Association between serum glucose level and spot sign in intracerebral hemorrhage

Impaired microglial glycolysis promotes inflammatory responses after intracerebral haemorrhage via HK2-dependent mitochondrial dysfunction

INTRODUCTION

Intracerebral haemorrhage (ICH) is a devastating disease that leads to severe neurological deficits. Microglia are the first line of defence in the brain and play a crucial role in neurological recovery after ICH, whose activities are primarily driven by glucose metabolism. However, little is known regarding the status of glucose metabolism in microglia and its interactions with inflammatory responses after ICH.

OBJECTIVES

This study investigated microglial glycolysis and its mechanistic effects on microglial inflammation after ICH.

METHODS

We explored the status of glucose metabolism in the ipsilateral region and in fluorescence-activated-cell-sorting-isolated (FACS-isolated) microglia via 2-deoxy-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) analyses and gamma emission, respectively. Energy-related targeted metabolomics, along with 13C-glucose isotope tracing, was utilised to analyse glycolytic products in microglia. Mitochondrial membrane potential and mitochondrial reactive oxygen species (MitoROS) accumulation was assessed by flow cytometry. Behavioural, western blotting, gene regulation, and enzymatic activity analyses were conducted with a focus on microglia.

RESULTS

Neurological dysfunction was strongly correlated with decreased FDG-PET signals in the perihaematomal region, where microglial uptake of FDG was reduced. The decreased quantity of glucose-6-phosphate (G-6-P) in microglia was attributed to the downregulation of glucose transporter 1 (GLUT1) and hexokinase 2 (HK2). Enhanced inflammatory responses were driven by HK2 suppression via decreased mitochondrial membrane potential, which could be rescued by MitoROS scavengers. HK inhibitors aggravated neurological injury by suppressing FDG uptake and enhancing microglial inflammation in ICH mice.

CONCLUSION

These findings indicate an unexpected metabolic status in pro-inflammatory microglia after ICH, consisting of glycolysis impairment caused by the downregulation of GLUT1 and HK2. Additionally, HK2 suppression promotes inflammatory responses by disrupting mitochondrial function, providing insight into the mechanisms by which inflammation may be facilitated after ICH and indicating that metabolic enzymes as potential targets for ICH treatment.

Prevention and treatment of ischaemic and haemorrhagic stroke in people with diabetes mellitus: a focus on glucose control and comorbidities

Diabetes mellitus is a significant risk factor for both ischaemic and haemorrhagic stroke, affecting up to a third of individuals with cerebrovascular diseases. Beyond being a risk factor for stroke, diabetes and hyperglycaemia have a negative impact on outcomes after ischaemic and haemorrhagic stroke. Hyperglycaemia during the acute ischaemic stroke phase is associated with a higher risk of haemorrhagic transformation and poor functional outcome, with evidence in favour of early intervention to limit and manage severe hyperglycaemia. Similarly, intensive glucose control nested in a broader bundle of care, including blood pressure, coagulation and temperature control, can provide substantial benefit for clinical outcomes after haemorrhagic stroke. As micro- and macrovascular complications are frequent in people with diabetes, cardiovascular prevention strategies also need to consider tailored treatment. In this regard, the broader availability of sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists can allow tailored treatments, particularly for those with heart failure and chronic kidney disease as comorbidities. Here, we review the main concepts of hyperacute stroke management and CVD prevention among people with diabetes, capitalising on results from large studies and RCTs to inform clinicians on preferred treatments.

The role of hyperglycemia in the outcome of intracerebral hemorrhage: A causative analysis

BACKGROUND

Hyperglycemia in the acute phase of intracerebral hemorrhage (ICH) has been associated with poor functional outcomes, however all interventions to lower glucose have yielded neutral or negative results. We attempt an explanation of the causal role of hyperglycemia in ΙCH outcome using generalized structural equation modeling.

MATERIALS AND METHODS

Consecutive primary ICH patients admitted to an academic hospital between 2007 and 2018 were identified. Patients with missing baseline or follow up CT scans and without 90 day follow up status were excluded. We constructed a causal model accounting for pre-defined markers of ICH severity to evaluate the association between mean 72 h glucose and 90 day functional outcome measured by modified Rankin Scale, dichotomized as favorable ≤2 or unfavorable >2.

