Temporal organization of cerebrovascular accidents: a retrospective, preliminary study about stroke in Ferrara, Italy.
An epidemiologic retrospective study was conducted from January 1984 to December 1988 on subjects admitted into the Institute of Semeiotica Medica of the University of Ferrara (as a general medicine, unselective department) and presenting a stroke. Year, month and hour of onset of symptoms in 141 patients (all resident in Ferrara, mean age 74.3 +/- 8.3 years) were carefully recorded. The definition of precise clock hour was reached only in 108 cases. The data were then analyzed by means of Halberg's single cosinor. Time series analysis showed a seasonal pattern of disease onset, characterized by a circannual rhythm with acrophase in late winter - early spring (-83.9 degrees). A significant circadian rhythm was found too, with acrophase at afternoon (-242.8 degrees).
Manfredini
R
R
Institute of Semeiotica Medica, University of Ferrara.
Squarzoni
G
G
Gallerani
M
M
Franceschini
F
F
Bariani
L
L
Fersini
C
C
D000368:Aged; D002561:Cerebrovascular Disorders / Q000453:epidemiology*; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D012189:Retrospective Studies; D013997:Time Factors