Neuroaxonal Injury May Mediate the Association Between Hyperglycemia and Prognosis in Spontaneous Subarachnoid Hemorrhage

Hyperglycemia during early brain injury (EBI) period after spontaneous subarachnoid hemorrhage (SAH) is associated with poor outcome, but the underlying physiopathology is unknown. This study assessed if hyperglycemia during EBI is associated with markers of neuroaxonal injury and whether these biomarkers partially account for the association between hyperglycemia and poor clinical outcome. Ninety-two SAH patients admitted within 24 h of bleeding onset were prospectively included. Glucose levels were measured at arrival and every 6 h for 72 h. Serum neurofilament light chain (NFL) levels were measured at 72 h. Functional outcome was assessed with the modified Rankin Scale (mRS) at 90 days (poor outcome, mRS > 2). The association between glucose metrics, NFL levels, and clinical outcome was assessed with univariate and multivariate analyses. Mediation analysis was performed to examine the potential chain in which NFL may mediate the relationship between glucose and functional outcome. Higher glucose and NFL levels during EBI were associated with poor clinical outcome in adjusted analysis. NFL levels were associated with older age, higher initial severity, and higher glucose levels during EBI period. In adjusted mediation analyses, the association between glucose and clinical outcome was significantly mediated by NFL levels. The mediator NFL explained 25% of the association between glucose during EBI period and poor functional outcome at 90 days. In SAH, the association between glucose levels during EBI and poor clinical outcome might be significantly mediated by NFL levels. The link between hyperglycemia and poor clinical outcome might be explained in part through secondary neuroaxonal injury.

Multimodal imaging of the role of hyperglycemia following experimental subarachnoid hemorrhage

Hyperglycemia has been linked to worsening outcomes after subarachnoid hemorrhage (SAH). Nevertheless, the mechanisms involved in the pathogenesis of SAH have been scarcely evaluated so far. The role of hyperglycemia was assessed in an experimental model of SAH by T2 weighted, dynamic contrast-enhanced magnetic resonance imaging (T2W and DCE-MRI), [18F]BR-351 PET imaging and immunohistochemistry. Measures included the volume of bleeding, the extent of cerebral infarction and brain edema, blood brain barrier disruption (BBBd), neutrophil infiltration and matrix metalloprotease (MMP) activation. The neurofunctional outcome, neurodegeneration and myelinization were also investigated. The induction of hyperglycemia increased mortality, the size of the ischemic lesion, brain edema, neurodegeneration and worsened neurological outcome during the first 3 days after SAH in rats. In addition, these results show for the first time the exacerbating effect of hyperglycemia on in vivo MMP activation, Intercellular Adhesion Molecule 1 (ICAM-1) expression and neutrophil infiltration together with increased BBBd, bleeding volume and fibrinogen accumulation at days 1 and 3 after SAH. Notably, these data provide valuable insight into the detrimental effect of hyperglycemia on early BBB damage mediated by neutrophil infiltration and MMP activation that could explain the worse prognosis in SAH.

Triglyceride Glucose Index and Prognosis of Patients with Subarachnoid Hemorrhage

OBJECTIVE

The triglyceride glucose (TyG) index is regarded as a reliable alternative indicator for measuring insulin resistance. We investigated the association between the prognosis of patients with subarachnoid hemorrhage (SAH)and the TyG index, explored the potential of the TyG index as a new biomarker for forecasting the outcomes of SAH patients, and explored independent risk factors for predicting the condition of SAH patients.

METHODS

A retrospective analysis was performed of patients who were admitted to a single center due to SAH. Differences in clinical data and correlation between laboratory indexes, disease severity score on admission, and prognosis score were compared between the 2 groups. The study employed multivariate logistic regression analysis to examine the independent influencing aspects of Glasgow Outcome Scale score. The receiver operating characteristic curve was drawn and the area under the curve (AUC) calculated to predict the best cutoff value of the degree of neurological impairment in patients with SAH.

RESULTS

Univariate analysis showed that Glasgow Coma Scale score (86.3% vs. 12.0%, P < 0.001), Hunt-Hess grade (88.2% vs. 15.7%, P < 0.001), white blood cell count (11.20 [7.9, 15.2] vs. 9.1 [7.0, 12.2], P = 0.027), and TyG index (1.49 [1.40, 1.59] vs. 1.16 [1.06, 1.27], P < 0.001) were statistically significantly different. Multivariate analysis showed that TyG index, Hunt-Hess grade, and GCS score were independent risk factors for poor prognosis.

CONCLUSIONS

Patients with SAH may benefit from using the TyG index as a predictive method. In our clinical practice, the TyG index is beneficial for managing diseases and making decisions. More research is required to determine if improved TyG index control would lead to better clinical results in the future.

