Acute hyperglycemia adversely affects stroke outcome: a magnetic resonance imaging and spectroscopy study

Comparison of admission random glucose, fasting glucose, and glycated hemoglobin in predicting the neurological outcome of acute ischemic stroke: a retrospective study

Background

Hyperglycemia is a known predictor of negative outcomes in stroke. Several glycemic measures, including admission random glucose, fasting glucose, and glycated hemoglobin (HbA1c), have been associated with bad neurological outcomes in acute ischemic stroke, particularly in nondiabetic patients. However, the predictive power of these glycemic measures is yet to be investigated.

Methods

This retrospective study enrolled 484 patients with acute ischemic stroke from January 2009 to March 2013, and complete records of initial stroke severity, neurological outcomes at three months, and glycemic measures were evaluated. We examined the predictive power of admission random glucose, fasting glucose, and HbA1c for neurological outcomes in acute ischemic stroke. Furthermore, subgroup analyses of nondiabetic patients and patients with diabetes were performed separately.

Results

Receiver operating characteristic (ROC) analysis revealed that admission random glucose and fasting glucose were significant predictors of poor neurological outcomes, whereas HbA1c was not (areas under the ROC curve (AUCs): admission random glucose = 0.564, p = 0.026; fasting glucose = 0.598, p = 0.001; HbA1c = 0.510, p = 0.742). Subgroup analyses of nondiabetic patients and those with diabetes revealed that only fasting glucose predicts neurological outcomes in patients with diabetes, and the AUCs of these three glycemic measures did not differ between the two groups. A multivariate logistic regression analysis of the study patients indicated that only age, initial stroke severity, and fasting glucose were independent predictors of poor neurological outcomes, whereas admission random glucose and HbA1c were not (adjusted odds ratio: admission random glucose = 1.002, p = 0.228; fasting glucose = 1.005, p = 0.039; HbA1c = 1.160, p = 0.076). Furthermore, subgroup multivariate logistic regression analyses of nondiabetic patients and those with diabetes indicated that none of the three glycemic measures were associated with poor neurological outcomes.

Discussion

Fasting glucose is an independent predictor of poor neurological outcomes in patients with acute ischemic stroke and had greater predictive power than that of admission random glucose and HbA1c. The predictive power of glycemic measures for poor neurological outcomes did not differ significantly between the nondiabetic patients and those with diabetes.

Poststroke glycemic variability increased recurrent cardiovascular events in diabetic patients

BACKGROUND AND PURPOSE

The association between blood glucose fluctuation and poststroke cardiovascular outcome has been largely unknown. This study attempted to evaluate whether initial glycemic variability increases cardiovascular events and mortality in diabetic patients with acute ischemic stroke.

METHODS

We recruited consecutive patients with acute ischemic stroke or transient ischemic attack from March 2005 to December 2014. A total of 674 patients with diabetes within 72 hours from stroke onset were included. The serum glucose levels were checked 4 times per day during the initial 3 hospital days. J-index, coefficients of variation and standard deviation were calculated for glycemic variability. Composite outcome (nonfatal stroke, nonfatal myocardial infarction, cardiovascular death) and all-cause mortality at 3 months were prospectively captured. Multivariable logistic regression analyses were done adjusting for covariates which can influence on cardiovascular outcomes.

RESULTS

Cardiovascular composite outcomes at 3 months were identified in 71 (10.5%): 11 (6.5%), 15 (8.9%), 18 (10.7%) and 27 (16.0%) in each J-index quartiles (P = .035). The highest quartile of J-index had significantly higher cardiovascular death (4.2%, 3.6%, 6.5% and 11.8%; P = .008). In multivariable logistic regression, age (odds ratio [OR] 1.045; 95% confidence interval [CI] 1.006-1.084), P = .021), NIH stroke scale (OR 1.078; 95% CI 1.024-1.134, P = .004), and the highest J-index (OR 12.058; 95% 1.890-76.912, P = .008) were significantly associated with 3-month cardiovascular composite outcome. Increased cardiovascular outcomes in highest J-index quartile were similar in both euglycemic and hyperglycemic groups.

CONCLUSION

The initial glycemic variability might increase cardiovascular events in acute ischemic stroke patients with diabetes.

Hyperglycemia and diabetes have different impacts on outcome of ischemic and hemorrhagic stroke

INTRODUCTION

Stroke is the second leading cause of long-term disability and death worldwide. Diabetes and hyperglycemia may impact the outcome of stroke. We examined the impact of hyperglycemia and diabetes on in-hospital death among ischemic and hemorrhagic stroke patients.

MATERIAL AND METHODS

Data from 766 consecutive patients with ischemic (83.15%) and hemorrhagic stroke were analyzed. Patients were classified into four groups: ischemic and diabetic; ischemic and non-diabetic; hemorrhagic and diabetic; and hemorrhagic and non-diabetic. Serum glucose was measured on admission at the emergency department together with biochemical and clinical parameters.

RESULTS

Mean admission glucose in ischemic stroke patients with diabetes was higher than in non-diabetic ones (p < 0.001) and in hemorrhagic stroke patients with diabetes than in those without diabetes (p < 0.05). Mean admission glucose in all patients who died was significantly higher than in patients who survived. In multivariate analysis, the risk factors for outcome in patients with ischemic stroke and without diabetes were age, admission glucose level and estimated glomerular filtration rate (eGFR), while in diabetics they were female gender, admission glucose level, and eGFR; in patients with hemorrhagic stroke and without diabetes they were age and admission glucose levels. The cut-off value in predicting death in patients with ischemic stroke and without diabetes was above 113.5 mg/dl, while in diabetics it was above 210.5 mg/dl.

CONCLUSIONS

Hyperglycemia on admission is associated with worsened clinical outcome and increased risk of in-hospital death in ischemic and hemorrhagic stroke patients. Diabetes increased the risk of in-hospital death in hemorrhagic stroke patients, but not in ischemic ones.

Hyperglycemia as a prognosis predictor of length of stay and functional outcomes in patients with acute ischemic stroke

BACKGROUND

Hyperglycemia has been shown to influence prognosis outcome of stroke. The objective of this study was to determine the correlation between hyperglycemia with length of stay (LOS) and functional outcomes in ischemic stroke patients. This is the first study to correlate hyperglycemia in ischemic stroke patients with their functional outcome as assessed by using Barthel index.

