Glucose Regulation in Acute Stroke Patients (GRASP) trial: a randomized pilot trial

Glucose Control and Risk of Symptomatic Intracerebral Hemorrhage Following Thrombolysis for Acute Ischemic Stroke: A SHINE Trial Analysis

BACKGROUND AND OBJECTIVES

Baseline hyperglycemia is associated with worse outcomes in acute ischemic stroke (AIS), including higher risk of symptomatic intracerebral hemorrhage (sICH) following treatment with thrombolysis. Prospective data are lacking to inform management of post-thrombolysis hyperglycemia. In a prespecified analysis from the Stroke Hyperglycemia Insulin Network Effort (SHINE) trial of hyperglycemic stroke management, we hypothesized that post-thrombolysis hyperglycemia is associated with a higher risk of sICH.

METHODS

Hyperglycemic AIS patients <12 hours onset were randomized to intensive insulin (target range 80-130 mg/dL) vs standard sliding scale (80-179 mg/dL) over a 72-hour period, stratified by treatment with thrombolysis. Three board-certified vascular neurologists independently reviewed all sICH events occurring within 7 days, defined by neurologic deterioration of ≥4 points on the NIH Stroke Scale (NIHSS). Associations between blood glucose control and sICH were analyzed using logistic regression accounting for NIHSS, age, systolic blood pressure, onset to thrombolysis time, and endovascular therapy (odds ratios [OR], 95% CI). Additional analysis compared patients in a high-risk group (age older than 60 years and NIHSS ≥8) vs all others. Categorical variables and outcomes were compared using the χ2 test (p < 0.05).

RESULTS

Of 1151 SHINE participants, 725 (63%) received thrombolysis (median age 65 years, 46% women, 29% Black, 18% Hispanic). The median NIHSS was 7, baseline blood glucose was 187 (interquartile range 153-247) mg/dL, and 80% were diabetic. Onset to thrombolysis time was 2.2 hours (1.6-2.9). Post-thrombolysis sICH occurred in 3.6% (3.0% intensive vs 4.3% standard glucose control, OR 1.10, 0.60-2.01, p = 0.697). In the first 12 hours, every 10 mg/dL higher glucose increased the odds of sICH (OR 1.08, 1.03-1.14, p = 0.004), and a greater proportion of glucose measures in the normal range (80-130 mg/dL) decreased the odds of sICH (0.89, 0.80-0.99, p = 0.030). These associations were strongest in the high-risk group (age older than 60 years and NIHSS ≥8).

DISCUSSION

In this prespecified analysis from the SHINE trial, intensive insulin therapy was not associated with a reduced risk of post-thrombolysis sICH compared with standard sliding scale. However, early post-thrombolysis hyperglycemia was associated with a higher risk of sICH overall, particularly in older patients with more severe strokes. Further prospective research is warranted to address the risk of sICH in hyperglycemic stroke patients undergoing endovascular therapy.

TRIAL REGISTRATION INFORMATION

NCT01369069.

Association of admission plasma glucose level and cerebral computed tomographic perfusion deficit volumes

INTRODUCTION

Hyperglycemia in acute ischemic stroke (AIS) is frequent and associated with worse outcome. Yet, strict glycemic control in AIS patients has failed to yield beneficial outcome. So far, the underlying pathophysiological mechanisms of admission hyperglycemia in AIS have remained not fully understood. We aimed to evaluate the yet equivocal association of hyperglycemia with computed tomographic perfusion (CTP) deficit volumes.

PATIENTS AND METHODS

We included 832 consecutive AIS and transient ischemic attack (TIA) patients who underwent CTP as a part of screening for recanalization treatment (stroke code) between 3/2018 and 10/2020, from the prospective cohort of Helsinki Stroke Quality Registry. Associations of admission glucose level (AGL) and CTP deficit volumes, namely ischemic core, defined as relative cerebral blood flow <30%, and hypoperfusion lesions Time-to-maximum (Tmax) >6 s and Tmax >10s, as determined with RAPID® software, were analyzed with a linear regression model adjusted for age, sex, C-reactive protein, and time from symptom onset to imaging.

RESULTS

AGL median was 6.8 mmol/L (interquartile range 5.9-8.0 mmol/L), and 222 (27%) patients were hyperglycemic (glucose >7.8 mmol/L) on admission. In non-diabetic patients (643 [77%]), AGL was significantly associated with volume of Tmax. >6 s (regression coefficient [RC] 4.8, 95% confidence interval [CI] 0.49-9.1), of Tmax >10s (RC 4.6, 95% CI 1.2-8.1), and of ischemic core (RC 2.6, 95% CI 0.64-4.6). No significant associations were shown in diabetic patients.

CONCLUSION

Admission hyperglycemia appears to be associated with both larger volume of hypoperfusion lesions and of ischemic core in non-diabetic stroke code patients with AIS and TIA.

Hyperglycemic control in acute ischemic stroke patients undergoing endovascular treatment: post hoc analysis of the Stroke Hyperglycemia Insulin Network Effort trial

BACKGROUND

Hyperglycemia has been associated with poor outcomes in acute ischemic stroke patients undergoing endovascular treatment. We analyzed the effect of intensive glucose control on death and disability rates in patients with acute ischemic stroke undergoing endovascular treatment.

METHODS

We analyzed the effect of intensive (serum glucose <110 mg/dL) glucose treatment (compared with standard treatment, serum glucose <180 mg/dL) in patients who received endovascular treatment in the Stroke Hyperglycemia Insulin Network Effort (SHINE) trial. We further analyzed the effect of area under the curve (AUC) of serum glucose, proportion of the time blood glucose was <140 mg/dL, and glucose variability defined as the glucose range during 72 hours. The primary outcomes were neurological deterioration within 72 hours and outcome at 90 days.

RESULTS

A total of 146 patients (mean age 68.1±13.9 years, 50.7% men) underwent endovascular treatment for acute ischemic stroke; 72 and 74 patients were randomized to intensive and standard treatments, respectively. The rates of death (20.3% and 22.2%), favorable 90-day primary outcome (17.6% and 19.4%), and serious adverse events (41.9% and 56.98%) were similar between the two groups. The AUC of serum glucose was not associated with death within 90 days (OR 1, 95% CI 1 to 1) or favorable outcome at 90 days (OR 1, 95% CI 1 to 1). Glucose variability was not associated with death or favorable outcome at 90 days.

CONCLUSION

We did not identify any beneficial effect of intensive glucose reduction on rates of death or favorable outcomes at 90 days among acute ischemic stroke patients undergoing endovascular treatment.

