Early neurological worsening in acute ischaemic stroke patients

Artificial intelligence/machine learning for neuroimaging to predict hemorrhagic transformation: Systematic review/meta-analysis

BACKGROUND AND PURPOSE

Early and reliable prediction of hemorrhagic transformation (HT) in patients with acute ischemic stroke (AIS) is crucial for treatment decisions and early intervention. The purpose of this study was to conduct a systematic review and meta-analysis on the performance of artificial intelligence (AI) and machine learning (ML) models that utilize neuroimaging to predict HT.

METHODS

A systematic search of PubMed, EMBASE, and Web of Science was conducted until February 19, 2024. Inclusion criteria were as follows: patients with AIS who received reperfusion therapy; AI/ML algorithm using imaging to predict HT; or presence of sufficient data on the predictive performance. Exclusion criteria were as follows: articles with less than 20 patients; articles lacking algorithms that operate solely on images; or articles not detailing the algorithm used. The quality of eligible studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 and Checklist for Artificial Intelligence in Medical Imaging. Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated using a random-effects model, and a summary receiver operating characteristic curve was constructed using the Reitsma method.

RESULTS

We identified six eligible studies, which included 1640 patients. Aside from an unclear risk of bias regarding flow and timing identified in two of the studies, all studies showed low risk of bias and applicability concerns in all categories. Pooled sensitivity, specificity, and DOR were .849, .878, and 45.598, respectively.

CONCLUSION

AI/ML models can reliably predict the occurrence of HT in AIS patients. More prospective studies are needed for subgroup analyses and higher clinical certainty and usefulness.

Predictive value of glycoprotein DKK3 for early neurological deterioration after ischemic stroke

OBJECTIVE

To explore the value of serum Dickkopf-3 (sDKK3) in predicting Early Neurological Deterioration (END) and in-hospital adverse outcomes in acute ischemic stroke (AIS) patients.

METHODS

AIS patients (n = 200) were included and assessed by the National Institutes of Health Stroke Rating Scale. Serum Dkk3 levels were assessed by ELISA. END was defined as an increase of ≥ 4 points in NIHSS score within 72h. The biological threshold of sDKK3 level and END occurrence were predicted based on X-tile software. Primary outcomes were END and all-cause death, and the secondary outcome was ICU admission during hospitalization. The logistic regression model and Cox risk regression model were applied to evaluate the relationship between DKK3 level and END incidence, all-cause in-hospital mortality, and in-hospital adverse outcomes (ICU admission).

RESULTS

During hospitalization, the incidence of END in patients with AIS was 13.0 %, and the mortality rate within 7 days after END was 11.54 % (3/26). In patients below the serum DKK3 cutoff (93.0 pg/mL), the incidence of END was 43.5 % (20/48). Patients with lower sDKK3 levels were associated with a 1.188-fold increased risk of developing END (OR = 1.188, 95 % CI 1.055‒1.369, p < 0.0001). However, there was no significant association with admission to the ICU. sDKK3 below the threshold (93.0 pg/mL) was a risk factor for death.

CONCLUSION

Predictive threshold levels of serum DKK3 based on X-tile software may be a potential predictive biomarker of in-hospital END in patients with AIS, and low levels of DKK3 are independently associated with increased in-hospital mortality.

Spontaneous Behavioural Recovery Following Stroke Relates to the Integrity of Parietal and Temporal Regions

Stroke is a devastating disease that results in neurological deficits and represents a leading cause of death and disability worldwide. Following a stroke, there is a degree of spontaneous recovery of function, the neural basis of which is of great interest among clinicians in their efforts to reduce disability following stroke and enhance rehabilitation. Conventionally, work on spontaneous recovery has tended to focus on the neural reorganization of motor cortical regions, with comparably little attention being paid to changes in non-motor regions and how these relate to recovery. Here we show, using structural neuroimaging in a macaque stroke model (N = 31) and by exploiting individual differences in spontaneous behavioural recovery, that the preservation of regions in the parietal and temporal cortices predict animal recovery. To characterize recovery, we performed a clustering analysis using Non-Human Primate Stroke Scale (NHPSS) scores and identified a good versus poor recovery group. By comparing the preservation of brain volumes in the two groups, we found that brain areas in integrity of brain areas in parietal, temporal and somatosensory cortex were associated with better recovery. In addition, a decoding approach performed across all subjects revealed that the preservation of specific brain regions in the parietal, somatosensory and medial frontal cortex predicted recovery. Together, these findings highlight the importance of parietal and temporal regions in spontaneous behavioural recovery.