A nomogram for predicting the risk of cerebral vasospasm after neurosurgical clipping in patients with aneurysmal subarachnoid hemorrhage

Purpose

Cerebral vasospasm (CVS) is a common complication that occurs after neurosurgical clipping of intracranial aneurysms in patients with aSAH. This complication can lead to clinical deterioration and a poor prognosis. The aim of this study is to explore the risk factors for CVS in aSAH patients who have undergone neurosurgical clipping, develop a nomogram for CVS, and evaluate its performance.

Methods

Patients with aSAH who underwent neurosurgical clipping in the Department of Neurosurgery from January 2018 to January 2023 were selected as the subjects of this research. The clinical data of these patients were retrospectively analyzed. Logistic multivariate regression analysis was employed to identify the independent risk factors of CVS. A clinical prediction model in the form of a nomogram for CVS was developed using the R programming language and subsequently evaluated for its performance and quality.

Results

A total of 156 patients with aSAH were included in the analysis, comprising 109 patients in the training set and 47 patients in the validation set. In the training cohort, 27 patients (24.77%) developed CVS after neurosurgical clipping, while in the validation cohort, 15 patients (31.91%) experienced CVS. Multivariate regression analysis revealed that age, Hcy, WBC, glucose/potassium ratio, aneurysm location, and modified Fisher grade were independent risk factors for CVS. The nomogram exhibited excellent discriminative performance in both the training set (AUC = 0.885) and the validation set (AUC = 0.906).

Conclusion

CVS was a prevalent complication following neurosurgical clipping in patients with aSAH, with a highly intricate pathogenesis and pathophysiological course. Early prediction of CVS represented a significant challenge in clinical practice. In this study, age, Hcy, WBC, glucose/potassium ratio, aneurysm location, and modified Fisher grade emerged as independent risk factors for CVS. The resulting nomogram demonstrated substantial predictive value.

GSK3β inhibitor TDZD8 ameliorates brain damage through both ROS scavenging and inhibition of apoptosis in hyperglycaemic subarachnoid haemorrhage rats

Hyperglycaemia is known to be associated with unfavourable outcomes in subarachnoid haemorrhage (SAH), but the pathogenic mechanism is unclear, and there is also a lack of effective therapeutic drugs in clinical practice. Phosphorylation of GSK3β at serine 9 can inhibit its activity to further worsen SAH. The aim of the present study was to evaluate the protective effect and the potential mechanism of the GSK3β inhibitor TDZD8 on brain injury in a hyperglycaemic SAH rat model. Hyperglycaemia was induced by intraperitoneal injection of streptozocin for 3 days. The SAH model was established by injecting fresh autologous femoral artery blood into the prechiasmatic cistern. p-GSK3β (Ser9) expression was induced by intraperitoneal injection of TDZD8 (30 min post-SAH). The expression levels of GSK3β, p-GSK3β, SOD1/2, caspase 3, Bax and Bcl-2 were detected by western blot analysis. Terminal deoxynucleotidyl transferase dUTP nick end-labelling (TUNEL) staining was used to detect neuronal apoptosis of basal temporal lobe. Neurological scores were calculated to determine behavioural recovery. Neuronal survival was detected by Nissl staining. Hyperglycaemia significantly decreased p-GSK3β expression, further exacerbated neurobehavioural deficits and increased oxidative stress and neuronal apoptosis in the brain after SAH compared to normal glycaemic SAH rats and hyperglycaemic rats. In addition, hyperglycaemic SAH rats had obvious oxidative stress and apoptosis. However, TDZD8 effectively decreased cleaved caspase 3 expression and TUNEL-positive cells and increased the Bcl2/Bax ratio, expression of SOD1/2 and activity of superoxide dismutase (SOD) enzyme compared with hyperglycaemic SAH rats. The GSK3β inhibitor TDZD8 has therapeutic potential for hyperglycaemic SAH. The neuroprotective effect of TDZD8 appears to be mediated through its antioxidative and antiapoptotic activity.

Changes in Cerebral Blood Flow and Diffusion-Weighted Imaging Lesions After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a common subtype of stroke and places a great burden on the family and society with a high mortality and disability rate and a poor prognosis. Many findings from imaging and pathologic studies have suggested that cerebral ischemic lesions visualized on diffusion-weighted imaging (DWI) in patients with ICH are not rare and are generally considered to be associated with poor outcome, increased risk of recurrent (ischemic and hemorrhagic) stroke, cognitive impairment, and death. In this review, we describe the changes in cerebral blood flow (CBF) and DWI lesions after ICH and discuss the risk factors and possible mechanisms related to the occurrence of DWI lesions, such as cerebral microangiopathy, cerebral atherosclerosis, aggressive early blood pressure lowering, hyperglycemia, and inflammatory response. We also point out that a better understanding of cerebral DWI lesions will be a key step toward potential therapeutic interventions to improve long-term recovery for patients with ICH.