METHODS

This is a prospective cohort study of patients admitted to the Stroke Unit of Dr. Sardjito General Hospital for ischemic stroke from January 2012 to June 2014. Subjects were selected in a consecutive manner until the required number of subjects was obtained. Data collected from medical records included the baseline social demographic variables and clinical variables. Bivariate and multivariate analyses with multiple linear regression analysis were used to identify correlation between hyperglycemia with LOS and functional outcomes.

RESULTS

In total, 208 patients were included, of which 126 (60.6%) were men. The mean age was 61.18 (SD = 10.45), and the mean LOS in our study was 4.52 (SD = 5.89) d. For the univariate analysis, factors associated with LOS were history of diabetes (p = 0.003), urinary tract infection (p = 0.025), hyperglycemia (p < 0.001) and moderate to severe Barthel index on admission (p < 0.001), and the independent factor was hyperglycemia (β: 6.212, p < 0.001) based on multivariate analysis. Furthermore, hyperglycemia was an independent factor of functional outcomes as measured with Barthel index (β: 9.185, p < 0.001).

CONCLUSIONS

Hyperglycemia is a prognosis predictor of LOS and functional outcomes of patients with acute ischemic stroke measured by discharge Barthel index.

Neurologic complications of cardiac and vascular surgery

This chapter will provide an overview of the major neurologic complications of common cardiac and vascular surgeries, such as coronary artery bypass grafting and carotid endarterectomy. Neurologic complications after cardiac and vascular surgeries can cause significant morbidity and mortality, which can negate the beneficial effects of the intervention. Some of the complications to be discussed include ischemic and hemorrhagic stroke, seizures, delirium, cognitive dysfunction, cerebral hyperperfusion syndrome, cranial nerve injuries, and peripheral neuropathies. The severity of these complications can range from mild to lethal. The etiology of complications can include a variety of mechanisms, which can differ based on the type of cardiac or vascular surgery that is performed. Our knowledge about neuropathology, prevention, and management of surgical complications is growing and will be discussed in this chapter. It is imperative for clinicians to be familiar with these complications in order to narrow the differential diagnosis, start early management, anticipate the natural history, and improve outcomes.

Acute, unanticipated, and prolonged superior vena cava occlusion during pneumonectomy

Acute, unanticipated superior vena cava (SVC) occlusion during thoracic surgery can have profound hemodynamic consequences and lead to devastating neurologic injury. We describe the successful anesthetic management of a pneumonectomy complicated by prolonged intraoperative SVC occlusion lasting a total of 290 minutes. To our knowledge, this represents the longest reported SVC occlusion time with no subsequent neurologic sequelae. Based on our favorable outcome and a review of the relevant literature, we offer a discussion of strategies for anesthetic management.

Management of acute cerebral ischaemia

Stroke is a major public health issue. Many are treatable in the acute stage, provided patients are admitted soon enough. The overall incidence of stroke in Western countries is approximately 2400 per year per million inhabitants, and 80% are due to cerebral ischaemia. The prevalence is approximately 12,000 per million inhabitants. Stroke is associated with increased long-term mortality, handicap, cognitive and behavioural impairments, recurrence, and an increased risk of other types of vascular events. There is strong evidence that stroke patients should be treated in dedicated stroke units; each time 24 patients are treated in a stroke unit, instead of a conventional ward, one death and one dependence are prevented. This effect does not depend on age, severity, and the stroke subtype. For this reason, stroke unit care is the cornerstone of the treatment of stroke, aiming at the detection and management of life-threatening emergencies, stabilization of most physiological parameters, and prevention of early complications. In cerebral ischaemia, besides this general management, specific therapies include intravenous recombinant tissue plasminogen activator, given as soon as possible and before 4.5hours, mechanical thrombectomy on top of rt-PA or alone in case of contra-indication to rt-PA, in patients with proximal large-vessel occlusion, aspirin 300mg, immediately or after 24hours in case of thrombolysis, and, in a few patients, decompressive surgery.

Hyperglycaemia and mortality

Several studies over the last decade have linked hyperglycaemia on hospital admission with subsequent mortality risk. The evidence is strongest for patients with myocardial infarction or acute coronary syndromes, but evidence also links hyperglycaemia with mortality from stroke and other medical illnesses. The effect seems independent of a previous diagnosis of diabetes mellitus; indeed, some studies suggest that mortality may be higher in patients with hyperglycaemia and no previous diabetes diagnosis compared with known diabetic patients. The effect on outcome of therapeutically lowering blood glucose levels has been considered in a small number of studies, but so far the results are conflicting. Further work is needed, focusing on more standardized surveys—previous studies vary in their use of blood or plasma, as well as cut-off levels for hyperglycaemia—and larger intervention studies.

Early care of acute hyperglycemia benefits the outcome of traumatic brain injury in rats

OBJECTIVE

Previous animal studies showed contradictory clinical observations on whether acute hyperglycemia contributes to poor outcome in traumatic brain injury (TBI). Herein, we tried to clarify this issue.

METHODS

Striking with depths of 3.0-4.25mm at right occipitoparietal brain region and with depth of 3.75mm at right/left occipitoparietal or right/left frontoparietal brain region were performed, respectively. Blood glucose and insulin levels were traced every four hours from 1 to 72h after striking. HOMA2-%S and HOMA2-%β were calculated. Modified neurological severity scores (mNSS) were used to evaluate neurological deficit within 72h.

RESULTS

Striking with depths of 3.5-4.25mm induced increase in blood glucose lasting up to 24h after striking. The levels of blood glucose after striking with depths of 3.75-4.25mm were significantly different from that of striking with the depth of 3.0mm. Striking with depth of 3.75mm at right/left occipitoparietal region induced higher blood glucose in 24h than that at right/left frontoparietal region. Insulin concentration increased slowly during 72h after striking. Striking also induced decrease in insulin sensitivity and secretion lasting 72h. Evaluation of mNSS revealed that severe striking (beyond 3.75mm) worsened nerve function than slight striking (<3.0mm). Intervention of acute hyperglycemia could decrease the mNSS from 2 to 7 days after TBI.

CONCLUSION

Our results suggested that only severe TBI could induce acute hyperglycemia by itself, and early care of acute hyperglycemia could benefit the outcome of TBI patients.

Elevated Fasting Blood Glucose Is Predictive of Poor Outcome in Non-Diabetic Stroke Patients: A Sub-Group Analysis of SMART

BACKGROUND

Although increasing evidence suggests that hyperglycemia following acute stroke adversely affects clinical outcome, whether the association between glycaemia and functional outcome varies between stroke patients with\without pre-diagnosed diabetes remains controversial. We aimed to investigate the relationship between the fasting blood glucose (FBG) and the 6-month functional outcome in a subgroup of SMART cohort and further to assess whether this association varied based on the status of pre-diagnosed diabetes.