Body temperature in the acute phase and clinical outcomes after acute ischemic stroke

BACKGROUND

This study aimed to examine whether post-stroke early body temperature is associated with neurological damage in the acute phase and functional outcomes at three months.

METHODS

We included 7,177 patients with acute ischemic stroke within 24 h of onset. Axillary temperature was measured daily in the morning for seven days. Mean body temperature was grouped into five quintiles (Q1: 35.1‒36.5°C, Q2: 36.5‒36.7°C, Q3: 36.7‒36.8°C, Q4: 36.8‒37.1°C, and Q5: 37.1‒39.1°C). Clinical outcomes included neurological improvement during hospitalization and poor functional outcome (modified Rankin scale score, 3-6) at three months. A logistic regression analysis was performed to evaluate the association between body temperature and clinical outcomes.

RESULTS

The patient's mean (SD) age was 70.6 (12.3) years, and 35.7% of patients were women. Mean body temperature was significantly associated with less neurological improvement from Q2 (odds ratios [95% confidence interval], 0.77 [0.65-0.99] vs. Q1) to Q5 (0.33 [0.28-0.40], P for trend <0.001) even after adjusting for potential confounders, including baseline neurological severity, C-reactive protein levels, and post-stroke acute infections. The multivariable-adjusted risk of poor functional outcome linearly increased from Q2 (1.36 [1.03-1.79]) to Q5 (6.44 [5.19-8.96], P for trend <0.001). These associations were maintained even in the analyses excluding patients with acute infectious diseases. Multivariable-adjusted risk of poor functional outcome was higher in patients with early body temperature elevation on days 1-3 and with longer duration with body temperature >37.0°C.

CONCLUSIONS

Post-stroke early high body temperature is independently associated with unfavorable outcomes following acute ischemic stroke.

Morphological predictors of neurological deterioration in patients with acute isolated pontine infarct

OBJECTIVE

To investigate morphological predictors of neurological deterioration (ND) in patients with acute isolated pontine infarct.

METHODS

Acute isolated pontine infarct patients within 7 days after onset of stroke symptoms were included retrospectively and classified into ND and non-ND groups. Morphological phenotypes (paramedian pontine infarct [PPI], atypical PPI, small deep infarct, and other types), topographical location, and lesion size were evaluated on axial diffusion-weighted imaging.

RESULTS

There were 210 eligible patients, of whom 62 patients had ND (29.5%). The proportion of PPI was significantly higher in ND than that in non-ND (62.9% vs 39.6%). ND occurred more frequently in PPI patients than non-PPI patients (39.8% vs 20.5%). PPI located more frequently in lower pontine (20.4% vs 8.0%) and less in upper pontine (17.3% vs 30.4%, P = 0.028), and had larger ventro-dorsal length (13.8 ± 3.8 vs 9.9 ± 3.1) and width (8.3 ± 2.3 vs 6.2 ± 1.8) than non-PPI patients. The morphological phenotype of PPI was an independent risk factor for ND (OR 4.81, 95%CI 1.54-15.07, P = 0.007) in patients with isolated pontine infarct. The ventro-dorsal length of pontine infarct lesion was associated with ND (OR 1.18, 95%CI 1.01, 1.37, P = 0.034) in PPI patients.

CONCLUSIONS

The morphological phenotype of PPI was a potential predictor for ND in patients with acute isolated pontine infarct. The ventro-dorsal length of pontine infarct lesion was possibly associated with ND in PPI patients.

Machine Learning Models for Predicting Early Neurological Deterioration and Risk Classification of Acute Ischemic Stroke

This study aimed to create machine learning models for predicting early neurological deterioration and risk classification in acute ischemic stroke (AIS) before intravenous thrombolysis (IVT). The study included 704 AIS patients categorized into END and non-END groups. The least absolute shrinkage and selection operator (LASSO) regression was employed to select the best predictors from clinical indicators, leading to the creation of Model 1. Univariate and multivariate logistic regression analyses identified independent predictive factors for END from inflammatory cell ratios. These factors were combined with clinical indicators, forming Model 2. Receiver operating characteristic (ROC) curves assessed the models' predictive performance. Key variables for Model 1 included the NIHSS score, systolic blood pressure, and lymphocyte percentage. Neutrophil-to-Lymphocyte ratio, Platelet-to-Neutrophil ratio, and Platelet-to-Lymphocyte ratio independently predicted END. Model 1 exhibited moderate predictive ability (AUC 0.721 in training, AUC 0.635 in test). Model 2, which integrated clinical indicators and inflammatory cell ratios, demonstrated strong performance in both training (AUC 0.862) and test (AUC 0.816). Machine learning models, combining clinical indicators and inflammatory cell ratios before IVT, accurately predict END and associated risk in AIS.

