Seasonal variation of cerebral hemorrhage in 236 consecutive cases in Brussels.

Abstract

Background and Purpose: Seasonal variation in the incidence of cerebral hemorrhage has been previously demonstrated. In this study, we sought to identify the climatological data best correlated with this seasonal variation.Methods: In a retrospectively studied sequential series of 236 patients with nontraumatic cerebral hemorrhage observed in Brussels over a period of 8 years, we cumulatively grouped the dates of stroke occurrence into a single calendar year.Results: We found marked seasonal variation in incidence, with the highest value (23%) observed in November-December and the lowest (10%) in July-August Seasonal variations in incidence of cerebral hemorrhage were shown to be correlated not only with the inverse of ambient temperature, but also with the inverse of hours of sunshine and with ambient humidity. We found no difference between hypertensive and normotensive patients.Conclusions: Our study fails to bear out the hypothesis that the higher incidence of cerebral hemorrhage in late autumn and winter is due to the influence of low ambient temperature on blood pressure. (Stroke 1992^3:24-27)

Differing Temporal Patterns of Onset in Subgroups of Patients With Intracerebral Hemorrhage

“…The number of patients varied widely, and not all series were large enough to have the statistical power for reliable conclusions. 1,5,[11][12][13][14]16,[31][32][33][34][35][36] The diagnosis of ICH was confirmed by imaging studies or autopsy in a few studies, 2,6,13,15,32,33,37,38 and it is often unclear whether ICH was spontaneous or primary. 3-5,8 -12,14 -16,31-34,39,40 In some studies, cases were identified on the basis of International Classification of Diseases (ICD) discharge codes, 8,9,10,39 whereas others included subarachnoid hemorrhage (SAH) 32 or excluded elderly patients.…”

“…3-5,8 -12,14 -16,31-34,39,40 In some studies, cases were identified on the basis of International Classification of Diseases (ICD) discharge codes, 8,9,10,39 whereas others included subarachnoid hemorrhage (SAH) 32 or excluded elderly patients. 13 Among studies on the seasonal distribution of ICH, some found increased occurrence of ICH [1][2][3][4][5][6][7][8][9][10]13 in winter, whereas others indicated peaks in other seasons 11,14,37 or no significant seasonal variation at all. 16,[31][32][33][34][35]38,39 However, the most consistent seasonal variation described was a seasonal pattern with a peak of incidence in winter and a minimum in summer.…”

“…Intracerebral hemorrhage (ICH) seems to occur more frequently during the winter months [1][2][3][4][5][6][7][8][9][10] and during the morning waking hours. 7,[11][12][13][14][15][16] Seasonal and diurnal blood pressure variations have been considered a possible explanation for these patterns of onset.…”

“…No previous studies have analyzed all temporal patterns of ICH onset in the same population together with the relation to changes in air temperature. A few studies present partial analyses related to the etiology of ICH 6 or to major clinical and demographic variables. 5,15,29 The aim of the present study was to further analyze the circadian, weekly, and yearly variations in occurrence of ICH on the basis of the time of onset of symptoms in a large population of patients, to evaluate the relationship between the occurrence of ICH and changes in air temperature, and to determine whether or not subgroups with specific clinical characteristics exhibit different patterns of onset.…”

Innovative Approaches Helpful to Enhance Knowledge on Weather-Related Stroke Events Over a Wide Geographical Area and a Large Population

“…[1][2][3][4][5][6][7][8][9] Nevertheless, as reported in a recent review, 10 authors often described discordant effects of both air temperature and atmospheric pressure.…”