Predictors of chronic migraine
Recent data from a systematic review and meta-analysis point to clinical and sociodemographic factors associated with migraine chronification
INTERNATIONAL HEADACHE SOCIETY
London, UK: A meta-analysis published in the journal Cephalalgia, the official journal of the International Headache Society, highlights the predictors of chronic migraine. The study, entitled “Predictors of episodic migraine transformation to chronic migraine: A systematic review and meta-analysis of observational cohort studies”, was coordinated by Dr. Dawn Buse, from the Department of Neurology at Albert Einstein College of Medicine, New York, USA.
Chronic migraine is defined by the International Classification of Headache Disorders – ICHD-3 as having headaches for ? 15 days per month, for ? 3 months, which ? 8 days/month are linked to migraine. Several factors have been associated with migraine chronification, such as depression, anxiety, sleep disorders, obesity, other pain disorders comorbidities, allodynia, female sex, medication overuse, coffee, major life events, and low income. However, these studies are not devoid of biases and limitations that may underestimate or overestimate these factors.
In this meta-analysis, Dr. Dawn Buse and colleagues pointed out the main factors contributing to the evolution of episodic migraine to the chronic form. Excluding biases and poor-quality studies, Dr. Buse and her co-authors showed that, significantly, only the following factors were associated with chronic migraine:
Suffering from depression increases the chances of progressing to chronic migraine by 58 %. This is, in fact, a psychiatric comorbidity widely observed in many other migraine studies.
High Frequency of Attacks
Having ? 5 attacks per month increases 3.1 times, while ? 10 attacks per month lead to a 5.9-fold increase in the risk for chronic migraine. In fact, these findings raise a permanent debate surrounding the chronic migraine diagnostic criteria. In a comment also published in Cephalalgia (When Does Chronic Migraine Strike?), Dr. Patricia Pozo-Rosich, from the Headache Unit, Neurology Department, Vall d’Hebron University Hospital, Barcelona, Spain, underscores that from the functional and emotional disability perspective, patients with ? 10 attacks per month show no difference from chronic migraine patients. In this sense, Dr. Buse also affirms: “An average monthly headache day frequency of 10 days/month is usually considered high frequency episodic migraine, which looks in many ways similar to people with chronic migraine and may be managed in similar ways such as considering preventive therapy and behavioral therapies to treat or prevent poor outcomes in functional and emotional disability.”