The prognostic value of hyperglycemia in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

Recent studies have demonstrated that hyperglycemia may result in a poor prognosis following aneurysmal subarachnoid hemorrhage (aSAH). However, the association between hyperglycemia and the clinical outcome of aSAH has not been clearly established thus far. Therefore, we performed a systematic review and meta-analysis to investigate the association between hyperglycemia and the development of aSAH. We completed a literature search in four databases (PubMed, EMBASE, Cochrane Library, and Web of Science) up to November 1, 2021, including all eligible studies investigating the prognostic value of hyperglycemia in patients with aSAH. We performed a quality assessment of included studies using the Newcastle-Ottawa Quality Assessment Scale. The pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated to assess the association of hyperglycemia in aneurysmal subarachnoid hemorrhage. A total of 35 studies with 11,519 patients were finally included in the meta-analysis. Nineteen studies reported the association between hyperglycemia and poor outcome, 12 studies reported the association between hyperglycemia and all-cause mortality, 7 studies reported the association between hyperglycemia and cerebral vasospasm, and 9 studies reported the association between hyperglycemia and cerebral infarction. The pooled data of these studies suggested that hyperglycemia was significantly associated with poor functional outcomes (odds ratio [OR], 1.29; 95% confidence interval [CI], 1.17-1.42; P < 0.00001; I² = 83%), all-cause mortality (OR, 1.02; 95% CI, 1.01-1.04; P = 0.0006; I² = 89%), cerebral vasospasm (OR, 1.02; 95% CI, 1.01-1.02; P = 0.0002; I² = 35%), and cerebral infarction (OR, 1.16; 95% CI, 1.09-1.23; P < 0.00001; I² = 10%) in aSAH patients. These findings suggested that assessing for hyperglycemia at admission may help clinicians to identify critically ill patients and complete patient stratification early, which may achieve better management and improve the prognosis of patients with aSAH.

Clinical relevance of glucose metrics during the early brain injury period after aneurysmal subarachnoid hemorrhage: An opportunity for continuous glucose monitoring

Hyperglycaemia, hypoglycaemia and higher glucose variability during the Early Brain Injury (EBI) period of aneurysmal subarachnoid hemorrhage (aSAH) have been associated with poor clinical outcome. However, it is unclear whether these associations are due to direct glucose-driven injury or if hyperglycaemia simply acts as a marker of initial severity. Actually, strict glucose control with intensive insulin therapy has not been demonstrated as an effective strategy for improving clinical outcomes after aSAH. Currently published studies describing an association between hyperglycaemia and prognosis in aSAH patients have been based on isolated glucose measurements and did not incorporate comprehensive dynamic evaluations, such as those derived from subcutaneous continuous glucose monitoring devices (CMG). Arguably, a more accurate knowledge on glycaemic patterns during the acute phase of aSAH could increase our understanding of the relevance of glycaemia as a prognostic factor in this disease as well as to underpin its contribution to secondary focal and diffuse brain injury. Herein, we have summarized the available evidence on the diagnostic and prognostic relevance of glucose metrics during the acute phase of cerebrovascular diseases, focusing in the EBI period after aSAH. Overall, obtaining a more precise scope of acute longitudinal glucose profiles could eventually be useful for improving glucose management protocols in the setting of acute aSAH and to advance toward a more personalized management of aSAH patients during the EBI phase.

Therapeutic Effect of Mitochondrial Division Inhibitor-1 (Mdivi-1) on Hyperglycemia-Exacerbated Early and Delayed Brain Injuries after Experimental Subarachnoid Hemorrhage