METHODS

Data of 2862 patients with acute ischemic stroke (629 with pre-diagnosed diabetics) enrolled from SMART cohort were analyzed. Functional outcome at 6-month post-stroke was measured by modified Rankin Scale (mRS) and categorized as favorable (mRS:0-2) or poor (mRS:3-5). Binary logistic regression model, adjusting for age, gender, educational level, history of hypertension and stroke, baseline NIHSS and treatment group, was used in the whole cohort to evaluate the association between admission FBG and functional outcome. Stratified logistic regression analyses were further performed based on the presence/absence of pre-diabetes history.

RESULTS

In the whole cohort, multivariable logistical regression showed that poor functional outcome was associated with elevated FBG (OR1.21 (95%CI 1.07-1.37), p = 0.002), older age (OR1.64 (95% CI1.38-1.94), p<0.001), higher NIHSS (OR2.90 (95%CI 2.52-3.33), p<0.001) and hypertension (OR1.42 (95%CI 1.13-1.98), p = 0.04). Stratified logistical regression analysis showed that the association between FBG and functional outcome remained significant only in patients without pre-diagnosed diabetes (OR1.26 (95%CI 1.03-1.55), p = 0.023), but not in those with premorbid diagnosis of diabetes (p = 0.885).

CONCLUSION

The present results demonstrate a significant association between elevated FBG after stroke and poor functional outcome in patients without pre-diagnosed diabetes, but not in diabetics. This finding confirms the importance of glycemic control during acute phase of ischemic stroke especially in patients without pre-diagnosed diabetes. Further investigation for developing optimal strategies to control blood glucose level in hyperglycemic setting is therefore of great importance.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00664846.

Admission hyperglycemia and outcome after intravenous thrombolysis: is there a difference among the stroke-subtypes?

BACKGROUND

The prognostic influence of hyperglycemia in acute stroke has been well established. While in cortical stroke there is a strong association between hyperglycemia and poor outcome, this relation is less clear in lacunar stroke. It has been suggested that this discrepancy is present among patients treated with intravenous tissue plasminogen activator (tPA), but confirmation is needed.

METHODS

In two prospectively collected cohorts of patient treated with intravenous tPA for acute ischemic stroke, we investigated the effect of hyperglycemia (serum glucose level >8 mmol/L) on functional outcome in lacunar and non-lacunar stroke. Poor functional outcome was defined as modified Rankin Scale score ≥ 3 at 3 months.

RESULTS

A total of 1012 patients was included of which 162 patients (16%) had lacunar stroke. The prevalence of hyperglycemia did not differ between stroke subtypes (22% vs 21%, p = 0.85). In multivariate analysis hyperglycemia was associated with poor functional outcome in non-lacunar stroke (OR 2.1, 95% CI 1.39-3.28, p = 0.001). In patients with lacunar stroke, we did not find an association (OR 1.8, 95% CI 0.62-4.08, p = 0.43).

CONCLUSION

This study confirms a difference in prognostic influence of hyperglycemia between non-lacunar and lacunar ischemic stroke.

Impact of glucose fluctuation on acute cerebral infarction in type 2 diabetes

OBJECTIVE

This study aimed to describe the frequency and temporal profile of acute cerebral infarction (ACI) using a continuous glucose monitoring system (CGMS) in patients with and without type 2 diabetes mellitus (T2DM) and explore the impact of blood glucose fluctuations on the short-term prognosis of ACI.

METHODS

The subjects were divided into four groups: T2DM with acute cerebral infarction (DMCI, Group A, n=56); T2DM without acute cerebral infarction (DM-NCI, Group B, n=36); Acute cerebral infarction patients without T2DM (NDM-CI, Group C, n=54); Healthy control group (NG, Group D, n=36). The National Institutes of Health Stoke Scale (NIHSS) and modified Rankin scale (mRs) were collected in Group A and C. All subjects were monitored for 72 hours using the CGMS. Indices such as fasting blood glucose (FBG) and mean amplitude of glycemic excursions (MAGE) were calculated. Glycemic excursions were compared between Group A, B, C and Group D, respectively. Multiple linear regression analysis and logistic analysis was applied.

RESULTS

MAGE is related to NIHSS, homocysteine (HCY), HOMA-IR, FBG, CRP and IMT, while NIHSS is related to CRP, HCY, HOMA-IR, IMT. The factors impacting the short-term prognosis of ACI were NIHSS, HBA1C and MAGE.

CONCLUSION

Larger glucose fluctuations are associated with more stroke risk factors and are associated with a poorer short-term prognosis. More attention should be paid to glucose fluctuations in patients with ACI and a history of T2DM.

Association between Serum Lipid Profiles and Early Neurological Deterioration in Acute Ischemic Stroke

BACKGROUND

Dyslipidemia is associated with chronic cardiovascular disease. However, the effect of dyslipidemia on acute ischemic stroke is unclear. We hypothesized that dyslipidemia could contribute to early neurological deterioration (END) after ischemic stroke.

METHODS

A total of 410 acute ischemic stroke patients who were admitted to our stroke center within 24 hours after ictus were consecutively included in this study. END was defined as any new neurological symptoms/signs or any neurological worsening occurring during the admission and/or within 3 weeks after the index stroke. Multivariable logistic regression was used to examine the independent association between lipid indices and END.

RESULTS

Mean age was 68.2 ± 13.3 years, 241 (58.8%) were male, and 78 (19.0%) experienced END. Almost END occurred within 3 days after admission (n = 70, 89.7%), and the majority of END was stroke progression (n = 68, 87.1%). In univariate analysis, high-density lipoprotein (HDL)-cholesterol levels (per 1 mmol/L; odds ratio [OR] .37; 95% CI .17-.80; P = .012) and apolipoprotein B (apoB)/apoA-I ratio (per 1 increase; OR 3.71; 95% CI 1.48-9.29; P = .005) were associated with END. In the multivariable analysis, adjusted ORs of END for the highest quartile of HDL-cholesterol and apoB/apoA-I ratio were .42 (95% CI .19-.94; P = .034) and 2.37 (95% CI 1.02-5.53; P = .045), respectively. The ratio of apoB/apoA-I was associated with END in large artery atherosclerosis stroke but not in other stroke subtypes.

CONCLUSIONS

Independent association of low HDL-cholesterol and high apoB/apoA-I ratio with END warrants further research to investigate if correction of the lipid profile during the acute period of ischemic stroke could reduce the risk of END.

