your puzzle.
Interview Notes Gretchen E. Tietjen, MD American Headache Society Study: “Chemokine levels in the jugular venous blood of migraine without aura patients during attacks” Study: “Endogenous glucocorticoids may serve as biomarkers for migraine chronification” Study: “Diabetes is associated wi...