Stroke of undetermined cause: workup and secondary prevention. Curr Opin Neurol. 2016;29:4-8. [PMID: 26641813 DOI: 10.1097/wco.0000000000000280]

Increased plasma levels of N-terminal pro-B-type natriuretic peptide as biomarker for the diagnosis of cardioembolic ischaemic stroke

BACKGROUND

Despite comprehensive study, the aetiology of stroke is not identified in 35% of cases.

AIMS

We conducted a study to assess the diagnostic capacity of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in the identification of ischaemic stroke of cardioembolic origin. The secondary purpose of the study was to evaluate the prognostic value of NT-proBNP for predicting 90-day all-cause mortality.

METHODS

We designed a prospective observational study including patients hospitalised due to stroke between March 2019 and March 2020. Blood samples were collected on admission to the emergency department and serum NT-proBNP levels were determined. Statistical analysis was performed using a bivariate logistic regression model and receiver operating characteristic (ROC) and Kaplan-Meier curves. Statistical significance was established at p<.05.

RESULTS

The study included 207 patients with first ischaemic stroke. Plasma NT-proBNP levels were significantly higher (p<.001) in the cardioembolic stroke group (2069pg/mL±488.5). ROC curves showed that NT-proBNP>499pg/mL was the optimum value for diagnosing cardioembolic ischaemic stroke (sensitivity, 82%; specificity, 80%). Moreover, plasma NT-proBNP levels>499pg/mL were independently associated with cardioembolic stroke (OR: 9.881; p=.001). Finally, NT-proBNP>1500pg/mL was useful for predicting 90-day mortality (sensitivity, 70%; specificity, 93%).

CONCLUSIONS

NT-proBNP was independently associated with cardioembolic stroke and should be quantified in blood tests within 24h of stroke onset. High plasma levels (>499pg/mL) may indicate an underlying cardioembolic cause, which should be further studied, while NT-proBNP >1500pg/mL was associated with increased 90-day mortality.

Effect of stroke etiology on endovascular thrombectomy with or without intravenous alteplase: a subgroup analysis of DIRECT-MT

BACKGROUND

Stroke etiology might influence the clinical outcomes in patients with large vessel occlusion receiving endovascular treatment (EVT) with or without thrombolysis.

OBJECTIVE

To examine whether stroke etiology resulted in different efficacy and safety in patients treated with EVT-alone or EVT preceded by intravenous alteplase (combined therapy).

METHODS

We assessed the efficacy and safety of treatment strategy based on prespecified stroke etiology, cardioembolism (CE), large-artery atherosclerosis (LAA), and undetermined cause (UC) for patients enrolled in the DIRECT-MT trial. The primary outcome was the modified Rankin Scale (mRS) score at 90 days. Multivariate ordinal logistic regression analysis was used to calculate the adjusted common OR for a shift of better mRS score for EVT-alone versus combined therapy. A term was entered to test for interaction.

RESULTS

In this study, 656 patients were grouped into three prespecified stroke etiologic subgroups. The adjusted common ORs for improvement in the 90-day ordinal mRS score with EVT-alone were 1.2 (95% CI 0.8 to 1.8) for CE, 1.6 (95% CI 0.8 to 3.3) for LAA, and 0.8 (95% CI 0.5 to 1.3) for UC. Compared with CE, EVT-alone was more likely to result in an mRS score of 0-1 (p_interaction=0.047) and extended Thrombolysis in Cerebral Infarction ≥2b (p_interaction=0.041) in the LAA group. The differences in mortality and symptomatic intracranial hemorrhage within 90 days were not significant between the subgroups (p＞0.05).

CONCLUSIONS

The results did not support the hypothesis that a specific treatment strategy based on stroke etiology should be used for patients with large vessel occlusion (NCT03469206).

Role of imaging in early diagnosis of acute ischemic stroke: a literature review

Stroke is a serious health condition that is responsible for more than 5% of total deaths. Near 20% of patients experiencing stroke die every year, resulting in the stroke being at the top of the list of preventable causes of death. Once an acute stroke is suspected, a golden hour of less than an hour is available to prevent the undesirable consequences. Since neuroimaging is mandatory in the diagnosis of stroke, the proper use of neuroimaging could help saving time and planning the right treatment for the patient. Some of the available imaging methods help us with rapid results, while others benefit us from a more accurate diagnosis. Hereby, we aim to provide a clinical review of the advantages and disadvantages of different available neuroimaging methods in approaching acute stroke to help clinicians choose the best method according to the settings.

