Influence of chronotype on migraine characteristics.

BACKGROUND: The aim of this study was to investigate chronotype in migraine patients and possible influences on the clinical expression of the disease. METHODS: During a one-year period, all consecutive patients admitted to two third-level headache centres with a new diagnosis of migraine were enrolled in a cross-sectional study. All subjects were submitted to the Morningness-Eveningness Questionnaire (MEQ-SA) and then classified in five different categories, from late to early-rising chronotype. Differences and trends among MEQ-SA categories and years from migraine onset, attacks' intensity and frequency were analysed first with analysis of variance, then with a multivariate/generalized linear model. RESULTS: One hundred seventy one migraine patients were included. Early-rising patients showed a lower migraine attacks frequency and longer disease duration with respect to late-rising patients. The categorical variable containing the five circadian types was able to identify a significantly different trend both for the monthly attacks frequency and for the disease duration (p < 0.0001 and p < 0.0001, respectively, analysis of variance). The results were also confirmed after correction for main influencing variables (multivariate/generalized linear model). The intensity of migraine attacks was not influenced by chronotype. CONCLUSIONS: According to the results of the present study, chronotype seems to influence number and duration of migraine attacks. Although sleep-wake cycle is a well-recognized factor able to influence thalamic-cortical synchronization, it usually does not receive appropriate consideration during migraine patients' assessment.