Background: Neurological deficits following subarachnoid hemorrhage (SAH) are caused by early or delayed brain injuries. Our previous studies have demonstrated that hyperglycemia induces profound neuronal apoptosis of the cerebral cortex. Morphologically, we found that hyperglycemia exacerbated late vasospasm following SAH. Thus, our previous studies strongly suggest that post-SAH hyperglycemia is not only a response to primary insult, but also an aggravating factor for brain injuries. In addition, mitochondrial fusion and fission are vital to maintaining cellular functions. Current evidence also shows that the suppression of mitochondrial fission alleviates brain injuries after experimental SAH. Hence, this study aimed to determine the effects of mitochondrial dynamic modulation in hyperglycemia-related worse SAH neurological prognosis. Materials and methods: In vitro, we employed an enzyme-linked immunosorbent assay (ELISA) to detect the effect of mitochondrial division inhibitor-1 (Mdivi-1) on lipopolysaccharide (LPS)-induced BV-2 cells releasing inflammatory factors. In vivo, we produced hyperglycemic rats via intraperitoneal streptozotocin (STZ) injections. Hyperglycemia was confirmed using blood-glucose measurements (>300 mg/dL) 7 days after the STZ injection. The rodent model of SAH, in which fresh blood was instilled into the craniocervical junction, was used 7 days after STZ administration. We investigated the mechanism and effect of Mdivi-1, a selective inhibitor of dynamin-related protein (Drp1) to downregulate mitochondrial fission, on SAH-induced apoptosis in a hyperglycemic state, and evaluated the results in a dose−response manner. The rats were divided into the following five groups: (1) control, (2) SAH only, (3) Diabetes mellitus (DM) + SAH, (4) Mdivi-1 (0.24 mg/kg) + DM + SAH, and (5) Mdivi-1 (1.2 mg/kg) + DM + SAH. Results: In vitro, ELISA revealed that Mdivi-1 inhibited microglia from releasing inflammatory factors, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6. In vivo, neurological outcomes in the high-dose (1.2 mg/kg) Mdivi-1 treatment group were significantly reduced compared with the SAH and DM + SAH groups. Furthermore, immunofluorescence staining and ELISA revealed that a high dose of Mdivi-1 had attenuated inflammation and neuron cell apoptosis by inhibiting Hyperglycemia-aggravated activation, as well as microglia and astrocyte proliferation, following SAH. Conclusion: Mdivi-1, a Drp-1 inhibitor, attenuates cerebral vasospasm, poor neurological outcomes, inflammation, and neuron cell apoptosis following SAH + hyperglycemia.

Effect of stress-induced hyperglycemia after non-traumatic non-aneurysmal subarachnoid hemorrhage on clinical complications and functional outcomes

Background

Despite having an overall benign course, non‐traumatic non‐aneurysmal subarachnoid hemorrhage (naSAH) is still accompanied by a risk of clinical complications and poor outcomes. Risk factors and mechanisms of complications and poor outcomes after naSAH remain unknown. Our aim was to explore the effect of stress‐induced hyperglycemia (SIH) on complication rates and functional outcomes in naSAH patients.

Methods

We retrospectively reviewed patients with naSAH admitted to our institution between 2013 and 2018. SIH was identified according to previous criterion. Symptomatic vasospasm, delayed cerebral infarction, and hydrocephalus were identified as main complications. Outcomes were reviewed using a modified Rankin Scale (mRS) at discharge, 3 months, and 12 months. A statistical analysis was conducted to reveal the associations of SIH with complications and outcomes.

Results

A total of 244 naSAH patients were included in the cohort with 74 (30.3%) SIH. After adjusting for age, gender, hypertension, Hunt and Hess (HH) grade, modified Fisher Scale (mFS), intraventricular hemorrhage (IVH), and subarachnoid blood distribution, SIH was significantly associated with symptomatic vasospasm (p < 0.001, 12.176 [4.904–30.231]), delayed cerebral infarction (p < 0.001, 12.434 [3.850–40.161]), hydrocephalus (p = 0.008, 5.771 [1.570–21.222]), and poor outcome at 12 months (p = 0.006, 5.506 [1.632–18.581]), whereas the correlation between SIH and poor outcome at discharge (p = 0.064, 2.409 [0.951–6.100]) or 3 months (p = 0.110, 2.029 [0.852–4.833]) was not significant. Incorporation of SIH increased the area under curve (AUC) of ROC in the combined model for predicting symptomatic vasospasm (p = 0.002), delayed cerebral infarction (p = 0.024), hydrocephalus (p = 0.037), and 12‐month poor outcome (p = 0.087).

Conclusions

SIH is a significant and independent risk factor for symptomatic vasospasm, delayed cerebral infarction, hydrocephalus, and long‐term poor outcome in naSAH patients. Identifying SIH early after naSAH is important for decision‐making and treatment planning.

Attenuation in Proinflammatory Factors and Reduction in Neuronal Cell Apoptosis and Cerebral Vasospasm by Minocycline during Early Phase after Subarachnoid Hemorrhage in the Rat

Background

Subarachnoid hemorrhage (SAH) is an important subcategory of stroke due to its high mortality rate as well as severe complications such as neurological deficit. It has been suggested that cerebral inflammation is a major factor in advanced brain injury after SAH. Microglia and astrocytes are known supporting cells in the development and maintenance of inflammation in central nervous system. However, the role of microglia and astrocytes in the development of inflammation and neuronal cell apoptosis during the early phase after SAH has not been thoroughly investigated.

