Transient ischemic attack: definition, diagnosis, and risk stratification

A systematic review of the incidence and outcomes of ICD-11 defined stroke

BACKGROUND

The World Health Organisation has expanded the definition of stroke to include people with symptoms less than 24 h if they have evidence of stroke on neuroimaging. The impact is that people previously diagnosed as having a transient ischaemic attack (TIA) would now be considered to have had a stroke. This change will impact incidence and outcomes of stroke and increase eligibility for secondary prevention. We aimed to evaluate the new ICD-11 criteria retrospectively to previous TIA studies to understand the change in incidence and outcomes of this type of stroke.

METHODS

We conducted a systematic review of observational studies of the incidence and outcomes of clinically defined TIA. We searched PubMed, EMBASE, and Google Scholar from inception to 23rd May 2023. Study quality was assessed using a risk of bias tool for prevalence studies.

FINDINGS

Our review included 25 studies. The rate of scan positivity for stroke among those with clinically defined TIA was 24 %, (95 % CI, 16-33 %) but with high heterogeneity (I2 = 100 %, p <0.001). Sensitivity analyses provided evidence that heterogeneity could be explained by methodology and recruitment method. The scan positive rate when examining only studies at low risk of bias was substantially lower, at 13 % (95 % CI, 11-15 %, I2 = 0, p = 0.77). We estimate from population-based incidence studies that ICD-11 would result in an increase stroke incidence between 4.8 and 10.5 per 100,000 persons/year. Of those with DWI-MRI evidence of stroke, 6 % (95 % CI, 3-11 %) developed a recurrent stroke in the subsequent 90 days, but with substantial heterogeneity (I2 = 67 %, p = 0.02).

CONCLUSION

The impact of the ICD-11 change in stroke definition on incidence and outcomes may have been overestimated by individual studies. Community-based stroke services with access to DWI MRI are likely to accurately diagnose greater numbers of people with mild ICD-11 stroke, increasing access to effective prevention.

Effect of atorvastatin calcium plus clopidogrel in the treatment of patients with transient ischemic attacks and its effect on blood lipids and platelets

OBJECTIVE

To explore the clinical effect of atorvastatin calcium combined with clopidogrel in the treatment of patients with transient ischemic attacks (TIAs) and its effect on blood lipids and platelets.

METHODS

Low-density lipoprotein cholesterol (LDL-C)], platelet-related parameters [prothrombin time (PT), activated partial thromboplastin time (APTT), platelet count (PLT)], incidence of cerebral infarction, and adverse reactions.

RESULTS

The clinical outcomes of the experimental group patients were significantly better than those of the control group patients (p < 0.05). The experimental group exhibited notably lower levels of TG, TC, and LDL-C compared to the control group (p < 0.05). Platelet-related indices-PT, APTT, and PLT-showed no significant differences between groups before and after treatment (p > 0.05). The incidence of cerebral infarction was notably lower in the experimental group (p < 0.005), while the occurrence of adverse reactions showed no significant difference between groups (p > 0.05).

CONCLUSION

Atorvastatin calcium combined with clopidogrel demonstrates a positive impact on individuals with TIAs by significantly lowering levels of LDL, total cholesterol, and triglycerides. However, it is noteworthy that platelet-related indices did not exhibit significant differences between the experimental and control groups. While the observed improvements in blood lipids are attributed to the effects of atorvastatin, the combination with clopidogrel did not show a substantial influence on platelet-related parameters. Thus, the overall therapeutic impact, particularly on platelet-related indices, may require further investigation and clarification. Despite these nuances, our findings suggest potential benefits in reducing the risk of adverse reactions and cerebral infarction, supporting the consideration of this approach for wider clinical use.

Neuroimaging biomarkers of cognitive recovery after ischemic stroke

Post-stroke cognitive impairment affects more than one-third of patients after an ischemic stroke (IS). Identifying markers of potential cognitive recovery after ischemic stroke can guide patients' selection for treatments, enrollment in clinical trials, and cognitive rehabilitation methods to restore cognitive abilities in post-stroke patients. Despite the burden of post-stroke cognitive impairment, biomarkers of cognitive recovery are an understudied area of research. This narrative review summarizes and critically reviews the current literature on the use and utility of neuroimaging as a predictive biomarker of cognitive recovery after IS. Most studies included in this review utilized structural Magnetic Resonance Imaging (MRI) to predict cognitive recovery after IS; these studies highlighted baseline markers of cerebral small vessel disease and cortical atrophy as predictors of cognitive recovery. Functional Magnetic Resonance Imaging (fMRI) using resting-state functional connectivity and Diffusion Imaging are potential biomarkers of cognitive recovery after IS, although more precise predictive tools are needed. Comparison of these studies is limited by heterogeneity in cognitive assessments. For all modalities, current findings need replication in larger samples. Although no neuroimaging tool is ready for use as a biomarker at this stage, these studies suggest a clinically meaningful role for neuroimaging in predicting post-stroke cognitive recovery.