Predictors of Early Neurological Deterioration and Functional Outcome in Acute Ischemic Stroke: The Importance of Large Artery Disease, Hyperglycemia and Inflammatory Blood Biomarkers

BACKGROUND

Early neurological deterioration (END) in acute ischemic stroke (AIS) can be associated with poor outcome. The aim of this study was to investigate the association between infarction subtypes, biomarkers and END, and to identify patients with risk of unfavorable functional outcome.

MATERIALS AND METHODS

This prospective study enrolled 101 patients with AIS. Neurological status was evaluated according to NIHSS at acute onset, on days 2, 3, and 90. END was defined as ≥2-point increase of NIHSS within 72 hours. Functional outcome was assessed using NIHSS and the modified Rankin Scale (mRS) at day 90.

RESULTS

END was observed in 20, 8%. Patients with large artery disease had higher risk of developing END compared with patients with cardioembolism or small vessel disease (p <0.01). Significant higher blood glucose level and leukocytes were observed in the END group. Patients with END had higher scores of mRS at day 90 (p <0.01). Levels of NSE, IL-6, hsCRP and NT-proBNP were higher in the patients with unfavorable compared with favorable functional outcome.

CONCLUSION

Large artery disease, high blood glucose and leukocytes levels are associated with END. Elevated levels of blood markers NSE, IL-6, HsCRP and NT-proBNP indicate poor functional outcome at 90 days after AIS. These patients must be identified and be offered treatment immediately in order to improve the functional outcome after AIS.

Monocyte to High-Density Lipoprotein Ratio Is Associated With Early Neurological Deterioration in Acute Isolated Pontine Infarction

Objectives: The monocyte to high-density lipoprotein ratio (MHR) has been considered to be a novel inflammatory marker of atherosclerotic cardiovascular disease. However, its role in the acute phase of acute isolated pontine infarctions remains elusive. We explored whether an association existed between elevated MHR levels and early neurological deterioration (END) in patients with isolated pontine infarction.

Methods: Data from 212 patients with acute isolated pontine infarction were retrospectively analyzed. We examined the MHR in quartiles of increasing levels to evaluate for possible threshold effects. END was defined as an elevation in the total National Institutes of Health Stroke Scale (NIHSS) score ≥2 or an increase in NIHSS score ≥1 in motor power within the first week after symptom onset. Patients were divided into an END group and a non-END group. The association of MHR on END following pontine infarction was examined by logistic regression models after adjusting for age, NIHSS at admission, basilar artery stenosis, history of hypertension or hyperlipidemia or stroke, infarct size, fasting blood glucose, and paramedian pontine infarction.

Results: The mean MHR was 0.44 ± 0.22. A total of 58 (27.36%) patients were diagnosed with END. END occurred within the first 48 h after hospitalization in 38 patients (65.52%). After adjusting for confounding and risk factors, the multivariate logistic regression analysis showed NIHSS at admission [odds ratio (OR), 1.228; 95% confidence interval (CI), 1.036–1.456], basilar artery stenosis (OR, 2.843; 95% CI, 1.205–6.727), and fasting blood glucose (OR, 1.296; 95% CI, 1.004–1.672) were independently associated with END. The odds ratio of END increased as the quartile level of MHR increased, with the lowest quartile used as the reference value. Compared to the first quartile of MHR, the third and fourth quartiles were associated with 4.847-fold (95% CI, 1.532–15.336) and 5.824-fold (95% CI, 1.845–18.385) higher odds of END in multivariate analysis.

Conclusions: Elevated MHR levels may be valuable as a biomarker of END in patients with isolated pontine infarction. The elevated MHR was independently associated with END in isolated pontine infarction.