Materials and Methods

Sprague-Dawley rats were divided into 4 groups (n = 6/group): sham group, animals subjected to SAH without treatment, SAH animals pretreated with the microglia inhibitor minocycline (50 mg/kg, ip), and SAH animals pretreated with the astrocyte inhibitor fluorocitrate (50 mg/kg, ip). SAH was induced by injecting autologous blood (1 ml/kg) into the cistern magna on day 0. Pretreatment with minocycline or fluorocitrate was given three days prior to the induction of SAH. Rats were sacrificed 6 hr after SAH, and their cerebral spinal fluids were used to measure protein levels of neuroinflammatory cytokines IL-1β, IL-6, and TNF-α by ELISA. In addition, the cerebral cortex was utilized to determine the levels of caspase-3 by western blot and to evaluate neuronal cell apoptosis by immunohistochemistry staining and detect microglia and astrocyte by immunofluorescence staining for Iba-1 and GFAP. In this study, all SAH animals were given an injection of autologous blood and SAH rats treated with minocycline or fluorocitrate received ip injections on day 1, 2, and 3 before inducing SAH. Neurological outcome was assessed by ambulation and placing/stepping reflex responses on day 7.

Results

Immunofluorescence staining showed that SAH induced proliferation of microglia and astrocyte and minocycline inhibited the proliferation of both microglia and astrocyte. However, fluorocitrate inhibited only the proliferation of astrocyte. ELISA analysis showed that SAH upregulated TNF-α and IL-1β, but not IL-6 at 6 hr after SAH. Minocycline, but not fluorocitrate, attenuated the upregulation of TNF-α and IL-1β. Western blot analysis and immunohistochemistry staining showed that SAH induced neuronal cell apoptosis. Pretreatment with minocycline, but not fluorocitrate, decreased SAH-induced neuronal death and cerebral vasospasm. Furthermore, significant improvements in neurobehavioral outcome were seen in the minocycline treatment group, but not in animals treated with fluorocitrate.

Conclusions

Microglia may play an important role to regulate neuronal cell apoptosis and cerebral vasospasm through inhibiting inflammation at an early phase after SAH in the rat.

Blocking Hepatoma-Derived Growth Factor Attenuates Vasospasm and Neuron Cell Apoptosis in Rats Subjected to Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is an important subcategory of stroke due to its unacceptably high mortality rate as well as the severe complications it causes, such as cerebral vasospasm, neurological deficits, and cardiopulmonary abnormality. Hepatoma-derived growth factor (HDGF) is a growth factor related to normal development and is involved in liver development and regeneration. This study explored the relationship between SAH and HDGF. Sixty rats were divided into five groups (n = 12/group): (A) control group; (B) rHDGF ab only group [normal animals treated with 50 µM recombinant HDGF antibodies (rHDGF ab)]; (C) SAH group; (D) SAH + pre-rHDGF ab group (SAH animals pre-treated with 50 µM rHDGF ab into the subarachnoid space within 24 h before SAH); and (E) SAH + post-rHDGF ab group (SAH animals post-treated with 50 µM rHDGF ab into the subarachnoid space within 24 h after SAH). At 48 h after SAH, serum and cerebrospinal fluid (CSF) samples were collected to measure the levels of pro-inflammatory factors by ELISA, and rat cortex tissues were used to measure protein levels by western blot analysis. Immunofluorescence staining for Iba-1, GFAP, TUNEL, and NeuN was detected proliferation of microglia and astrocyte and apoptosis of neuron cells. Neurological outcome was assessed by ambulation and placing/stepping reflex responses. Morphology assay showed that pre-treatment and post-treatment with rHDGF ab attenuated vasospasm after SAH. SAH up-regulated the levels of TNF-α, IL-1β, and IL-6 in both the CSF and serum samples, and both pre- and post-treatment with rHDGF ab inhibited the up-regulation of these pro-inflammatory factors, except for the serum IL-6 levels. Western blot analysis demonstrated that SAH up-regulated pro-BDNF and NFκB protein levels, and both pre- and post-treatment with rHDGF ab significantly reduced the up-regulation. The result from immunofluorescence staining showed that SAH induced proliferation of microglia and astrocyte and apoptosis of neuron cells. Both pre- and post-treatment with rHDGF ab significantly attenuated proliferation of microglia and astrocyte and inhibited apoptosis of neuron cells. Furthermore, treatment with rHDGF ab significantly improved neurological outcome. Blocking HDGF attenuates neuron cell apoptosis and vasospasm through inhibiting inflammation in brain tissue at early phase after SAH.

Propofol But Not Desflurane Maintains Rat Cerebral Arteriolar Responses to Acetylcholine During Acute Hyperglycemia

BACKGROUND

Acute hyperglycemia causes vascular endothelial dysfunction in various organs including the cerebral vessels. It is associated with increased mortality and morbidity in the perioperative period. The impact of anesthetic agents on cerebral vasodilatory responses during hyperglycemia remains unclear. We investigated endothelial function in rat cerebral arterioles during acute hyperglycemia, under propofol or desflurane anesthesia.

MATERIALS AND METHODS

A closed cranial window preparation was used to measure changes in pial arteriole diameter induced by topical application of acetylcholine (ACh), an endothelium-dependent vasodilator, in rats anesthetized with propofol or desflurane. Pial arteriole responses to ACh were measured during normoglycemia and hyperglycemia. We then investigated whether the response of cerebral arterioles to acute hyperglycemia under propofol anesthesia were related to propofol or its vehicle, intralipid.