The Prognostic Significance of Early Glycemic Profile in Acute Ischemic Stroke Depends on Stroke Subtype

It is still unclear whether early glycemic profile after admission for acute ischemic stroke (IS) has the same prognostic significance in patients with lacunar and non-lacunar infarction. Data from 4011 IS patients admitted to a Stroke Unit (SU) were retrospectively analyzed. Lacunar IS was diagnosed by clinical criteria. A continuous indicator of early glycemic profile was calculated as the difference of fasting serum glucose (FSG) measured within 48 h after admission and random serum glucose (RSG) measured on admission. Logistic regression was used to estimate the association with a combined poor outcome defined as early neurological deterioration, severe stroke at SU discharge, or 1-month mortality. Among patients without hypoglycemia (RSG and FSG > 3.9 mmol/L), an increasing glycemic profile increased the likelihood of a poor outcome for non-lacunar (OR, 1.38, 95%CI, 1.24-1.52 in those without diabetes; 1.11, 95%CI, 1.05-1.18 in those with diabetes) but not for lacunar IS. Among patients without sustained or delayed hyperglycemia (FSG < 7.8 mmol/L), an increasing glycemic profile was unrelated to outcome for non-lacunar IS but decreased the likelihood of poor outcome for lacunar IS (OR, 0.63, 95%CI, 0.41-0.98). Early glycemic profile after acute IS has a different prognostic significance in non-lacunar and lacunar patients.

Continuous glucose monitoring in acute ischemic stroke patients treated with endovascular therapy: A pilot study to assess feasibility and accuracy

INTRODUCTION

Hyperglycemia is common in acute ischemic stroke and is associated with larger infarct volume and unfavorable functional outcome, also in patients who undergo reperfusion therapy. Hyperglycemia during reperfusion may be a therapeutic target. However, previous randomized trials on the effect of glucose lowering in the acute phase of ischemic stroke failed to demonstrate effects on clinical outcome. Inaccurate glucose measurements and not focussing on patients who undergo reperfusion therapy are possible explanations. Our aim was to study the feasibility and accuracy of continuous glucose monitoring (CGM) in patients with acute ischemic stroke undergoing endovascular treatment (EVT).

METHODS

All consecutive patients with ischemic stroke and large vessel occlusion (LVO) of the anterior circulation who were eligible for endovascular therapy within 24 hours of symptom onset and presenting at the emergency department of Isala Hospital Zwolle, the Netherlands, were enrolled in this study. CGM was performed using a Freestyle Libre Flash 2 device (FSL-CGM, Abbot Diabetes Care, Alameda, California, USA) which was implanted on arrival at the emergency department. Feasibility was defined as the number of patients who could be registered for 24 hours and delay in door-to-groin time because of sensor implantation. Accuracy of CGM versus capillary and venous based plasma glucose values was determined with the Parkes error grid analysis.

RESULTS

Twenty-three patients were included of whom 20 completed 24 hours monitoring (87%). One patient did not give permission to use the data; one sensor broke during implantation and one meter was broken after a sensor was shot in so no measurements could be recorded. There was no significant delay in treatment due to implantation of the sensor and no adverse events. One hundred percent of CGM data are in zones A and B of the Parkes error grid analysis so data out of the sensor can be interpreted as accurate.

CONCLUSION

In this study, we showed that continuous glucose monitoring in patients with acute ischemic stroke due to large vessel occlusion of the anterior circulation in patients who were treated with endovascular therapy is feasible, safe and accurate.

Admission hyperglycemia, stroke subtypes, outcomes in acute ischemic stroke

AIMS

Whether admission hyperglycemia is differentially associated with early vascular outcomes in acute ischemic stroke (AIS) depending on stroke subtype has been incompletely delineated.

METHODS

In a multicenter, prospective stroke registry, patients with AIS were categorized based on admission glucose levels into normoglycemia, moderate hyperglycemia, and severe hyperglycemia (<140mg/dl, 140-179mg/dl, and ≥180mg/dl, respectively) groups. Multivariate analysis assessed the interaction between the hyperglycemia and ischemic stroke subtypes of large artery atherothrombosis (LAA), cardioembolism (CE), and small vessel occlusion (SVO) and early vascular outcomes (3-month stroke, all-cause mortality, and composite of stroke, MI, and all-cause mortality).

RESULTS

Among the 32,772 patients (age:69.0±12.6yrs, male:58.4%) meeting eligibility criteria, 61.9% were in the normoglycemia group, 19.5% were in the moderate hyperglycemia group, and 18.7% were in the severe hyperglycemia group. Substantial interactions between hyperglycemia groups and stroke subtypes were observed for 3-month stroke (P_interaction = 0.003) and composite of stroke, MI, and all-cause mortality (P_interaction = 0.001), with differential recurrence strongest among CE, intermediate among LAA, and least among SVO.

CONCLUSIONS

Hyperglycemia was differently associated with the risk of 3-month stroke by ischemic stroke subtype. The associations of hyperglycemia with 3-month stroke were greatest in CE subtype but not in SVO subtype. These results suggest that the effect of glucose-lowering treatment after AIS may differ according to stroke subtype.

A review of stress-induced hyperglycaemia in the context of acute ischaemic stroke: Definition, underlying mechanisms, and the status of insulin therapy

The transient elevation of blood glucose produced following acute ischaemic stroke (AIS) has been described as stress-induced hyperglycaemia (SIH). SIH is common even in patients with AIS who have no previous diagnosis of diabetes mellitus. Elevated blood glucose levels during admission and hospitalization are strongly associated with enlarged infarct size and adverse prognosis in AIS patients. However, insulin-intensive glucose control therapy defined by admission blood glucose for SIH has not achieved the desired results, and new treatment ideas are urgently required. First, we explore the various definitions of SIH in the context of AIS and their predictive value in adverse outcomes. Then, we briefly discuss the mechanisms by which SIH arises, describing the dual effects of elevated glucose levels on the central nervous system. Finally, although preclinical studies support lowering blood glucose levels using insulin, the clinical outcomes of intensive glucose control are not promising. We discuss the reasons for this phenomenon.

Pre-diabetes, Diabetes, Hyperglycemia, and Stroke: Bittersweet Therapeutic Opportunities

PURPOSEOF REVIEW

Diabetes mellitus (DM) causes systemic vascular complications. Chronic hyperglycemia is a hallmark of DM and appears to be at least partially responsible for the vascular complications. In addition, hyperglycemia during acute tissue injury has been postulated to augment the injury. This review addresses the potential therapeutic benefits related to ischemic stroke from lowering hyperglycemia in two settings, in chronic hyperglycemia and during acute ischemic stroke.

RECENT FINDINGS

A recent efficacy trial to lower hyperglycemia during acute ischemic stroke showed no significant benefit overall as well as in patient subgroups. This finding helps to establish good clinical practice protocols for patients with acute ischemic stroke and hyperglycemia. Hyperglycemia appears to be a key mediator of the systemic vascular complications of DM. Despite current lack of evidence that lowering hyperglycemia during acute ischemic stroke improves functional outcome, unanswered questions remain in specific acute ischemic stroke settings that warrant additional research.