Admission Glucose Levels May Increase the Risk for Early Neurological Deterioration in Females With Acute Ischemic Stroke

Background and purpose: Early neurological deterioration (END) is associated with poor outcome for patients with acute ischemic stroke (AIS). Patients with hyperglycemia have increased risk for stroke and tend to have poor outcome with and without diabetes after stroke. The present study aimed to determine if blood glucose was associated with END and if sex difference was present in the development of END in AIS patients.

Methods: A total of 220 consecutive patients (both males and females) with AIS between 2012 and 2015 were screened for this retrospective study. After exclusion, 213 patients were included for analysis. Propensity-score matching was used for normalization of variables including stroke severity, time from symptom onset to treatment, and treatment methods.

Results: END was present in 68 patients (31.9%). Multivariate regression analysis showed that the risk of END was significantly higher in males with AIS than in females (P < 0.001), and admission blood glucose level was independently associated with END (P < 0.001). However, subgroup analysis demonstrated that admission glucose levels were significantly associated with increased risk for END only in females, but not in males (P = 0.008). When the cutoff value of 107.1 mg/dL was used, the admission blood glucose level had a significant predictive value for END prediction with a sensitivity of 100% and a specificity of 53% in female patients.

Conclusions: The data demonstrated that sex difference was present for the development of END in AIS patients with an increased risk for males. The present study also showed that admission glucose level could be an important predicting factor for END in female patients with AIS.

Neurologic deterioration in patients with acute ischemic stroke or transient ischemic attack

OBJECTIVE

To improve epidemiologic knowledge of neurologic deterioration (ND) in patients with acute ischemic stroke (AIS).

METHODS

In this prospective observational study, we captured ND prospectively in 29,446 patients with AIS admitted to 15 hospitals in Korea within 7 days of stroke onset. ND was defined as an increase in NIH Stroke Scale (NIHSS) score ≥2 (total), or ≥1 (motor or consciousness), or any new neurologic symptoms. Change in incidence rate after stroke onset, causes, factors associated with ND, modified Rankin Scale (mRS) score at 3 months and 1 year, and a composite of stroke, myocardial infarction, and all-cause death at 1 year were assessed.

RESULTS

ND occurred in 4,299 (14.6%) patients. The highest rate, 6.95 per 1,000 person-hours incidence, was within the first 6 hours, which decreased to 2.09 within 24-48 hours, and 0.66 within 72-96 hours after stroke onset. Old age, female sex, diabetes, early arrival, large artery atherosclerosis as a stroke subtype, high NIHSS scores, glucose level, systolic blood pressure, leukocytosis at admission, recanalization therapy, TIA without a relevant lesion, and steno-occlusion of relevant arteries were associated with ND. The causes were stroke progression (71.8%) followed by recurrence (8.5%). Adjusted relative risks (95% CI) for poor outcome (mRS 3-6) at 3 months and 1 year were 1.75 (1.70-1.80) and 1.70 (1.65-1.75), respectively. The adjusted hazard ratio (95% CI) for the composite event was 1.59 (1.45-1.74).

CONCLUSIONS

ND should be taken into consideration as a factor that may influence the outcome in acute ischemic stroke.

Asymmetrical cortical vein sign predicts early neurological deterioration in acute ischemic stroke patients with severe intracranial arterial stenosis or occlusion

Background

Susceptibility weighted imaging (SWI) provides an approximate assessment of tissue perfusion and shows prominent hypointense cortical veins in the ischemic territory because of the increased concentration of deoxyhemoglobin. We aimed to evaluate whether asymmetrical prominent cortical vein sign (APCVS) on SWI can predict early neurological deterioration (END) in acute ischemic stroke patients with severe intracranial arterial stenosis or occlusion (SIASO).

Methods

One hundred and nine acute ischemic stroke patients with SIASO who underwent SWI were retrospectively recruited. END was defined as an increase in the National Institutes of Health Stroke Scale score ≧2 points despite standard treatment in the first 72 h after admission. The APCVS was defined as more and/or large vessels with greater signal loss than those in the opposite hemisphere on SWI.

Results

Thirty out of the 109 (27.5%) patients developed END. Sixty (55.0%) patients presented with APCVS on SWI. APCVS occurred in 24 (80%) patients with END, whereas it only occurred in 36 (45.6%) patients without END (P = 0.001). Patients with APCVS were more likely to have END (40.0%, vs. 12.2%, P = 0.001) than those without END. Multivariate logistic regression indicated that APCVS (OR = 4.349, 95% C.I. = 1.580–11.970, P = 0.004) was a significant predictor of END in acute ischemic stroke patients with SIASO, adjusted for previous stroke history and acute infarct volume.

