title: Patient demographic and clinical features and circadian variation in onset of ischemic stroke.
abstract: BACKGROUND
  Studies have reported circadian variation in the onset of ischemic stroke, which may carry important pathophysiological implications. However, there is no detailed information about circadian variations among the subtypes of stroke.
  
  
  OBJECTIVE
  To determine whether subgroups of patients with ischemic stroke with specific clinical characteristics would exhibit different circadian patterns, to more systematically examine the role of possible triggering or precipitating factors.
  
  
  METHODS
  Analysis of the effects of demographic, medical, and pathophysiological factors on the circadian pattern of an unselected series of patients with ischemic stroke consecutively admitted to our hospital.
  
  
  RESULTS
  The study included 1656 patients. As in other studies, the peak of stroke onset occurred in the morning, with a second peak in the evening. Circadian variation in ischemic stroke onset was shown to be independent of clinical variables considered.
  
  
  CONCLUSIONS
  Our study confirms the circadian rhythm of stroke reported in previous studies. There is a chronological pattern of ischemic stroke in the morning, which appears to be independent of the presence of risk factors and of clinical stroke subtypes. The role of circadian variability of blood pressure (present in patients with and without hypertension) and a concurrent morning hypercoagulability are suggested as possible determinants of this pattern. Preventive pharmacological interventions aimed at specifically targeting the morning rise in risk factors could be advantageous in reducing the overall risk of ischemic stroke.
authors.affiliation: Section of Clinical Neurology, Dipartimento di Discipline Medico-Chirurgiche della Comunicazione e del Comportamento, University di Ferrara, Corso della Giovecca 203, I-44100 Ferrara, Italy. ilaria.casetta@libero.it
authors.forename: Ilaria
authors.initials: I
authors.lastname: Casetta
authors.forename: Enrico
authors.initials: E
authors.lastname: Granieri
authors.forename: Elisa
authors.initials: E
authors.lastname: Fallica
authors.forename: Olga
authors.initials: O
authors.lastname: la Cecilia
authors.forename: Ezio
authors.initials: E
authors.lastname: Paolino
authors.forename: Roberto
authors.initials: R
authors.lastname: Manfredini
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000453:epidemiology*; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012890:Sleep; D020521:Stroke / Q000453:epidemiology*