Stroke Seasonality and Weather Association in a Middle East Country: A Single Tertiary Center Experience

Association between short-term exposure to meteorological factors on hospital admissions for hemorrhagic stroke: an individual-level, case-crossover study in Ganzhou, China

BACKGROUND

Hemorrhagic stroke (HS) is associated with significant disability and mortality. However, the relationship between meteorological factors and hemorrhagic stroke, as well as the potential moderating role of these factors, remains unclear.

METHODS

Daily data on HS, air pollution, and meteorological conditions were collected from January 2015 to December 2021 in Ganzhou to analyze the relationship between meteorological factors and HS admissions. This analysis employed a time-stratified case-crossover design in conjunction with a distributional lag nonlinear model. Additionally, a bivariate response surface modelling was utilized to further investigate the interaction between meteorological factors and particulate matter. The study also stratified the analyses by gender and age. To investigate the potential impact of extreme weather conditions on HS, this study defined the 97.5th percentile as representing extremely high weather conditions, while the 2.5th percentile was classified as extremely low.

RESULTS

In single-day lags, the risk of admissions for HS was significantly associated with extremely low temperature (lag 1-2 and lag 13-14), extremely low humidity (lag 1 and lag 9-12), and extremely high precipitation (lag 2-7). Females exhibited greater susceptibility to extremely low temperature than males within the single-day lag pattern in the subcomponent layer, with a maximum relative risk (RR) that was 7% higher. In the cumulative lag analysis, the risk of HS admissions was significantly associated with extremely high temperature (lag 0-8∼lag 0-14), extremely low humidity (lag 0-2∼lag 0-14), and extremely high precipitation (lag 0-4∼lag 0-14). Within the cumulative lag day structure of the subcomponent layer, both extremely low and extremely high temperature had a more pronounced effect on females and aged ≥65 years. The risk of HS admissions was positively associated with extremely high barometric pressure in the female subgroups (lag 0-1 and lag 0-2). The highest number of HS admissions occurred when high PM2.5 concentrations coexisted with low precipitation.

CONCLUSIONS

Meteorological factors were significantly associated with the risk of hospital admissions for HS. Individuals who were female and aged ≥65 years were found to be more susceptible to these meteorological influences. Additionally, an interaction was observed between airborne particulate matter and meteorological factors. These findings contributed new evidence to the association between meteorological factors and HS.

High average daily temperature in summer and the incidence of thrombolytic treatment for acute ischemic stroke

INTRODUCTION

Meteorological factors can increase stroke risk; however, their impact is not precisely understood. Heat waves during summer increase total mortality. Therefore, we hypothesized that the average daily temperature in summer may correlate with the incidence of thrombolytic treatment for acute ischemic stroke in Budapest and Pest County, Hungary.

METHODS

We analyzed the relationship between the average daily temperature in summer months and the daily number of thrombolytic treatments (TT) performed with the indication of acute ischemic stroke between 1st June and 31st August each year from 2007 to 2016. The analysis was also performed after the omission of the data of the last day of the months due to possible psychosocial impact reported in our previous study. Spearman's correlation was used for statistical analysis.

RESULTS

No significant correlation was found between the average summer daily temperature and the number of TT in the entire sample of the 10-year period. When omitting the data of the last day of each month, positive correlations were suspected in 2014 (r=0.225, P=0.034) and 2015 (r=0.276, P=0.009).

CONCLUSION

Our findings did not confirm an association between the average daily temperature in summer and the daily number of TT throughout the examined 10-year period. However, importantly, in 2014 and 2015, the years with the highest average daily temperatures in this period, a positive correlation was found. The level of correlation is modest, indicating that risk factors, both meteorological and non-meteorological, other than the average temperature, play equally important roles in determining the incidence of thrombolytic treatment for acute ischemic stroke on the population level.

Forecasting extremely high ischemic stroke incidence using meteorological time serie

MOTIVATION

The association between weather conditions and stroke incidence has been a subject of interest for several years, yet the findings from various studies remain inconsistent. Additionally, predictive modelling in this context has been infrequent. This study explores the relationship of extremely high ischaemic stroke incidence and meteorological factors within the Slovak population. Furthermore, it aims to construct forecasting models of extremely high number of strokes.