Rationale and design of Short-Term EXenatide therapy in Acute ischaemic Stroke (STEXAS): a randomised, open-label, parallel-group study

INTRODUCTION

Both hyperglycaemia and hypoglycaemia in acute ischaemic stroke (AIS) are associated with increased infarct size and worse functional outcomes. Thus, therapies that can maintain normoglycaemia during stroke are clinically important. Glucagon-like peptide 1 (GLP-1) analogues, including exenatide, are routinely used in the treatment of hyperglycaemia in type 2 diabetes, but data on the usefulness of this class of agents in the management of elevated glucose levels in AIS are limited. Owing to their glucose-dependent mechanism of action, GLP-1 analogues are associated with a low risk of hypoglycaemia, which may give them an advantage over intensive insulin therapy in the acute management of hyperglycaemia in this setting.

METHODS AND ANALYSIS

The Short-Term EXenatide therapy in Acute ischaemic Stroke study is a randomised, open-label, parallel-group pilot study designed to investigate the efficacy of exenatide at lowering blood glucose levels in patients with hyperglycaemia with AIS. A total of 30 patients presenting with AIS and blood glucose levels >10 mmol/L will be randomised to receive the standard therapy (intravenous insulin) or intravenous exenatide for up to 72 h. Outcomes including blood glucose levels within the target range (5-10 mmol/L), the incidence of hypoglycaemia and the feasibility of administering intravenous exenatide in this patient population will be assessed. A follow-up visit at 3 months will facilitate evaluation of neurological outcomes post-stroke.

ETHICS AND DISSEMINATION

This study has been approved by the local Institutional Review Board (Northern Sydney Local Health District Human Research Ethics Committee). The study results will be communicated via presentations at scientific conferences and through publication in peer-reviewed journals.

CONCLUSIONS

As GLP-1 analogues require elevated glucose levels to exert their insulin potentiating activity, the use of exenatide in the management of hyperglycaemia in AIS may reduce the incidence of hypoglycaemia, thereby conferring a benefit in morbidity and mortality for patients in the long term.

TRIAL REGISTRATION NUMBER

ACTRN12614001189617.

Admission Glucose Level Predicts In-hospital Mortality in Patients with Acute Pulmonary Embolism Who Were Treated with Thrombolytic Therapy

BACKGROUND

Elevated admission serum glucose level is associated with unfavourable clinical outcomes in various clinical conditions. The aim of this study was to investigate the relationship between admission glucose levels and in-hospital and long-term adverse clinical outcomes in patients with pulmonary embolism (PE) treated with thrombolytic therapy.

METHODS

A total of 183 consecutive confirmed acute PE patients (98 female and 85 male; mean age 61.9 ± 15.7 years) who were treated with thrombolytic therapy enrolled in this study. The study population was categorised into four quartiles according to admission serum glucose levels (group I: glucose ≤115 mg/dl; group II: glucose >115-141 mg/dl; group III: glucose >141-195 mg/dl; and group IV: glucose ≥196 mg/dl).

RESULTS

In-hospital mortality was significantly higher in group IV (28.8 %) compared to group III (15.2 %), group II (6.6 %), and group I (2.1 %) (p < 0.001). In multivariate analysis, admission glucose level (OR 1.013, 95 % CI 1.004-1.021, p = 0.004) and admission anaemia (OR 0.602, 95 % CI 0.380-0.955, p = 0.03) were independent predictors of in-hospital mortality. The mean follow-up period was 34 months. During long-term follow-up, all-cause mortality, recurrent PE, major and minor bleeding were similar among the four groups.

CONCLUSION

Admission glucose level is a simple, inexpensive, easily available, and effective laboratory parameter for predicting in-hospital mortality in patients with PE.

Resveratrol provides neuroprotection by inhibiting phosphodiesterases and regulating the cAMP/AMPK/SIRT1 pathway after stroke in rats

Dysfunction of energy metabolism can be a significant and fundamental pathophysiological basis for strokes. In studies of both humans and rodents, resveratrol, a natural polyphenol, has been reported to provide protection from cerebral ischemic injury by regulating expression of silent mating type information regulation 2 homolog 1 (SIRT1). However, direct evidence demonstrating that resveratrol exerts neuroprotection from cerebral ischemia injury by decreasing energy consumption is still lacking. Therefore, the aim of this study was to elucidate the mechanisms and signaling pathways through which resveratrol regulates energy metabolism in the ischemic brain, and to identify potential targets of resveratrol. ATP levels in brain tissues were detected by high performance liquid chromatography. SIRT1 and the phosphorylation of adenosine-monophosphate-activated protein kinase (P-AMPK) expressiones were evaluated by western blot. Levels of phosphodiesterase (PDEs) and cAMP were quantitated by real-time PCR and ELISA, respectively. Results showed that resveratrol significantly reduced the harmful effects of cerebral ischemic injury in vivo. Moreover, levels of ATP, p-AMPK, SIRT1, and cAMP were increased by resveratrol and PDE inhibitors. In conclusion, our findings indicate that resveratrol provides neuroprotection by inhibiting PDEs and regulating the cAMP/AMPK/SIRT1 pathway, which reduces ATP energy consumption during ischemia.

Distinct and complementary roles for α and β isoenzymes of PKC in mediating vasoconstrictor responses to acutely elevated glucose

BACKGROUND AND PURPOSE

We investigated the hypothesis that elevated glucose increases contractile responses in vascular smooth muscle and that this enhanced constriction occurs due to the glucose-induced PKC-dependent inhibition of voltage-gated potassium channels.

EXPERIMENTAL APPROACH

Patch-clamp electrophysiology in rat isolated mesenteric arterial myocytes was performed to investigate the glucose-induced inhibition of voltage-gated potassium (Kv ) current. To determine the effects of glucose in whole vessel, wire myography was performed in rat mesenteric, porcine coronary and human internal mammary arteries.

KEY RESULTS

Glucose-induced inhibition of Kv was PKC-dependent and could be pharmacologically dissected using PKC isoenzyme-specific inhibitors to reveal a PKCβ-dependent component of Kv inhibition dominating between 0 and 10 mM glucose with an additional PKCα-dependent component becoming evident at concentrations greater than 10 mM. These findings were supported using wire myography in all artery types used, where contractile responses to vessel depolarization and vasoconstrictors were enhanced by increasing bathing glucose concentration, again with evidence for distinct and complementary PKCα/PKCβ-mediated components.

