Clinical and biochemical diagnosis of small-vessel disease in acute ischemic stroke

Malignant Isolated Cortical Vein Thrombosis as the Initial Manifestation of Primary Antiphospholipid Syndrome: Lessons on Diagnosis and Management From a Case Report

Background

Antiphospholipid syndrome (APS) with isolated cortical vein thrombosis (ICoVT) is an extremely rare but potentially malignant entity. It is particularly challenging to diagnose APS-related ICoVT because of the non-specific clinical manifestations and the frequent absence of typical neuroimaging. Moreover, there is currently limited knowledge on the clinical features and management strategies for the condition. Delays in diagnosis and treatment may lead to life-threatening consequences.

Case Presentation

We present a rare case of a 74-year-old Chinese woman who presented with sudden onset of headache and right arm weakness that mimicked acute ischemic stroke. Her initial computed tomography was unremarkable, and intravenous thrombolysis was performed. Serial neuroimages confirmed ICoVT 4 days after symptom onset, and low-molecular-weight heparin (LMWH) was started at a dose of 0.4 ml twice per day, according to the 2019 Chinese guidelines. The workup for the predisposing causes of ICoVT revealed triple positivity APS. LMWH dose was adjusted according to the anti-Xa chromogenic assay. However, the patient’s condition deteriorated rapidly, and there was a progressive enlargement of the venous infarction despite treatment with anticoagulants. Transtentorial herniation developed on day 12, and decompressive craniectomy was immediately performed. The patient’s symptoms did not improve significantly after surgery, and she remained aphasic and hemiplegic at the 3-month follow-up, with a modified Rankin Scale score of 5.

Conclusion

ICoVT is a rare yet potentially fatal manifestation of APS, and its diagnosis and treatment are extremely challenging. Timely diagnosis, prompt treatment, and close monitoring are essential to improve the clinical prognosis of patients with APS-related ICoVT.

The Potential Impact of Neuroimaging and Translational Research on the Clinical Management of Lacunar Stroke

Lacunar infarcts represent one of the most frequent subtypes of ischemic strokes and may represent the first recognizable manifestation of a progressive disease of the small perforating arteries, capillaries, and venules of the brain, defined as cerebral small vessel disease. The pathophysiological mechanisms leading to a perforating artery occlusion are multiple and still not completely defined, due to spatial resolution issues in neuroimaging, sparsity of pathological studies, and lack of valid experimental models. Recent advances in the endovascular treatment of large vessel occlusion may have diverted attention from the management of patients with small vessel occlusions, often excluded from clinical trials of acute therapy and secondary prevention. However, patients with a lacunar stroke benefit from early diagnosis, reperfusion therapy, and secondary prevention measures. In addition, there are new developments in the knowledge of this entity that suggest potential benefits of thrombolysis in an extended time window in selected patients, as well as novel therapeutic approaches targeting different pathophysiological mechanisms involved in small vessel disease. This review offers a comprehensive update in lacunar stroke pathophysiology and clinical perspective for managing lacunar strokes, in light of the latest insights from imaging and translational studies.

Circulating Extracellular Vesicle Proteins and MicroRNA Profiles in Subcortical and Cortical-Subcortical Ischaemic Stroke

In order to investigate the role of circulating extracellular vesicles (EVs), proteins, and microRNAs as damage and repair markers in ischaemic stroke depending on its topography, subcortical (SC), and cortical-subcortical (CSC) involvement, we quantified the total amount of EVs using an enzyme-linked immunosorbent assay technique and analysed their global protein content using proteomics. We also employed a polymerase chain reaction to evaluate the circulating microRNA profile. The study included 81 patients with ischaemic stroke (26 SC and 55 CSC) and 22 healthy controls (HCs). No differences were found in circulating EV levels between the SC, CSC, and HC groups. We detected the specific expression of C1QA and Casp14 in the EVs of patients with CSC ischaemic stroke and the specific expression of ANXA2 in the EVs of patients with SC involvement. Patients with CSC ischaemic stroke showed a lower expression of miR-15a, miR-424, miR-100, and miR-339 compared with those with SC ischaemic stroke, and the levels of miR-339, miR-100, miR-199a, miR-369a, miR-424, and miR-15a were lower than those of the HCs. Circulating EV proteins and microRNAs from patients with CSC ischaemic stroke could be considered markers of neurite outgrowth, neurogenesis, inflammation process, and atherosclerosis. On the other hand, EV proteins and microRNAs from patients with SC ischaemic stroke might be markers of an anti-inflammatory process and blood–brain barrier disruption reduction.

