Chronic Migraine Defined (A Correction)

In All Migraineurs Are Different — So Stop Judging Me!, I wrote “…losing two days a week to migraine does not meet the clinical definition of chronic migraine, which is 15 or more migraine days a month.” Leora delicately pointed out that this is incorrect. Chronic migraine is actually defined as 15 or more headache days a month, eight of which are migraine. That’s my summary at least.

Verbatim, the current criteria for chronic migraine according to the International Headache Society follows. I’ve left out the footnotes; check the link for details.

A)    Headache (tension-type and/or migraine) on ≥15 days per month for at least 3 months*

B)     Occurring in a patient who has had at least five attacks fulfilling criteria for 1.1 Migraine without aura

C)    On ≥8 days per month for at least 3 months headache has fulfilled C1 and/or C2 below, that is, has fulfilled criteria for pain and associated symptoms of migraine without aura

1)     Has at least two of a-d

a)      unilateral location

b)     pulsating quality

c)      moderate or severe pain intensity

d)      aggravation by or causing avoidance of routine physical activity (e.g. walking or climbing stairs)

and at least one of a or b

a)      nausea and/or vomiting

b)     photophobia and phonophobia

2)     Treated and relieved by triptan(s) or ergot before the expected development of C1 above

D)    No medication overuse† and not attributed to another causative disorder‡

I’m not sure if my initial statement was outdated or just outright wrong, but it doesn’t really matter. I appreciate readers who are willing to point out my mistakes without calling me an idiot! Thanks, Leora.