Relationship between Circadian Variation in Ictus of Aneurysmal Subarachnoid Hemorrhage and Physical Activity

OBJECTIVE

The circadian pattern of the onset time of aneurysmal subarachnoid hemorrhage (aSAH) has been reported by various authors. However, the effect of the degree of physical exertion on the circadian pattern has not been studied in detail. Therefore, we conducted this study to investigate the effect of physical exertion on the circadian pattern of aSAH.

METHODS

Of the 335 patients presenting with aSAH from January 2012 to December 2017, 234 patients with identifiable onset time and metabolic equivalent (MET) values were enrolled. The onset time of aSAH was divided into 4-hour intervals. The patient's physical exertion was then assessed on a scale between 1 and 8 METs using generally accepted MET values, and categorized into two groups-light exertion (1 to 4 METs) and moderate to heavy exertion (5 to 8 METs)-to determine the effect of the degree of physical exertion on the onset time distribution of aSAH. Multivariate analysis was used to calculate the odds ratio (OR) between the two groups to determine the effect of the degree of physical exertion on each set of time periods.

RESULTS

There was a definite bimodal onset pattern that peaked at 08:00-12:00 hours followed by 16:00-20:00 hours (p <0.001). MET values at all time intervals were found to be significantly higher than the night time (00:00-04:00 hours) values (p<0.031). The MET value distribution showed a unimodal pattern that slightly differed from the bimodal distribution of the onset time of aSAH. There were no significant differences in the ORs of each time interval according to the degree of the MET value.

CONCLUSION

This study reaffirmed that aSAH occurs in a bimodal pattern, especially showing the highest prevalence in the morning. Although aSAH could be related to daily activity, there were no significant changes in diurnal variations affected by the degree of physical exertion.

Circaseptan variation in case-fatality rate for patients with acute subarachnoid hemorrhage (Takashima Stroke Registry 1988-2003)

We explored the circaseptan variation in 28-day case-fatalities for patients with subarachnoid hemorrhage (SAH) across days of the week. Data were obtained from the Takashima Stroke Registry, which covers approximately 50000 residents of central Japan. There were 169 first-ever SAH cases registered during the period 1988-2003 (68 in males, 101 in females). We divided the SAH cases into two groups according to the day on which the SAH occurred: "weekend" and "weekday". The 28-day case-fatality rate and 95% confidence interval (CI) were calculated. Multiple logistic regression analysis was used to calculate the adjusted odds ratio (95% CI) for weekday fatalities by entering all relevant patient-level variables into the model. The 28-day case-fatality rate for SAH was higher on weekdays (51.7%) than on weekends (32.6%; odds ratio 2.19; 95% CI: 1.10-4.49). The differences in fatality rate persisted after adjustment for age, sex, severity, family history of stroke and patient history of hypertension, diabetes mellitus, dyslipidemia, drinking and smoking. We observed a circaseptan variation in fatalities from SAH, with higher fatality rates during weekdays in our study population.

Involvement of meteorological factors and sex in the occurrence of subarachnoid hemorrhage in Japan

The sex difference in the seasonal occurrence of subarachnoid hemorrhage (SAH) and the association of meteorological factors in Japan were analyzed in 1006 consecutive patients with SAH in Toyama, Japan from 1996 to 2000. The study investigated whether these meteorological factors could explain the seasonality of the incidence of SAH in each sex. Seasonal variation of SAH occurrence peaked in spring in men, but peaked in spring and winter in women. The difference between maximum temperature and minimum temperature was the greatest on the day previous to SAH occurrence in multiple individuals in men, whereas mean humidity was the greatest on that day in women. Interestingly, the difference between maximum temperature and minimum temperature peaked in spring and mean humidity in winter from the meteorological data over the 5 years. The relationship between humidity and occurrence of SAH may explain the sex difference of the incidence of aneurysmal SAH. The humidity change may be a specific and additional meteorological factor for the incidence of SAH in women.