Conclusions

In acute ischemic stroke patients with SIASO, the APCVS might be a useful neuroimaging marker for predicting END, which suggests the importance of evaluation of perfusion status.

High risk of early neurological worsening of lacunar infarction

BACKGROUND AND PURPOSE

We aimed to evaluate factors associated with neurological worsening among patients with lacunar or non-lacunar infarction admitted within 3 hours and between 3 and 24 hours after stroke onset.

METHODS

All patients admitted to Haukeland university hospital between 2006 and 2016 with acute cerebral infarction on MRI and admission within 24 hours were included. Repeated National Institute of Health Stroke Scale (NIHSS) scoring was performed in all patients whenever possible. Neurological worsening during the hospital stay was defined as NIHSS score increase ≥3 compared to NIHSS score on admission.

RESULTS

In patients with lacunar infarction admitted within 3 hours of onset, neurological worsening was associated with low NIHSS score on admission, low body temperature, and leukoaraiosis, whereas only internal carotid artery stenosis or occlusion was associated with neurological worsening in non-lacunar infraction. For patients admitted 3-24 hours after onset, neurological worsening was associated with low body temperature, high systolic blood pressure, and short time from onset to admission in patients with lacunar infarction, whereas high systolic blood pressure, high NIHSS score on admission, middle cerebral artery occlusion, and high blood glucose were associated with neurological worsening in patients with non-lacunar infarction (all P < 0.05).

CONCLUSIONS

Lacunar infarctions with minor neurological deficits within 3 hours of stroke onset are at high risk of neurological worsening especially if concomitant low body temperature and leukoaraiosis.

Stroke Longitudinal Volumetric Measures Correlate with the Behavioral Score in Non-Human Primates

Stroke is the second leading cause of death worldwide. Brain imaging data from experimental rodent stroke models suggest that size and location of the ischemic lesion relate to behavioral outcome. However, such a relationship between these two variables has not been established in Non-Human Primate (NHP) models. Thus, we aimed to evaluate whether size, location, and severity of stroke following controlled Middle Cerebral Artery Occlusion (MCAO) in NHP model correlated to neurological outcome. Forty cynomolgus macaques underwent MCAO, after four mortalities, thirty-six subjects were followed up during the longitudinal study. Structural T2 scans were obtained by magnetic resonance imaging (MRI) prior to, 48 h, and 30 days post-MCAO. Neurological function was assessed with the Non-human Primate Stroke Scale (NHPSS). T2 whole lesion volume was calculated per subject. At chronic stages, remaining brain volume was computed, and the affected hemisphere parceled into 50 regions of interest (ROIs). Whole and parceled volumetric measures were analyzed in relation to the NHPSS score. The longitudinal lesion volume evaluation showed a positive correlation with the NHPSS score, whereas the remaining brain volume negatively correlated with the NHPSS. Following ROI parcellation, NHPSS outcome correlated with frontal, temporal, occipital, and middle white matter, as well as the internal capsule, and the superior temporal and middle temporal gyri, and the caudate nucleus. These results represent an important step in stroke translational research by demonstrating close similarities between the NHP stroke model and the clinical characteristics following a human stroke and illustrating significant areas that could represent targets for novel neuroprotective strategies.

The Role of Ejection Fraction to Clinical Outcome of Acute Ischemic Stroke Patients

AIMS

The aim of the study was to determine the effect of left ventricular ejection fraction on clinical outcomes of acute ischemic stroke patients.

STUDY DESIGN

This study design was a prospective cohort observational study.

PLACE AND DURATION OF STUDY

This study was conducted at Stroke Unit, Neurology Ward, and Cardiology Ward at the Dr. Sardjito Hospital, Yogyakarta, Indonesia, between July and December 2016.

MATERIALS AND METHODS

Hospitalized acute ischemic stroke patients were recruited, with sample was taken by consecutive sampling until reaching amount fulfilling inclusion criterion was 62 persons. In this study, clinical outcomes were measured by National Institutes of Health Stroke Scale (NIHSS) scores as well as dependent variables and left ventricular ejection fraction as independent variables. Logistic regression analyses were performed to discover any potential independent variable that can influence the left ventricular ejection fraction role at the clinical outcomes with NIHSS scores.