RESULTS

Primary analyses included 410 patients (70.4 ± 13.8years, 43 % female). Mean 72 h glucose was 137.5 ± 33.4mg/dl and 102 (25 %) patients were diabetic. On univariable analysis, higher glucose levels were negatively correlated with favorable outcome (p < 0.0001). However in the structural equation model, this relationship was significantly attenuated (p = 0.06) after accounting for the causal effect of diabetes (p < 0.0001), hematoma volume (p < 0.0001), intraventricular extension (p = 0.01) and Glasgow coma scale (p = 0.001) on glucose levels. On secondary analyses stratifying by diagnosis of diabetes, higher glucose levels were negatively correlated with favorable outcome in patients without diabetes (p = 0.04), but not in patients with diabetes (p = 0.35).

CONCLUSIONS

Hyperglycemia may be a downstream effect of other markers of ICH severity, particularly among patients without diabetes, suggesting a possible explanation for the limited evidence of glucose lowering interventions in outcome.

Acute Hyperglycemia and In-Hospital Mortality in Spontaneous Intracerebral Hemorrhage

Hyperglycemia is reported to predict worse outcome in patients with stroke, including intracerebral hemorrhage (ICH). In 83 consecutive cases of ICH at a tertiary stroke center, hyperglycemia (serum glucose >7 mmol/L) compared to normoglycemia at presentation was associated with higher rates of in-hospital mortality (51.2% vs. 26.2%, OR 2.3, CI 1.2-7.6, p = 0.02). The association with in-hospital mortality withstood adjustment for age, ICH volume, intraventricular hemorrhage, and infratentorial ICH location, but not baseline Glasgow Coma Scale. Acute hyperglycemia is associated with in-hospital mortality in spontaneous ICH patients, though this may be an indirect, rather than a causal relationship.

Analysis of glucose metabolism by 18F-FDG-PET imaging and glucose transporter expression in a mouse model of intracerebral hemorrhage

The relationship between cerebral glucose metabolism and glucose transporter expression after intracerebral hemorrhage (ICH) is unclear. Few studies have used positron emission tomography (PET) to explore cerebral glucose metabolism after ICH in rodents. In this study, we produced ICH in mice with an intrastriatal injection of collagenase to investigate whether glucose metabolic changes in 18F-fluoro-2-deoxy-D-glucose (FDG)-PET images are associated with expression of glucose transporters (GLUTs) over time. On days 1 and 3 after ICH, the ipsilateral striatum exhibited significant hypometabolism. However, by days 7 and 14, glucose metabolism was significantly higher in the ipsilateral striatum than in the contralateral striatum. The contralateral hemisphere did not show hypermetabolism at any time after ICH. Qualitative immunofluorescence and Western blotting indicated that the expression of GLUT1 in ipsilateral striatum decreased on days 1 and 3 after ICH and gradually returned to baseline by day 21. The 18F-FDG uptake after ICH was associated with expression of GLUT1 but not GLUT3 or GLUT5. Our data suggest that ipsilateral cerebral glucose metabolism decreases in the early stage after ICH and increases progressively in the late stage. Changes in 18F-FDG uptake on PET imaging are associated with the expression of GLUT1 in the ipsilateral striatum.

Noncontrast Computed Tomography-Based Radiomics Analysis in Discriminating Early Hematoma Expansion after Spontaneous Intracerebral Hemorrhage

Objective

To determine whether noncontrast computed tomography (NCCT) models based on multivariable, radiomics features, and machine learning (ML) algorithms could further improve the discrimination of early hematoma expansion (HE) in patients with spontaneous intracerebral hemorrhage (sICH).