Subarachnoid haemorrhage

Subarachnoid haemorrhage accounts for only 5% of strokes, but occurs at a fairly young age. Sudden headache is the cardinal feature, but patients might not report the mode of onset. CT brain scanning is normal in most patients with sudden headache, but to exclude subarachnoid haemorrhage or other serious disorders, a carefully planned lumbar puncture is also needed. Aneurysms are the cause of subarachnoid haemorrhage in 85% of cases. The case fatality after aneurysmal haemorrhage is 50%; one in eight patients with subarachnoid haemorrhage dies outside hospital. Rebleeding is the most imminent danger; a first aim is therefore occlusion of the aneurysm. Endovascular obliteration by means of platinum spirals (coiling) is the preferred mode of treatment, but some patients require a direct neurosurgical approach (clipping). Another complication is delayed cerebral ischaemia; the risk is reduced with oral nimodipine and probably by maintaining circulatory volume. Hydrocephalus might cause gradual obtundation in the first few hours or days; it can be treated by lumbar puncture or ventricular drainage, dependent on the site of obstruction.

Circumstances, Activities, and Events Precipitating Aneurysmal Subarachnoid Hemorrhage

Medical records of 513 patients with aneurysmal subarachnoid hemorrhage were reviewed to analyze the factors precipitating aneurysmal rupture. There was no seasonal difference in incidence. A significantly higher incidence was observed during 6:00 AM to 9:00 AM and 6:00 PM to 9:00 PM when engaging in daily routines such as defecation/micturition, brushing teeth/washing face/dressing, eating/drinking, and taking a bath. These activities are associated with a Valsalva maneuver that results in sudden pressure changes across the aneurysmal wall precipitating aneurysmal rupture. Aneurysmal rupture occurred most frequently during talking, chatting, watching television, or staying home without any strenuous physical activity. Considering the time spent, the highest incidence rate was found during defecation/micturition. There was no significant difference between men and women or between younger and older age groups regarding activities or events preceding aneurysmal rupture. Hypertension was the most common pre-existing medical problem. The main results are the same as those of the previous study except for aging of the patients.

Triggers of subarachnoid hemorrhage: role of physical exertion, smoking, and alcohol in the Australasian Cooperative Research on Subarachnoid Hemorrhage Study (ACROSS)

BACKGROUND AND PURPOSE

Unaccustomed strenuous physical exertion can trigger myocardial infarction, but little is known about the mechanisms precipitating subarachnoid hemorrhage (SAH).

METHODS

We identified all cases of first-ever SAH among the combined populations (2.8 million) of 4 urban centers in Australia and New Zealand. Information on the type, time, and intensity of exposures in the 26 hours before the onset of SAH was ascertained by structured interviews. We used the case-crossover technique to assess the risk of SAH associated with transient exposures of moderate to extreme physical exertion, heavy cigarette smoking, and binge alcohol consumption.

RESULTS

We registered 432 first-ever cases of SAH (62% women; mean age, 56.5 years). A definite time of onset of SAH was established for 393 patients (91%), and information on the levels of physical activity in the preceding 26 hours was obtained in 338 (78%). Of these patients, 19% engaged in moderate to extreme exertion (>or=5 metabolic equivalents) in the 2 hours before SAH, which was associated with a tripling in the risk of SAH (odds ratio [OR], 2.7; 95% CI, 1.6 to 4.6). There was no evidence of any association between heavy cigarette smoking or binge drinking and risk of SAH in the subsequent 2 hours (OR, 1.1; 95% CI, 0.4 to 3.7; and OR, 0.41; 95% CI, - infinity to 5.3). Habitual exercise did not appear to alter the risk of SAH associated with moderate to extreme exertion.

CONCLUSIONS

Moderate to extreme physical exertion tripled the risk of SAH, but there was no association between transient heavy smoking or binge drinking and risk of SAH. These data suggest that heavy physical activity may trigger SAH.

Seasonal variation in the incidence of aneurysmal subarachnoid hemorrhage in hospital- and community-based studies

OBJECT

The aim of this study was to examine seasonal variations in the onset of aneurysmal subarachnoid hemorrhage (SAH) in one hospital-based and one community-based patient series.

