Influence of the β-fibrinogen-455G/A polymorphism on development of ischemic stroke and coronary heart disease

BACKGROUND

Ischemic stroke (IS) and coronary heart disease (CHD) are two vascular disorders that are a common cause of death worldwide. Several studies have assessed the association of the β-fibrinogen-455G/A (FGB-455G/A) polymorphism and risk of IS and CHD, but the results are still inconsistent. Our study aimed to investigate whether the FGB-455G/A polymorphism was associated with susceptibility to IS and CHD by using meta-analysis.

METHODS

Relevant studies were identified from PubMed, Embase and four Chinese database up to July 2013.Data were analyzed and processed by Stata 11.2. A pooled OR with 95% CI was calculated to estimate the strength of the genetic association. Cumulative meta-analysis was performed to assess the tendency of pooled OR over time.

RESULTS

45 studies based on a total of 7238 cases and 7395 controls were included in our meta-analysis. The results indicated that the FGB-455G/A polymorphism is associated with the risk of IS when compared with the dominant model (OR=1.518, 95%CI=1.279-1.802 for AA+GA vs. GG). In the subgroup analysis by ethnicity, significantly elevated risks were associated with the A allele in Asians (OR=1.700, 95%CI=1.417-2.040), but not in Caucasians (OR=0.942, 95%CI=0.813-1.091). Both the hypertension and non-hypertension subgroups reached significant results, but no significance was found when stratified according to sex or subtype of IS. Results indicate that the FGB-455G/A polymorphism is associated with CHD (OR=1.802, 95%CI=1.445-2.246).

CONCLUSION

Our meta-analysis suggests that the FGB-455G/A polymorphism contributes to susceptibility to IS and CHD.

The dual role of astrocyte activation and reactive gliosis

Astrocyte activation and reactive gliosis accompany most of the pathologies in the brain, spinal cord, and retina. Reactive gliosis has been described as constitutive, graded, multi-stage, and evolutionary conserved defensive astroglial reaction [Verkhratsky and Butt (2013) In: Glial Physiology and Pathophysiology]. A well- known feature of astrocyte activation and reactive gliosis are the increased production of intermediate filament proteins (also known as nanofilament proteins) and remodeling of the intermediate filament system of astrocytes. Activation of astrocytes is associated with changes in the expression of many genes and characteristic morphological hallmarks, and has important functional consequences in situations such as stroke, trauma, epilepsy, Alzheimer's disease (AD), and other neurodegenerative diseases. The impact of astrocyte activation and reactive gliosis on the pathogenesis of different neurological disorders is not yet fully understood but the available experimental evidence points to many beneficial aspects of astrocyte activation and reactive gliosis that range from isolation and sequestration of the affected region of the central nervous system (CNS) from the neighboring tissue that limits the lesion size to active neuroprotection and regulation of the CNS homeostasis in times of acute ischemic, osmotic, or other kinds of stress. The available experimental data from selected CNS pathologies suggest that if not resolved in time, reactive gliosis can exert inhibitory effects on several aspects of neuroplasticity and CNS regeneration and thus might become a target for future therapeutic interventions.

Loss of Integrity: Impairment of the Blood-brain Barrier in Heavy Metal-associated Ischemic Stroke

Although stroke is one of the leading causes of death and disability worldwide, preventive or therapeutic options are still limited. Therefore, a better understanding of the pathophysiological characteristics of this life-threatening disease is urgently needed. The incidence and prevalence of ischemic stroke are increased by exposure to certain types of xenobiotics, including heavy metals, suggesting the possible toxicological contribution of these compounds to the onset or aggravation of stroke. Among the potential targets, we have focused on alterations to cerebral endothelial cells (CECs), which play important roles in maintaining the functional integrity of brain tissue.

Intravenous immunoglobulin (IVIg) provides protection against endothelial cell dysfunction and death in ischemic stroke

BACKGROUND

The brain endothelium is a key component of the blood brain barrier which is compromised following ischemia, allowing infiltration of damaging immune cells and other inflammatory molecules into the brain. Intravenous immunoglobulin (IVIg) is known to reduce infarct size in a mouse model of experimental stroke.

FINDINGS

Flow cytometry analysis showed that the protective effect of IVIg in ischemia and reperfusion injury in vivo is associated with reduced leukocyte infiltration, suggesting an involvement of the endothelium. In an in vitro model of ischemia, permeability analysis of the mouse brain endothelial cell line bEnd.3 revealed that IVIg prevented the loss of permeability caused by oxygen and glucose deprivation (OGD). In addition, western blot analysis of these brain endothelial cells showed that IVIg prevented the down-regulation of tight junction proteins claudin 5 and occludin and the decline in anti-apoptotic proteins Bcl-2 and Bcl-XL caused by OGD.

CONCLUSION

IVIg protects endothelial cells from ischemic insult. These studies support the use of IVIg as a pharmacological intervention for stroke therapy.

Stroke and diabetes mellitus

Diabetes is a condition of accelerated vascular aging. Patients with diabetes have approximately twice the risk of stroke compared to nondiabetics. Hyperglycemia is a strong risk factor for poor outcome after stroke, but it may be simply a marker of poor outcome rather than a cause. Glucose lowering has not been shown to be associated with improved prognosis. Similarly, long-term prevention of stroke risk among diabetic patients is not improved with glucose-lowering therapies. Stroke prevention and treatment remains generic among diabetic patients. The future, however, may be brighter, with multiple new agents recently available. We await the outcome of these agents on macrovascular complications such as stroke.

Isolated Pulmonary Edema without Myocardial Stunning in Brainstem Strokes

INTRODUCTION

Ischemic stroke has been associated with stunned myocardium and neurogenic pulmonary edema (NPE). We studied a population of patients with large vessel brainstem ischemic stroke to see if there was an increased risk of pulmonary edema associated with strokes in this region independent of myocardial stunning.

HYPOTHESIS

Large vessel ischemic strokes of the brainstem are associated with neurogenic pulmonary edema and occur independently of myocardial stunning.

METHODS

This is a retrospective case control study of 1,278 patient admissions. Two hundred ten patients were identified with large vessel ischemic stroke or transient ischemic attack (mean age 65 years, 55% female, 50% black). Infarction locations included: brainstem (N=22), right middle cerebral artery involving the insula (N=38), left middle cerebral artery involving the insula (N=37), and transient ischemic attack (N=113). Multivariate logistic regression models for presence of echocardiographic wall motion abnormalities, QTc-interval prolongation, elevated serum troponin, and pulmonary edema were developed to examine the relative contribution of stroke location and markers of cardiopulmonary dysfunction to each respective outcome, controlling for patient characteristics.

RESULTS

Large vessel brainstem stroke was associated with pulmonary edema (adjusted OR 29.23, 95% CI 1.90-449.51) but not cardiac abnormalities. Large vessel left middle cerebral artery stroke was also associated with pulmonary edema (76.44, 6.93-843.54) as well as QTc-interval prolongation (4.55, 10.77-19.24). Large vessel right middle cerebral artery stroke was associated with pulmonary edema (10.88, 1.02-116.70) as well as elevated serum troponin (10.51, 1.71-64.82).

CONCLUSION

In a retrospective case control study, large vessel brainstem stroke was associated with the development of pulmonary edema independent of cardiac abnormalities associated with myocardial stunning, suggesting a separate brainstem pathophysiologic mechanism which directly affects the lungs but not the heart.

Serum 25-hydroxyvitamin d deficiency in ischemic stroke and subtypes in Indian patients

BACKGROUND AND PURPOSE

Vitamin D deficiency is common across all age groups and may contribute to cardiovascular diseases. Serum 25-hydroxyvitamin D deficiency causing ischemic stroke has been documented in recent reports.

AIM

To investigate the association of serum 25-hydroxyvitamin D deficiency with ischemic stroke and subtypes.

METHODS

We recruited 250 consecutive ischemic stroke patients and 250 age and sex matched controls attending the Department of Neurology, at Yashoda hospital, Hyderabad, India, from January 2011 to December 2012. All ischemic stroke patients underwent stroke subtyping. We measured 25-hydroxyvitamin D by chemiluminescence test, serum calcium, phosphorus, alkaline phosphatase, and C-reactive protein (CRP) in cases and controls.