Prevalence of the Frank's sign by aetiopathogenic stroke subtype: A prospective analysis

BACKGROUND AND PURPOSE

The Frank's sign is a diagonal earlobe crease running from the tragus to the edge of the auricle at an angle of 45°. Many studies have associated this sign with coronary artery disease and some with cerebrovascular disease. The objective of this study was to analyse the prevalence of the Frank's sign in patients suffering from acute stroke with a particular focus on its prevalence in each of the five aetiopathogenic stroke subtypes. Special interest is given to embolic stroke of undetermined source (ESUS), correlating the sign with clinical and radiological markers that support an underlying causal profile in this subgroup.

METHODS

Cross-sectional descriptive study including 124 patients admitted consecutively to a stroke unit after suffering an acute stroke. The Frank's sign was evaluated by the same blinded member of the research team from photographs taken of the patients. The stroke subtype was classified following SSS-TOAST criteria and the aetiological study was performed following the ESO guidelines.

RESULTS

The Frank's sign was present in 75 patients and was more prevalent in patients with an ischaemic stroke in comparison with haemorrhagic stroke (63.9 vs. 37.5, p<0.05). A similar prevalence was found in the different ischaemic stroke subtypes. The Frank's sign was significantly associated with age, particularly in patients older than 70 who had vascular risk factors. Atherosclerotic plaques found in carotid ultrasonography were significantly more frequent in patients with the Frank's sign (63.6%, p<0.05). Analysing the ESUS, we also found an association with age and a higher prevalence of the Frank's sign in patients with vascular risk factors and a tendency to a high prevalence of atherosclerosis markers.

CONCLUSION

The Frank's sign is prevalent in all aetiopathogenic ischaemic stroke subtypes, including ESUS, where it could be helpful in suspecting the underlying cardioembolic or atherothrombotic origin and guiding the investigation of atherosclerosis in patients with ESUS and the Frank's sign.

Absent Left Anterior Descending Coronary Artery as a Potential Cause of Ischemic Stroke: A Case Report

BACKGROUND Embolic stroke of undetermined source (ESUS) represents 20-30% of ischemic strokes, with a high risk of recurrence. It usually requires an extensive diagnostic evaluation to address the potential etiologies. Coronary artery anomaly (CAA) of the left anterior descending artery (LAD) is uncommon, and it is known to be linked to myocardial complications. The association of this anomaly with ischemic strokes has not been reported yet. Here, we report on a rare case of a young patient with hypoplastic LAD complicated by an impaired ventricular function that resulted in left ventricular (LV) thrombus formation as a source of recurrent ischemic strokes. CASE REPORT A 36-year-old man had a 4-year history of recurrent strokes despite maintaining antiplatelet treatment. He had no pre-existing vascular risk factors or relevant family history. The initial stroke etiology work-up was inconclusive. A transesophageal echocardiogram showed moderate ventricular hypokinesia. A coronary angiogram was initiated, and a hypoplastic (LAD) artery anomaly was found. At first, the antiplatelet therapy was maintained. Later on, he presented with transient focal neurological symptoms indicative of a transient ischemic attack. Repeated echocardiograms detected left ventricular thrombus. Apixaban was started, with successful thrombus resolution in a one-month follow-up echocardiogram. He has not had a further recurrent ischemic event for 18 months. CONCLUSIONS This case suggests that CAAs might be considered as an associated etiology of ESUS in a young patient with recurrent cerebral events. In a clinical setting, we encourage early use of advanced cerebral and cardiac imaging modalities to accurately determine the stroke etiology, target the appropriate treatment, and prevent a further neurological sequel.