ABCD2, ABCD2-I, and OTTAWA scores for stroke risk assessment: a direct retrospective comparison

Transient ischemic attack (TIA) is a neurologic emergency characterized by cerebral ischemia eliciting a temporary focal neurological deficit. Many clinical prediction scores have been proposed to assess the risk of stroke after TIA; however, studies on their clinical validity and comparisons among them are scarce. The objective is to compare the accuracy of ABCD², ABCD²-I, and OTTAWA scores in the prediction of a stroke at 7, 90 days, and 1 year in patients presenting with TIA. Single-centre, retrospective study including patients with TIA admitted to the Emergency Department of our third-level, University Hospital, between 2018 and 2019. Five hundred three patients were included. Thirty-nine (7.7%) had a stroke within 1 year from the TIA: 9 (1.7%) and 24 (4.7%) within 7 and 90 days, respectively. ABCD², ABCD²-I, and OTTAWA scores were significantly higher in patients who developed a stroke. AUROCs ranged from 0.66 to 0.75, without statistically significant differences at each time-point. Considering the best cut-off of each score, only ABCD² > 3 showed a sensitivity of 100% only in the prediction of stroke within 7 days. Among clinical items of each score, duration of symptoms, previous TIA, hemiparesis, speech disturbance, gait disturbance, previous cerebral ischemic lesions, and known carotid artery disease were independent predictors of stroke. Clinical scores have moderate prognostic accuracy for stroke after TIA. Considering the independent predictors for stroke, our study indicates the need to continue research and prompts the development of new tools on predictive scores for TIA.

FLAIR Vascular Hyperintensity: An Important MRI Marker in Patients with Transient Ischemic Attack

Purpose

We aimed to investigate the prevalence of fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVHs) and the clinical-radiological correlation in transient ischemic attack (TIA) patients.

Materials and Methods

We performed a retrospective analysis of TIA patients who had undergone magnetic resonance imaging (MRI) within 24 h of symptom onset. Two independent neuroradiologists investigated the presence of FVHs, large-artery severe stenosis or occlusion (LASO) in magnetic resonance angiograms, and the nature of factors associated with FVH.

Results

A total of 207 patients were enrolled in this study. FVHs were detected in 42 (20.3%) patients, in whom atrial fibrillation (AF) was confirmed in 25 (59.5%) cases and LASO was confirmed in 30 (71.4%) cases. The corresponding figures were 33 (20.0%) and 10 (6.1%), respectively, for the 165 FVH-negative patients. Logistic regression analysis showed that time from symptom onset to MRI (odds ratio [OR] = 0.82, 95% CI 0.76-0.97, p = 0.042), previous stroke (OR = 2.95, 95% CI 1.58-6.74, p = 0.002), AF (OR = 5.83, 95% CI 2.24-9.46, p < 0.001), and LASO (OR = 4.28, 95% CI 2.96-10.28, p < 0.001) were independently associated with FVH. Overall, the sensitivity and specificity of FVH for predicting LASO were 0.75 and 0.93, respectively, and the positive predictive value, negative predictive value, and accuracy were 0.71, 0.94, and 0.89, respectively. The area under the receiver operating characteristic curve was 0.839. FVH-positive TIA patients with LASO had less AF (14 [46.7%] versus 11 [91.7%], p = 0.019) and longer times from symptom onset to MRI (6.8 ± 2.8 h versus 4.8 ± 1.3 h, p = 0.004) than those without LASO.

Conclusion

The presence of FVH could be an important marker in TIA patients. Many factors, including LASO, AF, and time from symptom onset to MRI, are associated with the detection of FVH.

Stopping "transient ischemic attacks" by antiplatelet withdrawal

Introduction

Transient ischemic attack (TIA) is considered to be an important risk factor for the development of ischemic stroke and requires complete etiopathogenic evaluation and prompt initiation of secondary prevention treatment. In addition, an accurate differential diagnosis should be performed in order to exclude other disorders mimicking TIA.

Methods

In this case report, we describe the clinical and neuroimaging evaluation and the differential diagnosis of a patient with suspected crescendo TIAs.

Results

A 79-year-old man presented with recurrent episodes of right-sided numbness over the past 7 months, despite different single and dual antiplatelet therapies that were sequentially prescribed for suspected TIAs. Brain MRI revealed cortical superficial siderosis, symmetrical periventricular leukoencephalopathy and enlarged perivascular spaces. Cerebral amyloid angiopathy was considered in the differential diagnosis of the patient. Antiplatelet withdrawal was recommended and led to complete remission of the patient’s transient focal neurological episodes (TFNE) that were initially misdiagnosed as TIAs.

Discussion

Cortical superficial siderosis has been implicated as a key neuroimaging feature of cerebral amyloid angiopathy, a diagnosis which can be supported by the additional radiological findings of symmetrical white matter hyperintensities and enlarged perivascular spaces. Antiplatelet treatment in patients with cortical superficial siderosis may increase the frequency and severity of TFNE, while it increases exponentially the risk of intracerebral hemorrhage. The present case highlights that recognition of cortical superficial siderosis is crucial in the management of patients presenting with transient focal neurological symptoms that can be misdiagnosed as recurrent TIAs.

Ischemic stroke with a preceding Trans ischemic attack (TIA) less than 24 hours and thrombolytic therapy

Background

Acute ischemic stroke attack with and without a recent TIA may differ in clinical risk factors, and this may affect treatment outcomes following thrombolytic therapy. We examined whether the odds of exclusion or inclusion for thrombolytic therapy are greater in ischemic stroke with TIA less than 24 h preceding ischemic stroke (recent-TIA) as compared to those without recent TIA or non-TIA > 24 h and less than 1 month (past-TIA).

Methods

A retrospective hospital-based analysis was conducted on 6315 ischemic stroke patients, of whom 846 had proven brain diffusion-weighted magnetic resonance imaging (DW-MRI) of an antecedent TIA within 24 h prior to ischemic stroke. The logistic regression model was developed to generate odds ratios (OR) to determine clinical factors that may increase the likelihood of exclusion or inclusion for thrombolytic therapy. The validity of the model was tested using a Hosmer-Lemeshow test, while the Receiver Operating Curve (ROC) was used to test the sensitivity of our model.

