Inflammation in Migraine…or Not…: A Critical Evaluation of the Evidence

Andrew Charles MD; Sinifunanya E. Nwaobi MD, PhD; Peter Goadsby MD, PhD

Disclosures

Headache. 2021;61(10):1575-1578. 

In This Article

Inflammation and Chronicity

Migraine is an episodic disorder that may increase in frequency over time. The hypothesis that migraine attacks primarily involve inflammation requires that inflammatory processes are activated spontaneously and last 4–72 h (or that inflammation can be present in the absence of clinical symptoms). The inflammation hypothesis also implies that rapid response to acute migraine therapies is either due to rapidly reduced inflammation or that symptoms may resolve in the face of persistent inflammation. Some have proposed that although inflammation is not required for acute attacks, it may be involved in the "chronification" of migraine over time.[34] Aside from pain, however, even with chronic migraine, there are no clinical or imaging indicators of chronic inflammation. Furthermore, levels of inflammatory substances are not consistently increased in chronic migraine.[22] Acute or chronic inflammation could play a role in secondary headache caused by infection, injury, or autoimmune disease and could also be involved in the exacerbation of migraine in these clinical settings. Such secondary exacerbation of a primary headache does not necessarily indicate, however, that inflammation is a primary mechanism for the primary headache disorder.

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