RESULTS

Out of 250 stroke patients, 190 (76%) were men and mean age was 58.4±11.1 years (age range-26-89 years). 25-hydroxyvitamin D deficiency was observed in 122 (48.8%) stroke patients and 79 (31.6%) controls (P=0.001). Among stroke patients, serum 25-hydroxyvitamin D deficiency was found in 54.9% (50/91) of patients with large artery atherosclerosis, 54% (20/37) in cardioembolic stroke, 44.4% (20/45) in small artery diseases, 42.8% (15/35) in stroke of other determined etiology and 40.4% (17/42) in stroke of un-determined etiology. Multiple logistic regression analysis showed an independent association of 25-hydroxyvitamin D deficiency with ischemic stroke (odds ratio: 1.6; 95% CI 1.2-2.8). The association was strongest with large artery atherosclerosis (odds ratio: 2.4; 95% CI 1.6-3.5) and cardioembolic stroke (odds ratio: 2.0; 95% CI 1.0-3.2).

CONCLUSIONS

We found that 25-hydroxyvitamin D deficiency had an independent association with ischemic stroke. The association was established in large artery arthrosclerosis and cardioembolic stroke.

Cerebral arterial infarction in inflammatory bowel diseases

It has been estimated that up to 10% of hypercoagulable state manifestations in patients with inflammatory bowel disease (IBD) are ischemic strokes. The literature search through MEDLINE and EMBASE highlighted 33 case reports of IBD patients complicated with cerebral arterial infarction during the course of their disease. Most of these patients presented with either left or right sided hemiparesis on admission, while the most common site of arterial infarction was either the right or the left middle cerebral artery. Thrombocytosis and anemia were the most commonly observed potential risk factors for stroke in the laboratory analysis. Other coagulation abnormalities, hereditary thrombotic mutations, hyperhomocysteinemia, hyperlipidemia, structural cardiac abnormalities, endocarditis and cerebral artery vasculitis have also been reported in some of the cases that were reviewed. Even though many of these findings are commonly observed in IBD patients, literature data is still controversial about their causal relationship to ischemic stroke. Similarly, there is also lack of steady evidence and official guidelines for stroke management in both children and adults with IBD comorbidity. Finally, an algorithm based on both the American Heart Association and European Stroke Organization guidelines for stroke management and prevention in the general population, is presented as a reference point for the treatment of IBD patients who are complicated by an ischemic cerebral event.

Study of the neuroprotective effects of memantine in patients with mild to moderate ischemic stroke

Ischemic stroke is amongst the top four causes of mortality and the leading cause of disability in the world. The aim of this study was to evaluate the efficacy of a high dose memantine on neurological function of patients with ischemic stroke. In a randomized, 2 armed, open-label study, patients with mild to moderate cerebral thromboembolic event (CTEE) who admitted to Imam Hossein Hospital, Tehran, Iran, during preceding 24 hours, entered the study. Patients allocated in two study groups of memantine (as add-on therapy) and control. All patients were managed based on the American Heart Association and American Stroke Association (AHA/ASA) guidelines. Patients in memantine group received conventional treatment plus memantine 20 mg TID. The National Institute of Health Stroke Scale (NIHSS) was determined and recorded daily. The primary objective was comparison of the changes in NIHSS in the study groups at day 1 and day 5 of intervention. Significance level of p<0.05 was considered for statistical analysis. Patients were randomly allocated in control (15 women and 14 men, age 70.78 ± 10.92 years) and memantine (16 women and 8 men, age 73.33 ± 9.35 years) groups. There were no significant differences in age and sex distribution of two study groups as well as in comorbidities and concurrent drugs. NIHSS changes were significantly different between control (1.24 ± 0.96) and memantine group (2.96 ± 0.1), (p < 0.0001). Our results reveal that memantine added to standard treatment of CTEE could result in a remarkable decrease in the NIHSS confirming improvement of the neurological function of the patients.

Association of TLR6 single nucleotide polymorphisms and clinical features of ischemic stroke in Korean population

Recent studies showed association between diseases and TLR6 polymorphisms. To investigate whether TLR6 polymorphisms are associated with the development of ischemic stroke, four single nucleotide polymorphisms (SNPs) of the TLR6 gene (rs1039559, rs3821985, rs3775073, and rs5743818) were analyzed in 120 patients with ischemic stroke (IS) and 278 control subjects. All ischemic stroke patients were classified into clinical subgroups according to NHISS and MBI. SNPStats was used to obtain odds ratios (ORs), 95% confidence intervals (CIs), and P values. Multiple logistic regression models (codominant1, codominant2, dominant, recessive, and log-additive) were performed to analyze the genetic data. Two SNPs (rs3821985 and rs3775073) of the TLR6 gene were associated with the NHISS in ischemic stroke patients (P< 0.05). Also, three SNPs (rs1039559, rs3821985, and rs3775073) showed association with MBI in ischemic stroke patients (P< 0.05). These results suggest that SNPs of TLR6 (rs1039559, rs3821985, and rs3775073) may be affect the disease characteristics of stroke, such as NIHSS and MBI.

Trends of the Incidence of Ischemic Stroke Thrombolysis over Seven Years and One-Year Outcome: A Population-Based Study in Joinville, Brazil

Background

In a population-based setting, we aimed to measure the incidence trends of ischemic stroke (IS) thrombolysis, thrombolysis times, proportion of symptomatic intracerebral hemorrhage (sICH), 30-day case fatality and functional outcomes. We also compared the 12-month functional status between thrombolyzed and nonthrombolyzed patients.

Methods

Using data from the Joinville Population-Based Stroke Registry, we prospectively ascertained a cohort of all thrombolyses done in Joinville citizens, Southern Brazil, from 2005 to 2011. For the definition of sICH we used European Cooperative Acute Stroke Study (ECASS) II criteria.

Results

Over 7 years, 6% (220/3,552) of all IS were thrombolyzed. The thrombolysis incidence increased from 1.4 [95% confidence interval (CI), 0.6-2.9] in 2005 to 9.8 (7.3-12.9) per 100,000 population in 2011 (p < 0.0001). The thrombolysis incidence age-adjusted to the world population in 2011 was 11 (8.2-14.3) per 100,000. Only 30% (50/165) were thrombolyzed within 1 h of arrival at hospital. In 7 days, 6.4% (14/220) had sICH and 57% (8/14) of those died. In the 2009-2011 period, a favorable functional outcome [modified Rankin scale (mRS) 0-1] at 12 months among patients who received thrombolysis was more frequent [mRS 0-1; 36% (38/107)] than among patients who did not receive thrombolysis [mRS 0-1; 24% (131/544); p = 0.016]. The logistic regression showed that thrombolyzed IS patients had a more favorable outcome (mRS 0-1; HR 2.13; 95% CI, 1.2-3.7; p < 0.016) than nonthrombolyzed patients.

Conclusion

In a population setting of a middle income country, the thrombolysis incidence and outcomes were similar to those of other well-structured services. After 1 year, patients thrombolyzed in the 4.5-hour time window had a better outcome. More than proportions, rates provide additional information and could be used to benchmark services against others.

Early and intermediate prognosis of intravenous thrombolytic therapy in acute ischemic stroke subtypes according to the causative classification of stroke system

Objectives: Intravenous thrombolytic therapy has established acceptable results in treating ischemic stroke. However, there is little information on treatment outcome especially in different subtypes. The aim of current study was to evaluate early and intermediate prognosis in intravenous thrombolytic therapy for acute ischemic stroke subtypes.

Methodology: Forty eligible patients (57.5% male with mean age of 63.18±13.49 years) with definite ischemic stroke who were admitted to emergency department of Imam Reza University Hospital, in the first 180 minutes after occurrence received recombinant tissue plasminogen activator. All investigation findings were recorded and stroke subtypes were determined according to the Causative Classification of Stroke System. Stroke severity forms including modified Rankin Scale (mRS) and National Institutes of Health Stroke Scale (NIHSS) scores were recorded for all patients in first, seven and 90 days after stroke and disease outcome was evaluated.