Treatment of neuropsychiatric systemic lupus erythematosus: clinical challenges and future perspectives

Introduction: Neuropsychiatric (NP) involvement represents an emerging frontier in systemic lupus erythematosus (SLE), posing significant challenges due to its clinical diversity and obscure pathophysiology. The authors herein discuss selected aspects in the management of NPSLE based on existing literature and our experience, aiming to facilitate routine medical care.Areas covered: Research related to diagnosis, neuroimaging, treatment and outcome is discussed, focusing on data published in PubMed during the last 5 years. Selected translational studies of clinical relevance are included.Expert opinion: Identification of NPSLE patients who may benefit from appropriate treatment can be facilitated by attribution algorithms. Immunosuppressants are typically indicated in recurrent seizures, optic neuritis, myelopathy, psychosis and peripheral nerve disease, although a low threshold is recommended for cerebrovascular disease and other NP manifestations, especially when SLE is active. With the exception of stroke with positive antiphospholipid antibodies, anti-coagulation is rarely indicated in other syndromes. Refractory NPSLE can be treated with rituximab, whereas the role of other biologics remains unknown. Advances in the fields of biomarkers, neuroimaging for brain structural, perfusion or functional abnormalities, and design of novel compounds targeting not only systemic autoimmunity but also inflammatory and regenerative pathways within the nervous system, hold promise for optimizing NPSLE management.

RNA expression studies in stroke: what can they tell us about stroke mechanism?

PURPOSE OF REVIEW

Diagnosis of stroke and understanding the mechanism of stroke is critical to implement optimal treatment. RNA expressed in peripheral blood cells is emerging as a precision biomarker to aid in stroke diagnosis and prediction of stroke cause. In this review, we summarize available data regarding the role of RNA to predict stroke, the rationale for these changes, and a discussion of novel mechanistic insight and clinical applications.

RECENT FINDINGS

Differences in RNA gene expression in blood have been identified in patients with stroke, including differences to distinguish ischemic from hemorrhagic stroke, and differences between cardioembolic, large vessel atherosclerotic, and small vessel lacunar stroke cause. Gene expression differences show promise as novel stroke biomarkers to predict stroke of unclear cause (cryptogenic stroke). The differences in RNA expression provide novel insight to stroke mechanism, including the role of immune response and thrombosis in human stroke. Important insight to regulation of gene expression in stroke and its causes are being acquired, including alternative splicing, noncoding RNA, and microRNA.

SUMMARY

Improved diagnosis of stroke and determination of stroke cause will improve stroke treatment and prevention. RNA biomarkers show promise to aid in the diagnosis of stroke and cause determination, as well as providing novel insight to mechanism of stroke in patients. While further study is required, an RNA profile may one day be part of the stroke armamentarium with utility to guide acute stroke therapy and prevention strategies and refine stroke phenotype.

The value of STAF (Score for the Targeting of Atrial Fibrillation) in Patients with Cryptogenic Embolic Stroke

Introduction

The aim of the present study was to predict paroxysmal atrial fibrillation (PAF) in acute ischemic stroke patients with presumed cryptogenic embolic etiology.

Methods

In this retrospective cohort study, demographics, blood tests, data of neuroimaging studies such as non-contrast computed tomography (NCCT), magnetic resonance imaging (MRI), standard 12-lead electrocardigraphy (ECG), 24-hour Holter ECG, echocardiography was collected. The diagnostic work-up to detect atrial fibrillation (AF) was either medical history of the patient or 12-lead ECG or 24-hour Holter ECG or continuous ECG monitoring. Score for the targeting of atrial fibrillation (STAF) was calculated for all patients. Cryptogenic ischemic stroke (CS) patients with and without documented AF were recorded.

Results

Between July 2014 and December 2015, a total of 133 of the 258 patients with CS were included in this study. Overall, 133 patients were enrolled and AF was detected in 30 (22.6%) patients. In univariate analysis gender (p<0.001), age (p=0.001), smoking habit (p=0.004), aortic and mitral valve insufficiency (p=0.014 and p=0.021), left ventricular systolic dysfunction (p=0.04), and left atrial dilatation (p=0.03) were predictors of AF but multivariate analysis showed that only gender and age were independent predictors of AF in patients with presumed cryptogenic ischemic stroke. According to ROC analysis, area under the curve was 70% and the sensitivity and specificity of STAF score of ≥5 was 86% and 71% respectively.

Conclusion

STAF score predicted with fair accuracy, and has a limited use for the risk of PAF in stroke patients.