A Novel Combination of Blood Biomarkers and Clinical Stroke Scales Facilitates Detection of Large Vessel Occlusion Ischemic Strokes

Acute ischemic stroke caused by large vessel occlusions (LVOs) is a major contributor to stroke deaths and disabilities; however, identification for emergency treatment is challenging. We recruited two separate cohorts of suspected stroke patients and screened a panel of blood-derived protein biomarkers for LVO detection. Diagnostic performance was estimated by using blood biomarkers in combination with NIHSS-derived stroke severity scales. Multivariable analysis demonstrated that D-dimer (OR 16, 95% CI 5–60; p-value < 0.001) and GFAP (OR 0.002, 95% CI 0–0.68; p-value < 0.05) comprised the optimal panel for LVO detection. Combinations of D-dimer and GFAP with a number of stroke severity scales increased the number of true positives, while reducing false positives due to hemorrhage, as compared to stroke scales alone (p-value < 0.001). A combination of the biomarkers with FAST-ED resulted in the highest accuracy at 95% (95% CI: 87–99%), with sensitivity of 91% (95% CI: 72–99%), and specificity of 96% (95% CI: 90–99%). Diagnostic accuracy was confirmed in an independent cohort, in which accuracy was again shown to be 95% (95% CI: 87–99%), with a sensitivity of 82% (95% CI: 57–96%), and specificity of 98% (95% CI: 92–100%). Accordingly, the combination of D-dimer and GFAP with stroke scales may provide a simple and highly accurate tool for identifying LVO patients, with a potential impact on time to treatment.

The emerging value of serum D-dimer measurement in the work-up and management of ischemic stroke

Background

Elevated D-dimer levels are a marker of both thrombin formation and fibrinolysis. Currently D-dimer measurement is routinely used for ruling out venous thromboembolism and diagnosis/monitoring of disseminated intravascular coagulation. Recent emerging data suggest that D-dimer may become an important biomarker in ischemic stroke as well as in cardiovascular diseases.

Aims

To outline the clinical utility of D-dimer in work-up and management of ischemic stroke.

Summary

D-dimer measurement is most useful in stroke with active cancer as it can confirm etiologic diagnosis, predict recurrent stroke risk, and aid treatment decision in cancer-associated stroke. In cryptogenic stroke, high D-dimer levels can also provide clues for the cause of stroke as occult cancer and undetected cardiac embolic source as occult atrial fibrillation and may be helpful in treatment decision making of secondary stroke prevention. Serial D-dimer measurements should be further studied to monitor antithrombotic therapy effectiveness in both cardiogenic and cryptogenic etiologies.

Conclusion

Accumulating data suggests the utility of D-dimer test in the management of ischemic stroke, although the evidence is still limited. Future studies would clarify the role of D-dimer measurement in ischemic stroke.

Plasma D-dimer levels are associated with stroke subtypes and infarction volume in patients with acute ischemic stroke

BACKGROUND

It has been suggested that modestly elevated circulating D-dimer values may be associated with acute ischemic stroke (AIS). Thus, the purpose of this study was to investigate the association between plasma D-dimer level at admission and AIS in Chinese population.

METHODS

In a prospective observational study, plasma D-dimer levels were measured using a particle-enhanced, immunoturbidimetric assay on admission in 240 Chinese patients with AIS. The National Institutes of Health Stroke Scale (NIHSS) score was assessed on admission blinded to D-dimer levels.

RESULTS

Plasma median D-dimer levels were significantly (P = 0.000) higher in AIS patients as compared to healthy controls (0.88; interquartiler range [IQR], 0.28-2.11 mg/L and 0.31; IQR, 0.17-0.74 mg/L). D-dimer levels increased with increasing severity of stroke as defined by the NIHSS score(r = 0.179, p = 0.005) and infarct volume(r = 0.425, p = 0.000). Those positive trends still existed even after correcting for possible confounding factors (P = 0.012, 0.000; respectively). Based on the Receiver operating characteristic (ROC) curve, the optimal cut-off value of plasma D-dimer levels as an indicator for diagnosis of cardioembolic strokes was projected to be 0.91 mg/L, which yielded a sensitivity of 83.7% and a specificity of 81.5%, the area under the curve was 0.862(95% confidence interval [CI], 0.811-0.912).

CONCLUSION

We had shown that plasma D-dimer levels increased with increasing severity of stroke as defined by the NIHSS score and infarct volume. These associations were independent other possible variables. In addition, cardioembolic strokes can be distinguished from other stroke etiologies by measuring plasma D-dimer levels very early (0-48 hours from stroke symptom onset).

