Predicting Botox Response for Chronic Migraine

When a patient asks if Botox will help them, the usual response is along the lines of, “Quite possibly, but you’ll have to try it to find out.” A patient’s blood levels of calcitonin gene-related peptide (CGRP) could predict whether a person with chronic migraine will respond to Botox, according to a study published in the journal Headache‘s June edition.

Researchers believe that a patient’s CGRP levels could predict whether Botox will be effective with 95% accuracy. In their study of 81 chronic migraineurs, those who had a CGRP level above a certain threshold were 28 times more likely to respond to Botox than those with CGRP levels below that threshold. (If CGRP sounds familiar, it’s probably because the research findings on migraine prevention drugs that made the news this spring are CGRP antibodies.) This is only one study and it was small. More studies will need to investigate and confirm a connection between Botox response and CGRP before doctors will begin checking CGRP levels before giving a patient Botox.

In the meantime, if you’re looking to figure out if Botox will help you, something called pain directionality is the best current predictor. Pain directionality is whether your pain feels like it is exploding, imploding or ocular. People with imploding or ocular pain are more likely to find relief from Botox than those with exploding pain.

Multiple studies have explored the connection between pain directionality and Botox response; here’s one you can read for free. However, headache specialist Alexander Mauskop warns that pain directionality “is not a very reliable predictor because some people have difficulty categorizing their pain in that way and because even if they do describe it clearly one way or another, this predictor is far from 100% accurate.”