Materials and Methods

We retrospectively reviewed 261 patients with sICH who underwent initial NCCT within 6 hours of ictus and follow-up CT within 24 hours after initial NCCT, between April 2011 and March 2019. The clinical characteristics, imaging signs and radiomics features extracted from the initial NCCT images were used to construct models to discriminate early HE. A clinical-radiologic model was constructed using a multivariate logistic regression (LR) analysis. Radiomics models, a radiomics-radiologic model, and a combined model were constructed in the training cohort (n = 182) and independently verified in the validation cohort (n = 79). Receiver operating characteristic analysis and the area under the curve (AUC) were used to evaluate the discriminative power.

Results

The AUC of the clinical-radiologic model for discriminating early HE was 0.766. The AUCs of the radiomics model for discriminating early HE built using the LR algorithm in the training and validation cohorts were 0.926 and 0.850, respectively. The AUCs of the radiomics-radiologic model in the training and validation cohorts were 0.946 and 0.867, respectively. The AUCs of the combined model in the training and validation cohorts were 0.960 and 0.867, respectively.

Conclusion

NCCT models based on multivariable, radiomics features and ML algorithm could improve the discrimination of early HE. The combined model was the best recommended model to identify sICH patients at risk of early HE.

Incidence and Prognostic Impact of Intracranial Hemorrhage after Endovascular Treatment for Acute Large Vessel Occlusion

INTRODUCTION

Endovascular treatment (EVT) is effective against acute cerebral large vessel occlusion (LVO). However, it has been associated with a high incidence of intracranial hemorrhage (ICH). Because the incidence of ICH and prognostic impact of ICH were not scrutinized in general patients, we investigated the impact of ICH after EVT on functional outcome at 90 days in patients with acute LVO.

METHODS

RESCUE-Japan Registry 2 was a multicenter registry that enrolled 2,420 consecutive patients with acute LVO within 24 h of onset. We analyzed 1,281 patients who received EVT and compared the functional outcomes between those with and without ICH (ICH and no-ICH groups, respectively) within 24 h after EVT. We explored the factors associated with ICH and prognostic impact of symptomatic ICH (SICH) among patients with ICH. We estimated the adjusted odds ratios (ORs) for good functional outcome as modified Rankin Scale scores 0-2 and mortality. We also explored the prognostic impact of symptomatic ICH (SICH) among patients with ICH.

RESULTS

ICH occurred in 333 patients (26.0%). Several factors such as perioperative edaravone, stent retriever, and baseline glucose were associated with development of ICH within 24 h. A good outcome was observed in 80 (24.0%) and 454 (47.9%) patients in the ICH and no-ICH groups, respectively, and the adjusted OR was 0.3 (95% confidence interval [CI] = 0.2-0.5, p < 0.0001). Incidence of mortality within 90 days was not significantly different between the groups (adjusted OR 1.2; 95% CI: 0.7-1.9, p = 0.5). SICH was observed in 36 (10.8%) of 333 patients with ICH, and the good outcomes were 8.3 and 25.9% in patients with SICH and asymptomatic ICH (AICH), respectively (p = 0.02). Mortality at 90 days was 30.6 and 7.1% in patients with SICH and AICH, respectively (p < 0.0001).

CONCLUSIONS

The functional outcomes at 90 days were significantly worse in patients who developed ICH after receiving EVT for acute LVO, but the mortality was generally similar.

Hematoma Expansion in Intracerebral Hemorrhage: An Update on Prediction and Treatment

Intracerebral hemorrhage (ICH) is the most lethal type of stroke, but there is no specific treatment. After years of effort, neurologists have found that hematoma expansion (HE) is a vital predictor of poor prognosis in ICH patients, with a not uncommon incidence ranging widely from 13 to 38%. Herein, the progress of studies on HE after ICH in recent years is updated, and the topics of definition, prevalence, risk factors, prediction score models, mechanisms, treatment, and prospects of HE are covered in this review. The risk factors and prediction score models, including clinical, imaging, and laboratory characteristics, are elaborated in detail, but limited by sensitivity, specificity, and inconvenience to clinical practice. The management of HE is also discussed from bench work to bed practice. However, the upmost problem at present is that there is no treatment for HE proven to definitely improve clinical outcomes. Further studies are needed to identify more accurate predictors and effective treatment to reduce HE.