CONCLUSIONS AND IMPLICATIONS

Our results provide compelling evidence that glucose-induced PKCα/PKCβ-mediated inhibition of Kv current in vascular smooth muscle causes an enhanced constrictor response. Inhibition of Kv current causes a significant depolarization of vascular myocytes leading to marked vasoconstriction. The PKC dependence of this enhanced constrictor response may present a potential therapeutic target for improving microvascular perfusion following percutaneous coronary intervention after myocardial infarction in hyperglycaemic patients.

Prognostic Significance of Hyperglycemia in Acute Intracerebral Hemorrhage: The INTERACT2 Study

BACKGROUND AND PURPOSE

We aimed to determine associations of baseline blood glucose and diabetes mellitus with clinical outcomes in participants of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT2).

METHODS

INTERACT2 was an international prospective, open, blinded end point, randomized controlled trial of 2839 patients with spontaneous intracerebral hemorrhage (<6 hours) and elevated systolic blood pressure randomly assigned to intensive (target systolic blood pressure <140 mm Hg) or guideline-based (systolic blood pressure <180 mm Hg) BP management. Associations of hyperglycemia at presentation (>6.5 mmol/L) and combined and separate poor outcomes of death and major disability (scores of 3-6, 3-5, and 6, respectively, on the modified Rankin scale) at 90 days were determined in logistic regression models.

RESULTS

In 2653 patients with available data, there were 1348 (61%) with hyperglycemia and 292 (11%) with diabetes mellitus. Associations of baseline blood glucose and poor outcome were strong and near continuous. After adjustment for baseline variables, the highest fourth (7.9-25.0 mmol/L) of blood glucose was significantly associated with combined poor outcome (adjusted odds ratio 1.35, 95% confidence interval 1.01-1.80; P trend 0.015). Diabetes mellitus also predicted poor outcome (adjusted odds ratio 1.46, 95% confidence interval 1.05-2.02; P=0.023), though more important for residual disability than death on separate analysis.

CONCLUSIONS

Hyperglycemia and diabetes mellitus are independent predictors of poor outcome in patients with predominantly mild to moderate severity of intracerebral hemorrhage. These data support guideline recommendations for good glycemic control in patients with intracerebral hemorrhage.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00716079.

The Influence of Acute Hyperglycemia in an Animal Model of Lacunar Stroke That Is Induced by Artificial Particle Embolization

Animal and clinical studies have revealed that hyperglycemia during ischemic stroke increases the stroke's severity and the infarct size in clinical and animal studies. However, no conclusive evidence demonstrates that acute hyperglycemia worsens post-stroke outcomes and increases infarct size in lacunar stroke. In this study, we developed a rat model of lacunar stroke that was induced via the injection of artificial embolic particles during full consciousness. We then used this model to compare the acute influence of hyperglycemia in lacunar stroke and diffuse infarction, by evaluating neurologic behavior and the rate, size, and location of the infarction. The time course of the neurologic deficits was clearly recorded from immediately after induction to 24 h post-stroke in both types of stroke. We found that acute hyperglycemia aggravated the neurologic deficit in diffuse infarction at 24 h after stroke, and also aggravated the cerebral infarct. Furthermore, the infarct volumes of the basal ganglion, thalamus, hippocampus, and cerebellum but not the cortex were positively correlated with serum glucose levels. In contrast, acute hyperglycemia reduced the infarct volume and neurologic symptoms in lacunar stroke within 4 min after stroke induction, and this effect persisted for up to 24 h post-stroke. In conclusion, acute hyperglycemia aggravated the neurologic outcomes in diffuse infarction, although it significantly reduced the size of the cerebral infarct and improved the neurologic deficits in lacunar stroke.

Recovery Potential After Acute Stroke

In acute stroke, the major factor for recovery is the early use of thrombolysis aimed at arterial recanalization and reperfusion of ischemic brain tissue. Subsequently, neurorehabilitative training critically improves clinical recovery due to augmention of postlesional plasticity. Neuroimaging and electrophysiology studies have revealed that the location and volume of the stroke lesion, the affection of nerve fiber tracts, as well as functional and structural changes in the perilesional tissue and in large-scale bihemispheric networks are relevant biomarkers of post-stroke recovery. However, associated disorders, such as mood disorders, epilepsy, and neurodegenerative diseases, may induce secondary cerebral changes or aggravate the functional deficits and, thereby, compromise the potential for recovery.

Fermented soybeans, Chungkookjang, prevent hippocampal cell death and β-cell apoptosis by decreasing pro-inflammatory cytokines in gerbils with transient artery occlusion

Since Chungkookjang, a short-term fermented soybean, is known to improve glucose metabolism and antioxidant activity, it may prevent the neurological symptoms and glucose disturbance induced by artery occlusion. We investigated the protective effects and mechanisms of traditional (TFC) and standardized Chungkookjang fermented with Bacillus licheniformis (BLFC) against ischemia/reperfusion damage in the hippocampal CA1 region and against hyperglycemia after transient cerebral ischemia in gerbils. Gerbils were subjected to either an occlusion of the bilateral common carotid arteries for 8 min to render them ischemic or a sham operation. Ischemic gerbils were fed either a 40% fat diet containing 10% of either cooked soybean (CSB), TFC, or BLFC for 28 days. Neuronal cell death and cytokine expression in the hippocampus, neurological deficit, serum cytokine levels, and glucose metabolism were measured. TFC and BLFC contained more isoflavonoid aglycones than CSB. Artery occlusion increased the expressions of IL-1β and TNF-α as well as cell death in the hippocampal CA1 region and induced severe neurological symptoms. CSB, TFC, and BLFC prevented the neuronal cell death and the symptoms such as dropped eyelid, bristling hair, reduced muscle tone and flexor reflex, and abnormal posture and walking patterns, and suppressed cytokine expressions. CSB was less effective than TFC and BLFC. Artery occlusion induced glucose intolerance due to decreased insulin secretion and β-cell mass. TFC and BLFC prevented the impairment of glucose metabolism by artery occlusion. Especially TFC and BLFC increased β-cell proliferation and suppressed the β-cell apoptosis by suppressing TNF-α and IL-1β which in turn decreased cleaved caspase-3 that caused apoptosis. In conclusion, TFC and BLFC may prevent and alleviate neuronal cell death in the hippocampal CA1 region and neurological symptoms and poststroke hyperglycemia in gerbils with artery occlusion. This might be associated with increased isoflavonoid aglycones.