Results: The etiology of stroke was large artery atherosclerosis in 20%, cardio-aortic embolism in 45%, small artery occlusion in 17.5% and undetermined causes in 17.5%. NIHSS and mRS scores were significantly improved during time (P < 0.001 in both cases). Three months mortality rate was 25%. Among the etiologies, patients with small artery occlusion and then cardio-aortic embolism had lower NIHSS score at arrival (P = 0.04). Caplan-meier analysis showed that age, sex and symptom to needle time could predict disease outcome.

Conclusion: Intravenous thrombolytic therapy is accompanied by good early and intermediate outcome in most patients with ischemic stroke. Small artery occlusion subtype had less disease severity and higher improvement.

Is there a correlation between hs-CRP levels and functional outcome of Ischemic Stroke?

Objective: C-reactive protein, a well known marker of inflammation is being investigated as a probable marker of predicting acute cardiovascular events and its severity. The aim of the present study was to assess the possible role of highly-sensitivity C-reactive protein (hs-CRP) in predicting short-term functional outcome of ischemic stroke.

Methodology: A prospective study was conducted on subjects admitted with first attack of confirmed ischemic stroke. It included 50 male and 52 female. Serum hs-CRP was measured in the 2^nd (CRP-D2) and 5^th days (CRP-D5) post-stroke. Modified Rankin scale (MRS) was measured in all subjects in the 2^nd (MRS-D2), 5^th days (MRS-D5) and also 3 month (MRS-M3) after stroke to assess the short-term functional outcome and mortality of subjects.

Results: The mean age of the patients was 71.75±11.44 years. The mortality rate was 47.1% in the third months after stroke. There was no significant correlation between CRP-D2 and MRS-M3 and also between CRP-D5 and MRS-M3 (P>0.05). However there was a significant association between high CRP-D2 (CRP>3) and MRS-M3 and also between high CRP-D5 and MRS-M3 (P<0.005).

Conclusion: This study showed that the value of CRP by itself could not predict the severity of short-term functional disability and it might not be useful as a clinical tool for predicting outcome.

Onset of Orolingual Angioedema After Treatment of Acute Brain Ischemia with Alteplase Depends on the Site of Brain Ischemia: A Meta-analysis

Background:

Alteplase is used to treat acute ischemic stroke. However, it has several documented adverse effects, including the development of orolingual angioedema (OA). Although, OA is a rare side-effect, it is thought to be life-threatening and is difficult to treat. Until date, little is known about this condition and a better understanding of OA may contribute to improve the morbidity and mortality amongst patients that develop this condition.

Materials and Methods:

Using the PubMed and Medknow databases, we searched for peer reviewed published articles on OA after alteplase administration in 1950-2012. We gathered demographic data and investigated the relationship between the location of OA, neurological symptoms and the site of cerebral ischemia. In addition, we studied the effects of hypertensive premedication on OA development. We identified 19 published manuscripts that fulfilled our search criteria. These manuscripts reported 41 cases of OA after alteplase administration.

Results:

We found that this condition is associated with cerebral ischemia (P < 0.012) and that 65.9% (n = 27) of patients who developed OA had a hypertensive drug as a premedication.

Conclusions:

Although OA is a rare side-effect of alteplase, it can occur depending upon the localization of acute cerebral ischemia.

Cell based therapies for ischemic stroke: from basic science to bedside

Cell therapy is emerging as a viable therapy to restore neurological function after stroke. Many types of stem/progenitor cells from different sources have been explored for their feasibility and efficacy for the treatment of stroke. Transplanted cells not only have the potential to replace the lost circuitry, but also produce growth and trophic factors, or stimulate the release of such factors from host brain cells, thereby enhancing endogenous brain repair processes. Although stem/progenitor cells have shown a promising role in ischemic stroke in experimental studies as well as initial clinical pilot studies, cellular therapy is still at an early stage in humans. Many critical issues need to be addressed including the therapeutic time window, cell type selection, delivery route, and in vivo monitoring of their migration pattern. This review attempts to provide a comprehensive synopsis of preclinical evidence and clinical experience of various donor cell types, their restorative mechanisms, delivery routes, imaging strategies, future prospects and challenges for translating cell therapies as a neurorestorative regimen in clinical applications.

Increasing pressure of external counterpulsation augments blood pressure but not cerebral blood flow velocity in ischemic stroke

External counterpulsation (ECP) is a noninvasive method used to augment cerebral perfusion but the optimal use of ECP in ischemic stroke has not been well documented. We aimed to investigate the effects of ECP treatment pressure on cerebral blood flow and blood pressure (BP). We recruited 38 ischemic stroke patients with large artery occlusive disease and 20 elderly controls. We commenced ECP treatment pressure at 150 mmHg and gradually increased to 187.5, 225 and 262.5 mmHg. Mean cerebral blood flow velocities (CBFV) of bilateral middle cerebral arteries and continuous beat-to-beat BP were recorded before ECP and during each pressure increment for 3 minutes. Patient CBFV data was analyzed based on whether it was ipsilateral or contralateral to the infarct. Mean BP significantly increased from baseline in both stroke and control groups after ECP commenced. BP increased in both groups following raised ECP pressure and reached maximum at 262.5 mmHg (patients 16.9% increase versus controls 16.52%). The ipsilateral CBFV of patients increased 5.15%, 4.35%, 4.55% and 3.52% from baseline under the four pressures, respectively. All were significantly higher than baseline but did not differ among different ECP pressures; contralateral CBFV changed likewise. Control CBFV did not increase under variable pressures of ECP. ECP did increase CBFV of our patients to a roughly equal degree regardless of ECP pressure. Among the four ECP pressures tested, we recommend 150 mmHg as the optimal treatment pressure for ischemic stroke due to higher risks of hypertension-related complications with higher pressures.

In vivo Tracking of Human Neural Stem Cells Following Transplantation into a Rodent Model of Ischemic Stroke

BACKGROUND AND OBJECTIVES

Ischemic stroke caused by middle cerebral artery occlusion (MCAo) is the major type of stroke, but there are currently very limited options for cure. It has been shown that neural stem cells (NSCs) or neural precursor cells (NPCs) can survive and improve neurological deficits when they are engrafted in animal models of various neurological diseases. However, how the transplanted NSCs or NPCs are act in vivo in the injured or diseased brain is largely unknown. In this study, we utilized magnetic resonance imaging (MRI) techniques in order to understand the fates of human NSCs (HB1.F3) following transplantation into a rodent model of MCAo.

METHODS AND RESULTS

HB1.F3 human NSCs were pre-labeled with ferumoxides (Feridex(®))-protamine sulfate complexes, which were visualized and examined by MRI up to 9 weeks after transplantation. Migration of the transplanted cells to the infarct area was further confirmed by histological methods.

CONCLUSIONS

Based on these observations, we speculate that the transplanted NSCs have the extensive migratory ability to the injured site, which will in turn contribute to functional recovery in stroke.

Impact of gender-age interaction on the outcome of ischemic stroke in an Italian cohort of patients treated according to a standardized clinical pathway

BACKGROUND

Stroke outcome has been reported as worse in women, especially in terms of disability. As for mortality, the data are conflicting, with some reports suggesting a female advantage. Our objective was to explore such issues in an Italian cohort of patients managed by a standardized clinical pathway (CPW) and, as such, homogeneous in terms of clinical management.

METHODS

Data from a cohort of 1993 patients (987 women and 1006 men) with first-ever ischemic stroke, consecutively referred to an in-hospital Clinical Pathway Program from January 1, 2001 to December 31, 2009, were retrospectively analyzed. The relationship between female gender and one-month outcome was assessed with adjustment for age, stroke severity and premorbid disability.

RESULTS

The outcome was worse in women in terms of disability (age-adjusted odds ratio 2.03, 95% CI 1.69-2.46), while no difference was found for mortality. In multivariate models, female gender turned out to be associated with a lower case-fatality rate (adjusted hazard ratio 0.65, 95% CI 0.48-0.89, P=0.007), whereas the odds ratio for disability decreased but remained significant (OR 1.30; 95% CI 1.01-1.69). We found a significant interaction between gender and age in the case-fatality rate, and a female survival advantage was apparent only below 50 years.

