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

Abstract

Background and Purpose-The purpose of this study was to further analyze the temporal patterns of onset of intracerebral hemorrhage (ICH) and to determine whether or not subgroups with specific clinical characteristics exhibit different patterns of onset. Methods-The daily, weekly, and yearly variations in occurrence of ICH together with the relationship between ICH occurrence and changes in air temperature were evaluated in 1018 patients. Patients were grouped according to the presumed etiology of ICH: hypertensive ICH, secondary ICH, and ICH of undetermined origin. The contribution of demographic and clinical factors to the temporal distributions of ICH was also evaluated. Results-Marked differences in seasonal and diurnal patterns of ICH onset were observed in the different groups. The incidence of hypertensive ICH reflected seasonal and circadian changes in blood pressure, whereas the latter did not seem related to the onset of nonhypertensive ICH. The seasonal pattern was more evident in elderly patients with hypertensive ICH than in younger subjects. No significant weekly variations were observed; however, risk was greater on Monday in the working population. Conclusions-Our results suggest that the higher incidence of ICH in the colder months is due to the effect of low temperatures on blood pressure and that the clustering of ICH events in the morning is due to the increase in sympathetic tone, and consequent increase in blood pressure, on awakening. (Stroke. 2000;31:1538-1544.)

Association of Breakfast Intake With Incident Stroke and Coronary Heart Disease

“…Several previous studies have shown that cerebral by guest on May 11, 2018 http://stroke.ahajournals.org/ Downloaded from hemorrhage occurs more frequently in the morning than during the remainder of the day. [18][19][20] Therefore, it may be important to reduce the frequency or duration of high blood pressure in the morning to prevent cerebral hemorrhage, and eating breakfast everyday might achieve this. Witbracht et al 21 suggested that skipping breakfast was associated with stress-independent overactivity in the hypothalamic-pituitary-adrenal axis because of a longer period of fasting, leading to elevated blood pressure in the morning.…”

Effect of Seasonal and Monthly Variation in Weather and Air Pollution Factors on Stroke Incidence in Seoul, Korea

“…Most studies have demonstrated that the incidence of stroke increases in the winter and spring and decreases in the summer and autumn. [3][4][5][6][7][8][9][10][11] However, some studies have reported increases in the incidence of stroke in response to dramatic temperature changes in the spring and autumn, [12][13][14] whereas in other studies, no seasonal variation has been demonstrated. [15][16][17] Because most previous studies have addressed large regions with varying climate, studies on smaller regions with similar weather and environments could provide important information on this topic.…”

Potential Triggering Factors of Intracerebral Hemorrhage

“…For SAH it has been suggested that hypertensive patients may be more susceptible to external stressors than normotensive patients [9, 11]. Previously analysis of our sample of ICH patients suggested that the occurrence of hypertensive ICH reflected seasonal and circadian variations in BP, whereas changes in BP did not seem to influence the occurrence of nonhypertensive ICH [5]. …”

“…BP has a seasonal pattern related to temperature with higher values in winter and lower values in summer [1], and a circadian rhythm related to the sleep-wake cycle with lower values during rest/sleep and inactivity, a rise on awakening and higher values during the rest of the day [2]. The winter and morning rises in BP have been invoked to explain the increased number of vascular events in the cold months [3, 4, 5, 6, 7]and in the morning waking hours [5, 8, 9, 10, 11, 12, 13, 14]. …”