METHODS

The study population consisted of 941 patients with aneurysmal SAH who were admitted to Shimane Prefectural Central Hospital and 358 patients who were treated in Izumo City, Japan. When investigated as a whole, no significant seasonal variations were found in either population; however, in both series, statistically significant seasonal trends, with a peak in winter and a nadir in summer, were found among patients aged 59 years or younger (p < 0.05 for the hospital-based series and p < 0.005 for the community-based series), but not among those aged 60 years or older, regardless of sex. In the hospital-based series, seasonal variations were most apparent at certain times of day, with significant variations observed between 8:00 a.m. and 10:00 a.m. or 8:00 a.m. and noon (p < 0.001 and p < 0.005, respectively), regardless of patient age, and between 4:00 p.m. and 6:00 p.m. for patients aged 59 years or younger (p < 0.05). Consequently, seasonal variations were significant during daytime hours (between 8:00 a.m. and 8:00 p.m., p < 0.005) but not during the night (between 8:00 p.m. and 8:00 a.m.). Similar tendencies were found in the community-based series. Among patients aged 59 years or younger who had no risk factors for SAH, these seasonal variations were significant in both series. In patients with untreated hypertension, who were current smokers and daily alcohol drinkers, however, no significant patterns were observed in either series, even among younger patients.

CONCLUSIONS

In both hospital- and community-based studies, aneurysmal SAH appears to undergo seasonal variation, with a peak in winter and a nadir in summer. This seasonal pattern may be derived mainly from the occurrence of SAH in the morning, but may also be modified by patient age and SAH risk factors, resulting in the masking of significant seasonal patterns when all patients are considered together.

Circadian fluctuations in onset of subarachnoid hemorrhage. New data on aneurysmal and perimesencephalic hemorrhage and a systematic review

BACKGROUND AND PURPOSE

Several studies have found a morning peak in onset of stroke. A similar peak has been suggested for subarachnoid hemorrhage (SAH), which seems in contradiction with the physical activities associated with aneurysmal rupture. Most studies included only a few patients with SAH. We analyzed time of onset of aneurysmal SAH in our patients and in data pooled from previous studies. We also studied time of onset in patients with perimesencephalic hemorrhage, which is believed to have a nonaneurysmal venous origin.

METHODS

Of all 468 patients registered from 1989 through 1995, 385 fulfilled the criteria for aneurysmal SAH and 37 the criteria for perimesencephalic hemorrhage. Time of onset was categorized in 2-hour and 6-hour intervals. We did a Medline search to find previous studies on time of onset of SAH and pooled the data in 2-hour, 3-hour, and 6-hour intervals. Analysis of all intervals was performed by calculating rate ratios with 95% confidence intervals by means of Poisson methods.

RESULTS

The risk of aneurysmal rupture was lower at night (from 12 PM to 6 AM) in our series and in the pooled-data series. Risk remained high throughout the day and evening, we found the same fluctuation in onset but without a nadir around noon.

CONCLUSIONS

The risk of aneurysmal SAH is low during the night and at noon and high during working hours. This circadian fluctuation parallels that of blood pressure and suggests that an increase in blood pressure is a risk factor for aneurysmal rupture.

Weekend and holiday increase in the onset of ischemic stroke in young women

BACKGROUND AND PURPOSE

Chronobiological analyses of stroke onset may throw some light on the mechanisms that trigger stroke. Observations may generate new hypotheses for identifying significant causal relationships.

METHODS

In the present study, both the circadian and the weekend and holiday versus workday times of the onset of ischemic cerebral infarction were determined for 723 consecutive subjects, aged 16 to 60 years, who were admitted for hospital treatment in the acute phase without any selection.

RESULTS

Among young adults (16 to 40 years) and women, more infarctions occurred during weekends and holidays than were expected. Young women in particular had an increased risk for brain infarction during weekends and holidays (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.26 to 3.63). In a multivariate analysis, age of 16 to 30 years (OR, 3.13; 95% CI, 1.57 to 6.50), female sex (OR 1.71; 95% CI, 1.12 to 2.63), and recent drinking of alcohol (P < .01) were associated with the onset of brain infarction during weekends and holidays, whereas current cigarette smoking was associated with the onset of brain infarction during workdays (P < .001). A morning increase in the onset of brain infarction was observed among middle-aged people during both weekends/holidays and workdays. Among young adults, however, an evening increase was also seen during weekends/holidays and workdays.

CONCLUSIONS

We found that young adults and women are frequently stricken by brain infarction during weekends and holidays and that the circadian distribution of the onset of brain infarction among young adults is different from that of middle-aged people. These observations suggest that there may be stroke-triggering activities that are associated with lifestyle.