CONCLUSIONS

Our study confirms the excess risk of disability after stroke in women, although it is mostly explained by the occurrence of the most severe clinical syndromes. As for mortality, female gender seems to play a protective role, at least in the short-term and in younger patients.

Ischemic stroke and intestinal bleeding under dabigatran in metabolic myopathy

OBJECTIVES

The subsequent occurrence of an ischemic thromboembolic event and a bleeding shortly after discontinuation of dabigatran has not been published.

CASE REPORT

In an 89-year-old female with atrial fibrillation dabigatran had been started 11 days before admission, following a transitory ischemic attack. Phenprocoumon had been stopped 1 month earlier because of a hematoma after a fall. Although dabigatran was discontinued already on hospital day 1, she experienced an intestinal bleeding on hospital day three and an ischemic stroke on hospital day 6. As blood coagulation parameters were still abnormal on hospital day 2, intestinal bleeding was attributed to the prolonged antithrombotic effect or the interaction of dabigatran with the comedication. Stroke was attributed to the absence of a sufficient antithrombotic effect or a rebound effect 5 days after discontinuation of dabigatran. Clinical neurological examination additionally suggested a neuromuscular disorder.

CONCLUSIONS

Ischemic stroke and intestinal bleeding may consecutively occur shortly after stopping dabigatran. Coagulation parameters may remain abnormal even 2 days after discontinuation of dabigatran. Dabigatran should be applied with caution in elderly patients with renal insufficiency who also take drugs, which enhance the absorption of dabigatran.

Rapid and simultaneous quantitation of prostanoids by UPLC-MS/MS in rat brain

The metabolites of arachidonic acid (AA) produced from the cyclooxygenase (COX) pathway, collectively termed as prostanoids, and from the CYP 450 pathway, eicosanoids, have been implicated in various neuro-degenerative and neuroinflammatory diseases. This study developed a quantitative UPLC-MS/MS method to simultaneously measure 11 prostanoids including prostaglandins and cyclopentenone metabolites in the rat brain cortical tissue. Linear calibration curves ranging from 0.104 to 33.3ng/ml were validated. The inter-day and intra-day variance for all metabolites was less than 15%. The extraction recovery efficiency and matrix (deionized water) effects measured at 12.5ng/ml (750pg on column) ranged from 88 to 100% and 3 to 14%, respectively, with CV% values below 20%. Additionally, applying the processing and extraction conditions of this method to our previous CYP450 eicosanoids method resulted in overall improvement in extraction recovery and reduction in matrix effects at low (0.417ng/ml) and high (8.33ng/ml) concentrations. In rat brain cortical tissue samples, concentrations of prostanoids ranged from 10.2 to 937pmol/g wet tissue and concentration of eicosanoids ranged from 2.23 to 793pmol/g wet tissue. These data demonstrate that the successive measurement of prostanoids and eicosanoids from a single extracted sample of rat brain tissue can be achieved with a UPLC-MS/MS system and that this method is necessary for evaluation of these metabolites to delineate their role in various neuroinflammatory and cerebrovascular disorders.

fenestration: a differential diagnostic challenge in acute ischemic stroke

We present a case of a man presenting with vertigo and nausea who was found to have multifocal infarcts in the posterior circulation on magnetic resonance imaging (MRI). An magnetic resonance angiography (MRA) demonstrated focal widening and central signal dropout in the distal vertebral artery consistent with arterial fenestration. Transcranial Doppler ultrasonography showed turbulent flow and a spike waveform suggestive of an intra-luminal thrombus. This was confirmed by computed tomography (CT) angiography. Following the initiation of dual antiplatelet therapy, the signal abnormalities on transcranial doppler (TCD) resolved suggesting dissolution of the thrombus. This case highlights the diagnostic pitfalls that may arise when relying on only one modality for assessing intracranial vasculature and the importance of clarifying the diagnosis of basilar thrombosis or fenestration.

Bicyclol upregulates transcription factor Nrf2, HO-1 expression and protects rat brains against focal ischemia

Oxidative damage plays a detrimental role in the pathophysiology of cerebral ischemia and may represent a therapeutic target. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) controls the coordinated expression of the important antioxidant and detoxification genes through a promotor sequence termed the antioxidant response element. Bicyclol has been proved to elicit a variety of biological effects through its antioxidant and anti-inflammatory properties. But the underlying mechanisms are poorly understood. In this study, the role of bicyclol in cerebral ischemia and its potential mechanism were investigated.

METHODS

Male Sprague-Dawley rats were randomly assigned to five groups: MCAO (middle cerebral artery occlusion), Vehicle (MCAO+0.5% sodium carboxymethylcellulose), By-L (Vehicle+bicyclol 50mg/kg), By-H (Vehicle+bicyclol 100mg/kg) and Sham operated groups. Bicyclol was administered intragastrically once a day for 3 consecutive days; after 1h of bicyclol pretreatment on the third day, rat ischemic stroke was induced by MCAO. Neurological deficit, infarct volume, and brain edema were detected at 24h after stroke. Western blot and RT-qPCR were used to measure the expression of Nrf2, HO-1 and SOD1. MDA was detected by the spectrophotometer.

RESULTS

Compared with MCAO group, By-H group significantly ameliorated neurological deficit, lessened the infarct volume and brain edema, increased the expression of Nrf2, HO-1 and SOD1 (P<0.05), and decreased the content of MDA (P<0.05).

CONCLUSIONS

Bicyclol protected the rat brain from ischemic damage caused by MCAO, and this effect may be through the upregulation of the transcription factor Nrf2 expression.

Clinical predictors and outcome of patients of acute stroke requiring ventilatory support: a prospective hospital based cohort study

The purpose of this study was to identify clinical factors which may help in predicting the requirement of support of mechanical ventilation (MV) in patients with stroke. This was a prospective cohort study done at a tertiary referral center of India, from December 2008 to December 2009. All consecutive patients of acute stroke, who were admitted from emergency or through outpatient department, and were ≥ 18 years and in whom written consent was available, were considered for the study. Of 193 patients included in the study, 60 (31.08%) patients were intubated due to various reasons. Multivariate analysis of statistically significant and most clinically important variables showed that overall predictor accuracy of requirement of mechanical ventilation is 88% if patients had history of progression of symptoms (OR = 10.38; p<0.001), loss of consciousness at the time of onset (OR=3.18; p=0.011) and GCS motor score ≤ 5 (p < OR = 34.62; 0.001). The findings of this study suggest that factors including the presence of poor sensorium, the progression of symptom and low motor GCS are independent predictors of requirement of mechanical ventilation in patients with stroke and appropriate and cautious timely use of MV can help in improving mortality and morbidity from stroke.

Aspirin resistant patients with recent ischemic stroke

Some patients with a recent ischemic stroke who are being treated with aspirin as an antiaggregant suffer a new ischemic stroke. These patients (15-25%) have been called unresponsive to aspirin or aspirin resistant. The aspirin-resistant patients have a four-time greater risk of suffering a stroke. Furthermore, these strokes are generally more severe, with increased infarct volume and greater risk of recurrence. There is currently no ideal laboratory test to detect the resistance to the antiaggregant effect of aspirin. The study of resistance to aspirin would only be indicated in selected cases. In these patients, one should first rule out any "pseudo-resistance" to aspirin (lack of compliance, concomitant treatments that interfere with the action of the aspirin).