Results

In the recent-TIA ischemic stroke population, patients with a history of alcohol abuse (OR = 5.525, 95% CI, 1.003–30.434, p = 0.05), migraine (OR = 4.277, 95% CI, 1.095–16.703, p = 0.037), and increasing NIHSS score (OR = 1.156, 95% CI, 1.058–1.263, p = 0.001) were associated with the increasing odds of receiving rtPA, while older patients (OR = 0.965, 95% CI, 0.934–0.997, P = 0.033) were associated with the increasing odds of not receiving rtPA.

Conclusion

In recent-TIA ischemic stroke patients, older patients with higher INR values are associated with increasing odds of exclusion from thrombolytic therapy. Our findings demonstrate clinical risks factors that can be targeted to improve the use and eligibility for rtPA in in recent-TIA ischemic stroke patients.

A predictive analytics model for differentiating between transient ischemic attacks (TIA) and its mimics

Background

Transient ischemic attack (TIA) is a brief episode of neurological dysfunction resulting from cerebral ischemia not associated with permanent cerebral infarction. TIA is associated with high diagnostic errors because of the subjective nature of findings and the lack of clinical and imaging biomarkers. The goal of this study was to design and evaluate a novel multinomial classification model, based on a combination of feature selection mechanisms coupled with logistic regression, to predict the likelihood of TIA, TIA mimics, and minor stroke.

Methods

We conducted our modeling on consecutive patients who were evaluated in our health system with an initial diagnosis of TIA in a 9-month period. We established the final diagnoses after the clinical evaluation by independent verification from two stroke neurologists. We used Recursive Feature Elimination (RFE) and Least Absolute Shrinkage and Selection Operator (LASSO) for prediction modeling.

Results

The RFE-based classifier correctly predicts 78% of the overall observations. In particular, the classifier correctly identifies 68% of the cases labeled as “TIA mimic” and 83% of the “TIA” discharge diagnosis. The LASSO classifier had an overall accuracy of 74%. Both the RFE and LASSO-based classifiers tied or outperformed the ABCD2 score and the Diagnosis of TIA (DOT) score. With respect to predicting TIA, the RFE-based classifier has 61.1% accuracy, the LASSO-based classifier has 79.5% accuracy, whereas the DOT score applied to the dataset yields an accuracy of 63.1%.

Conclusion

The results of this pilot study indicate that a multinomial classification model, based on a combination of feature selection mechanisms coupled with logistic regression, can be used to effectively differentiate between TIA, TIA mimics, and minor stroke.

The Association of Autonomic Nervous System Function With Ischemic Stroke, and Treatment Strategies

Acute ischemic stroke, especially minor stroke, and transient ischemic attack have high risks of recurrence and exacerbation into severe ischemic strokes. It remains challenging to perform risk stratification and screen high-risk groups for initiation of early treatment in these patients. Moreover, with the growing population of patients with chronic small vessel disease, the mechanisms and clinical implications require further investigation. Traditional tools such as the ABCD2 score (age, blood pressure, clinical features, duration of symptoms, diabetes) have only moderate predictive value in patients with transient ischemic attack or minor stroke. By contrast, measurement of changes in heart rate variability (HRV) is an important and novel tool for risk stratification and outcome prediction in patients with cardiovascular diseases, as it reflects the overall level of autonomic nervous system dysfunction. Thus, abnormal HRV may be useful for prognosis and improve stratification of stroke patients with diverse risks. HRV may also partially explain autonomic nervous dysfunction and other manifestations during the process of chronic cerebral small vessel disease. In summary, measurement of HRV may contribute to early initiation of interventions in acute or chronic stroke patients using novel treatments involving rebalancing of autonomic nervous system function.

The Association Between an Antecedent of Transient Ischemic Attack Prior to Onset of Stroke and Functional Ambulatory Outcome

BACKGROUND

Specific clinical risk factors linked to transient ischemic attack (TIA) could affect functional ambulatory outcome following thrombolytic therapy in patients having ischemic stroke with a prior TIA (TIA-ischemic stroke). This issue was investigated in this study.

METHODS

We retrospectively analyzed data from 6379 ischemic stroke patients of which 1387 presented with an antecedent TIA prior to onset of stroke. We used logistic regression model to identify demographic and clinical risk factors that are associated with functional ambulatory outcome in patients with TIA-ischemic stroke treated with thrombolytic therapy.

RESULTS

In a population of TIA-ischemic stroke who received recombinant tissue plasminogen activator, patients with a history of stroke (odds ratio [OR] = 3.229, 95% confidence interval [CI] = 1.494-6.98, P = .003) were associated with increasing odds of improvement in functional ambulation, while the female gender (OR = 0.462, 95% CI = 0.223-0.956, P = .037) was associated with reducing odds of improvement. In the non-TIA group, dyslipidemia (OR = 1.351, 95% CI = 1.026-1.781, P = .032) and blood glucose (OR = 1.003, 95% CI = 1.0-1.005, P = .041) were associated with the increasing odds of improvement while older patients (OR = 0.989, 95% CI = 0.98-0.999, P = .029) with heart failure (OR = 0.513, 95% CI = 0.326-0.808, P = .004) and higher lipid level (OR = 0.834, 95% CI = 0.728-0.955, P = .009) were associated with reducing odds of improvement in ambulation.

CONCLUSION

In a population of TIA-ischemic stroke with thrombolytic therapy and a clearly defined TIA without focal ischemic injury, regardless of associated clinical risk factors, a TIA prior to a stroke is not associated with reducing odds of improved ambulatory outcome, except in female patients with TIA-ischemic stroke.