RESULTS

Multivariate analyses revealed that several variables were significantly interacted with the influence of left ventricular ejection fraction at the clinical outcomes with NIHSS scores. These variables were the left ventricular ejection fraction <48% (95% confidence interval [CI]: 0.691-0.925; P = 0.001), left ventricular ejection fraction + low high-density lipoprotein (HDL) (95% CI: 0.73-0.949; P = 0,001), left ventricular ejection fraction + diabetes mellitus (DM) (95% CI: 0.799-0.962; P = 0,001), and left ventricular ejection fraction + low HDL + DM (95% CI: 0.841-0.98; P = 0,001).

CONCLUSION

The influence of the lower left ventricular ejection fraction to clinical outcome of ischemic stroke patients has a worsening of neurological deficit outcome by considering the combination of several independent variables including the DM and low HDL.

Elevated body temperature in ischemic stroke associated with neurological improvement

OBJECTIVES

Some studies suggest that high body temperature within the first few hours of ischemic stroke onset is associated with improved outcome. We hypothesized an association between high body temperature on admission and detectable improvement within 6-9 hours of stroke onset.

MATERIALS AND METHODS

Consecutive ischemic stroke patients with NIHSS scores obtained within 3 hours and in the interval 6-9 hours after stroke onset were included. Body temperature was measured on admission.

RESULTS

A total of 315 patients with ischemic stroke were included. Median NIHSS score on admission was 6. Linear regression showed that NIHSS score 6-9 hours after stroke onset was inversely associated with body temperature on admission after adjusting for confounders including NIHSS score <3 hours after stroke onset (P<.001). The same result was found in patients with proximal middle cerebral occlusion on admission.

CONCLUSIONS

We found an inverse association between admission body temperature and neurological improvement within few hours after admission. This finding may be limited to patients with documented proximal middle cerebral artery occlusion on admission and suggests a beneficial effect of higher body temperature on clot lysis within the first three hours.

Risk Factors of Neurological Deterioration in Patients with Cerebral Infarction due to Large-Artery Atherosclerosis

BACKGROUND

In some patients with acute ischemic stroke, neurological deterioration (ND) is observed, and it is difficult to predict at the time of admission. Especially in some patients with large-artery atherosclerosis (LAA), aggressive medical treatments and surgical interventions might be helpful to prevent ND. Therefore, we investigated factors associated with ND in patients with LAA.

METHODS

We studied patients with LAA who were admitted to our hospital. We divided them into 2 groups with (group 1) and without deterioration (group 2), and evaluated their medical records, risk factors, and radiological findings, such as number of diffusion-positive lesion and degree of stenosis.

RESULTS

Our study population consisted of 171 patients; 71 (41.5%) did and 100 (58.5%) did not suffer deterioration. By univariate analysis, blood pressure (BP), heart rate, National Institutes of Health Stroke Scale (NIHSS) score, number of diffusion-positive lesion, count of red blood cell, high-density lipoprotein, and degree of stenosis differed significantly between the 2 groups. By multivariate analysis, systolic BP (≥170 mm Hg, odds ratio: 7.20, P <.001) was associated with ND. Furthermore, number of diffusion-weighted image (DWI)-positive lesion (≥8), degree of stenosis (>80.0%), and NIHSS score (≥4) were also independent factors associated with ND.

CONCLUSIONS

High BP, severity of neurological deficit at the time of admission, and radiological findings, such as degree of stenosis and number of DWI-positive lesion, are independently associated with ND in patients with LAA.

Effect of paracetamol (acetaminophen) on body temperature in acute stroke: A meta-analysis

PURPOSE

The objective of this study was to assess the efficacy of paracetamol (acetaminophen) on body temperature in acute stroke.

METHODS

Medline, Cochrane Central Register of Controlled Trials, EMBASE, Chinese BioMedical Literature Database, China National Knowledge Infrastructure, and the World Health Organization (WHO) International Clinical Trials Registry Platform were searched electronically. Relevant journals and references of studies included were hand-searched for randomized controlled trials (RCT) and controlled clinical trials (CCT) regarding the efficacy of paracetamol (acetaminophen) on body temperature in acute stroke. Two reviewers independently performed data extraction and quality assessment. Data were analyzed using RevMan 5.3 software by the Cochrane Collaboration.