Microembolic signal detection by transcranial Doppler: Old method with a new indication

Transcranial Doppler (TCD) is useful for investigation of intracranial arterial blood flow and can be used to detect a real-time embolic signal. Unfortunately, artefacts can mimic the embolic signal, complicating interpretation and necessitating expert-level opinion to distinguish the two. Resolving this situation is critical to achieve improved accuracy and utility of TCD for patients with disrupted intracranial arterial blood flow, such as stroke victims. A common type of stroke encountered in the clinic is cryptogenic stroke (or stroke with undetermined etiology), and patent foramen ovale (PFO) has been associated with the condition. An early clinical trial of PFO closure effect on secondary stroke prevention failed to demonstrate any benefit for the therapy, and research into the PFO therapy generally diminished. However, the recent publication of large randomized control trials with demonstrated benefit of PFO closure for recurrent stroke prevention has rekindled the interest in PFO in patients with cryptogenic stroke. To confirm that emboli across the PFO can reach the brain, TCD should be applied to detect the air embolic signal after injection of agitated saline bubbles at the antecubital vein. In addition, the automated embolic signal detection method should further facilitate use of TCD for air embolic signal detection after the agitated saline bubbles injection in patients with cryptogenic stroke and PFO.

Subpixel x-ray imaging with an energy-resolving detector

The detector pixel size can be a severe limitation in x-ray imaging of fine details in the human body. We demonstrate a method of using spectral x-ray measurements to image the spatial distribution of the linear attenuation coefficient on a length scale smaller than one pixel, based on the fact that interfaces parallel to the x-ray beam have a unique spectral response, which distinguishes them from homogeneous materials. We evaluate the method in a simulation study by simulating projection imaging of the border of an iodine insert with [Formula: see text] in a soft tissue phantom. The results show that the projected iodine profile can be recovered with an RMS resolution of 5% to 34% of the pixel size, using an ideal energy-resolving detector. We also validate this method in an experimental study by imaging an iodine insert in a polyethylene phantom using a photon-counting silicon-strip detector. The results show that abrupt and gradual transitions can be distinguished based on the transmitted x-ray spectrum, in good agreement with simulations. The demonstrated method may potentially be used for improving visualization of blood vessel boundaries, e.g., in acute stroke care.

Stroke prevention

Patients who have had a stroke are at high risk for recurrent stroke, myocardial infarction, and vascular death. Prevention of these events should be initiated promptly after stroke, because many recurrent events occur early, and should be tailored to the precise cause of stroke, which may require specific treatment. Lifestyle advice including abstinence from smoking, regular exercise, Mediterranean-style diet, and reduction of salt intake and alcohol consumption are recommended for all patients with stroke. For most patients with ischemic stroke or TIA, control of risk factors, including lowering blood pressure under 140/90mmHg and LDL cholesterol under 1g/L, together with antiplatelet or oral anticoagulant therapy, depending on the cause of stroke, have been shown to decrease the risk of recurrent stroke and cardiovascular events. Aspirin, clopidogrel, or the combination of aspirin and dipyridamole, are all acceptable options for secondary prevention in patients with ischemic stroke or TIA of arterial origin. Dual therapy with aspirin and clopidogrel might be considered for 3 weeks after a minor ischemic stroke or TIA and for 3 months in patients with stroke due to severe intracranial stenosis. Oral anticoagulants are very effective to prevent cardioembolic stroke. Non-VKA oral anticoagulants have a favorable risk-benefit profile compared with VKAs, with significant reductions in stroke, intracranial hemorrhage, mortality, with similar major bleeding, but increased gastrointestinal bleeding. Carotid endarterectomy reduces the risk of ipsilateral stroke in patients with recent (<6 months) non disabling ischemic stroke or TIA in the territory and severe carotid artery stenosis. Carotid stenting is a potential alternative to surgery in patients younger than ≈70 years or patients with greater risk of surgery due to anatomic or medical conditions or specific circumstances such as radiation-induced stenosis or restenosis after surgery. For patients with hemorrhagic stroke due to hypertension-associated small vessel disease or cerebral amyloid angiopathy, strict control of blood pressure is essential. Restarting oral anticoagulants in patients after intracranial hemorrhage is a difficult decision that should weigh the risks of recurrent ischemic and hemorrhage stroke with and without oral anticoagulants. Several areas of uncertainty persist including the optimal target of blood pressure in patients with cerebrovascular disease, the benefit of PFO closure in patients with PFO-associated stroke, of stenting procedures in patients with atherosclerotic intracranial artery or extracranial vertebral artery stenosis, and of interventional procedures in patients with brain arteriovenous or cavernous malformations.