Cardio embolic stroke and blood biomarkers: diagnosis and predictors of short-term outcome

Background

The brain is a productive source of a variety of enzymes and any brain injury like a stroke to brain tissue could similarly result in an increase in these enzymes in cerebrospinal fluid and serum. Evaluation of these enzymes represents a simple method for the ischemic stroke subtype diagnosis and prognosis. Objective: This study aimed to determine the role of brain natriuretic peptide (BNP), d-dimer, creatine–kinase-MB (CK-MB), C-reactive protein (CRP) serum levels, and globulin/albumin ratio in the diagnosis of CES stroke and its ability to predict short-term outcome.

Methods

This study was conducted on 96 patients with acute ischemic stroke, subdivided into two groups: group Ι was 48 patients with cardio-embolic stroke and group ΙΙ was 48 patients with non-cardio-embolic. All patients were subjected to the assessment of serum BNP, d-dimer and CK-MB, and CRP and globulin/albumin ratio within the first 24 h of stroke. In the third week, they were assessed by mRS.

Results

The mean levels of BNP, d-dimer level, and CK-MB were significantly higher in patients with cardio-embolic stroke than in patients with non-cardio-embolic stroke (P < 0.001) and also were associated with poor short-term outcome.

Conclusion

Elevated plasma levels of BNP, d-dimer levels, and CK-MB can be used as surrogate biomarkers for the diagnosis of cardio-embolic stroke and prediction of poor short-term outcomes.

The weekend effect revisited: evidence from the Upper Austrian stroke registry

Empirical evidence on the so-called 'weekend-effect' on stroke mortality is mixed with some studies reporting significantly higher mortality for weekend admissions and others finding no difference. The aim of this paper is to enhance the evidence on the weekend-effect on stroke mortality using a rich stroke registry data set from Upper Austria and to discuss underlying reasons for the heterogeneity in results. Using logistic regressions and ordinary least squares regressions with hospital and year-fixed effects, the outcomes of weekend versus weekday admissions are compared for patients admitted to 16 hospitals in Upper Austria with transient ischemic attack (TIA), cerebral infarction or hemorrhage between 2007 and 2015. The primary outcomes include in-hospital mortality, 30-day and 90-day all-cause mortality as well as the length of hospital stay. In addition, we analyze differences in process-quality indicators between weekdays and weekends. Our results show that on weekends there are on average 25% fewer admissions than on weekdays with significantly higher in-hospital mortality. Adjusting for case-mix, the association between weekend admissions and mortality becomes null suggesting that the higher mortality on weekends is explained by heterogeneities in admissions rather than health-care quality.

Rate and associated factors of transient ischemic attack misdiagnosis

Background and purpose

The goal of this study was to investigate the rate and associated factors of Transient Ischemic Attack (TIA) misdiagnosis.

Methods

We retrospectively analyzed consecutive patients with an initial diagnosis of TIA in the emergency department (ED) in a 9-month period. All hospitalized TIA patients were evaluated by a neurologist within 24 h and had at least one hospital discharge follow-up visit within three months. Patients' clinical data and neuroimaging were reviewed. The final diagnosis was independently verified by two stroke neurologists.

Results

Out of 276 patients with the initial diagnosis of TIA, 254 patients (mean age 68.7 ± 15.4 years, 40.9% male, 25.2% final diagnosis of TIA) were included in the analysis. Twenty-four patients (9.4%) were referred to our rapid-access TIA clinic. The rate of TIA misdiagnosis among TIA clinic referred patients was 45.8%. Among the 230 patients in inpatient setting, the rate of TIA misdiagnosis was 60.0%. A hospital discharge diagnosis of TIA was observed in 54.3% of hospitalized patients; however, only 24.8% had the final diagnosis of TIA. Among hospitalized patients, the univariate analysis suggests a significant difference (P < .05) between the two groups (correctly versus misdiagnosed patients) in terms of hospital discharge diagnosis, final diagnosis, history of diabetes mellitus, and coronary artery disease. In regression model hospital discharge diagnosis (P < .001), final diagnosis (P < .001), and diabetes mellitus (P = .018) retained independent association with TIA misdiagnosis.

Conclusion

Our study indicates a high rate of TIA misdiagnosis in the emergency department, hospital, and outpatient clinics.

•

We observed a high rate of TIA misdiagnosis in the ED, hospital, and outpatient clinics.

•

We did not observe any differences between correctly diagnosed and misdiagnosed TIAs in terms of ED presenting symptoms.

•

Small number of hospitalized TIA patients required an intervention or had a diagnosis that could justify hospitalization.

•

A rapid-access TIA clinic can relocate the care for low/medium-risk TIA patients from inpatient to outpatient setting.

Acute EEG Patterns Associated With Transient Ischemic Attack

BACKGROUND

Transient ischemic attack (TIA) is characterized by stroke-like neurologic signs and symptoms in the absence of demonstrable structural neuropathology. There is no test for TIA, with classification often reliant on subjective, retrospective report. Functional brain measures such as the electroencephalogram (EEG) may be helpful in objectively detecting and describing the pathophysiology of TIA, but this has not been adequately examined.

METHODS

EEG was obtained from a single electrode over the left frontal lobe during 3-minute resting-state and auditory oddball conditions administered to consecutive patients within 72 hours of admission to the acute stroke ward of a tertiary hospital. Separately, patients were classified by their treating team as having suffered either an ischemic stroke (n = 10) or a TIA (n = 10). Relative power of delta, theta, alpha, and beta EEG frequency bands were extracted for comparison between the 2 clinical groups and an existing normative sample of 10 healthy, age-, gender-, and education-matched older adults.