Association of hyperglycemia and computed tomographic perfusion deficits in patients who underwent endovascular treatment for acute ischemic stroke caused by a proximal intracranial occlusion: A subgroup analysis of a randomized phase 3 trial (MR CLEAN)

INTRODUCTION

Hyperglycemia is highly prevalent in patients with acute ischemic stroke and is associated with increased risk of symptomatic intracranial hemorrhage, larger infarct size and unfavorable outcome. Furthermore, glucose may modify the effect of endovascular treatment (EVT) in patients with ischemic stroke. Hyperglycemia might lead to accelerated conversion of penumbra into infarct core. However, it remains uncertain whether hyperglycemia on admission is associated with the size of penumbra or infarct core in acute ischemic stroke. In this study, we aimed to assess the association between hyperglycemia and Computed Tomographic Perfusion (CTP) derived parameters in patients who underwent EVT for acute ischemic stroke.

METHODS

We used data from the MR CLEAN study (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands). Hyperglycemia was defined as admission serum glucose of >7.8 mmol/L. Dichotomized and quantiles of glucose levels were related to size of core, penumbra and core penumbra ratio. Hypoperfused area is mean transient time 45% higher than that of the contralateral hemisphere. Core is the area with cerebral blood volume of <2 mL/100 g and penumbra is the area with cerebral blood volume > 2 mL/100 g. Core-penumbra ratio is the ischemic core divided by the total volume of hypoperfused tissue (core plus penumbra) multiplied by 100. Adjustments were made for age, sex, NIHSS on admission, onset-imaging time and diabetes mellitus.

RESULTS

Hundred seventy-three patients were included. Median glucose level on admission was 6.5 mmol/L (IQR 5.8-7.5 mmol/L) and thirty-five patients (20%) were hyperglycemic. Median core volume was 33.3 mL (IQR 13.6-62.4 mL), median penumbra volume was 80.2 mL (IQR 36.3-123.5 mL) and median core-penumbra ratio was 28.5% (IQR 18.6-45.8%). Patients with hyperglycemia on admission had larger core volumes and core penumbra ratio than normoglycemic patients with a regression coefficient of 15.1 (95% confidence interval (CI), 1.8 to 28.3) and 11.5 (95% confidence interval (CI), 3.4 to 19.7) respectively.

CONCLUSION

Hyperglycemia on admission was associated with larger ischemic core volume and larger core-penumbra ratio in patients with acute ischemic stroke who underwent endovascular treatment.

Stress Hyperglycemia Does Not Affect Clinical Outcome of Diabetic Patients Receiving Intravenous Thrombolysis for Acute Ischemic Stroke

Although stress hyperglycemia represents a main risk factor for poor outcome among patients with acute ischemic stroke (AIS) undergoing recanalization therapy, we have limited information regarding a possible influence of the premorbid diabetic status on this association. We recruited consecutive patients admitted to the Udine University Hospital with AIS who were treated with intravenous thrombolysis (IVT) from January 2015 to September 2020. On the basis of the premorbid diabetic status, our sample was composed of 130 patients with and 371 patients without diabetes. The glucose-to-glycated hemoglobin ratio (GAR) was used to measure stress hyperglycemia. Patients were stratified into 3 groups by tertiles of GAR (Q1–Q3). The higher GAR index was, the more severe stress hyperglycemia was considered. Among diabetic patients we did not observe any significant association between severe stress hyperglycemia and outcome measures (three-month poor outcome: Q1, 53.7%; Q2, 53.5%; Q3, 58.7%; p = 0.854; three-month mortality: Q1, 14.6%; Q2, 9.3%; Q3, 23.9%; p = 0.165; symptomatic intracranial hemorrhage: Q1, 7.3%; Q2, 14%; Q3, 19.6%; p = 0.256). Differently, non-diabetic subjects with more severe stress hyperglycemia showed a higher prevalence of three-month poor outcome (Q1, 32.2%; Q2, 27.7%; Q3, 60.3%; p = 0.001), three-month mortality (Q1, 9.1%; Q2, 8.4%; Q3, 18.3%; p = 0.026), and symptomatic intracranial hemorrhage (Q1, 0.8%; Q2, 0.8%; Q3, 9.9; p = 0.001). After controlling for several confounders, severe stress hyperglycemia remained a significant predictor of three-month poor outcome (OR 2.1, 95% CI 1.03–4.28, p = 0.041), three-month mortality (OR 2.39, 95% CI 1.09–5.26, p = 0.029) and symptomatic intracranial hemorrhage (OR 12.62, 95% CI 1.5–106, p = 0.02) among non-diabetics. In conclusion, premorbid diabetic status seems to influence outcome in AIS patients receiving IVT. Indeed, odds of functional dependency, mortality and hemorrhagic complications were significantly increased in patients with more severe stress hyperglycemia only when they were not affected by diabetes.

Glycemic Control in Hospitalized Stroke Patients: A Review

PURPOSE OF REVIEW

The purpose of this review is to discuss clinical trials involving glycemic control in hospitalized stroke patients and to review oral medications used in glycemic control. GLP-1 agonists, which have some preliminary studies in ischemic stroke, will also be reviewed.

RECENT FINDINGS

Until recently, glycemic control targets in hospitalized stroke patients remained unclear. The SHINE (Stroke Hyperglycemia Insulin Network Effort) trial demonstrated no significant difference between aggressive versus standard of care glycemic control in the acute ischemic stroke patient. Although SHINE demonstrated a lack of statistical difference in glycemic control targets, many questions remain including glycemic control in patients with other stroke types (SAH, ICH). The role of non-insulin-based medications in glycemic control for hospitalized stroke patients remains unclear and presents an opportunity for further research. Finally, GLP-1 agonists present an interesting area of research for acute ischemic stroke.

Diabetes, Vascular Aging and Stroke: Old Dogs, New Tricks?

BACKGROUND

Stroke remains a leading cause of death and disability throughout the world. It is well established that Diabetes Mellitus (DM) is a risk factor for stroke, while other risk factors include dyslipidaemia and hypertension. Given that the global prevalence of diabetes steadily increases, the need for adequate glycaemic control and prevention of DM-related cardiovascular events remains a challenge for the medical community. Therefore, a re-examination of the latest data related to this issue is of particular importance.

OBJECTIVE

This review aims to summarise the latest data on the relationship between DM and stroke, including epidemiology, risk factors, pathogenesis, prevention and biomarkers.

METHODS

For this purpose, comprehensive research was performed on the platforms PubMed, Google Scholar and EMBASE with a combination of the following keywords: diabetes mellitus, stroke, macrovascular complications, diabetic stroke, cardiovascular disease.

CONCLUSIONS

Much progress has been made in stroke in people with DM in terms of prevention and early diagnosis. In the field of prevention, the adaptation of the daily habits and the regulation of co-morbidity of individuals play a particularly important role. Simultaneously, the most significant revolution has been brought by the relatively new treatment options that offer protection to the cardiovascular system. Moreover, many prognostic and diagnostic biomarkers have been identified, paving the way for early and accurate diagnoses. However, to date, there are crucial points that remain controversial and need further clarification.

