Fig. 2From: Circadian rhythms of migraine attacks in episodic and chronic patients: a cross sectional study in a headache center populationCircadian rhythm of migraine attacks in the 786 patients. The 16.578 attacks were divided among the 24 h. The distribution was not uniform, for a reduction of the attacks in the night hours. (Bootstrap, Tukey estimator 4.49, distorsion − 0.03)Back to article page