RESULTS

Analysis of variance with post hoc testing identified pronounced delta activity in stroke patients, while alpha and beta power were elevated in TIA patients. Both patient groups exhibited attenuated theta activity compared with healthy controls. Receiver operating characteristic curve analysis identified thresholds for each EEG frequency capable of distinguishing the 3 participant groups.

CONCLUSIONS

TIA, ischemic stroke, and healthy aging are each associated with distinct electrophysiological profiles. These preliminary findings suggest that acute EEG may be helpful in elucidating the pathophysiology and reversibility of TIA symptoms, and further exploration of the value of this unique functional brain data is encouraged.

Galectins in the Pathogenesis of Cerebrovascular Accidents: An Overview

Due to limitations of neuroimaging, such as the isodense appearance of blood to neuronal tissue in subacute hemorrhagic stroke, a body of studies have been performed to evaluate candidate biomarkers which may aid in accurate determination of cerebrovascular accident type. Beyond aiding in the delineation of stroke cause, biomarkers could also confer useful prognostic information to help clinicians plan use of resources. One of the candidate biomarkers studied for detection of cerebrovascular accident (CVA) includes a class of proteins called galectins. Galectins bind β-galactoside through a highly conserved carbohydrate recognition domain, endowing an ability to interact with carbohydrate moieties on glycoproteins, some of which are relevant to CVA response. Furthermore, galectins-1, -2, -3, -9, and -12 are expressed in tissues relevant to CVA, and some exhibit characteristics (eg, extracellular secretion) that could render feasible their detection in serum. Galectins-1 and -3 appear to have the largest amounts of preclinical evidence, consistently demonstrating increased activity and expression levels during CVA. However, a lack of standardization of biochemical assays across cohort studies limits further translation of these basic science studies. This review aims to increase awareness of the biochemical roles of galectins in CVA, while also highlighting challenges and remaining questions preventing the translation of basic science observations into a clinically useful test.

The Impact of Transient Ischemic Attack (TIA) on Brain and Behavior

Transient ischemic attack (TIA) was originally defined as self-resolving focal cerebral ischemia with symptoms lasting <24 h. The newer definition also added the limitation that there should be no evidence of acute brain tissue infarction, to recognize that acute injury to the brain can result from ischemia of <24-h duration. However, several recent findings suggest that having a TIA correlates with deficits that can persist far beyond the resolution of clinical symptoms, even in the absence of imaging evidence of ischemic tissue injury. These deficits may be the result of subtle perturbations to brain structure and/or function that are not easily appreciated using the standard clinical and imaging tools that are currently employed in practice. Here, we will discuss evidence that suggests that TIA may lead to lasting changes to the structure and function of the brain.

Brain Functional Reserve in the Context of Neuroplasticity after Stroke

Stroke is the second cause of death and more importantly first cause of disability in people over 40 years of age. Current therapeutic management of ischemic stroke does not provide fully satisfactory outcomes. Stroke management has significantly changed since the time when there were opened modern stroke units with early motor and speech rehabilitation in hospitals. In recent decades, researchers searched for biomarkers of ischemic stroke and neuroplasticity in order to determine effective diagnostics, prognostic assessment, and therapy. Complex background of events following ischemic episode hinders successful design of effective therapeutic strategies. So far, studies have proven that regeneration after stroke and recovery of lost functions may be assigned to neuronal plasticity understood as ability of brain to reorganize and rebuild as an effect of changed environmental conditions. As many neuronal processes influencing neuroplasticity depend on expression of particular genes and genetic diversity possibly influencing its effectiveness, knowledge on their mechanisms is necessary to understand this process. Epigenetic mechanisms occurring after stroke was briefly discussed in this paper including several mechanisms such as synaptic plasticity; neuro-, glio-, and angiogenesis processes; and growth of axon.

A Novel Model for Studying Voltage-Gated Ion Channel Gene Expression during Reversible Ischemic Stroke

The dysfunction of voltage-gated ion channels contributes to the pathology of ischemic stroke. In this study, we developed rat models of transient ischemic attack (TIA) and reversible ischemic neurological deficit (RIND) that was induced via the injection of artificial embolic particles during full consciousness, that allow us to monitor the neurologic deficit and positron emission tomography (PET) scans in real-time. We then evaluated the infarction volume of brain tissue was confirmed by 2,3,5-triphenyl tetrazolium chloride (TTC) staining, and gene expressions were evaluated by quantitative real-time PCR (qPCR). We found that rats with TIA or RIND exhibited neurological deficits as determined by negative TTC and PET findings. However, the expression of voltage-gated sodium channels in the hippocampus was significantly up-regulated in the qPCR array study. Furthermore, an altered expression of sodium channel β-subunits and potassium channels, were observed in RIND compared to TIA groups. In conclusion, to our knowledge, this is the first report of the successful evaluation of voltage-gated ion channel gene expression in TIA and RIND animal models. This model will aid future studies in investigating pathophysiological mechanisms, and in developing new therapeutic compounds for the treatment of TIA and RIND.

Elevated Levels of Serum β2-Glycoprotein I/Oxidized Low-Density Lipoprotein Complexes Are Associated with Cerebral Infarction in Patients with Type 2 Diabetes Mellitus

Background

To determine whether the levels of β2-glycoprotein I (β2-GPI)/oxidized low-density lipoprotein (oxLDL) complexes are correlated with cerebral infarction in patients with type 2 diabetes mellitus (T2DM).