Hypoglycemic Hemiparesis Masquerading As Ischemic Stroke: When Guideline Fails

Background:

Hypoglycemia may rarely present as hemiparesis and sometimes it is difficult to differentiate from ischemic stroke. When random blood sugar (RBS) value is between 50 and 80 mg % in patients presenting with focal neurological deficit, no guideline exists to consider the possibility of hypoglycemia before initiating thrombolytic therapy.

Clinical Case:

A 58-year-old male, who was a known case of diabetes and hypertension, was brought to the emergency room with acute onset of right hemiparesis and dysarthria of 90 minutes duration. His NIHSS Score was 9, blood pressure was 150/90 mm of Hg and RBS was 79 mg% on admission. His CT scan brain was normal and was considered for thrombolysis. Resident doctor not aware of previous sugar repeated RBS before thrombolysis which was surprisingly 60 mg% 60 minutes after the first RBS. Even though he was a candidate for thrombolysis, intravenous 25 % dextrose was administered considering the possibility of hypoglycemia. He made a complete recovery within 20 minutes and thrombolytic therapy was withheld.

Is intensive glucose control bad for critically ill patients? A systematic review and meta-analysis

Background: The monitoring and management of blood glucose concentration are standard practices in critical settings as hyperglycaemia has been shown close association with poorer outcomes. Several meta-analyses have revealed that intensive glucose control has no benefit in decreasing short-term mortality among critically ill patients, while the studies these meta-analyses have incorporated have been largely divergent. We aim to perform a more comprehensive meta-analysis addressing this problem to provide stronger evidence. Methods: We conducted comprehensive searches for relevant randomized controlled studies in online databases, including the Cochrane Library, EMBASE, and PubMed databases, up to September 1, 2018. The clinical data, which included all-cause mortality, severe hypoglycemia, need for RRT, infection resulting in sepsis, ICU mortality, 90-day mortality, 180-day mortality, and hospital and ICU lengths of stay, were screened and analyzed after data extraction. We applied odds ratios (ORs) to analyze dichotomous outcomes and mean differences for continuous outcomes with a random effects model. Results: A total of 57 RCTs involving a total of 21840 patients were finally included. Patients admitted to the ICU who underwent intensive glucose control showed significantly reduced all-cause mortality (OR: 0.89; 95% CI: 0.80-1.00; P=0.04; I2=32%), reduced infection rate (OR: 0.65, 95% CI: 0.51-0.82, P=0.0002; I2=47%), a lower occurrence of acquired sepsis (OR: 0.80, 95% CI: 0.65-0.99, P=0.04; I2=0%) and shortened length of ICU stay (MD: -0.70, 95% CI: -1.21--0.19, P=0.007, I2=70%) when compared to the same parameters as those treated with the usual care strategy. However, patients in the intensive glucose control group presented with a significantly higher risk of severe hypoglycemia (OR: 5.63, 95% CI: 4.02-7.87, P<0.00001; I2=67%). Conclusions: Critically ill patients undergoing intensive glucose control showed significantly reduced all-cause mortality, length of ICU stay and incidence of acquired infection and sepsis compared to the same parameters in patients treated with the usual care strategy, while the intensive glucose control strategy was associated with higher occurrence of severe hypoglycemic events.

Empagliflozin attenuates transient cerebral ischemia/reperfusion injury in hyperglycemic rats via repressing oxidative-inflammatory-apoptotic pathway

Hyperglycemia is one of the ischemic neuronal damage triggers that exacerbate the response to oxidative stress, inflammation, and apoptosis induced by cerebral ischemia/reperfusion (I/R) injury. Empagliflozin, a sodium-glucose cotransporter 2 (SGLT 2) inhibitor, was shown to effectively reduce hyperglycemia and glucotoxicity besides improving glycemic control in diabetics. Therefore, the present study was conducted to investigate the neuroprotective effect of empagliflozin against cerebral I/R injury in hyperglycemic rats. Hyperglycemia was induced by streptozotocin (55 mg/kg), and transient cerebral I/R was induced by bilateral common carotid occlusion for 30 min followed by 24-h reperfusion. Either empagliflozin (10 mg/kg; i.p.) or gliclazide (2 mg/kg, p.o.) was administered at 1 and 24 h after reperfusion. Treatment with empagliflozin showed a significant amelioration of behavioral/neurological functions and histopathological changes observed in brain tissues of hyperglycemic rats subjected to cerebral I/R injury. Comparable to gliclazide, empagliflozin decreased cerebral infarct volume along with suppression of cerebral oxidative stress, inflammatory, and apoptotic markers in brain tissues of hyperglycemic I/R-injured rats. These findings suggested that empagliflozin can significantly alleviate neuronal damage resulting from global I/R injury induced in hyperglycemic rats. The proposed neuroprotective effect of empagliflozin may be attributed to its glycemic control effect and related antioxidant, anti-inflammatory, and antiapoptotic effects.

Insulin in the Management of Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

OBJECTIVE

The role of tight glycemic control in the management of acute ischemic stroke remains uncertain. Our goal is to evaluate the effects of tight glucose control with insulin therapy after acute ischemic stroke.

METHODS

We searched PubMed, CENTRAL, and Embase for randomized controlled trials (RCTs) that evaluated the effects of tight glycemic control (70-135 mg/dL) in acute ischemic stroke. Analysis was performed using fixed-effects and random-effects models. Outcomes were death, independence, and modified Rankin Scale (mRS) score at ≥90 days follow-up, and symptomatic or severe hypoglycemia during treatment.

RESULTS

Twelve RCTs including 2734 patients were included. Compared with conventional therapy or placebo, tight glycemic control was associated with similar rates of mortality at ≥90 days follow-up (pooled odds ratio [pOR], 0.99; 95% confidence interval [CI], 0.79-1.22]; I² = 0%), independence at ≥90 days follow-up (pOR, 0.95; 95% CI, 0.79-1.14; I² = 0%) and mRS scores at ≥90 days follow-up (standardized mean difference, 0.014; 95% CI, -0.15 to 0.17; I² = 0%). In contrast, tight glycemic control was associated with increased rates of symptomatic or severe hypoglycemia during treatment (pOR, 5.2; 95% CI, 1.7-15.9; I² = 28%).

CONCLUSIONS

Tight glucose control after acute ischemic stroke is not associated with improvements in mortality, independence, or mRS score and leads to higher rates of symptomatic or severe hypoglycemia.

Intensive vs Standard Treatment of Hyperglycemia and Functional Outcome in Patients With Acute Ischemic Stroke: The SHINE Randomized Clinical Trial

IMPORTANCE

Hyperglycemia during acute ischemic stroke is common and is associated with worse outcomes. The efficacy of intensive treatment of hyperglycemia in this setting remains unknown.

OBJECTIVES

To determine the efficacy of intensive treatment of hyperglycemia during acute ischemic stroke.

