title: Acute intracerebral haemorrhage: circadian and circannual patterns of onset.
abstract: Hypothesis of the circannual and circadian variation in onset of intracerebral haemorrhage (CH) was verified, by means of single cosinor method and chi-square test for goodness of fit, in 161 consecutive patients (94 men and 67 women) admitted into the Institute of Neurosurgery of Ferrara Hospital, Italy, over 9 years. The majority of CH occurred in the morning between 06.00 AM and 12.00 noon (36.7% of cases, p < 0.001); when considering the specific anatomical sites, typical supratentorial haemorrhages showed a similar pattern (37.4%, p = 0.01). A similar morning behavior was found when considering subgroups by sex (men 36.2%, women 37.3%), age > or = 60 years (42.5%), no presence of hypertension (39.7%), no presence of diabetes mellitus (33.3%) and non-smokers (30.4%). The results by cosinor analysis yielded a circadian rhythmicity both for total sample and, for the men's subgroup, with a morning peak at 11.44 and 11.25, respectively. For women, however, spectral analysis found a significant ultradian cycle, having a period of 12 h (p = 0.01). A circannual periodicity, with a prevalent peak in February, was found for total sample and males subgroups, too. The results of this study confirm that intracerebral haemorrhages present a characteristic circadian and circannual pattern in onset.
authors.affiliation: Emergency Department of St. Anna Hospital, Ferrara, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Gallerani
authors.forename: G
authors.initials: G
authors.lastname: Trappella
authors.forename: R
authors.initials: R
authors.lastname: Manfredini
authors.forename: M
authors.initials: M
authors.lastname: Pasin
authors.forename: M
authors.initials: M
authors.lastname: Napolitano
authors.forename: A
authors.initials: A
authors.lastname: Migliore
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002543:Cerebral Hemorrhage / Q000453:epidemiology* / Q000209:etiology; D002940:Circadian Rhythm / Q000502:physiology; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012621:Seasons; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology / Q000209:etiology