RESULTS

ACh resulted in a dose-dependent dilation of cerebral arterioles during propofol and desflurane anesthesia under normoglycemic conditions. The vasodilatory effects of ACh were also maintained under hyperglycemic conditions during propofol anesthesia, but the vasodilator response to ACh was significantly impaired during hyperglycemia compared with normoglycemia with desflurane anesthesia. The vasodilatory effects of ACh were maintained during normoglycemia and hyperglycemia in rats receiving propofol or intralipid.

CONCLUSIONS

Rat pial arteriole responses to ACh are maintained during conditions of acute hyperglycemia with propofol anesthesia but suppressed compared with normoglycemia with desflurane anesthesia.

Stress-Induced Hyperglycemia and Remote Diffusion-Weighted Imaging Lesions in Primary Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Stress-induced hyperglycemia (SIH) is the relative transient increase in glucose during a critical illness such as intracerebral hemorrhage (ICH) and is likely to play an important role in the pathogenesis of remote diffusion-weighted imaging (DWI) lesion (R-DWIL) in primary ICH. We sought to determine the association between SIH and the occurrence of R-DWILs.

METHODS

We prospectively enrolled primary ICH patients within 14 days after onset from November 2016 to May 2018. In these patients, cerebral magnetic resonance imaging was performed within 14 days after ICH onset. R-DWIL was defined as a hyperintensity signal in DWI with corresponding hypointensity in apparent diffusion coefficient, and at least 20 mm apart from the hematoma. SIH was measured by stress-induced hyperglycemia ratio (SHR). SHR was calculated by fasting blood glucose (FBG) divided by estimated average glucose derived from glycosylated hemoglobin. The included patients were dichotomized into two groups by the 50th percentile of SHR, and named as SHR (-P50) group and SHR (P50+) group, respectively. We evaluated the association between SHR and R-DWIL occurrence using multivariable logistic regression modeling adjusted for potential confounders.

RESULTS

Among the 288 patients enrolled, forty-six (16.0%) of them had one or more R-DWILs. Compared with the patients in the lower 50% of SHR (SHR [-P50]), the odds ratio (OR) [95% confidence interval (CI)] for the higher 50% of SHR (SHR [P50+]) group for R-DWIL occurrence was 3.13 (1.39-7.07) in the total population and 6.33 (2.19-18.30) in population absent of background hyperglycemia after adjusting for potential covariates. Similar results were observed after further adjusted for FBG.

CONCLUSIONS

Our study demonstrated that SIH was associated with the occurrence of R-DWILs in patients with primary ICH within 14 days of symptom onset.

Soluble receptor for advanced glycation end products as a biomarker of symptomatic vasospasm in subarachnoid hemorrhage

OBJECTIVE

The receptor for advanced glycation end products (RAGE) is a membrane protein associated with the induction of oxidative stress and inflammation in several pathological conditions. Previous studies have demonstrated that soluble RAGE (sRAGE) acts as a decoy for RAGE and protects cells against RAGE-mediated injury. The authors and other groups have reported that the expression of RAGE increases after brain ischemia and subarachnoid hemorrhage (SAH), and deletion of RAGE or overexpression of sRAGE improves neuronal survival. It has also been demonstrated that the plasma sRAGE level could be a predictor of the outcome after ischemic stroke. This study aimed to evaluate plasma sRAGE as a biomarker for symptomatic vasospasm (SVS) in SAH patients, as well as a rat model.

METHODS

The authors measured and compared plasma sRAGE levels in 27 SAH patients (7 with SVS and 20 without SVS) from day 5 to day 14 post-SAH. They also examined plasma sRAGE levels and expression of RAGE and heme oxygenase-1 (HO-1) in a rat SAH model.

RESULTS

The relative plasma sRAGE levels were significantly lower in the SVS group than in the non-SVS group of patients. A cut-off value of 0.84 for predicting SVS was considered to be appropriate for the relative plasma sRAGE levels on day 7 versus day 5. In the rat SAH model, plasma sRAGE levels were significantly lower than those in sham-treated rats, and the expressions of RAGE and HO-1 were enhanced in the SAH group compared with the non-SAH group.

CONCLUSIONS

Plasma sRAGE levels can be used as a potential biomarker for predicting SVS after SAH.

Effects of Lutein on Brain Damage and Vasospasm in an Experimental Subarachnoid Hemorrhage Model

OBJECTIVE

Vasospasm developing after subarachnoid hemorrhage (SAH) is an important cause of mortality and morbidity. Lutein is a carotenoid with antioxidant and anti-inflammatory properties. The aim of present study was to investigate effects of lutein on the basilar artery and nerve tissues.