Early metabolic changes following ischemia onset in rats: an in vivo diffusion-weighted imaging and 1H-magnetic resonance spectroscopy study at 7.0 T

Despite improvements in imaging techniques, it remains challenging to quantitatively assess the time of ischemic onset of an acute ischemic stroke. It is crucial to evaluate the early signs of infarction, which are predictive of responses to recombinant tissue plasminogen activator within a treatment window of 4.5 h after stroke induction. The aim of the present study was to assess and quantify the onset time for hyperacute middle cerebral artery occlusion (MCAO) ischemic stroke by measuring the apparent diffusion coefficient (ADC) of diffusion‑weighted imaging (DWI) and 1H‑magnetic resonance spectroscopy (MRS) at 7.0 T. DWI, conventional T2‑weighted imaging (T2WI) and subsequent focal ADCs were employed to evaluate ischemic brain lesions in a rat model of MCAO (n=20) at different time‑points following a stroke. A quantitation of local changes in metabolite concentrations within the lesions was performed using MRS. Proton metabolites were quantified automatically using LCModel software. At 30 min after MCAO, intense signals were observed in the DWI spectra of all animals. No abnormal signal was observed within 3 h by T2WI. ADC images of the central area, peripheral striping and on the fringes of the infarction demonstrated a lower signal than that of the normal side. The ADC decreased significantly within 30 min after infarction, followed by a gradual elevation in volatility levels and then becoming relatively stable at a lower level 3 h later. MRS exhibited a consistent elevation of lactate and reduced N‑acetyl aspartic acid. Glutamate and taurine reached a maximum 2 h after MCAO and began to decrease 1 h later. In conclusion, the present study demonstrated that hyperacute ischemic stroke can be quantitatively detected with the application of ADC, DWI and MRS. These methods may also be used to quantitatively assess the ischemic onset time of a hyperacute stroke.

Impaired leptomeningeal collateral flow contributes to the poor outcome following experimental stroke in the Type 2 diabetic mice

Collateral status is an independent predictor of stroke outcome. However, the spatiotemporal manner in which collateral flow maintains cerebral perfusion during cerebral ischemia is poorly understood. Diabetes exacerbates ischemic brain damage, although the impact of diabetes on collateral dynamics remains to be established. Using Doppler optical coherent tomography, a robust recruitment of leptomeningeal collateral flow was detected immediately after middle cerebral artery (MCA) occlusion in C57BL/6 mice, and it continued to grow over the course of 1 week. In contrast, an impairment of collateral recruitment was evident in the Type 2 diabetic db/db mice, which coincided with a worse stroke outcome compared with their normoglycemic counterpart db/+, despite their equally well-collateralized leptomeningeal anastomoses. Similar to the wild-type mice, both db/+ and db/db mice underwent collateral growth 7 d after MCA stroke, although db/db mice still exhibited significantly reduced retrograde flow into the MCA territory chronically. Acutely induced hyperglycemia in the db/+ mice did not impair collateral flow after stroke, suggesting that the state of hyperglycemia alone was not sufficient to impact collateral flow. Human albumin was efficacious in improving collateral flow and outcome after stroke in the db/db mice, enabling perfusion to proximal MCA territory that was usually not reached by retrograde flow from anterior cerebral artery without treatment. Our results suggest that the impaired collateral status contributes to the exacerbated ischemic injury in mice with Type 2 diabetes, and modulation of collateral flow has beneficial effects on stroke outcome among these subjects.

Emergency management of ischemic stroke in children

OPINION STATEMENT

Children who present with acute neurological symptoms suggestive of a stroke need immediate clinical assessment and urgent neuroimaging to confirm diagnosis. Magnetic resonance imaging (MRI) is the investigation of first choice due to limited sensitivity of computed tomography (CT) for detection of ischaemia. Acute monitoring should include monitoring of blood pressure and body temperature, and neurological observations. Surveillance in a paediatric high dependency or intensive care unit and neurosurgical consultation are mandatory in children with large infarcts at risk of developing malignant oedema or haemorrhagic transformation. Thrombolysis and/or endovascular treatment, whilst not currently approved for use in children, may be considered when stroke diagnosis is confirmed within 4.5 to 6 h, provided there are no contraindications on standard adult criteria. Standard treatment consists of aspirin, but anticoagulation therapy is frequently prescribed in stroke due to cardiac disease and extracranial dissection. Steroids and immunosuppression have a definite place in children with proven vasculitis, but their role in focal arteriopathies is less clear. Decompressive craniotomy should be considered in children with deteriorating consciousness or signs of raised intracranial pressure.

Hyperglycaemia, insulin therapy and critical penumbral regions for prognosis in acute stroke: further insights from the INSULINFARCT trial

BACKGROUND

Recently, the concept of 'clinically relevant penumbra' was defined as an area saved by arterial recanalization and correlated with stroke outcome. This clinically relevant penumbra was located in the subcortical structures, especially the periventricular white matter. Our aims were to confirm this hypothesis, to investigate the impact of admission hyperglycemia and of insulin treatment on the severity of ischemic damages in this area and to study the respective contributions of infarct volume and ischemic damage severity of the clinically relevant penumbra on 3-month outcome.

METHODS

We included 99 patients from the INSULINFARCT trial. Voxel-Based Analysis was carried on the Apparent Diffusion Coefficient (ADC) maps obtained at day one to localize the regions, which were more damaged in patients i) with poor clinical outcomes at three months and ii) without arterial recanalization. We determined the intersection of the detected areas, which represents the clinically relevant penumbra and investigated whether hyperglycemic status and insulin regimen affected the severity of ischemic damages in this area. We performed logistic regression to examine the contribution of infarct volume or early ADC decrease in this strategic area on 3-month outcome.

FINDINGS

Lower ADC values were found in the corona radiata in patients with poor prognosis (p< 0.0001) and in those without arterial recanalization (p< 0.0001). The tracking analysis showed that lesions in this area interrupted many important pathways. ADC values in this area were lower in hyperglycemic than in normoglycemic patients (average decrease of 41.6 ± 20.8 x10(-6) mm2/s) and unaffected by the insulin regimen (p: 0.10). ADC values in the clinically relevant penumbra, but not infarct volumes, were significant predictors of 3-month outcome.

CONCLUSION

These results confirm that the deep hemispheric white matter is part of the clinically relevant penumbra and show that hyperglycaemia exacerbates the apparition of irreversible ischemic damage within 24 hours in this area. However, early intensive insulin therapy fails to protect this area from infarction.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00472381.

Uric acid improves glucose-driven oxidative stress in human ischemic stroke

OBJECTIVE

A study was undertaken to test in a subgroup reanalysis of the URICO-ICTUS trial whether uric acid is superior to placebo in improving the functional outcome in patients with acute stroke and hyperglycemia.

