Clinical differences between menstrual migraine and nonmenstrual migraine: a systematic review and meta-analysis of observational studies.

ABSTRACT

BACKGROUND AND PURPOSE: Approximately 60% of female migraineurs experience menstrual migraine (MM). Whether MM is a distinct clinical entity with more severe migraine attacks and a worse prognosis than nonmenstrual migraine (nMM) is still under debate. We conducted a systematic review and meta-analysis to investigate clinical differences between MM and nMM patients. METHODS: A systematic literature search was performed to identify observational studies comparing MM and nMM patients' clinical characteristics. Quality of evidence grades of the synthesized effect estimates for each outcome were determined following the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines. RESULTS: Of 1837 identified studies, 16 were eligible for inclusion. MM patients had more migraine attacks per month (MD 0.65, 95% CI 0.05-1.24) than nMM patients; however, the quality of evidence was "low" according to the GRADE assessment. They also had more headache days (MD 0.86, 95% CI 0.12-1.60) per month, a higher rate of family history of migraine (OR 1.41 95% CI 1.12-1.78), migraine aggravation with physical activity (OR 1.60, 95% CI 1.35-1.89), a younger age at migraine onset (MD - 0.99, 95% CI - 1.78 to - 0.19), and a higher risk of accompanying symptoms (OR 2.31, 95% CI 1.72-3.10) than nMM patients; however, the quality of evidence was "very low". CONCLUSIONS: There were differences between MM and nMM, showing that MM patients have a worse profile than nMM patients, but the quality of evidence is too low to draw definite conclusions on the separation/unification of the two clinical entities.