METHODS

Wistar rats were randomly divided into 3 groups: control (group 1), SAH (group 2), and SAH treated with lutein (group 3). Lutein was administered for 3 days by means of orogastric gavage. Basilar artery lumen area, wall thickness, serum total antioxidant status, serum total oxidant status, and oxidative stress index were calculated. Histopathologic and immunohistochemical analyses were conducted.

RESULTS

No statistically significant difference was found between groups in terms of wall thickness; lumen area; and serum total antioxidant status, serum total oxidant status, and oxidative stress index values. A statistically significant difference was found between groups colored with terminal deoxynucleotidyl transferase dUTP nick end labeling (P < 0.005). Post hoc analysis was used to examine the results between groups. Results of group 1 and group 3 were equal (P = 1) and lower than group 2 (P = 0.04 and P = 0.006, respectively).

CONCLUSIONS

Lutein was found to have a positive effect on width of the basilar artery lumen area. Therefore, positive effects of lutein on vasospasm might be statistically significant if lutein is administered at higher doses. Lutein was found to be effective in preventing brain damage after SAH. To our knowledge, this study is the first in the literature to examine the effect of lutein on vasospasm and brain damage after SAH.

Characterization of tracheotomized patients after spontaneous subarachnoid hemorrhage

Spontaneous subarachnoid hemorrhage (SAH) is a catastrophic event with high disability and fatality rates. Post-SAH survivors may require prolonged intubation with the assistance of mechanical ventilators, and some patients will undergo tracheostomy to facilitate their pulmonary hygiene and airway protection. The aim of this study is to identify the incidence and risk factors of the need for tracheostomy after spontaneous SAH. We used a retrospective approach and enrolled 838 adult patients with a primary diagnosis of spontaneous SAH who survived >7 days after hospitalization. Medical information was retrieved from the administrative database utilizing diagnostic and procedure codes by the International Classification of Diseases, Ninth Revision, Clinical Modification. Patients with first-ever SAH included 329 men and 509 women, and their average age was 56.9 ± 14.4 years, ranging between 18 and 91 years. Fifty-eight of these 838 patients underwent tracheostomy procedures, and the overall incidence was 6.9%. In a multivariate logistic regression model, the independent risk factors of the need for tracheostomy were underlying diabetes mellitus (P = .02), hydrocephalus (P < .01), and pneumonia (P < .01). The mean duration of hospital stay was 26.0 ± 15.3 and 16.8 ± 12.2 days for patients with and without a tracheostomy, respectively (P < .01). In conclusion, a significant percentage of post-SAH survivors underwent tracheostomy during acute hospitalization. Attention to independent risk factors, including preexisting diabetes mellitus, concomitant hydrocephalus, and nosocomial pneumonia, is essential for timely patient selection for tracheostomy.

Management of Subarachnoid Hemorrhage

Subarachnoid hemorrhage is an often devastating intracranial hemorrhage resulting from acute bleeding into the subarachnoid space. Although its overall incidence is less than that of acute ischemic stroke, sub-arachnoid hemorrhage carries increased risks of both mortality and disability. Although many patients with subarachnoid hemorrhage are transferred to specialty centers, they might initially present to small community-based hospitals. Treatment for these patients is complex, requiring specialized care and knowledge, and various complications can occur quickly and without warning. Therefore, all members of the health care team who care for these patients must understand proper management. Nurses in the intensive care unit play an important role in influencing outcomes, as they are best positioned to recognize neurological decline and provide rapid intervention. This article discusses the anatomy relevant to, and the epidemiology and pathophysiology of, subarachnoid hemorrhage and provides an overview of current evidence and clinical guidelines for managing this brain injury.

Serum Glucose and Potassium Ratio as Risk Factors for Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Cerebral vasospasm is associated with poor prognosis in patients with aneurysmal subarachnoid hemorrhage (SAH), and biomarkers for predicting poor prognosis have not yet been established. We attempted to clarify the relationship between serum glucose/potassium ratio and cerebral vasospasm in patients with aneurysmal SAH.

METHODS

We studied 333 of 535 aneurysmal SAH patients treated between 2006 and 2016 (123 males, 210 females; mean age 59.7 years; range 24-93). We retrospectively analyzed the relationship between cerebral vasospasm grade and clinical risk factors, including serum glucose/potassium ratio.

