Efficacy of Anti-IL-6 Treatments on Migraine in Patients Treated With Anti-IL-6 for a Rheumatological Condition

Migraine affects approximately 15% of the global population. Its prevalence doubles or even triples in individuals with chronic inflammatory conditions, such as chronic inflammatory rheumatic diseases (34%), multiple sclerosis (MS) (46%), or endometriosis (35%). The prevalence of chronic migraine - defined as at least 15 headache days per month (on average over the past 3 months), of which at least 8 days have migrainous features - is also higher in certain conditions such as MS (4%) compared to the general population (1%). The mechanisms underlying migraine and its chronification remain uncertain, but inflammation appears to play an important role in its pathophysiology: it is present from the onset of a migraine attack, represented by the release of pro-inflammatory cytokines that sensitize the trigeminal system and promote the occurrence of new attacks. The investigators' recent bibliographic work has demonstrated elevated levels of interleukin-6 (IL-6), a pro-inflammatory cytokine, in the blood of episodic migraine patients between attacks (migrainous status) compared to non-migrainous subjects, and in chronic migraine patients compared to episodic migraine patients (chronic migraine status). IL-6 appears to play a role in the pathophysiology of migraine, and elevated levels may represent a marker of poorer response to prophylactic treatments. IL-6 levels are also elevated in inflammatory rheumatic diseases and are associated with disease severity. The efficacy of IL-6 pathway-blocking treatments in inflammatory rheumatic diseases is now well established, and these agents are commonly used for this indication. IL-6 could therefore represent a shared pathophysiological link between migraine and inflammatory rheumatic diseases. However, no study to date has measured the effect of IL-6-blocking treatments on migraine. This study therefore aims to assess the effect of anti-IL-6 treatments on migraine in migrainous patients followed in the rheumatology department of the Clermont-Ferrand University Hospital and treated with anti-IL-6 therapy for their rheumatological condition (rheumatoid arthritis, polymyalgia rheumatica, etc.). It will provide preliminary results regarding the effect of anti-IL-6 agents on migraine and could justify future therapeutic studies.