Material/Methods

The levels of β2-GPI/oxLDL complexes, oxLDL, routine lipid/lipoprotein parameters, oxidative stress molecules, and inflammatory factors were measured in 78 healthy controls, 82 diabetics without cerebral infarction, and 79 diabetics with cerebral infarction. Correlation, multiple linear regression, and logistic regression analyses were performed.

Results

Serum β2-GPI/oxLDL complexes and oxLDL levels were significantly elevated in cerebral infarction in patients with T2DM (β2-GPI/oxLDL: 1.09±0.16 U/mL; oxLDL: 47.83±8.17 mmol/L) compared with T2DM without cerebral infarction (β2-GPI/oxLDL: 0.95±0.13 U/mL; oxLDL: 41.24±7.12 mmol/L) and healthy controls (β2-GPI/oxLDL: 0.81±0.12 U/mL; oxLDL: 27.97±4.57 mmol/L). The levels of β2-GPI/oxLDL complex in lacunar infarction (1.16±0.15 U/ml) were significantly higher than atherothrombotic infarction (1.07±0.19 U/ml) and cardioembolic infarction (1.00±0.23 U/ml). In all patients with T2DM, the β2-GPI/oxLDL levels were positively correlated with total cholesterol (r=0.474, p=0.001) and triglycerides (r=0.431, p=0.003). oxLDL levels were positively correlated with total cholesterol (r=0.445, p=0.002). The logistic regression analysis indicated that elevated β2-GPI/oxLDL and oxLDL levels were independently associated with diabetic cerebral infarction.

Conclusions

Elevated levels of serum β2-GPI/oxLDL complexes are associated with cerebral infarction in patients with T2DM, especially in those with lacunar infarction.

Imaging of Ischemic Stroke

PURPOSE OF REVIEW

This article provides an overview of cerebrovascular hemodynamics, acute stroke pathophysiology, and collateral circulation, which are pivotal in the modern imaging of ischemic stroke that guides the care of the patient with stroke.

RECENT FINDINGS

Neuroimaging provides extensive information on the brain and vascular health. Multimodal CT and MRI delineate the hemodynamics of ischemic stroke that may be used to guide treatment decisions and prognosticate regarding expected outcomes. Mismatch imaging with either CT or MRI may identify patients with salvageable regions who are at risk and likely to benefit from reperfusion therapy, even if they are outside the standard time window. Imaging of collateral circulation and determination of collateral grade may predict greater reperfusion, lower hemorrhage risk, and better functional outcome. Current neuroimaging technology also enables the identification of patients at high risk of hemorrhagic transformation or those who may be harmed by treatment or unlikely to benefit from it.

SUMMARY

This article reviews the use and impact of imaging for the patient with ischemic stroke, emphasizing how imaging builds upon clinical evaluation to establish diagnosis or etiology, reveal key pathophysiology, and guide therapeutic decisions.

Motor Impairments in Transient Ischemic Attack Increase the Odds of a Subsequent Stroke: A Meta-Analysis

Background and purpose

Transient ischemic attack (TIA) increases the risk for a subsequent stroke. Typical symptoms include motor weakness, gait disturbance, and loss of coordination. The association between the presence of motor impairments during a TIA and the chances of a subsequent stroke has not been examined. In the current meta-analysis, we examine whether the odds of a stroke are greater in TIA individuals who experience motor impairments as compared with those who do not experience motor impairments.

Methods

We conducted a systematic search of electronic databases as well as manual searches of the reference lists of retrieved articles. The meta-analysis included studies that reported an odds ratio relating motor impairments to a subsequent stroke, or the number of individuals with or without motor impairments who experienced a subsequent stroke. We examined these studies using rigorous meta-analysis techniques including random effects model, forest and funnel plots, I², publication bias, and fail-safe analysis.

Results

Twenty-four studies with 15,129 participants from North America, Australia, Asia, and Europe qualified for inclusion. An odds ratio of 2.11 (95% CI, 1.67–2.65, p = 0.000) suggested that the chances of a subsequent stroke are increased by twofolds in individuals who experience motor impairments during a TIA compared with those individuals who have no motor impairments.

Conclusion

The presence of motor impairments during TIA is a significantly high-risk clinical characteristic for a subsequent stroke. The current evidence for motor impairments following TIA relies exclusively on the clinical reports of unilateral motor weakness. A comprehensive examination of motor impairments in TIA will enhance TIA prognosis and restoration of residual motor impairments.

THE STRUCTURAL FEATURES OF VASCULAR ENDOTHELIUM IN ACUTE CEREBRAL ISCHEMIA

The aim of the research was to study the number and structural properties of desquamated endothelial cells (DECs) in the peripheral blood in carotid ischemic stroke (CIS) and carotid transient ischemic attacks (TIAs) and its connection with the marker of endothelial dysfunction - endothelin-1. We examined 35 patients with the first CIS, on days 1st and 10th, and also 34 patients with symptomatic carotid TIAs, on days 1st and 10th of the observation. Middle age of the examined patients with a CIS was 63,7±1,0. Middle age of the examined patients with the ТIАs was 54,7±1,0. 25 practically healthy persons were examined as a group of control. Neurologic deficit was assessed with the National Institutes of Health Stroke Scale (NIHSS). DECs were estimated by CD34 immunobead capture in the peripheral venous blood of patients and persons of control group. We studied the level of endothelin-1 in the peripheral venous blood of patients and persons of control group using the enzyme immunoassay using the Biomedica (Austria) during the first 24 hrs and on day 10. Statistical processing of the obtained results was carried out using statistical analysis package Statistica. In this case, the mean value, the standard error and the correlation analysis were determined. Samples were compared using the Student's criterion (t) and the correlation coefficient (r). During an examination of 35 patients in the acute period of CIS and 34 patients with carotid TIAs using the immunocytochemical method the number of DECs was studied in venous blood. The quantitative analysis of vascular endothelium in acute cerebral ischemias showed its statistically unreliable differences in CIS and TIAs. A conclusion is drawn about the general mechanisms of endothelial dysfunction in CIS and TIAs. The number of DECs significantly correlates with the terms of disease. Regress of this indicator is noted in patients by the end of follow-up in both observation groups. During the first 24 hrs in patients with CIS and TIAs density of DECs of blood directly correlates with the level of endothelin-1 blood. The endothelin-1 level tends to decrease by the 10th day of observation and the correlation force with the DECs level is correspondingly reduced.