CT Angiography and Presentation NIH stroke Scale in Predicting TIA in Patients Presenting with Acute Stroke Symptoms

Patient candidacy for acute stroke intervention, is currently assessed using brain computed tomography angiography (CTA) evidence of significant stenosis/occlusion (SSO) with a high National Institutes of Health Stroke Scale (NIHSS) (>6). This study examined the association between CTA without significant stenosis/occlusion (NSSO) and lower NIHSS (≤ 6) with transient ischemic attack (TIA) and other good clinical outcomes at discharge. Patients presenting <8 hours from stroke symptom onset, had an NIHSS assessment and brain CTA performed at presentation. Good clinical outcomes were defined as: discharge diagnosis of TIA, modified Rankin Score [mRS] ≤ 1, and home as the discharge disposition. Eighty-five patients received both an NIHSS at presentation and a CTA at 4.2 ± 2.2 hours from stroke symptom onset. Patients with NSSO on CTA as well as those with NIHSS≤6 had better outcomes at discharge (p<0.001). NIHSS ≤ 6 were more likely than NSSO (p=0.01) to have a discharge diagnosis of TIA (p<0.001). NSSO on CTA and NIHSS ≤ 6 also correlated with fewer deaths (p<0.001). Multivariable analyses showed NSSO on CTA (Adjusted OR: 5.8 95% CI: 1.2-27.0, p=0.03) independently predicted the discharge diagnosis of TIA. Addition of NIHSS ≤ 6 to NSSO on CTA proved to be a stronger independent predictor of TIA (Adjusted OR 18.7 95% CI: 3.5-98.9, p=0.001).

Platelet-derived microparticles are implicated in remote ischemia conditioning in a rat model of cerebral infarction

AIM

Remote ischemic preconditioning protects against ischemic organ damage by giving short periods of subcritical ischemia to a remote organ. We tested the hypothesis that remote ischemic conditioning can attenuate cerebral stroke in a rat middle cerebral artery occlusion (MCAO) model by microparticles (MPs).

METHODS AND RESULTS

MPs were extracted from healthy rats that underwent hindlimb ischemia-reperfusion preconditioning (RIPC), and were transfused into rats that had undergone MCAO without RIPC. The transfusion resulted in an increase in platelet-derived MPs in blood and reduction in infarction area, confirmed by both 2-3-5-triphenyltetrazolium chloride staining and magnetic resonance imaging, albeit to a lesser degree than RIPC itself. Behavioral tests (modified Neurological Severity Score [mNSS]) were calculated to judge the behavioral change. However, no significant difference was observed after MP transfusion in 24 h or the following consecutive 9 days.

CONCLUSIONS

RIPC induces an increase in MPs, and platelet-derived MPs may confer at least part of the remote protective effect against cerebral ischemic-reperfusion injury.

Clinical neurogenetics: stroke

Understanding the genetic architecture of cerebrovascular disease holds promise of novel stroke prevention strategies and therapeutics that are both safe and effective. Apart from a few single-gene disorders associated with cerebral ischemia or intracerebral hemorrhage, stroke is a complex genetic phenotype that requires careful ascertainment and robust association testing for discovery and validation analyses. The recently uncovered shared genetic contribution between clinically manifest stroke syndromes and closely related intermediate cerebrovascular phenotypes offers effective and efficient approaches to complex trait analysis.

Endovascular treatment of intracranial atherosclerotic disease

Stroke is the third leading cause of death in the United States. Intracranial atherosclerotic disease plays a role in cerebrovascular accidents, with well-characterized modifiable and nonmodifiable risk factors. Surgical bypass has so far not proved to be superior to medical therapy. Both medical and endovascular therapies for intracranial atherosclerosis have evolved since the initial off-label use of cardiac devices for its treatment. Initial reports on the results of stent placement for symptomatic high-grade intracranial atherosclerotic disease were initially encouraging. However, debate remains as to the optimal treatment of symptomatic intracranial atherosclerotic disease.

Incidence and trends of stroke and its subtypes in Changsha, China from 2005 to 2011

During the 1990s no significant changes were found for the high incidence of ischemic stroke (IS) in Changsha, in contrast to the increase observed in Beijing and Shanghai. However, the epidemiological patterns of stroke may change with economic development. This study aimed to examine the characteristics of stroke incidence transition in Changsha from 2005 to 2011. In 2007 two communities with a registered population of about 100,000 were selected and data from stroke patients who presented between 2005 and 2007 were retrospectively collected from January to June 2008. From January to December 2007 a stroke surveillance network was established and stroke patients who presented between 2008 and 2011 were prospectively registered. From 2005 to 2011 the mean annual age-adjusted incidence of first-ever stroke was 168.5/100,000 (95% confidence interval [CI] 159.0-178.0/100,000), with 189.3/100,000 (95% CI 175.1-178.0/100,000) for men and 148.7/100,000 (95% CI 136.0-161.4/100,000) for women. The mean annual age-adjusted incidence of IS, intracranial hemorrhage and subarachnoid hemorrhage was 72.6/100,000 (95% CI 66.3-78.9/100,000), 85.1/100,000 (95% CI 78.3-91.9/100,000) and 9.4/100,000 (95% CI 7.1-11.7/100,000), respectively. During the study period, the age-adjusted incidence of stroke increased at an annual rate of 3.7% (p=0.001); at 4.2% for men (p=0.001) and 3.1% for women (p=0.026). The age-adjusted incidence of IS increased at an annual rate of 3.5% (p=0.003) but no significant changes were seen for hemorrhagic stroke. Characteristics of stroke incidence transition may reflect underlying changes in risk factors and there is an urgent need to identify these factors and launch appropriate public health campaigns.

Brain infarction with a predilection for cerebellum in a patient with double-outlet left ventricle and vascular malformations

Double-outlet left ventricle (DOLV) is a rare congenital heart disease characterized by the origin of the great arteries arising predominantly or completely from the left ventricle. In this report, we describe a case with brain infarction with a predilection for cerebellum in a patient with DOLV and vascular malformations. The cerebellar predilection of ischemic lesions appeared to have been caused by hemodynamic effects related to the specific anatomy of the brachiocephalic trunk. This is further supported by our observation that the mean flow velocity was significantly higher in the vertebral arteries than in the common carotid arteries.

Comparative analysis of the neurovascular injury and functional outcomes in experimental stroke models in diabetic Goto-Kakizaki rats

Diabetes worsens functional outcome and is associated with greater hemorrhagic transformation (HT) after ischemic stroke. We have shown that diabetic Goto-Kakizaki (GK) rats develop greater HT and neurological deficit despite smaller infarcts after transient middle cerebral artery occlusion (MCAO) with the suture model. However, the impact of (1) the duration of ischemia/reperfusion (I/R); (2) the method of ischemia; and (3) acute glycemic control on neurovascular injury and functional outcome in diabetic stroke remained unanswered. Wistar and GK rats were subjected to variable MCAO by suture or embolus occlusion. A group of GK rats were treated with insulin or metformin before stroke with suture occlusion. In all groups, infarct size, edema, HT occurrence and severity, and functional outcome were measured. Infarct size at 24h was smaller in GK rats with both suture and embolic MCAO, but expanded with longer reperfusion period. Edema and HT were increased in GK rats after 90min and 3h occlusion with the suture model, but not in the embolic MCAO. Neurological deficit was greater in diabetic rats. These findings suggest that diabetes accelerates the development of HT and amplifies vascular damage in the suture model where blood flow is rapidly reestablished. Acute metformin treatment worsened the infarct size, HT, and behavior outcome, whereas insulin treatment showed a protective effect. These results suggest that the impact of ischemia/reperfusion on neurovascular injury and functional outcome especially in disease models needs to be fully characterized using different models of stroke to model the human condition.

The arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene SG13S114 polymorphism and ischemic stroke in Chinese population: a meta-analysis

Previous studies have indicated that the arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene SG13S114 polymorphism is associated with risk of ischemic stroke (IS), but the results remain inconclusive even in Chinese population. A meta-analysis of 10 case-control studies was conducted on the relationship between ALOX5AP SG13S114 polymorphism and susceptibility to IS in Chinese population published domestically and abroad from September 2007 to December 2012. Data were extracted by two authors and pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Meta-analysis results showed that the significant association between SG13S114 variant and IS was found under the allelic (OR=0.87, 95% CI: 0.80-0.96, P=0.004), dominant (OR=0.75, 95% CI: 0.62-0.92, P=0.005), and recessive (OR=0.89, 95% CI: 0.82-0.97, P=0.005) genetic models in Chinese population. In subgroup meta-analysis, SG13S114 variant and atherothrombotic stroke, rather than lacunar stroke, showed the significant association under the allelic (OR=0.86, 95% CI: 0.80-0.92, P<0.0001), dominant (OR=0.72, 95% CI: 0.57-0.91, P=0.006), and recessive (OR=0.86, 95% CI: 0.78-0.95, P=0.002) models. ALOX5AP SG13S114 polymorphism is associated with susceptibility to IS in Chinese population.