DESIGN, SETTING, AND PARTICIPANTS

The Stroke Hyperglycemia Insulin Network Effort (SHINE) randomized clinical trial included adult patients with hyperglycemia (glucose concentration of >110 mg/dL if had diabetes or ≥150 mg/dL if did not have diabetes) and acute ischemic stroke who were enrolled within 12 hours from stroke onset at 63 US sites between April 2012 and August 2018; follow-up ended in November 2018. The trial included 1151 patients who met eligibility criteria.

INTERVENTIONS

Patients were randomized to receive continuous intravenous insulin using a computerized decision support tool (target blood glucose concentration of 80-130 mg/dL [4.4-7.2 mmol/L]; intensive treatment group: n = 581) or insulin on a sliding scale that was administered subcutaneously (target blood glucose concentration of 80-179 mg/dL [4.4-9.9 mmol/L]; standard treatment group: n = 570) for up to 72 hours.

MAIN OUTCOMES AND MEASURES

The primary efficacy outcome was the proportion of patients with a favorable outcome based on the 90-day modified Rankin Scale score (a global stroke disability scale ranging from 0 [no symptoms or completely recovered] to 6 [death]) that was adjusted for baseline stroke severity.

RESULTS

Among 1151 patients who were randomized (mean age, 66 years [SD, 13.1 years]; 529 [46%] women, 920 [80%] with diabetes), 1118 (97%) completed the trial. Enrollment was stopped for futility based on prespecified interim analysis criteria. During treatment, the mean blood glucose level was 118 mg/dL (6.6 mmol/L) in the intensive treatment group and 179 mg/dL (9.9 mmol/L) in the standard treatment group. A favorable outcome occurred in 119 of 581 patients (20.5%) in the intensive treatment group and in 123 of 570 patients (21.6%) in the standard treatment group (adjusted relative risk, 0.97 [95% CI, 0.87 to 1.08], P = .55; unadjusted risk difference, -0.83% [95% CI, -5.72% to 4.06%]). Treatment was stopped early for hypoglycemia or other adverse events in 65 of 581 patients (11.2%) in the intensive treatment group and in 18 of 570 patients (3.2%) in the standard treatment group. Severe hypoglycemia occurred only among patients in the intensive treatment group (15/581 [2.6%]; risk difference, 2.58% [95% CI, 1.29% to 3.87%]).

CONCLUSIONS AND RELEVANCE

Among patients with acute ischemic stroke and hyperglycemia, treatment with intensive vs standard glucose control for up to 72 hours did not result in a significant difference in favorable functional outcome at 90 days. These findings do not support using intensive glucose control in this setting.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01369069.

Influence of Hyperglycemia Associated with Enteral Nutrition on Mortality in Patients with Stroke

Objectives: To evaluate in patients admitted for stroke: (1) The frequency of hyperglycaemia associated with enteral nutrition (EN). (2) The risk of morbidity and mortality associated with the development of this type of hyperglycaemia.

METHODS

A longitudinal observational study was conducted in 115 non-diabetic patients admitted for stroke with EN. Age, functional capacity (Rankin scale), and blood plasma glucose (BPG) were recorded. Hyperglycaemia was considered as: a value higher than 126 mg/dL before the EN and/or a value higher than 150 mg/dL after a week of enteral nutrition. According to this, three groups were differentiated: HyperES: Those who had hyperglycemia before the beginning of the EN (33% patients); NoHyper: those who did not have hyperglycemia before or after (47.8% patients); and HyperEN: Those who did not have hyperglycemia before but suffered it after the beginning of the EN (19.1% patients).

RESULTS

The age was 72.72 (15.32) years. A higher rate of mortality was observed in the HyperEN group 45.50%, than HyperES 15.80% or NoHyper: 10.90%). A lower recovery of the oral feeding was observed in those patients of the HyperEN group 27.30%, than HyperES: 42.10% or NoHyper: 61.80%). In the multivariate analysis adjusting for age, sex, and Rankin scale the development of hyperglycemia in those who did not have it at the beginning (HyperEN) was an independent risk factor for non-recovery of the oral feeding (OR: 4.21 (1.20-14.79), p = 0.02); and mortality adjusted for age, sex and Rankin scale (OR: 6.83 (1.76-26.47), p < 0.01).

CONCLUSIONS

In non-diabetic patients admitted for stroke with EN, the development of hyperglycaemia in relation to enteral nutrition supposes an independent risk factor for mortality and for the non-recovery of the oral feeding.

Hyperglycaemia does not increase perfusion deficits after focal cerebral ischaemia in male Wistar rats

Background:

Hyperglycaemia is associated with a worse outcome in acute ischaemic stroke patients; yet the pathophysiological mechanisms of hyperglycaemia-induced damage are poorly understood. We hypothesised that hyperglycaemia at the time of stroke onset exacerbates ischaemic brain damage by increasing the severity of the blood flow deficit.

Methods:

Adult, male Wistar rats were randomly assigned to receive vehicle or glucose solutions prior to permanent middle cerebral artery occlusion. Cerebral blood flow was assessed semi-quantitatively either 1 h after middle cerebral artery occlusion using ^99mTc-D, L-hexamethylpropyleneamine oxime (^99mTc-HMPAO) autoradiography or, in a separate study, using quantitative pseudo-continuous arterial spin labelling for 4 h after middle cerebral artery occlusion. Diffusion weighted imaging was performed alongside pseudo-continuous arterial spin labelling and acute lesion volumes calculated from apparent diffusion coefficient maps. Infarct volume was measured at 24 h using rapid acquisition with refocused echoes T₂-weighted magnetic resonance imaging.

Results:

Glucose administration had no effect on the severity of ischaemia when assessed by either ^99mTc-HMPAO autoradiography or pseudo-continuous arterial spin labelling perfusion imaging. In comparison to the vehicle group, apparent diffusion coefficient–derived lesion volume 2–4 h post-middle cerebral artery occlusion and infarct volume 24 h post-middle cerebral artery occlusion were significantly greater in the glucose group.

Conclusions:

Hyperglycaemia increased acute lesion and infarct volumes but there was no evidence that the acute blood flow deficit was exacerbated. The data reinforce the conclusion that the detrimental effects of hyperglycaemia are rapid, and that treatment of post-stroke hyperglycaemia in the acute period is essential but the mechanisms of hyperglycaemia-induced harm remain unclear.

