[Influence of changes in climate and the calendar on the onset of a migraine crisis].

Several factors have been demonstrated to play a role in triggering acute episode of migraine headache. On the basis of observation, others have been suggested but not confirmed. Variations in climate are among the latter. Over a one-year period, we observed a population of 304 patients with migraine residing in a precise climatic zone. The frequency of acute episodes could be analyzed for 148 among them. There were 4,421 acute episodes recorded during the year. The periodicity during the year was compared with climate parameters: temperature (maximal, minimal, average), wind (force and direction), atmospheric pressure, rain, sunshine, relative humidity, and icy, foggy and stormy weather. Moon cycles were also assessed. No correlations were found between climate parameters or variations there of and onset of migraine. Variations in climate would thus appear to have no effect on migraine. Inversely, the results of this study demonstrated a day effect with a higher number of episodes on Saturday and less on Monday and Tuesday. The triggering effect of catamenia on many acute episodes was also confirmed.