Conference Coverage
WASHINGTON, DC—Noncephalic pain is associated with a higher likelihood of progression from episodic migraine to chronic migraine, according to research presented at the 57th Annual Scientific Meeting of the American Headache Society.
The findings resulted from the Chronic Migraine Epidemiology and Outcomes (CaMEO) study, which was initiated in the fall of 2012. The prospective, Web-based investigation surveyed individuals with migraine and chronic migraine using cross-sectional modules embedded in a longitudinal design. The researchers used the survey’s Comorbidity/Endophenotype module to study 12,810 individuals with migraine, of whom 8,908 were randomized and completed the second assessment snapshot module three months after baseline.
Overall, 8,139 (91.4%) respondents had episodic migraine and 769 (8.6%) had chronic migraine, said Ann I. Scher, PhD, Deputy Director and Professor of Preventative Medicine and Biometrics at the Uniformed Services University of the Health Sciences in Bethesda, Maryland. At baseline, subjects were asked to identify noncephalic pain sites by location (ie, head, face, neck or shoulders, back, arms or hands, legs or feet, chest, abdomen or pelvis, or other), pain frequency, and pain intensity. Frequency was rated on a scale from 0, indicating “never,” to 4, indicating “always.” Intensity was rated on a scale from 0, indicating “no pain,” to 10, indicating “worst pain imaginable.”
At three months, the investigators followed up with patients to determine whether they still had either chronic or episodic migraine. They also performed multivariate binary regression analysis to determine whether the noncephalic pain sites were an indicator of progression from episodic to chronic migraine, based on the aforementioned factors as well as sociodemographic factors.
Subjects with episodic migraine at baseline tended to remain stable. In all, 278 (3.4%) patients with episodic migraine progressed to chronic migraine after three months. However, 385 (50.1%) of patients with chronic migraine at baseline were still classified as such after three months, meaning that nearly half transformed from chronic to episodic migraine. After the investigators adjusted for pain site scores and sociodemographic factors, regression models indicated that while noncephalic pain is common for both episodic and chronic migraine, the odds of progressing from episodic to chronic migraine increased by about 30% for each noncephalic pain site (odds ratio [OR], 1.30). For people with chronic migraine, the odds of remaining stable after three months increased by about 6% with each noncephalic pain site (OR, 1.06).
—Deepak Chitnis