CHADS2 and CHA2DS2-VASc Scores Predict the Risk of Ischemic Stroke Outcome in Patients with Interatrial Block without Atrial Fibrillation

Aim: To evaluate the role of CHADS₂ and CHA₂DS₂-VASc scores in predicting the risk of ischemic stroke or transient ischemic attack (TIA) outcomes in patients with interatrial block (IAB) without a history of atrial fibrillation (AF).

Methods: A retrospective study was conducted, including 1,046 non-anticoagulated inpatients (612 males, 434 females; mean age: 63 ± 10 years) with IAB and without AF. IAB was defined as P-wave duration > 120 ms using a 12-lead electrocardiogram. CHADS₂ and CHA₂DS₂-VASc scores were retrospectively calculated. The primary outcomes evaluated were ischemic stroke or TIA.

Results: During the mean follow-up period of 4.9 ± 0.7 years, 55 (5.3%) patients had an ischemic stroke or TIA. Receiver operating characteristic (ROC) curve analysis showed that the CHADS₂ score [area under the curve (AUC), 0.638; 95% confidence interval (CI), 0.562–0.715; P = 0.001] and the CHA₂DS₂-VASc score (AUC, 0.671; 95% CI, 0.599–0.744; P <0.001) were predictive of ischemic strokes or TIA. Cut-off point analysis showed that a CHADS₂ score ≥ 3 (sensitivity = 0.455 and specificity = 0.747) and a CHA₂DS₂-VASc score ≥ 4 (sensitivity = 0.564 and specificity = 0.700) provided the highest predictive value for ischemic stroke or TIA. The multivariate Cox regression analysis showed that CHADS₂ [hazard ratio (HR), 1.442; 95% CI, 1.171–1.774; P = 0.001] and CHA₂DS₂-VASc (HR, 1.420; 95% CI, 1.203–1.677; P <0.001) scores were independently associated with ischemic stroke or TIA following adjustment for smoking, left atrial diameter, antiplatelet agents, angiotensin inhibitors, and statins.

Conclusions: CHADS₂ and CHA₂DS₂-VASc scores may be predictors of risk of ischemic stroke or TIA in patients with IAB without AF.

Carotid intervention following transient ischaemic attack: What are we waiting for?

Transient ischaemic attack secondary to carotid stenosis has the highest risk of stroke recurrence compared with other aetiological subtypes. International guidelines advocate carotid intervention within one to two weeks of the index neurological event. Traditionally, delayed carotid intervention was perceived to be a safer management strategy, yet classic trials of endarterectomy and recent meta-analysis of carotid intervention demonstrate the safety of hyperacute carotid intervention. Data from international studies suggest that targets are not being met, the reasons for which are multifactorial, but patients suffering transient or ocular symptoms are particularly delayed. Efforts should be made to conduct regional studies investigating the root causes of delayed intervention, with subsequent policy adjustment to expedite intervention, and interim optimisation of medical management to reduce the incidence of recurrent stroke.

Validation of the RRE-90 Scale to Predict Stroke Risk after Transient Symptoms with Infarction: A Prospective Cohort Study

Background and Purpose

The risk of stroke after a transient ischemic attack (TIA) for patients with a positive diffusion-weighted image (DWI), i.e., transient symptoms with infarction (TSI), is much higher than for those with a negative DWI. The aim of this study was to validate the predictive value of a web-based recurrence risk estimator (RRE; http://www.nmr.mgh.harvard.edu/RRE/) of TSI.

Methods

Data from the prospective hospital-based TIA database of the First Affiliated Hospital of Zhengzhou University were analyzed. The RRE and ABCD² scores were calculated within 7 days of symptom onset. The predictive outcome was ischemic stroke occurrence at 90 days. The receiver-operating characteristics curves were plotted, and the predictive value of the two models was assessed by computing the C statistics.

Results

A total of 221 eligible patients were prospectively enrolled, of whom 46 (20.81%) experienced a stroke within 90 days. The 90-day stroke risk in high-risk TSI patients (RRE ≥4) was 3.406-fold greater than in those at low risk (P <0.001). The C statistic of RRE (0.681; 95% confidence interval [CI], 0.592–0.771) was statistically higher than that of ABCD² score (0.546; 95% CI, 0.454–0.638; Z = 2.115; P = 0.0344) at 90 days.

Conclusion

The RRE score had a higher predictive value than the ABCD² score for assessing the 90-day risk of stroke after TSI.