Evidence that collaboration between HIF-1α and Notch-1 promotes neuronal cell death in ischemic stroke

Recent findings suggest that Notch-1 signaling contributes to neuronal death in ischemic stroke, but the underlying mechanisms are unknown. Hypoxia inducible factor-1α (HIF-1α), a global regulator of cellular responses to hypoxia, can interact with Notch and modulate its signaling during hypoxic stress. Here we show that Notch signaling interacts with the HIF-1α pathway in the process of ischemic neuronal death. We found that a chemical inhibitor of the Notch-activating enzyme, γ-secretase, and a HIF-1α inhibitor, protect cultured cortical neurons against ischemic stress, and combined inhibition of Notch-1 and HIF-1α further decreased neuronal death. HIF-1α and Notch intracellular domain (NICD) are co-expressed in the neuronal nucleus, and co-immunoprecipitated in cultured neurons and in brain tissue from mice subjected to focal ischemic stroke. Overexpression of NICD and HIF-1α in cultured human neural cells enhanced cell death under ischemia-like conditions, and a HIF-1α inhibitor rescued the cells. RNA interference-mediated depletion of endogenous NICD and HIF-1α also decreased cell death under ischemia-like conditions. Finally, mice treated with inhibitors of γ-secretase and HIF-1α exhibited improved outcome after focal ischemic stroke, with combined treatment being superior to individual treatments. Additional findings suggest that the NICD and HIF-1α collaborate to engage pro-inflammatory and apoptotic signaling pathways in stroke.

ATP-binding cassette transporter A1 R219K polymorphism and ischemic stroke risk in the Chinese population: a meta-analysis

Recently, many studies have been focused on the association between the ATP-binding cassette transporter A1 (ABCA1) gene R219K polymorphism and ischemic stroke (IS). However, the study results have been inconsistent, especially in the Chinese population. Therefore, we performed a meta-analysis to better clarify the association between the ABCA1 gene and IS. All of the relevant studies used in our meta-analysis were identified using PubMed, OVID, Cochrane Library, Chinese Wan Fang database, Chinese VIP database, China National Knowledge Infrastructure (CNKI), and China Biological Medicine Database (CBM) up to May 2013. Statistical analysis was conducted with STATA software version 11.0. Odds ratios with 95% confidence intervals were applied to evaluate the strength of the association between ABCA1 gene R219K polymorphism and IS. Heterogeneity was evaluated using the Q-test and I(2) statistic. The funnel plots, Begg's and Egger's regression tests were used to assess the publication bias. Our meta-analysis showed the dominant genetic model (OR=0.92, 95% CI: 0.88-0.96), the recessive genetic model (OR=0.73, 95% CI: 0.51-1.05), the homozygote genetic model (OR=0.64, 95% CI: 0.44-0.94), the heterozygote genetic model (OR=0.81, 95% CI: 0.69-0.95), and the allelic genetic model (OR=0.83, 95% CI: 0.69-0.99). For R219K in IS, there were significant associations with these genetic models, but not with the recessive genetic model. Our meta-analysis indicated that the ABCA1 gene R219K polymorphism might be associated with IS and the K allele might be a protective factor in the Chinese population.

Synthetic cannabis and acute ischemic stroke

An association between marijuana use and stroke has been previously reported. However, the health risks of newer synthetic cannabinoid compounds are less well known. We describe 2 cases that introduce a previously unreported association between synthetic cannabis use and ischemic stroke in young adults. A 22-year-old woman presented with dysarthria, left hemiplegia, and left hemianesthesia within hours of first use of synthetic cannabis. She was healthy and without identified stroke risk factors other than oral contraceptive use and a patent foramen ovale without venous thromboses. A 26-year-old woman presented with nonfluent aphasia, left facial droop, and left hemianesthesia approximately 12 hours after first use of synthetic cannabis. Her other stroke risk factors included migraine with aura, oral contraceptive use, smoking, and a family history of superficial thrombophlebitis. Both women were found to have acute, large-territory infarctions of the right middle cerebral artery. Our 2 cases had risk factors for ischemic stroke but were otherwise young and healthy and the onset of their deficits occurred within hours after first-time exposure to synthetic cannabis. Synthetic cannabis use is an important consideration in the investigation of stroke in young adults.

The current situation on vascular cognitive impairment after ischemic stroke in Changsha

The objectives of the study were to explore the prevalence and effects of vascular cognitive impairment (VCI) among ischemic stroke patients and to provide a basis for prevention and treatment strategies. A stratified cluster random sampling method was performed, and 689 ischemic stroke patients (over 40 years of age) were enrolled. All of the patients had received a neuropsychological assessment battery to assess cognitive function and self-designed questionnaires to collect relevant information. According to the cognitive status, the patients were divided into two groups, a case group and a control group. The caregivers of the patients were given a questionnaire concerning the awareness of and attitudes toward VCI. In this study, we determined that the prevalence of VCI was 41.8%. Aging, paraventricular white matter lesion (WML), macroangiopathy, high levels of alcohol, a lack of hobbies, and excessive sleep were risk factors for vascular cognitive impairment no dementia (VCIND). A high level of education, manual-work, low level of alcohol use, regular health checks, a vegetable-based diet, and more fruit and milk were protective factors for VCIND. Living alone, hyperlipidemia, transient ischemic attack, a family history of stroke, and brain atrophy were risk factors of vascular dementia (VD). A high educational level, a vegetable-based diet, and tea were protective factors for VD. The general public awareness of VCI was found to be insufficient, and there was a prejudice toward and lack of funding for the care of VCI patients. The prevalence of VCI is high in ischemic stroke patients, and there are different impact factors at different stages. Despite the high prevalence of VCI, the general public awareness is limited. Appropriate prevention measures should be developed to reduce the prevalence of VCI.

Acute foot drop syndrome mimicking peroneal nerve injury: an atypical presentation of ischemic stroke

Foot drop syndrome is a frequent neurologic condition usually caused by peroneal nerve damage. On rare occasions, foot drop may present as the single neurologic manifestation of intracranial lesions. We presented a 43-year-old man admitted to our hospital with acute weakness in the dorsiflexion of his right foot that appeared 3 days before admission. Brain magnetic resonance imaging diffusion-weighted sequence revealed a small area of restricted diffusion in the left frontal cortex. Three months later, his motor deficit had completely improved (modified Rankin scale score = 0). To our knowledge, this is the second report of sudden isolated foot drop caused by a cortical infarction.

Statins and the risks of stroke recurrence and death after ischemic stroke: the Fukuoka Stroke Registry

BACKGROUND AND PURPOSE

The findings of recent clinical trials suggest that treatment with high-dose statins reduces the risk of stroke recurrence. However, the doses approved in Japan are much lower than those in the previous studies. This study aimed to elucidate whether prescribed doses of statins reduce the risks of cerebrovascular events (CVEs: stroke recurrence or transient ischemic attack) and all-cause mortality in a cohort of Japanese patients with first-ever ischemic stroke.

METHODS

The 2822 eligible patients registered in the Fukuoka Stroke Registry with first-ever acute ischemic stroke from June 2007 to February 2011 were classified into statin users (n = 993) and non-users (n = 1829) at discharge, and followed up until March 2012. We assessed the cumulative risks of CVE and all-cause mortality by the Kaplan-Meier method, and calculated hazard ratios (HRs) and 95% confidential intervals (CIs) using the Cox proportional hazards model.

RESULTS

During the follow-up time (median, 2.0 years), 305 patients had CVEs and 345 died. The cumulative risks of CVE and death after 4 years were significantly lower in statin users than in non-users (13.8% versus 19.5%, P = 0.005 for CVE; 11.8% versus 21.7%, P < 0.001 for death). After adjusting for multiple confounding factors, statin treatment significantly reduced the risks of CVE (HR, 0.70; 95% CI, 0.53 to 0.92; P = 0.011) and all-cause mortality (HR, 0.67; 95% CI, 0.50 to 0.89; P = 0.006).

