Clinical characteristics of pure menstrual migraine and menstrually-related migraine: a cross-sectional online questionnaire study.

backgroundMigraine is a highly prevalent neurological disorder which is more common in women. Clinically, there are two subtypes of menstrual migraine, including pure menstrual migraine (PMM) and menstrually-related migraine (MRM). The former experiences migraine attacks only during the perimenstrual period, while the latter experiences migraine attacks during the perimenstrual period and at other times of the menstrual cycle. MRM accounts for 20-25% of female cases and is associated with greater severity and disability. Although hormonal fluctuations are implicated, the pathophysiology of these subtypes remains poorly understood, and treatment options are limited. Whether PMM and MRM differ clinically or in treatment response has not been systematically compared. This study compared their clinical characteristics and acute treatment responses, which may offer insights into menstrual migraine pathophysiology and help with precise treatment.

methodsA cross-sectional study was conducted among 430 female migraine patients recruited from the Headache Specialty Clinic of the First Affiliated Hospital of Soochow University using electronic questionnaires. According to the International Classification of Headache Disorders, 3rd edition (ICHD-3) criteria, participants were divided into PMM (n = 43) and MRM (n = 322). Concurrently, individuals whose migraine attacks were unrelated to menstruation were classified as NMM (n = 65). This analysis focused on the clinical characteristics and acute medication treatment responses between the PMM and MRM groups.

resultsCompared to MRM cases, PMM patients had shorter disease duration (6.8 ± 5.7 vs. 11.1 ± 8.6 years, P < 0.001), fewer prodromal symptoms (58.1% vs. 75.5%, P = 0.016) and accompanying symptoms, including nausea, ocular pain, and osmophobia (all P < 0.05). The efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) for acute attacks in the PMM group was superior to that in the MRM group, whether perimenstrual period (96.4% vs. 72.8%, P = 0.010) or non-menstrual period (96.4% vs. 78.3%, P = 0.031). Subgroup analysis of patients with low attack frequency (< 4 per month) confirmed that differences in prodromal symptoms and accompanying symptoms remained between PMM and MRM patients, suggesting that attack frequency alone does not explain these differences.

conclusionsPMM was associated with fewer prodromal and accompanying symptoms, while MRM presented with a broader range of symptoms. In the overall analysis, PMM showed a more favorable response to NSAIDs than MRM; however, this difference did not persist after controlling for attack frequency, suggesting it may be partly attributable to differences in migraine burden. By contrast, differences in prodromal and accompanying symptoms remained significant after adjustment, supporting intrinsic phenotypic distinctions between the two subtypes.