B-Type Natriuretic Peptides Help in Cardioembolic Stroke Diagnosis

Background and Purpose—

Determining the underlying cause of stroke is important to optimize secondary prevention treatment. Increased blood levels of natriuretic peptides (B-type natriuretic peptide/N-terminal pro-BNP [BNP/NT-proBNP]) have been repeatedly associated with cardioembolic stroke. Here, we evaluate their clinical value as pathogenic biomarkers for stroke through a literature systematic review and individual participants’ data meta-analysis.

Methods—

We searched publications in PubMed database until November 2013 that compared BNP and NT-proBNP circulating levels among stroke causes. Standardized individual participants’ data were collected to estimate predictive values of BNP/NT-proBNP for cardioembolic stroke. Dichotomized BNP/NT-proBNP levels were included in logistic regression models together with clinical variables to assess the sensitivity and specificity to identify cardioembolic strokes and the additional value of biomarkers using area under the curve and integrated discrimination improvement index.

Results—

From 23 selected articles, we collected information of 2834 patients with a defined cause. BNP/NT-proBNP levels were significantly elevated in cardioembolic stroke until 72 hours from symptoms onset. Predictive models showed a sensitivity >90% and specificity >80% when BNP/NT-proBNP were added considering the lowest and the highest quartile, respectively. Both peptides also increased significantly the area under the curve and integrated discrimination improvement index compared with clinical models. Sensitivity, specificity, and precision of the models were validated in 197 patients with initially undetermined stroke with final pathogenic diagnosis after ancillary follow-up.

Conclusions—

Natriuretic peptides are strongly increased in cardioembolic strokes. Future multicentre prospective studies comparing BNP and NT-proBNP might aid in finding the optimal biomarker, the best time point, and the optimal cutoff points for cardioembolic stroke identification.

Predictors of anxiety after stroke: a systematic review of observational studies

BACKGROUND

Anxiety disorders or symptoms are relatively common after stroke. A better understanding of the predictors of anxiety in stroke patients may improve the management of these disorders. The current review was conducted to determine the predictors of anxiety after stroke.

METHODS

Relevant articles concerning population, hospital, or rehabilitation-based studies were identified by searching 10 electronic databases up to May 2014. Methodological quality appraisal, including the validity of prognostic models and data extraction were conducted by 3 reviewers.

RESULTS

A total of 18 studies were identified. Data from 3 population-based studies including 8130 patients, 8 hospital-based studies including 1199 patients, and 7 rehabilitation-based studies including 1103 patients were evaluated. Prestroke depression, stroke severity, early anxiety, and dementia or cognitive impairment after stroke were the main predictors of poststroke anxiety. Older age, physical disability or impairment, and use of antidepressant drugs were not associated with the presence of anxiety. Limitations of studies included wide variation in screening tools and cutoff scores, variability in the time frame of screening for anxiety, use of extensive exclusion criteria, and questionable statistical internal and external validity of the models.

CONCLUSIONS

Lack of methodological and statistical rigor affects the validity of proposed models to predict anxiety after stroke. Future research should focus on testing proposed models on both internal and external samples to ultimately inform future clinical practice.

Thrombin generation in acute cardioembolic and non-cardioembolic ischemic stroke

OBJECTIVE

Increased thrombin generation, as measured by the Calibrated Automated Thrombogram (CAT), has recently been reported to predict ischemic stroke, especially stroke with a cardioembolic source. However, there are few studies on thrombin generation using CAT in patients with manifest ischemic stroke, particularly in patients with cardioembolic stroke not yet on anticoagulation.

MATERIALS AND METHODS

Therefore, a prospective cohort study of 205 stroke patients > 45 years of age was performed. They were recruited during their hospital stay or shortly thereafter. Inclusion criteria were ischemic stroke or TIA within two weeks and no atrial fibrillation (AF) in the history or at inclusion. Patients received a thumb ECG device in order to detect silent AF. Blood samples were collected at inclusion and after 1 month. Thrombin generation in plasma after addition of tissue factor was assessed in patients and in healthy controls.

RESULTS

Mean age of patients was 72 ± 7 years and 43% were females. Peak thrombin concentrations were variable among stroke patients but overall significantly higher at both time points (p < 0.0001) compared to controls, and tended to be highest in patients in whom paroxysmal atrial fibrillation was subsequently documented.

CONCLUSION

Thrombin generation in patients with acute cardioembolic and non-cardioembolic schemic stroke/TIA is variable but overall higher compared to healthy subjects. The long-term prognostic value of thrombin generation in patients with a recent ischemic stroke deserves further investigation.

Transient Focal Neurological Episodes, Cerebral Amyloid Angiopathy, and Intracerebral Hemorrhage Risk: Looking beyond TIAs

When most doctors encounter older patients with transient focal neurological symptoms, they usually suspect a diagnosis of transient ischemic attacks or some of their known mimics (including migraine auras or focal seizures). This article emphasizes new observations on transient focal neurological episodes in the context of cerebral amyloid angiopathy, a common but under-recognized small vessel disease most often encountered as a cause of symptomatic lobar intracerebral hemorrhage. Transient focal neurological episodes in cerebral amyloid angiopathy are of clinical and pathophysiological interest because they can mimic transient ischemic attacks, but are probably more often related to bleeding (especially superficial cortical siderosis or focal convexity sub-arachnoid hemorrhage) rather than ischemia. Importantly, such episodes may also herald a very high future risk of symptomatic intracerebral hemorrhage. The article highlights scenarios encountered in clinical practice and discusses implications for patient care including: (a) the value of blood-sensitive magnetic resonance imaging sequences in investigating transient focal neurological episodes; and (b) treatment implications, as giving antiplatelet or anticoagulant drugs for these episodes could increase the risk of serious intracerebral hemorrhage.