METHODS

Over a five-year period, a total of 52,036 cases of ischemic stroke were documented. Days exhibiting a notable surge in ischemic stroke occurrences (surpassing the 90th percentile of historical records) were identified as extreme cases. These cases were then scrutinized alongside daily meteorological parameters spanning from 2015 to 2019. To create forecasts for the occurrence of these extreme cases one day in advance, three distinct methods were employed: Logistic regression, Random Forest for Time Series, and Croston's method.

RESULTS

For each of the analyzed stroke centers, the cross-correlations between instances of extremely high stroke numbers and meteorological factors yielded negligible results. Predictive performance achieved by forecasts generated through multivariate logistic regression and Random Forest for time series analysis, which incorporated meteorological data, was on par with that of Croston's method. Notably, Croston's method relies solely on the stroke time series data. All three forecasting methods exhibited limited predictive accuracy.

CONCLUSIONS

The task of predicting days characterized by an exceptionally high number of strokes proved to be challenging across all three explored methods. The inclusion of meteorological parameters did not yield substantive improvements in forecasting accuracy.

Seasonal variability of lesions distribution in acute ischemic stroke: A retrospective study

Seasonal variability could have an impact on the incidence and outcome of stroke. However, little is known about the correlation between seasonal variability and location of acute cerebral infarction. This study aimed to explore the relationship between onset season and the lesions distribution of acute ischemic stroke (AIS). We retrospectively analysis data from 1488 AIS patients admitted to the Second Hospital of Tianjin Medical University from 2018 to 2022. All subjects completed head magnetic resonance imaging examination (MRI) and were divided into four groups according to the onset seasons. The lesions distribution of AIS was evaluated for anterior/posterior/double circulation infarction (DCI), unilateral/bilateral infarctions, and single/multiple cerebral infarctions based on MRI. Logistic regression models were employed to assess the association of season with lesions distribution of AIS. Subgroup analysis was performed in different stroke subtypes. Of 1488 patients, 387 (26.0%) AIS occurred in spring, 425 (28.6%) in summer, 331 (22.2%) in autumn and 345 (23.2%) in winter. Multivariate logistic regression demonstrated that the winter group had 2.15 times (95% CI:1.44-3.21) risk of multiple infarctions, 2.69 times (95% CI:1.80-4.02) of bilateral infarctions and 1.54 times (95% CI:1.05-2.26) of DCI compared with summer group, respectively. Subgroup analysis showed an increased risk of multiple (p < 0.01) or bilateral infarctions (p < 0.01) in small-artery occlusion (SAO) subtype, and higher risk of bilateral infarctions (p < 0.01) or DCI (p < 0.05) in large artery atherosclerosis (LAA) subtype during winter. No significant associations of season with lesions distribution in cardioembolism subtype. Our study highlighted a prominent seasonal variability in the lesions distribution of AIS, particularly in LAA and SAO subtypes. The findings could help to formulating meteorological risk warning strategies for different subtypes.

Seasonal Variation in Neurological Severity and Clinical Outcomes in Ischemic Stroke Patients - A 9-Year Study of 5,238 Patients

BACKGROUND

Because the effects of extreme weather conditions on stroke severity and outcomes are unclear, we evaluated seasonal variations in stroke severity and clinical outcomes.

METHODS AND RESULTS

Between 2012 and 2020 we enrolled 5,238 patients with acute ischemic stroke, who were divided into 4 seasons according to stroke onset: spring, summer, autumn and winter. We analyzed the effect of season on the severity and outcomes of all subjects. Multivariable analysis showed that the winter group had 1.234-fold increased risk of moderate-to-severe neurological deficits than the summer group (95% confidence interval (CI): 1.034-1.472, P=0.020). Compared with the summer group, the winter and the spring groups experienced 1.243- and 1.251-fold the risk of suffering from worse outcomes among all patients at 6-month follow-up (95% CI 1.008-1.534, P=0.042, 95% CI 1.013-1.544, P=0.037). The 1-year follow-up revealed similar results. Further comparison of each season in the 2012-2015 and 2016-2020 periods found that the proportion of poor outcomes in the latter autumn group was lower than that in the former time period, with significant differences in both 6-month and 1-year follow-up.

CONCLUSIONS

The onset season was related to the severity and clinical outcomes of ischemic stroke. Patients with winter onset had more severe neurological deficits and worse outcomes than those with summer onset.

