Will Botox Work For You? New Study May Provide a Clue
Ever since 2010, when the FDA approved Botox for the treatment of chronic migraine, migraineurs and/or our doctors have been eager to try it. (My neurologist, for instance, brings it up at every appointment, though at an $180 copay per treatment I’ve so far balked at the idea.) Many patients, including numerous Migraine.com readers and several of our contributors have experienced significant relief from the injections, some going from nearly daily migraines to as few as one every other week or so. Other patients, however, haven’t been so lucky.
For some migraineurs, Botox seems to do little or nothing. For a select few, it can even make matters worse by aggravating the neck muscles and/or triggering additional head pain. So, what’s a migraineur to do? Try or not try?
Researchers in Spain looked at the correlation between Botox response and two peptides that can be found in the blood: calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP). They recruited 81 adult patients with chronic migraine and 33 matched patients with no headache history. They then tested the CGRP and VIP levels of the participants prior to treating with Botox. They also measured the participants’ responses over the course of treatment.
The results of the study were striking, particularly when looking at CGRP levels.
Participants whose CGRP levels were above 72 pg/ml were 28 times more likely to respond positively to Botox treatment than participants whose CGRP levels were below 72 pg/ml. (Positive response, for the purposes of the study, was defined as an improvement of at least 33% in both the frequency of attacks and in a subjective analysis of a visual scale of 0-100.)
Though this certainly shows a correlation between CGRP levels and Botox responsiveness in chronic migraineurs in this study, readers should note it was a very small study. Therefore, additional researchers conducting their own studies will need to repeat and confirm the results before doctors will start using CGRP levels to determine whether to give a patient Botox. (If the results are confirmed, we’ll also need to wait for the CGRP test to become more widely available. At this point in time, only research laboratories can do it.)
For now, migraineurs who want to have some idea of whether or not Botox will work for them specifically may want to check out the research on pain directionality and Botox response.2
The gist of the pain directionality research seems to be that migraineurs who experience ocular/eye-popping pain and/or crushing, vice-like, or “imploding” pain seem to do better on Botox than migraineurs who experience exploding pain (i.e. pain that feels as though it is building up inside the head and then pushing out). Some migraineurs, however, may find it difficult to speak of their migraines in this way, and may therefore have little use for such a “test.” For these migraineurs (and I count myself among them), a blood test like the CGRP test may be particularly valuable.
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