CONCLUSIONS

Our findings suggest that low-dose statin may reduce the risks of CVE and death in Japanese patients with acute ischemic stroke.

[Ischemic stroke: A rare complication of liver hydatid cyst]

Hydatid cyst of the liver (HCL) is a widespread disease in North African countries. We report the case of a 39-year-old patient who was admitted in our intensive care unit because of anaphylactic shock due to a cracked HCL fortuitously discovered. This accident was also complicated by an ischemic stroke witch underline mechanisms are discussed.

Relation between left atrial enlargement and stroke subtypes in acute ischemic stroke patients

Objective

Increased atrial size is frequently seen in ischemic stroke patients in clinical practice. There is controversy about whether left atrial enlargement (LAE) should be regarded as a risk factor for cerebral infarction. We investigated the association between indexed left atrial volume (LAVI) and conventional stroke risk factors as well as stroke subtypes in acute ischemic stroke patients.

Methods

One hundred eighty two acute cerebral infarction patients were included in this study. Brain magnetic resonance imaging and transthoracic echocardiography were done for all patients within 30 days of diagnosis of acute cerebral infarction. Echocardiographic LAE was identified when LAVI was more than 27 mL/m². Stroke subtypes were classified by the Trial of Org 10171 in acute stroke treatment classification.

Results

There were significant differences between subjects with normal and increased LAVI in prevalence of stroke risk factors including atrial fibrillation (p = 0.001), hypertension (p = 0.000), valvular heart disease (p = 0.011) and previous stroke (p = 0.031). An increased LAVI was associated with cardioembolic subtype with an adjusted odds ratio was 6.749 (p = 0.002) compared with small vessel disease.

Conclusion

Increased LAVI was more prevalent in those who had cardiovascular risk factors, such as atrial fibrillation, hypertension, valvular heart disease and history of previous stroke. LAE influenced most patients in all subtypes of ischemic stroke but was most prevalent in the cardioembolic stroke subtype. Increased LAVI might be a risk factor of cerebral infarction, especially in patients with cardioembolic stroke subtype.

Cerebral microbleeds: their associated factors, radiologic findings, and clinical implications

Cerebral microbleeds (CMBs) are tiny, round dark-signal lesions that are most often detected on gradient-echo MR images. CMBs consist of extravasations of blood components through fragile microvascular walls characterized by lipohyalinosis and surrounding macrophages. The prevalence of CMBs in elderly subjects with no history of cerebrovascular disease is around 5%, but is much higher in patients with ischemic or hemorrhagic stroke. Development of CMBs is closely related to various vascular risk factors; in particular, lobar CMBs are thought to be associated with cerebral amyloid angiopathy. The presence of CMBs has been hypothesized to reflect cerebral-hemorrhage-prone status in patients with hypertension or amyloid microangiopathy. Stroke survivors with CMBs have been consistently found to have an elevated risk of subsequent hemorrhagic stroke or an antithrombotic-related hemorrhagic complication, although studies have failed to establish a link between CMBs and hemorrhagic transformation after thrombolytic treatment. A large prospective study is required to clarify the clinical significance of CMBs and their utility in a decision-making index.

Biomarkers of periodontitis and inflammation in ischemic stroke: A case-control study

Periodontitis is a common infectious disease associated with increased risk for ischemic stroke though presently unclear mechanisms. In a case-control study, we investigated salivary levels of four periodontal pathogens, as well as systemic and local inflammatory markers. The population comprised 98 patients with acute ischemic stroke (mean ± SD, 68.2 ± 9.7 yrs; 45.9% women) and 100 healthy controls (69.1 ± 5.2 yrs; 47.0% women). Patients were more often edentulous and had fewer teeth than controls (13.8 ± 10.8 versus 16.6 ± 10.1). After adjusting for stroke risk factors and number of teeth, controls had higher saliva matrix metalloproteinase-8 (MMP-8), myeloperoxidase (MPO), IL-1β, Aggregatibacter actinomycetemcomitans, and serum LPS activity levels. Patients had higher serum MMP-8 and MPO, and they were more often qPCR-positive for A. actinomycetemcomitans (37.9% versus 19.0%) and for ≥3 periodontopathic species combined (50.0% versus 33.0%). We conclude that controls more often had evidence of current periodontal infection with higher periodontal pathogen amount, endotoxemia, local inflammation and tissue destruction. Stroke patients more often had evidence of end-stage periodontitis with edentulism and missing teeth. They were more often carriers of several periodontopathic pathogens in saliva, especially A. actinomycetemcomitans. Additionally, inflammatory burden may contribute to high systemic inflammation associated with elevated stroke susceptibility.

Effect of middle cerebral artery territory ischemic stroke on QT interval

BACKGROUND

Prolonged QT interval associates with increased risk for sudden cardiac death after acute ischemic stroke. However, pathophysiology of prolonged QT interval after stroke is poorly elucidated. In this study, we investigated whether QT interval dynamics is different in patients with right and left middle cerebral artery (MCA) territory stroke.

METHOD

Electrocardiogram (ECG) intervals were compared between baseline (retrieved retrospectively from medical records) and admission (acquired at the acute hospital admission) in 33 patients (65 ± 9.5 years) with right or left MCA territory ischemic stroke. Head computed tomography (CT), cardiac ultrasound, and cardiac CT scans were undertaken.

RESULTS

Stroke was located in the right MCA territory in 21 (64%) and in the left MCA territory in 12 (36%) patients. Patients with right and left MCA stroke were similar with respect to time interval between baseline and admission ECG recordings, positive history of heart disease, and left ventricular dimensions. Increase in heart rate-corrected QT interval (QTc) from baseline to admission was demonstrated to occur more often in patients with right (16 of 21; 76%) than in patients with left (3 of 12; 25%; P < .01) MCA stroke. ΔQTc between baseline and admission was significantly longer in patients with right (23 ± 23 milliseconds) than in patients with left (-11 ± 19 milliseconds; P < .0001) MCA stroke. Percent ΔQTc between baseline and admission was longer in patients with right (5.5% ± 5.5%) than in patients with left (-2.6% ± 4.7%; P < .001) MCA stroke.

CONCLUSIONS

Right MCA ischemic stroke results in prolongation of QT interval. Findings indicate cerebral asymmetry in brain-heart interaction during acute ischemic stroke.

Brain-derived neurotrophic factor G196A polymorphism predicts 90-day outcome of ischemic stroke in Chinese: a novel finding

BACKGROUND AND PURPOSE

Recovery after stroke varies considerably between individuals. An abundance of evidence suggests that genetic factors contribute to stroke recovery. The aim of this study was to determine whether or not the BDNF G196A polymorphism independently influences the occurrence, severity, and 90-day functional outcome in Chinese patients with ischemic stroke (IS).

METHODS

BDNF G196A genetic variants were investigated in 494 IS and 346 controls. Severity was assessed by the National Institutes of Health Stroke Scale at the time of admission. Three hundred and eight patients were assessed 90 days post-stroke using the Modified Rankin Scale to determine stroke outcome.

RESULTS

We showed that a significant association existed between the BDNF G196A AA genotype and the occurrence of IS (P=0.021), even after adjustment for covariates (P=0.028). The AA genotype of the BDNF G196A was associated with a poor outcome of recovery 3 months after stroke onset (P=0.008) was a novel finding, independent of other known predictors of poor outcome (P=0.012).

CONCLUSIONS

The BDNF G196A polymorphism was significantly associated with the occurrence and long-term outcomes of IS, thus BDNF G196A may be used as a prognostic biomarker and therapeutic target in IS.