Clinical Characteristics of Ischemic Stroke Patients <50 Years Old at a University Hospital: A Retrospective Descriptive Study

Background Stroke is a leading cause of mortality and disability around the world. It is responsible for 10% of all fatalities and about 5% of all disabilities. Risk factors include age, hypertension (HTN), dyslipidemia, and atrial fibrillation. The incidence of acute ischemic stroke (AIS) is increasing among young adults compared to older ones. It has a direct impact on their quality of life and working activities while also burdening the healthcare system. Aim The aim of this study is to investigate the possible risk factors for ischemic stroke in patients who are under 50 years old. Methods This is a single-center retrospective record review of patients with ischemic stroke from 2010 to 2022. Eighty patients who had an ischemic stroke at an age below 50 were included in the analysis. Patients above or equal to 50 years old who had ischemic stroke and all patients with hemorrhagic stroke were excluded. Baseline characteristics, length of hospitalization, and in-hospital mortality were compared with different comorbidities. Results The mean age was 36.65 among males and females who had an ischemic stroke. 56.8% of them were non-Saudi, while 43.2% were Saudis. Diabetes, hypertension, and dyslipidemia were among the most frequent comorbidities among patients who had ischemic stroke, with a percentage of 82.7%. Other comorbidities, such as autoimmune disease, thrombophilia, and heart failure, were present. Conclusion There are different comorbidities found in patients who have had an ischemic stroke and are under 50 years old. However, diabetes and hypertension remain the most common risk factors.

The onset of cerebral infarction may be affected by differences in atmospheric pressure distribution patterns

Background

Some papers have highlighted a possible causal relationship between the onset of ischemic stroke and weather conditions. This study aimed to elucidate the onset mechanism of cerebral infarction from a meteorological approach. We focused on the atmospheric pressure distribution patterns (APDPs).

Methods

The subjects are 221 cases diagnosed as cardiogenic cerebral embolism (Group A) and 612 cases diagnosed as atherosclerotic cerebral thrombosis (Group B). We investigated the APDP on the date closest to the date and time of onset of cerebral infarction in each patient on the website and chose the most similar one from the reported 11 APDPs. Groups A and B were compared for clinical characteristics and the appearance rate of each APDP in each group.

Results

The clinical characteristics of Groups A and B were consistent with some previously reported clinical characteristics of cerebral embolism and cerebral thrombosis except for smoking. The appearance rate of the other high-pressure type, which cannot be classified as either the anticyclone belt type or the migratory anticyclone type, in Group B was statistically significantly higher than that in Group A, and the appearance rate of the anticyclone belt type in Group A was statistically significantly higher than that in Group B (p < 0.05, Fisher's exact probability method, respectively).

Conclusions

Cerebral embolism and cerebral thrombosis exhibited significant differences in APDPs on the day of onset. Dehydration particularly in the other high-pressure type or in the anticyclone belt type should be prevented. Further investigation should focus on the other meteorological factors.

Clinical characteristics and outcomes of ischemic stroke patients during Ramadan vs. non-Ramadan months: Is there a difference?

Objectives

To study the clinical characteristics and outcomes of patients experiencing an ischemic stroke during Ramadan vs. non-Ramadan months in a tertiary academic center in an Islamic country.

Methods

We retrospectively reviewed all patients with ischemic stroke (IS) in Ramadan and non-Ramadan months for four consecutive years (February 2016–June 2019). All demographics, vascular risk factors, laboratory results, modified Rankin Scale (mRS) at admission and discharge, National Institute Stroke Scale (NIHSS), and in-hospital complication data were collected for all patients.

Results

One thousand and 58 patients were included (non-Ramadan, n = 960; during Ramadan, n = 98). The mean age during Ramadan was 59 ± 13 years. Most non-Ramadan IS patients during Ramadan were male (68.5%; 57.1%, respectively). There was no statistical difference in vascular risk factors and medical history between the two groups. However, Ramadan patients had higher median NIHSS scores at discharge (p = 0.0045). In addition, more ICU admissions were noted among Ramadan patients (p = 0.009). In the gender-specific analysis for Ramadan patients, we found a statistically significant difference in smoking and urinary tract infection (p = 0.006, p = 0.005, respectively).

Conclusion

Based on our results, there was no difference, in general, between patients with IS during Ramadan and non-Ramadan months. However, IS patients had higher NIHSS scores at discharge and more ICU admissions during Ramadan. Last, we suggest future studies with larger sample sizes, longer duration, and including all types of strokes.