RESULTS

Five studies were included. To compare the efficacy of paracetamol (acetaminophen) in acute stroke, the pooled RR (Risk Ratio) and its 95% CI of body temperature reduction at 24h from the start of treatment were -0.3 (95% CI: -0.52 to -0.08), with statistical significance (P=0.007). Consistently, the pooled RR (Risk Ratio) and its 95% CI of body temperature at 24h from the start of treatment were -0.22 (-0.29, -0.15), with statistical significance (P<0.00001). When analyzing the body temperature reduction after 5days from the start of treatment, the pooled RR (Risk Ratio) and its 95% CI were 0.04 (95% CI: -0.20 to 0.29), with no statistical significance (P=0.73). For functional outcome (mRS≤2) analysis, the pooled RR and its 95% CI were 1.08 (0.88, 1.32), with no statistical significance (P=0.45). In addition, the difference of serious adverse events between acetaminophen and placebo was 0.86 (95% CI: 0.62 to 1.2), with no statistical significance (P=0.27).

CONCLUSION

Acetaminophen was revealed to have some favorable influence in body temperature reduction in acute stroke, but showed no important effect on improving functional outcome and reducing adverse events of patients.

WHAT THIS PAPER ADDS

What is already known on this subject? Paracetamol (acetaminophen) is one of the most commonly used antipyretic drugs and has some capability to reduce body temperature through acting on central nervous system.

WHAT THIS STUDY ADDS

Acetaminophen showed some capability to decrease body temperature for acute stroke. Acetaminophen could not improve functional outcome and reduce adverse events of patients with acute stroke.

Sex Differences in the Cerebral Collateral Circulation

Premenopausal women and intact female rodents sustain smaller cerebral infarctions than males. Several sex-dependent differences have been identified as potential contributors, but many questions remain unanswered. Mice exhibit wide variation in native collateral number and diameter (collateral extent) that is dependent on differences in genetic background, aging, and other comorbidities and that contributes to their also-wide differences in infarct volume. Likewise, variation in infarct volume correlates with differences in collateral-dependent blood flow in patients with acute ischemic stroke. We examined whether extent of pial collateral arterioles and posterior communicating collateral arteries (PComAs) differ depending on sex in young, aged, obese, hypertensive, and genetically different mice. We combined new data with meta-analysis of our previously published data. Females of C57BL/6J (B6) and BALB/cByJ (BC) strains sustained smaller infarctions than males after permanent MCA occlusion. This protection was unchanged in BC mice after introgression of the B6 allele of Dce1, the major genetic determinant of variation in pial collaterals among mouse strains. Consistent with this, collateral extent in these and other strains did not differ with sex. Extent of PComAs and primary cerebral arteries also did not vary with sex. No dimorphism was evident for loss of pial collateral number and/or diameter (collateral rarefaction) caused by aging, obesity, and hypertension, nor for collateral remodeling after pMCAO. However, rarefaction was greater in females with long-standing hypertension. We conclude that smaller infarct volume in female mice is not due to greater collateral extent, greater remodeling, or less rarefaction caused by aging, obesity, or hypertension.

Early neurological worsening in acute ischaemic stroke patients

Objectives

Neurological worsening in acute ischaemic stroke patients is common with significant morbidity and mortality.

Aims

To determine the factors associated with early neurological worsening within the first 9 h after onset of acute ischaemic stroke.

Materials & methods

The National Institute of Health Stroke Scale (NIHSS) was used to assess stroke severity. Early neurological worsening was defined as NIHSS score increase ≥4 NIHSS points within 9 h of symptom onset compared to NIHSS score within 3 h of symptom onset. Patients with early neurological worsening were compared to patients with unchanged or improved NIHSS scores.

Results

Of the 2484 patients admitted with ischaemic stroke, 552 patients had NIHSS score within 3 h of symptom onset, and 44 (8.0%) experienced early neurological worsening. The median NIHSS on admission was 8.4 in both groups. Early neurological worsening was associated with low body temperature on admission (P = 0.01), proximal compared to distal MCA occlusion (P = 0.007) and with ipsilateral internal carotid artery stenosis >50% or occlusion (P = 0.04). Early neurological worsening was associated with higher NIHSS day 7 (P < 0.001) and higher mortality within 7 days of stroke onset (P = 0.005).

Conclusions

Early neurological worsening has serious consequences for the short‐term outcome for patients with acute ischaemic stroke and is associated with low body temperature on admission, and with extracranially and intracranially large‐vessel stenosis or occlusion.