title: Circadian variation in stroke onset: identical temporal pattern in ischemic and hemorrhagic events.
abstract: Stroke is the culmination of a heterogeneous group of cerebrovascular diseases that is manifested as ischemia or hemorrhage of one or more blood vessels of the brain. The occurrence of many acute cardiovascular events--such as myocardial infarction, sudden cardiac death, pulmonary embolism, critical limb ischemia, and aortic aneurysm rupture--exhibits prominent 24 h patterning, with a major morning peak and secondary early evening peak. The incidence of stroke exhibits the same 24 h pattern. Although ischemic and hemorrhagic strokes are different entities and are characterized by different pathophysiological mechanisms, they share an identical double-peak 24 h pattern. A constellation of endogenous circadian rhythms and exogenous cyclic factors are involved. The staging of the circadian rhythms in vascular tone, coagulative balance, and blood pressure plus temporal patterns in posture, physical activity, emotional stress, and medication effects play central and/or triggering roles. Features of the circadian rhythm of blood pressure, in terms of their chronic and acute effects on cerebral vessels, and of coagulation are especially important. Clinical medicine has been most concerned with the prevention of stroke in the morning, when population-based studies show it is of greatest risk during the 24 h; however, improved protection of at-risk patients against stroke in the early evening, the second most vulnerable time of cerebrovascular accidents, has received relatively little attention thus far.
authors.affiliation: Vascular Diseases Center, Department of Clinical and Experimental Medicine, University of Ferrara, Italy. mfr@unife.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Manfredini
authors.forename: Benedetta
authors.initials: B
authors.lastname: Boari
authors.forename: Michael H
authors.initials: MH
authors.lastname: Smolensky
authors.forename: Raffaella
authors.initials: R
authors.lastname: Salmi
authors.forename: Olga
authors.initials: O
authors.lastname: la Cecilia
authors.forename: Anna
authors.initials: A
authors.lastname: Maria Malagoni
authors.forename: Erhard
authors.initials: E
authors.lastname: Haus
authors.forename: Fabio
authors.initials: F
authors.lastname: Manfredini
mesh_terms: D001777:Blood Coagulation / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002545:Brain Ischemia; D002543:Cerebral Hemorrhage; D002940:Circadian Rhythm / Q000502:physiology*; D005342:Fibrinolysis; D006801:Humans; D009043:Motor Activity; D004364:Pharmaceutical Preparations; D012890:Sleep; D013315:Stress, Psychological; D020521:Stroke / Q000503:physiopathology*; D013997:Time Factors
chemical_list: D004364:Pharmaceutical Preparations