Profile of intravenous glyburide for the prevention of cerebral edema following large hemispheric infarction: evidence to date

Glyburide (also known as glibenclamide) is a second-generation sulfonylurea drug that inhibits sulfonylurea receptor 1 (Sur1) at nanomolar concentrations. Long used to target K_ATP (Sur1–Kir6.2) channels for the treatment of diabetes mellitus type 2, glyburide was recently repurposed to target Sur1–transient receptor potential melastatin 4 (Trpm4) channels in acute central nervous system injury. Discovered nearly two decades ago, SUR1–TRPM4 has emerged as a critical target in stroke, specifically in large hemispheric infarction, which is characterized by edema formation and life-threatening brain swelling. Following ischemia, SUR1–TRPM4 channels are transcriptionally upregulated in all cells of the neurovascular unit, including neurons, astrocytes, microglia, oligodendrocytes and microvascular endothelial cells. Work by several independent laboratories has linked SUR1–TRPM4 to edema formation, with blockade by glyburide reducing brain swelling and death in preclinical models. Recent work showed that, following ischemia, SUR1–TRPM4 co-assembles with aquaporin-4 to mediate cellular swelling of astrocytes, which contributes to brain swelling. Additionally, recent work linked SUR1–TRPM4 to secretion of matrix metalloproteinase-9 (MMP-9) induced by recombinant tissue plasminogen activator in activated brain endothelial cells, with blockade of SUR1–TRPM4 by glyburide reducing MMP-9 and hemorrhagic transformation in preclinical models with recombinant tissue plasminogen activator. The recently completed GAMES (Glyburide Advantage in Malignant Edema and Stroke) clinical trials on patients with large hemispheric infarctions treated with intravenous glyburide (RP-1127) revealed promising findings with regard to brain swelling (midline shift), MMP-9, functional outcomes and mortality. Here, we review key elements of the basic science, preclinical experiments and clinical studies, both retrospective and prospective, on glyburide in focal cerebral ischemia and stroke.

Exposure to hypoglycemia and risk of stroke

In the treatment of both type 1 and type 2 diabetes mellitus, maintaining a euglycemic state represents one of the key challenges. Improper dosing and administration of glucose-lowering drugs is associated with an increased risk of recurrent hypoglycemia episodes. In addition, the risk of adverse cardiovascular events in diabetic patients, particularly myocardial infarctions and strokes, is well established. Current research indicates a potential link between the baseline risk of cardio/cerebrovascular events in diabetic patients and exposure to hypoglycemia. In this review of the literature, we aim to determine if a relationship exists between recurrent hypoglycemia and adverse neurovascular events.

European Stroke Organisation (ESO) guidelines on glycaemia management in acute stroke

Background

Hyperglycaemia is a frequent complication in acute stroke that has been shown to be independently associated with larger infarct size, haematoma growth, poor clinical outcome and mortality. This Guideline Document presents the European Stroke Organisation (ESO) Guidelines for the management of blood glucose levels in patients with acute ischemic or haemorrhagic stroke.

Methods

The working group identified related questions and developed its recommendations based on evidence from randomised controlled trials following the standard operating procedure of the ESO. This Guideline Document was reviewed and approved by the European Stroke Organisation Guidelines Committee and the European Stroke Organisation Executive Committee.

Results

We found low-quality evidence from clinical trials in ischemic or haemorrhagic stroke exploring the use of intravenous insulin aimed to achieve a tight glycaemic control with different glucose level targets and several other sources of heterogeneity. None of these trials neither the meta-analysis of them have demonstrated any significant benefit of tight glycaemic control with intravenous insulin in acute ischemic or haemorrhagic stroke patients on functional outcome or in survival and they have shown an increased risk for hypoglycaemia.

Conclusions

We suggest against the routine use of tight glycaemic control with intravenous insulin as a means to improve outcomes. The currently available data about the management of glycaemia in patients with acute stroke are limited and the strengths of the recommendations are therefore weak. Nevertheless, this does not prevent that hyperglycaemia in acute stroke patients could be treated as any other hospitalised patient.

Potential link between post-acute ischemic stroke exposure to hypoglycemia and hemorrhagic transformation

Hemorrhagic transformation is a severe complication of acute ischemic stroke owing to its limited treatment options and poor prognosis. In the last decade, the rates of hemorrhagic transformation incidence have been associated with blood glucose levels. In particular, hyperglycemia at the time of admission has been associated with increased rates of hemorrhagic transformation in acute ischemic stroke patients. Recent pilot clinical trials have attempted to use intensive insulin therapy during stroke treatment to reduce the severity of cerebral infarction and possibly alleviate the risk of hemorrhagic transformation. However, the results of these studies have shown no clear clinical benefit. In addition, intensive insulin therapy has increased rates of hypoglycemia which may be associated with larger infarct growth. We hypothesize that hypoglycemia, similarly to hyperglycemia, is a risk factor for worse outcomes in acute ischemic stroke by promoting hemorrhagic transformation. This review serves to call attention to patterns present within intensive insulin therapy trials and shed light into the pathophysiological effects of hypoglycemia. It is critical that efforts be directed toward the prevention of hemorrhagic transformation by optimizing insulin therapy during the treatment of acute ischemic stroke.

Glucocorticoid-associated blood glucose response and MS relapse recovery

OBJECTIVE

To determine the relationship between MS relapse recovery and blood glucose (BG) response to IV methylprednisolone (IVMP) treatment.

METHODS

We retrospectively identified 36 patients with MS admitted for IVMP treatment of acute relapse who had adequate data to characterize BG response, relapse severity, and recovery. The relationship between glucocorticoid-associated nonfasting BG (NFBG) and relapse recovery was assessed.

RESULTS

Highest recorded nonfasting BG (maximum NFBG [maxNFBG]) values were significantly higher in patients with MS without relapse recovery compared with those with recovery (271 ± 68 vs 209 ± 48 mg/dL, respectively; p = 0.0045). After adjusting for relapse severity, MS patients with maxNFBG below the group median were 6 times (OR = 6.01; 95% CI, 1.08-33.40; p = 0.040) more likely to experience relapse recovery than those with maxNFBG above the group median. In a multiple regression model adjusting for age, sex, and relapse severity, a 1-mg/dL increase in the maxNFBG was associated with 4.5% decrease in the probability of recovery (OR = 0.955; 95% CI, 0.928-0.983; p = 0.002).

CONCLUSIONS

These findings suggest that higher glucocorticoid-associated NFBG values in acutely relapsing patients with MS are associated with diminished probability of recovery. This relationship could reflect steroid-associated hyperglycemia and/or insulin resistance, defects in non-steroid-associated (e.g., prerelapse) glucose metabolism, or both. This study included only those admitted for an MS relapse, and it is this subset of patients for whom these findings may be most relevant. A prospective study to evaluate glucose regulation and MS relapse recovery in a broader outpatient MS population is under way.

