Pharmacologic Treatment for Migraine Prevention in Adults Practice Guideline Recommendations

Dr. Tesha Monteith talks with Dr. Tamara Pringsheim about the updated American Academy of Neurology (AAN) and American Headache Society (AHS) guidelines on pharmacologic treatment for migraine prevention in adults. 

Read the related article in Neurology ® .

Disclosures can be found at Neurology.org. 

Show transcript: 

Dr. Jose Merino (00:08):
This is Jose Merino, editor-in-chief of the Neurology Family of Journals. The Neurology Podcast provides practical information to neurologists and other clinicians to help them provide better care for their patients. Thanks for listening and have a great week.

Dr. Tesha Monteith (00:23):
Hi, this is Tesha Monteith with the Neurology Podcast. I'm excited to talk to you today about the update in Migraine Guideline: Pharmacologic Treatment for Migraine Prevention in Adults: Practice Guideline Recommendations, a report of the American Academy Neurology Guidelines Subcommittee, and the American Headache Society. Since the last guideline in 2012, there's been a lot of new advances, including the introduction of CGRP inhibitors for acute and preventive treatment.

(00:53):
With me to discuss is the lead author, Tamara Pringsheim, a neurologist at the Department of Clinical Neurosciences, Psychiatry, Pediatrics, and Community Health Sciences at the University of Calgary. How are you, Tamara?

Dr. Tamara Pringsheim (01:06):
Great. Thank you for asking me to talk to you about this.

Dr. Tesha Monteith (01:09):
Why don't you tell me a little bit about yourself and how you got involved in this work?

Dr. Tamara Pringsheim (01:14):
Sure. I've been working as a methodologist for the American Academy of Neurology Guidelines Subcommittee for a number of years, since 2015. Prior to that, I was a member of the guideline development subcommittee from 2011. I've worked on a number of different guidelines across neurological conditions.

Dr. Tesha Monteith (01:36):
Great. So how do these new guidelines compare, just broadly speaking, with the older guidelines?

Dr. Tamara Pringsheim (01:43):
I guess since the last guidelines were published more than 10 years ago, we've had changes to our methodological process. We had a major update to our guideline process manual in 2017, and guideline methodology has continued to evolve over that time period. And as well, a number of targeted treatments for migraine have come out. So there's been an explosion of evidence, particularly in the last five to seven years. And so we have a whole new class of medications available for migraine prevention, which really target our underlying understanding of the condition, whereas most of the other medications were discovered through serendipity.

Dr. Tesha Monteith (02:33):
So I know that you reviewed over 200 randomized controlled trials. And so how was the quality or confidence of the evidence determined?

Dr. Tamara Pringsheim (02:47):
With our process, we start by rating risk of bias for every article. This basically gets at a number of different features related to the clinical trial methodology and reporting, and it helps us determine how confident we are in the evidence. In order for us to be highly confident that the results that we are seeing reflect the truth, we typically need to have at least two Class 1 studies for any intervention outcome pair. The effect size estimate also has to meet a certain threshold in terms of the effect size and the precision surrounding that estimate. So if we feel that based on what the panel decides in terms of what is the minimal clinically important difference between an intervention and placebo, that will help us determine our confidence in the evidence.

(03:51):
So there's this critical coming together of the number of studies, the quality of studies, the effect size, and the precision of the evidence that helps us determine our confidence in the evidence. And all of this is done behind the scenes using a very algorithmic approach so that these rules are faithfully applied across the different interventions we're looking at. This complexity makes it hard for people to understand why certain drugs land in a certain area, but it's one of the things that we do to make this process standardized and rigorous.

Dr. Tesha Monteith (04:37):
So I do want to talk to you about that, where drugs have landed. One newer thing was that the review was not just episodic migraine, but also chronic migraine.

Dr. Tamara Pringsheim (04:47):
Yes.

Dr. Tesha Monteith (04:48):
Were there important differences in the strength of evidence between these populations?

Dr. Tamara Pringsheim (04:53):
One thing that's really important to remember is that the use of the term chronic migraine is fairly new. So a lot of the trials of the older headache preventive medications were done in the 80s and the 90s. And at this time, there wasn't a definition which distinguished chronic migraine in particular. So a lot of the trials for amitriptyline, for example, were not done in a purely episodic or chronic migraine population. And so this really contrasts with the newer studies where these populations were well-defined. And so we're going to have higher quality evidence or evidence specifically for chronic migraine with the new drugs, whereas for the old drugs, we won't have that.

Dr. Tesha Monteith (05:50):
Let's get into the preventive treatments that had the strongest level of evidence for episodic migraine.

Dr. Tamara Pringsheim (05:57):
We had high confidence in the evidence for two of the CGRP medications, erenumab and galcanezumab. Again, these high confi