High-Frequency Episodic Migraine is Similar to Chronic Migraine

By Kerrie Smyres

2 min read

“The emotional and functional impact in high-frequency episodic patients could be as disabling as in those with chronic migraine.” This comes from a study just published in the journal Cephalalgia this spring. Researchers looked at the somewhat arbitrary division of migraine into chronic and episodic and found high-frequency episodic migraine has more in common with chronic migraine than it does with low-frequency episodic migraine.

Low- versus high-frequency episodic migraine

The study looked at charts of 855 people with episodic migraine and 254 with chronic migraine. The group with episodic migraine were split into two categories based on headache frequency:

Low-frequency episodic migraine was 1-9 headache days a month.
High-frequency was 10-14 headache days a month.

(Patients usually talk about migraine days, but researchers use headache days. It is partly because it includes all headaches a person has in a month, whether or not the headache is obviously part of a migraine attack.)

What were the research results?

Researchers found:

Migraine attack characteristics in high-frequency episodic migraine have more in common with chronic migraine than low-frequency episodic migraine.
Levels of physical and emotional disability are similar in people with high-frequency episodic migraine and chronic migraine.
Treatments that are currently reserved for chronic migraine, like Botox, should be available to people with high-frequency episodic migraine.

This particular study classified migraine frequency in three categories: low- and high-frequency episodic migraine and chronic migraine.

The impact of frequency

The study looked at the impact of migraine frequency on 57 different variables, including specific symptoms like phonophobia and photophobia, dizziness and allodynia; pain characteristics; insomnia; psychiatric comorbidities; frequency of medication use; degree of disability; and whether preventive treatment was effective.

What were the differences?

Overall, episodic migraine and chronic migraine were significantly different. However, when episodic migraine was broken into low-frequency and high-frequency, high-frequency episodic migraine had more than twice as many variables in common with chronic migraine than with episodic migraine. Some differences between high-frequency episodic migraine and chronic migraine included attack intensity, psychiatric comorbidities, and analgesic use.

What about disability?

Importantly, researchers found no significant differences in the variables that evaluated emotional and function disability between high-frequency episodic migraine and chronic migraine. It led the researchers to conclude that perhaps 15 headache days a month may not be the appropriate cutoff for classifying chronic migraine and that people with high-frequency episodic migraine may need different treatments than they are currently offered.

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tammy-lrome Member
Thank you Kerrie, for writing this. High-frequency episodic is my baseline since age 5 yet my attack frequency and disability were not taken seriously until age 30 when I became chronic on a technicality -- a new and completely separate headache disorder. I used the results of a similar study as supporting evidence for my disability application. 10-12 attacks per month will wear you down just like 15+.
sismo Member
This makes so much sense to me, because when you are under full treatment as a chronic migraineur and your frequency is reduced to 10-14, while better, your lifestyle is still amazingly similar to before (at least in my experience). It took a really drastic reduction (5-6 per month total, regularly) until I really felt different. I don't know if I stopped at the "9" threshold on the way down, thankfully. At this level, I feel like myself. At the chronic level, I feel like a different person, or at best,a different version of myself.
bread Member
Thank you, Kerrie, for passing along a synopsis of this recent study. I'm very interested in reading the complete article. I've searched the online table of contents for each of Cephalgia's 2016 issues and couldn't see anything that sounded like the study you are referencing. Could you please provide the title, authors and/or month/year the article is published in? I'm an RN and can access the journal through work. Thanks!
1. Kerrie Smyres Moderator & Contributor
 Here's the reference: Torres-Ferrús, M.; Quintana, M.; Fernandez-Morales, J.; Alvarez-Sabin, J.; & Pozo-Rosich, R. (2016). When Does Chronic Migraine Strike? A Clinical Comparison of Migraine According to the Headache Days Suffered Per Month. Cephalalgia, first published on March 8, 2016 as doi:10.1177/0333102416636055 It might have been an early view article (published on the website before appearing in a print publication). Kerrie
2. Joanna Bodner Community Admin
 Hi there b.read, Here is the reference you are looking for: Torres-Ferrús, M.; Quintana, M.; Fernandez-Morales, J.; Alvarez-Sabin, J.; & Pozo-Rosich, R. (2016). When Does Chronic Migraine Strike? A Clinical Comparison of Migraine According to the Headache Days Suffered Per Month. Cephalalgia, first published on March 8, 2016 Hope this helps, but please let us know if you need any additional information! Joanna (Migraine.com Team)
bread Member
Thank you so much, Kerrie and Joanna, for the speedy reply and information. I just looked again in the March table of contents and there it was hiding in plain view--highlighted in a big grey box--right at the top of the list. I can't even blame a migraine on missing it...just a plain old headache from being on the computer a little too long. I see it is a free full text so I can access it from home. Thanks again!!