Hyperglycemia is associated with more severe cytotoxic injury after stroke

Hyperglycemia is a common complication after ischemic stroke, but its link to worse outcome is not well understood. We hypothesized that hyperglycemia may reflect an impaired metabolic response that is associated with worse cytotoxic brain injury. We performed retrospective analysis of magnetic resonance imaging from a cohort of acute ischemic stroke patients prospectively collected from 2006 to 2010 with baseline demographic and laboratory data as well as three-month outcomes. The severity of cytotoxic injury was quantified in vivo using apparent diffusion coefficient imaging by measuring the signal intensity within the stroke relative to the normal signal intensity of the contralateral hemisphere. Both hyperglycemia and lower apparent diffusion coefficient signal were associated with worse outcome after ischemic stroke (OR 0.239, p = 0.017; OR 1.11, p < 0.0001, respectively). Hyperglycemia was also associated with lower apparent diffusion coefficient (r = -0.32, p < 0.001). In multivariate analysis, apparent diffusion coefficient but not hyperglycemia was associated with outcome, suggesting that cytotoxicity may mediate the effect of hyperglycemia. For interventions designed to target hyperglycemia in acute ischemic stroke, a concomitant effect on the evolution of apparent diffusion coefficient may provide insight into whether hyperglycemia leads to or reflects worse cytotoxic injury.

Critical Care Management of Acute Ischemic Stroke

OPINION STATEMENT

Ischemic stroke accounts for approximately 85% of all strokes. Although severe strokes constitute a minority of cases, they are associated with a majority of the subsequent disability and death. Reperfusion therapy with intravenous tissue plasminogen activator (tPA) and/or endovascular thrombectomy is a mainstay of acute stroke management. Intensive care management of stroke is focused on reducing complications of reperfusion, such as hemorrhagic transformation, and minimizing secondary brain injury, including brain edema and progressive stroke. Additionally, severe stroke patients frequently need ventilatory or hemodynamic support provided in an intensive care unit (ICU) setting. Here, we discuss the current medical and surgical ICU management aspects of acute ischemic stroke and identify areas where ongoing studies may reveal new treatments to improve neurological recovery.

Cerebral Metabolism and the Role of Glucose Control in Acute Traumatic Brain Injury

This article reviews key concepts of cerebral glucose metabolism, neurologic outcomes in clinical trials, the biology of the neurovascular unit and its involvement in secondary brain injury after traumatic brain insults, and current scientific and clinical data that demonstrate a better understanding of the biology of metabolic dysfunction in the brain, a concept now known as cerebral metabolic energy crisis. The use of neuromonitoring techniques to better understand the pathophysiology of the metabolic crisis is reviewed and a model that summarizes the triphasic view of cerebral metabolic disturbance supported by existing scientific data is outlined. The evidence is summarized and a template for future research provided.

Cerebral ischemic damage in diabetes: an inflammatory perspective

Stroke is one of the leading causes of death worldwide. A strong inflammatory response characterized by activation and release of cytokines, chemokines, adhesion molecules, and proteolytic enzymes contributes to brain damage following stroke. Stroke outcomes are worse among diabetics, resulting in increased mortality and disabilities. Diabetes involves chronic inflammation manifested by reactive oxygen species generation, expression of proinflammatory cytokines, and activation/expression of other inflammatory mediators. It appears that increased proinflammatory processes due to diabetes are further accelerated after cerebral ischemia, leading to increased ischemic damage. Hypoglycemia is an intrinsic side effect owing to glucose-lowering therapy in diabetics, and is known to induce proinflammatory changes as well as exacerbate cerebral damage in experimental stroke. Here, we present a review of available literature on the contribution of neuroinflammation to increased cerebral ischemic damage in diabetics. We also describe the role of hypoglycemia in neuroinflammation and cerebral ischemic damage in diabetics. Understanding the role of neuroinflammatory mechanisms in worsening stroke outcome in diabetics may help limit ischemic brain injury and improve clinical outcomes.

Diabetes and Stroke: Epidemiology, Pathophysiology, Pharmaceuticals and Outcomes

There has been a significant increase in obesity rates worldwide with the corresponding surge in diabetes. Diabetes causes various microvascular and macrovascular changes often culminating in major clinical complications, 1 of which, is stroke. Although gains have been made over the last 2 decades in reducing the burden of stroke, the recent rise in rates of diabetes threatens to reverse these advances. Of the several mechanistic stroke subtypes, individuals with diabetes are especially susceptible to the consequences of cerebral small vessel diseases. Hyperglycemia confers greater risk of stroke occurrence. This increased risk is often seen in individuals with diabetes and is associated with poorer clinical outcomes (including higher mortality), especially following ischemic stroke. Improving stroke outcomes in individuals with diabetes requires prompt and persistent implementation of evidence-based medical therapies as well as adoption of beneficial lifestyle practices.

Impact of Comorbidities on Acute Injury and Recovery in Preclinical Stroke Research: Focus on Hypertension and Diabetes

Human ischemic stroke is very complex, and no single preclinical model can comprise all the variables known to contribute to stroke injury and recovery. Hypertension, diabetes, and hyperlipidemia are leading comorbidities in stroke patients. The use of predominantly young adult and healthy animals in experimental stroke research has created a barrier for translation of findings to patients. As such, more and more disease models are being incorporated into the research design. This review highlights the major strengths and weaknesses of the most commonly used animal models of these conditions in preclinical stroke research. The goal is to provide guidance in choosing, reporting, and executing appropriate disease models that will be subjected to different models of stroke injury.

Treatment of hyperglycaemia in patients with acute stroke

The proportion of diabetic patients who are hospitalised for stroke has been increasing in recent years, currently reaching almost a third of all cases of stroke. In addition, about half of patients with acute stroke present hyperglycaemia in the first hours of the stroke. Although hyperglycaemia in the acute phase of stroke is associated with a poor prognosis, its treatment is currently a topic of debate. There is no evidence that the adminstration of intravenous insulin to these patients offers benefits in terms of the evolution of the stroke. New studies in development, such as the SHINE study (Stroke Hyperglycemia Insulin Network Effort), may contribute to clarifying the role of intensive control of glycaemia during the acute phase of the stroke. Ultimately, patients who have presented with stroke should be screened for diabetes.

Acute ischemic stroke and hyperglycemia

To increase the comprehension about the profound effects of hyperglycemia within the first 48 hours poststroke on the outcomes of acute ischemic stroke, the authors reviewed multiple studies and literature reviews. Research supports the detrimental effects of hyperglycemia on the morbidity and mortality of patients diagnosed with acute ischemic stroke. The studies that were examined revealed that although further research is necessary, controlling hyperglycemia is overall beneficial to support superior clinical outcomes. The purpose of this article was to discuss the importance of not only glucose control but also the vital role of nurses in controlling glucose levels efficiently and immediately during the first 48 hours poststroke.

A guideline for the use of variable rate intravenous insulin infusion in medical inpatients

The present paper summarizes the key recommendations in a recent publication produced by the Joint British Diabetes Societies for Inpatient Care on the use of variable rate i.v. insulin infusion in 'medical' inpatients. The full guideline is available at http://www.diabetologists-abcd.org.uk/JBDS/JBDS_IP_VRIII.pdf and is designed to be a practical guide that can used by any healthcare professional who manages medical inpatients with hyperglycaemia. Its main aim is to allow variable rate i.v. insulin infusion to be used safely, effectively and efficiently for this specific group of inpatients.