RESULTS

Postoperative angiography revealed cerebral vasospasm in 112 patients (33.6%). Significant correlations existed between the ischemic complication due to cerebral vasospasm and glucose/potassium ratio (P < .0001), glucose (P = .016), and potassium (P = .0017). Serum glucose/potassium ratio was elevated in the cerebral vasospasm grade dependent manner (Spearman's r = 0.1207, P = .0279). According to the Glasgow Outcome Scale (GOS) score at discharge, 185 patients (55.5%) had a poor outcome (GOS scores 1-3). Serum glucose/potassium ratio was significantly correlated between poor outcome (GOS scores 1-3) and age (P < .0001), serum glucose/potassium ratio (P < .0001), glucose (P < .0001), potassium (P = .0004), white blood cell count (P = .0012), and cerebral infarction due to cerebral vasospasm (P < .0001). Multivariate logistic regression analyzes showed significant correlations between cerebral infarction due to cerebral vasospasm and serum glucose/potassium ratio (P = .018), glucose (P = .027), and potassium (P = .052).

CONCLUSIONS

Serum glucose/potassium ratio in cases of aneurysmal SAH was significantly associated with cerebral infarction due to cerebral vasospasm and GOS at discharge. Therefore, this factor was useful to predict prognosis in patients with cerebral vasospasm and aneurysmal SAH.

Association of Admission Serum Glucose-Phosphate Ratio with Severity and Prognosis of Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Serum hyperglycemia and hypophosphatemia have been reported to be common in patients with aneurysmal subarachnoid hemorrhage (aSAH). This study aimed to explore whether admission serum glucose-phosphate ratio was associated with the severity and prognosis of aSAH.

METHODS

We retrospectively analyzed 198 patients with aSAH who were admitted within 24 hours of hemorrhage to a single academic hospital from June 2016 to September 2017. The following determinations were recorded: aSAH severity on admission, assessment by the World Federation of Neurosurgical Societies grading scale (WFNS), Fisher score defined according to the computed tomography results, and 3-month outcome assessed by the Glasgow Outcome Scale. A statistical analysis of the clinical and laboratory risk factors of poor outcome was conducted.

RESULTS

Admission serum glucose-phosphate ratio was increased in a WFNS grade-dependent manner and was higher in patients who had a poor outcome than in those who had a good outcome 3 months after aSAH. Multiple binomial logistic regression analysis showed that serum glucose-phosphate ratio, along with age, WFNS grade, and intraventricular hemorrhage, was associated with 3-month poor outcome after aSAH when we controlled for Fisher score, acute hydrocephalus, delayed cerebral ischemia, symptomatic cerebral vasospasm, serum glucose and phosphate levels, and glucose-potassium ratio. Receiver operating characteristic analysis showed that the area under the curve for glucose-phosphate ratio was significantly higher than age and intraventricular hemorrhage.

CONCLUSIONS

The study shows that the glucose-phosphate ratio is a potential biomarker that can reflect disease severity and prognosis in aSAH patients.

Elevated glycated hemoglobin level and hyperglycemia after aneurysmal subarachnoid hemorrhage

OBJECTIVES

Elevated blood glucose is frequently detected early after aneurysmal subarachnoid hemorrhage (aSAH) and is considered a risk factor for poor neurological outcome. However it remains unclear whether hyperglycemia is caused by the SAH ictus or reflects a pre-existing hyperglycemic metabolism. In a prospective register we analysed glycated haemoglobin levels (HbA1c) in patients with aSAH and its influence on outcome.

PATIENTS AND METHODS

Between July 2012 and July 2014, 87 patients with confirmed aSAH were included (NCT02081820). Within 72h HbA1c levels were assessed as a measure for hyperglycemic metabolism preceding aSAH. Blood glucose levels were recorded upon admission. Patient outcome was recorded after 6 months using modified Rankin scale (mRS).

RESULTS

HbA1c levels did not correlate with initial neurological status (p=0.338, r=0.104). On the contrary, initial blood glucose levels correlated significantly with neurological status at admission (p=0.001, r=0.341). Additionally, HbA1c levels failed to show a significant influence on the occurrence of delayed cerebral ischemia (DCI) (p=0.400) or outcome after 6 months (p=0.790).

CONCLUSION

A pre-existing hyperglycemic metabolism does not contribute to the severity of aSAH or influences the quality of neurological recovery. Hyperglycemia after aSAH correlates with initial neurological status and patient outcome and is potentially attributable to the metabolic changes induced by the brain injury after the hemorrhage.

The role of nitric oxide in stroke

Stroke is considered to be an acute cerebrovascular disease, including ischemic stroke and hemorrhagic stroke. The high incidence and poor prognosis of stroke suggest that it is a highly disabling and highly lethal disease which can pose a serious threat to human health. Nitric oxide (NO), a common gas in nature, which is often thought as a toxic gas, because of its intimate relationship with the pathological processes of many diseases, especially in the regulation of blood flow and cell inflammation. However, recent years have witnessed an increased interest that NO plays a significant and positive role in stroke as an essential gas signal molecule. In view of the fact that the neuroprotective effect of NO is closely related to its concentration, cell type and time, only in the appropriate circumstances can NO play a protective effect. The purpose of this review is to summarize the roles of NO in ischemic stroke and hemorrhagic stroke.