METHODS

Patients were part of the URICO-ICTUS trial, a double-blind study that compared the administration of uric acid versus placebo in stroke patients treated with alteplase within 4.5 hours of onset. The effect of therapy on the rate of excellent outcome at 90 days (modified Rankin Scale ≤ 2) in each tertile of admission glucose was assessed with multivariate adjusted models in 409 of the 421 randomized patients who had available pretreatment glucose levels. The effect of therapy on infarct growth was assessed in 72 patients who had longitudinal multimodal brain imaging.

RESULTS

Uric acid was associated with an increased rate of excellent outcome in patients with glucose levels in the upper tertile range (odds ratio [OR] = 2.9, 95% confidence interval [CI] = 1.0-8.3). However, the effect was not apparent for patients in the middle tertile (OR = 1.6, 95% CI = 0.8-3.6) or lower tertile of glucose (OR = 1.1, 95% CI = 0.5-2.6). Uric acid therapy was more effective than placebo in limiting infarct growth in the upper tertile range (Mann-Whitney U test, p = 0.04) but not in the middle tertile (p = 0.95) or lower tertile of glucose (p = 0.30). Uric acid also proved superior to placebo in reducing infarct growth in patients with early recanalization.

INTERPRETATION

Uric acid therapy was associated with reduced infarct growth and improved outcome in patients with hyperglycemia during acute stroke.

pH-sensitive NMDA inhibitors improve outcome in a murine model of SAH

BACKGROUND

Despite intensive research, neurological morbidity from delayed cerebral ischemia remains common after aneurysmal subarachnoid hemorrhage (SAH). In the current study, we evaluate the neuroprotective effects of a pH-dependent GluN2B subunit-selective NMDA receptor antagonist in a murine model of SAH.

METHODS

Following induction of SAH, 12 ± 2 week old male C57-BL/6 mice received NP10075, a pH-dependent NMDA receptor antagonist, or vehicle. In a separate series of experiments, NP10075 and the non-pH sensitive NMDA antagonist, NP10191, were administered to normoglycemic and hyperglycemic mice. Both histological (right middle cerebral artery diameter, NeuN, and Fluoro-Jade B staining) and functional endpoints (rotarod latency and neuroseverity score) were evaluated to assess the therapeutic benefit of NP10075.

RESULTS

Administration of NP10075 was well tolerated and had minimal hemodynamic effects following SAH. Administration of the pH-sensitive NMDA antagonist NP10075, but not NP10191, was associated with a durable improvement in the functional performance of both normoglycemic and hyperglycemic animals. NP10075 was also associated with a reduction in vasospasm in the middle cerebral artery associated with hemorrhage. There was no significant difference between treatment with nimodipine + NP10075, as compared to NP10075 alone.

CONCLUSIONS

These data demonstrate that use of a pH-dependent NMDA antagonist has the potential to work selectively in areas of ischemia known to undergo acidic pH shifts, and thus may be associated with selective regional efficacy and fewer behavioral side effects than non-selective NMDA antagonists.

NADPH oxidase-2: linking glucose, acidosis, and excitotoxicity in stroke

SIGNIFICANCE

Neuronal superoxide production contributes to cell death in both glutamate excitotoxicity and brain ischemia (stroke). NADPH oxidase-2 (NOX2) is the major source of neuronal superoxide production in these settings, and regulation of NOX2 activity can thereby influence outcome in stroke.

RECENT ADVANCES

Reduced NOX2 activity can rescue cells from oxidative stress and cell death that otherwise occur in excitotoxicity and ischemia. NOX2 activity is regulated by several factors previously shown to affect outcome in stroke, including glucose availability, intracellular pH, protein kinase ζ/δ, casein kinase 2, phosphoinositide-3-kinase, Rac1/2, and phospholipase A2. The newly identified functions of these factors as regulators of NOX2 activity suggest alternative mechanisms for their effects on ischemic brain injury.

CRITICAL ISSUES

Key aspects of these regulatory influences remain unresolved, including the mechanisms by which rac1 and phospholipase activities are coupled to N-methyl-D-aspartate (NMDA) receptors, and whether superoxide production by NOX2 triggers subsequent superoxide production by mitochondria.

FUTURE DIRECTIONS

It will be important to establish whether interventions targeting the signaling pathways linking NMDA receptors to NOX2 in brain ischemia can provide a greater neuroprotective efficacy or a longer time window to treatment than provided by NMDA receptor blockade alone. It will likewise be important to determine whether dissociating superoxide production from the other signaling events initiated by NMDA receptors can mitigate the deleterious effects of NMDA receptor blockade.

Incidence, causes and predictors of neurological deterioration occurring within 24 h following acute ischaemic stroke: a systematic review with pathophysiological implications

Early neurological deterioration (END) following ischaemic stroke is a serious event with manageable causes in only a fraction of patients. The incidence, causes and predictors of END occurring within 24 h of acute ischaemic stroke (END24) have not been systematically reviewed. We systematically reviewed Medline and Embase from January 1990 to April 2013 for all studies on END24 following acute ischaemic stroke (<8 h from onset). We recorded the incidence and presumed causes of and factors associated with END24. Thirty-six studies were included. Depending on the definition used, the incidence of END24 markedly varied among studies. Using the most widely used change in National Institutes of Health Stroke Scale ≥4 definition, the pooled incidence was 13.8% following thrombolysis, ascribed to intracranial haemorrhage and malignant oedema each in ∼20% of these. As other mechanisms were rarely reported, in the majority no clear cause was identified. Few data on END24 occurring in non-thrombolysed patients were available. Across thrombolysed and non-thrombolysed samples, the strongest and most consistent admission predictors were hyperglycaemia, no prior aspirin use, prior transient ischaemic attacks, proximal arterial occlusion and presence of early CT changes, and the most consistent 24 h follow-up associated factors were no recanalisation/reocclusion, large infarcts and intracranial haemorrhage. Finally, END24 was strongly predictive of poor outcome. The above findings are discussed with emphasis on END without a clear mechanism. Data on incidence and predictors of the latter subtype is scarce, and future studies using systematic imaging protocols should address its underlying pathophysiology. This may in turn lead to rational preventative and therapeutic measures for this ominous event.