Quantitative clinical proteomic study of autopsied human infarcted brain specimens to elucidate the deregulated pathways in ischemic stroke pathology

Ischemic stroke, still lacking an effective neuroprotective therapy is the third leading cause of global mortality and morbidity. Here, we have applied an 8-plex iTRAQ-based 2D-LC-MS/MS strategy to study the commonly regulated infarct proteome from three different brain regions (putamen, thalamus and the parietal lobe) of female Japanese patients. Infarcts were compared with age-, post-mortem interval- and location-matched control specimens. The iTRAQ experiment confidently identified 1520 proteins with 0.1% false discovery rate. Bioinformatics data mining and immunochemical validation of pivotal perturbed proteins revealed a global failure of the cellular energy metabolism in the infarcted tissues as seen by the parallel down-regulation of proteins related to glycolysis, pyruvate dehydrogenase complex, TCA cycle and oxidative phosphorylation. The concomitant down-regulation of all participating proteins (SLC25A11, SLC25A12, GOT2 and MDH2) of malate-aspartate shuttle might be responsible for the metabolic in-coordination between the cytosol and mitochondria resulting in the failure of energy metabolism. The levels of proteins related to reactive gliosis (VIM, GFAP) and anti-inflammatory response (ANXA1, ANXA2) showed an increasing trend. The elevation of ferritin (FTL, FTH1) may indicate an iron-mediated oxidative imbalance aggravating the mitochondrial failure and neurotoxicity. The deregulated proteins could be useful as potential therapeutic targets or biomarkers for ischemic stroke.

BIOLOGICAL SIGNIFICANCE

Clinical proteomics of stroke has been lagging behind other areas of clinical proteomics like Alzheimer's disease or schizophrenia. Our study is the first quantitative clinical proteomics study where iTRAQ-2D-LC-MS/MS has been utilized in the area of ischemic stroke to obtain a comparative profile of human ischemic infarcts and age-, sex-, location- and post-mortem interval-matched control brain specimens. Different pathological attributes of ischemic stroke well-known through basic and pre-clinical research such as failure of cellular energy metabolism, reactive gliosis, activation of anti-inflammatory response and aberrant iron metabolism have been observed at the bedside. Our dataset could act as a reference for similar studies done in the future using ischemic brain samples from various brain banks across the world. A meta-analysis of these studies could help to map the pathological proteome specific to ischemic stroke that will guide the scientific community to better evaluate the pros and cons of the pre-clinical models for efficacy and mechanistic studies. Infarct being the core of injury should have the most intense regulation for several key proteins involved in the pathophysiology of ischemic stroke. Hence, a part of the up-regulated proteome could leak into the general circulation that may offer candidates of interest as potential biomarkers. In support of our proposed hypothesis, we report ferritin in the current study as one of the most elevated proteins in the infarct, which has been documented as a biomarker in the context of ischemic stroke by an independent study. Overall, our approach has the potential to identify probable therapeutic targets and biomarkers in the area of ischemic stroke.

Pathogenesis of acute stroke and the role of inflammasomes

Inflammation is an innate immune response to infection or tissue damage that is designed to limit harm to the host, but contributes significantly to ischemic brain injury following stroke. The inflammatory response is initiated by the detection of acute damage via extracellular and intracellular pattern recognition receptors, which respond to conserved microbial structures, termed pathogen-associated molecular patterns or host-derived danger signals termed damage-associated molecular patterns. Multi-protein complexes known as inflammasomes (e.g. containing NLRP1, NLRP2, NLRP3, NLRP6, NLRP7, NLRP12, NLRC4, AIM2 and/or Pyrin), then process these signals to trigger an effector response. Briefly, signaling through NLRP1 and NLRP3 inflammasomes produces cleaved caspase-1, which cleaves both pro-IL-1β and pro-IL-18 into their biologically active mature pro-inflammatory cytokines that are released into the extracellular environment. This review will describe the molecular structure, cellular signaling pathways and current evidence for inflammasome activation following cerebral ischemia, and the potential for future treatments for stroke that may involve targeting inflammasome formation or its products in the ischemic brain.

Antiplatelet therapy for carotid artery stenting

Carotid artery stenting (CAS) is less invasive and has a lower incidence of systemic complications such as myocardial infarction compared with carotid endarterectomy. However, CAS is known to have a high incidence of ischemic complications due to distal thromboembolism. Progress has been made in the development of various distal protection devices and protection methods aimed at preventing thromboembolism. Similar to these methods, perioperative antiplatelet therapy is also able to play a very important role in the prevention of ischemic events. Dual antiplatelet therapy has become standard for perioperative management of CAS.

C-reactive protein and long-term ischemic stroke prognosis

C-reactive protein (CRP) is an inflammatory biomarker of inflammation and may reflect progression of vascular disease. Conflicting evidence suggests CRP may be a prognostic biomarker of ischemic stroke outcome. Most studies that have examined the relationship between CRP and ischemic stroke outcome have used mortality or subsequent vascular event as the primary outcome measure. Given that nearly half of stroke patients experience moderate to severe functional impairments, using a biomarker like CRP to predict functional recovery rather than mortality may have clinical utility for guiding acute stroke treatments. The primary aim of this study was to systematically and critically review the relationship between CRP and long-term functional outcome in ischemic stroke patients to evaluate the current state of the literature. PubMed and MEDLINE databases were searched for original studies which assessed the relationship between acute CRP levels measured within 24 hours of symptom onset and long-term functional outcome. The search yielded articles published between 1989 and 2012. Included studies used neuroimaging to confirm ischemic stroke diagnosis, high-sensitivity CRP assay, and a functional outcome scale to assess prognosis beyond 30 days after stroke. Study quality was assessed using the REMARK recommendations. Five studies met all inclusion criteria. Results indicate a significant association between elevated baseline high sensitivity CRP and unfavorable long-term functional outcome. Our results emphasize the need for additional research to characterize the relationship between acute inflammatory markers and long-term functional outcome using well-defined diagnostic criteria. Additional studies are warranted to prospectively examine the relationship between high sensitivity CRP measures and long-term outcome.

Knockout of vascular early response gene worsens chronic stroke outcomes in neonatal mice

Vascular early response gene (Verge) is a novel immediate early gene that is highly expressed during developmental angiogenesis and after ischemic insults in adult brain. However, the role of Verge after neonatal injury is not known. In the present study, we investigated the hypothesis that Verge contributes to vascular remodeling and tissue repair after neonatal ischemic injury. The Rice-Vanucci model (RVM) was employed to induce neonatal stroke in both Verge knockout (KO) and wild-type (WT) postnatal day 10 (P10) mice. Histological and behavioral outcomes at acute (24h), subacute (7 days) and chronic (30 days) phases were evaluated. Angiogenesis, neurogenesis, and glial scar formation were also examined in the ischemic brain. No significant differences in outcomes were found between WT and Verge mice at 24h or 7 days after stroke. However genetic deletion of Verge led to pronounced cystic cavitation, decreased angiogenensis and glial scar formation in the ischemic hemisphere compared to WT mice at 30 days. Verge KO mice also had significantly worse functional outcomes at 30 days which was accompanied by decreased neurogenesis and angiogenesis in the ischemic hemisphere. Our study suggests that Verge plays an important role in the induction of neurogenesis and angiogenesis after ischemia, contributes to improved tissue repair, and enhances chronic functional recovery.

Transcranial doppler: Technique and common findings (Part 1)

Transcranial Doppler (TCD) can be aptly called as the doctor’s stethoscope of the brain. Since its introduction in 1982, by Rune Aaslid, TCD has evolved as a diagnostic, monitoring, and therapeutic tool. During evaluation of patients with acute ischemic stroke, TCD combined with cervical duplex ultrasonography provides physiological information on the cerebral hemodynamics, which is often complementary to structural imaging. Currently, TCD is the only diagnostic tool that can provide real time information about cerebral hemodynamics and can detect embolization to the cerebral vessels. TCD is a noninvasive, cost-effective, and bedside tool for obtaining information regarding the collateral flow across various branches of the circle of Willis in patients with cerebrovascular disorders. Advanced applications of TCD help in the detection of right-to-left shunts, vasomotor reactivity, diagnosis, and monitoring of vasospasm in subarachnoid hemorrhage and as a supplementary test for confirmation of brain death. This article describes the basic ultrasound physics pertaining to TCD insonation methods, for detecting the flow in intracranial vessels in addition to the normal and abnormal spectral flow patterns.