Nicotine pre-exposure reduces stroke-induced glucose transporter-1 activity at the blood-brain barrier in mice

Background

With growing electronic cigarette usage in both the smoking and nonsmoking population, rigorous studies are needed to investigate the effects of nicotine on biological systems to determine long-term health consequences. We have previously shown that nicotine exerts specific neurovascular effects that influence blood brain barrier (BBB) function in response to stroke. In this study, we investigated the effects of nicotine on carrier-mediated glucose transport into ischemic brain. Specifically, the present study investigates glucose transporter-1 (GLUT1) function and expression at the BBB in a focal brain ischemia model of mice pre-exposed to nicotine.

Methods

Nicotine was administrated subcutaneously by osmotic pump at the dose of 4.5 mg/kg/day for 1, 7, or 14 days to reflect the plasma levels seen in smokers. Ischemic-reperfusion (IR) injury was induced by 1 h transient middle cerebral artery occlusion (tMCAO) and 24 h reperfusion. Glucose transport was estimated using an in situ brain perfusion technique with radiolabeled glucose and brain vascular GLUT1 expression was detected with immunofluorescence.

Results

The nicotine pre-exposure (1, 7 & 14 day) resulted in significant reduction in D-glucose influx rate (K_in) across the BBB, with a 49% reduction in 14 day nicotine-infused animals. We observed a 41% increase in carrier-mediated glucose transport across the BBB in saline-infused tMCAO animals compared to saline-infused sham animals. Interestingly, in the tMCAO group of animals pre-exposed to nicotine for 14 days had significantly attenuated increased glucose transport by 80% and 38% compared to saline-infused tMCAO and sham animals respectively. Furthermore, immunofluorescence studies of GLUT1 protein expression in the brain microvascular endothelium confirmed that GLUT1 was also induced in saline-infused tMCAO animals and this protein expression induction was reduced significantly (P < 0.01) with 14 day nicotine pre-exposure in tMCAO animals.

Conclusions

Nicotine pre-exposure reduced the IR-enhanced GLUT1 transporter function and expression at the BBB in a focal brain ischemia mouse model. These studies suggest that nicotine exposure prior to stroke could create an enhanced glucose deprived state at the neurovascular unit (NVU) and could provide an additional vulnerability to enhanced stroke injury.

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.

Comparative Analysis of Different Methods of Ischemia/Reperfusion in Hyperglycemic Stroke Outcomes: Interaction with tPA

Acute hyperglycemia (HG) exacerbates reperfusion injury and aggravates tissue plasminogen activator (tPA)-induced hemorrhagic transformation (HT). Previous experimental hyperglycemic stroke studies employed very high blood glucose levels and exclusively used suture occlusion model to induce ischemia. Only few studies evaluated HG in embolic stroke and mostly involving the use of 10-fold higher dose of tPA than that is used in patients. However, the interaction between acute HG and low (human) dose tPA in different experimental models of stroke has never been reported. We first tested the impact of the severity of acute HG on stroke outcome. Building upon our findings, we then compared the impact of mild acute HG on neurovascular injury in rats subjected to suture or thromboembolic occlusion with and without low dose tPA. We assessed cerebral blood flow, neurobehavioral outcomes, infarction, hemorrhage, and edema. tPA did not change the infarct size in either control or hyperglycemic animals when compared to no tPA groups. HG increased HT and worsened functional outcomes in both suture and embolic occlusion models. The combination of HG and tPA exacerbated the vascular injury and worsened the neurological deficits more than each individual treatment in both models. Our findings show that the interaction between HG and even low dose tPA has detrimental effects on the cerebrovasculature and functional outcomes independent of the method of reperfusion.

Standards of scoring, monitoring, and parameter targeting in German neurocritical care units: a national survey

BACKGROUND

Optimal management of physiological parameters in neurological/neurosurgical intensive care units (NICUs) is largely unclear as high-quality evidence is lacking. The aim of this survey was to investigate if standards exist in the use of clinical scores, systemic and cerebral monitoring and the targeting of physiology values and in what way this affects clinical management in German NICUs.

METHODS

National survey, on-line anonymized questionnaire. German departments stating to run a neurological, neurosurgical or interdisciplinary neurological/neurosurgical intensive care unit were identified by a web-based search of all German hospitals and contacted via email.

RESULTS

Responses from 78 German NICUs were obtained. Of 19 proposed clinical/laboratory/radiological scores only 5 were used regularly by >60 %. Bedside neuromonitoring (NM) predominantly consisted of transcranial Doppler sonography (94 %), electroencephalography (92 %) and measurement of intracranial pressure (ICP) (90 %), and was installed if patients had or were threatened by elevated ICP (86 %), had specific diseases like subarachnoid hemorrhage (51 %) or were comatose (35 %). Although mean trigger values for interventions complied with guidelines or wide-spread customs, individual trigger values varied widely, e.g., for hyperglycemia (maximum blood glucose between 120 and 250 mg/dl) or for anemia (minimum hemoglobin values between 5 and 10 g/dl).

CONCLUSIONS

Although apparently aiming for standardization in neurocritical care, German NICUs show substantial differences in NM and monitoring-associated interventions. In terms of scoring and monitoring methods, German NICUs seem to be quite conservative. These survey results suggest a need of prospective and randomized interventional trials in neurocritical care to help define standards and target values.

Glibenclamide in cerebral ischemia and stroke

The sulfonylurea receptor 1 (Sur1)-transient receptor potential 4 (Trpm4) channel is an important molecular element in focal cerebral ischemia. The channel is upregulated in all cells of the neurovascular unit following ischemia, and is linked to microvascular dysfunction that manifests as edema formation and secondary hemorrhage, which cause brain swelling. Activation of the channel is a major molecular mechanism of cytotoxic edema and "accidental necrotic cell death." Blockade of Sur1 using glibenclamide has been studied in different types of rat models of stroke: (i) in conventional non-lethal models (thromboembolic, 1-2 h temporary, or permanent middle cerebral artery occlusion), glibenclamide reduces brain swelling and infarct volume and improves neurological function; (ii) in lethal models of malignant cerebral edema, glibenclamide reduces edema, brain swelling, and mortality; (iii) in models with rtPA, glibenclamide reduces swelling, hemorrhagic transformation, and death. Retrospective studies of diabetic patients who present with stroke have shown that those whose diabetes is managed with a sulfonylurea drug and who are maintained on the sulfonylurea drug during hospitalization for stroke have better outcomes at discharge and are less likely to suffer hemorrhagic transformation. Here, we provide a comprehensive review of the basic science, preclinical experiments, and retrospective clinical studies on glibenclamide in focal cerebral ischemia and stroke. We also compare the preclinical work in stroke models to the updated recommendations of the Stroke Therapy Academic Industry Roundtable (STAIR). The findings reviewed here provide a strong foundation for a translational research program to study glibenclamide in patients with ischemic stroke.