N-acetylaspartate decrease in acute stage of ischemic stroke: a perspective from experimental and clinical studies

N-acetylaspartate (NAA) appears in a prominent peak in proton magnetic resonance spectroscopy ((1)H-MRS) of the brain. Exhibition by NAA of time-dependent attenuation that reflects energy metabolism during the acute stage of cerebral ischemia makes this metabolite a unique biomarker for assessing ischemic stroke. Although magnetic resonance (MR) imaging is a powerful technique for inspecting the pathological changes that occur during ischemic stroke, biomarkers that directly reflect the drastic metabolic changes associated with acute-stage ischemia are strongly warranted for appropriate therapeutic decision-making in daily clinical settings. In this review, we provide a brief overview of NAA metabolism and focus on the use of attenuation in NAA as a means for assessing the pathophysiological changes that occur during the acute stage of ischemic stroke.

Neuroanatomic correlates of poststroke hyperglycemia

OBJECTIVE

A study was undertaken to determine associations between ischemic stroke sites and poststroke hyperglycemia (PSH).

METHODS

Nondiabetic patients with first ever ischemic stroke confirmed by imaging were prospectively included. Blood glucose level (BGL), National Institute of Health Stroke Scale (NIHSS) score, and clinical parameters were assessed on admission. BGL was dichotomized for elevated versus normal levels using a cutoff value of >7.0 mmol/l. Clinical parameters were correlated with BGL and were compared between patient groups with elevated versus normal glucose values. A voxel-based lesion symptom mapping (VLSM) analysis adjusted for confounding variables was performed correlating sites of ischemic lesions with PSH.

RESULTS

Of 1,281 stroke patients screened, 229 (mean age = 66.3 ± 15.9 years) met the inclusion criteria. Patients with elevated BGL were older, had higher NIHSS scores, and had larger infarcts compared to those without elevated glucose levels. Spearman rank analysis showed correlations between BGL and age, infarct size, heart rate (HR), and NIHSS scores (p ≤ 0.05). The VLSM analysis adjusted for these confounding factors demonstrated associations between PSH and damaged voxels in right hemispheric insular and opercular areas.

INTERPRETATION

The data indicate that damage in the right insulo-opercular areas contributes to PSH. The association between sympathetically mediated increase of HR and BGL suggests disinhibition of sympathetic outflow as a possible mechanism for PSH.

Republished: Society for Neuroscience in Anesthesiology and Critical Care expert consensus statement: Anesthetic management of endovascular treatment for acute ischemic stroke

Literature on the anesthetic management of endovascular treatment of acute ischemic stroke (AIS) is limited. Anesthetic management during these procedures is still mostly dependent on individual or institutional preferences. Thus, the Society of Neuroscience in Anesthesiology and Critical Care (SNACC) created a task force to provide expert consensus recommendations on anesthetic management of endovascular treatment of AIS. The task force conducted a systematic literature review (up to August 2012). Because of the limited number of research articles relating to this subject, the task force solicited opinions from experts in this area. The task force created a draft consensus statement based on the available data. Classes of recommendations and levels of evidence were assigned to articles specifically addressing anesthetic management during endovascular treatment of stroke using the standard American Heart Association evidence rating scheme. The draft consensus statement was reviewed by the Task Force, SNACC Executive Committee and representatives of Society of NeuroInterventional Surgery (SNIS) and Neurocritical Care Society (NCS) reaching consensus on the final document. For this consensus statement the anesthetic management of endovascular treatment of AIS was subdivided into 12 topics. Each topic includes a summary of available data followed by recommendations. This consensus statement is intended for use by individuals involved in the care of patients with acute ischemic stroke, such as anesthesiologists, interventional neuroradiologists, neurologists, neurointensivists and neurosurgeons.

The ischemic penumbra: the location rather than the volume of recovery determines outcome

PURPOSE OF REVIEW

The clinical efficiency of thrombolysis is explained by the rescue of ischemic penumbra areas resulting from early arterial recanalization. The perfusion-diffusion weighted imaging mismatch is a commonly used MRI surrogate of the ischemic penumbra. However, the randomized trials testing the mismatch hypothesis have been negative. We will review the 'mismatch concept' and the recent studies that aim to localize the clinically eloquent areas of penumbra in middle cerebral artery (MCA) infarcts.

RECENT FINDINGS

New methods of image analysis have shown that poor outcomes after MCA stroke are related to infarction of an extremely well localized area of the periventricular white matter and adjacent internal capsule, where projections and association tracts are crossing and converging. This area almost colocalizes with the area salvaged by early arterial recanalization and is located extremely close to the initial ischemic core.

SUMMARY

The location of the area that correlates with disability in MCA stroke patients and that is salvaged by early arterial recanalization is in the same specific region of the deep white matter, close to the initial ischemic core. These findings may have important implications for designing new recanalization trials and support the importance of basic research on white-matter neuroprotection.

Unexplained Early Neurological Deterioration After Intravenous Thrombolysis

Background and Purpose—

Early neurological deterioration (END) after anterior circulation stroke is a serious clinical event strongly associated with poor outcome. Regarding specifically END occurring within 24 hours of intravenous recombinant tissue-type plasminogen activator, apart from definite causes such as symptomatic intracranial hemorrhage and malignant edema whose incidence, predictors, and clinical management are well established, little is known about END without clear mechanism (END unexplained ).

Methods—

We analyzed 309 consecutive patients thrombolysed intravenously ≤4.5 hours from onset of anterior circulation stroke. END unexplained was defined as a ≥4-point deterioration on 24-hour National Institutes of Health Stroke Scale, without definite mechanism on concomitant imaging. END unexplained and no-END patients were compared for pretreatment clinical and imaging (including magnetic resonance diffusion and diffusion/perfusion mismatch volumes) data and 24-hour post-treatment clinical (including blood pressure and glycemic changes) and imaging (24-hour recanalization) data, using univariate logistic regression. Exploratory multivariate analysis was also performed after variable reduction, with bootstrap analysis for internal validation.

Results—

Among 33 END patients, 23 (7% of whole sample) had END unexplained . END unexplained was associated with poor 3-month outcome ( P <0.01). In univariate analysis, admission predictors of END unexplained included no prior use of antiplatelets ( P =0.02), lower National Institutes of Health Stroke Scale score ( P <0.01), higher glycemia ( P =0.03), larger mismatch volume ( P =0.03), and proximal occlusion ( P =0.01), with consistent results from the multivariate analysis. Among factors recorded during the first 24 hours, only no recanalization was associated with END unexplained in multivariate analysis ( P =0.02).

Conclusions—

END unexplained affected 7% of patients and accounted for most cases of END. Several predictors and associated factors were identified, with important implications regarding underlying mechanisms and potential prevention of this ominous event.