The relationship between plasma D-dimer levels and outcome of Chinese acute ischemic stroke patients in different stroke subtypes

High-level plasma D-dimer suggests hypercoagulable states. There is a lack of correlation study of plasma D-dimer level and prognosis according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. The goal of this study is to explore the relationship between the plasma D-dimer level and the outcome of acute ischemic stroke patients among different stroke subtypes. We conducted a study of acute ischemic stroke patients admitted to the Department of Neurology in Second Hospital of Lanzhou University within 7 days of symptom onset. They were divided into different groups based on their subtypes according to TOAST criteria. In all the patients the plasma D-dimer levels were detected within 24 h of admission. Clinical neurological assessments were performed in line with National Institutes of Health Stroke Scale (NIHSS) once daily on the day of admission and on the 14th day. The outcome was evaluated by neurological improvement rate. Comparisons were made among the different subtypes based on the level of plasma D-dimer and the outcome. A total of 300 patients with acute ischemic stroke were included, 40 with cardioembolism; 47 with large-artery atherosclerosis; 143 with small-artery occlusion, 5 with other etiology stroke; and 65 with undetermined etiology stroke. The level of plasma D-dimer was negatively related to the outcome (r = -0.41; P = 0.013). Patients with cardioembolism had the highest level of plasma D-dimer and they suffered the most serious neurological deficit and the worst outcome among the five subtypes, the difference was statistically significant (F = 5.34; P = 0.012); while the lacunar stroke patients had the best outcome with the lowest level of D-dimer. High-level plasma D-dimer of acute period strongly indicates an unfavorable clinical outcome.

Clinical symptoms and risk factors in cerebral microangiopathy patients

OBJECTIVE

Although the clinical manifestation and risk factors of cerebral microangiopathy (CM) remain unclear, the number of diagnoses is increasing. Hence, patterns of association among lesion topography and severity, clinical symptoms and demographic and disease risk factors were investigated retrospectively in a cohort of CM patients.

METHODS

Patients treated at the Department of Neurology, University of Bonn for CM (n = 223; 98m, 125f; aged 77.32±9.09) from 2005 to 2010 were retrospectively enrolled. Clinical symptoms, blood chemistry, potential risk factors, demographic data and ratings of vascular pathology in the brain based on the Wahlund scale were analyzed using Pearson's chi square test and one-way ANOVA.

RESULTS

Progressive cognitive decline (38.1%), gait apraxia (27.8%), stroke-related symptoms and seizures (24.2%), TIA-symptoms (22%) and vertigo (17%) were frequent symptoms within the study population. Frontal lobe WMLs/lacunar infarcts led to more frequent presentation of progressive cognitive decline, seizures, gait apraxia, stroke-related symptoms, TIA, vertigo and incontinence. Parietooccipital WMLs/lacunar infarcts were related to higher frequencies of TIA, seizures and incontinence. Basal ganglia WMLs/lacunar infarcts were seen in patients with more complaints of gait apraxia, vertigo and incontinence. Age (p = .012), arterial hypertension (p<.000), obesity (p<.000) and cerebral macroangiopathy (p = .018) were positively related to cerebral lesion load. For increased glucose level, homocysteine, CRP and D-Dimers there was no association.

CONCLUSION

This underlines the association of CM with neurological symptoms upon admission in a topographical manner. Seizures and vertigo are symptoms of CM which may have been missed in previous studies. In addition to confirming known risk factors such as aging and arterial hypertension, obesity appears to increase the risk as well. Since the incidence of CM is increasing, future studies should focus on the importance of prevention of vascular risk factors on its pathogenesis.

Decrease in uric acid in acute ischemic stroke correlates with stroke severity, evolution and outcome

BACKGROUND

Although uric acid (UA) is one of the most important antioxidants in plasma and appears to be neuroprotective in animal models, results from human studies are controversial. In this study, we investigated the kinetics of serum UA concentrations in the acute, subacute and chronic phase of ischemic stroke and its relation with initial stroke severity, stroke evolution in the subacute phase and long-term stroke outcome.

METHODS

Serum concentrations of UA were measured in 199 stroke patients at admission (median, 2.8 h after stroke onset), at 24 h, 72 h, day 7, month 1 and month 3 after onset of stroke. We evaluated the relationship between changes in UA concentrations and (a) stroke severity [patients with transient ischemic attack (TIA) vs. stroke patients, National Institutes of Health Stroke Scale (NIHSS) score at admission], (b) stroke evolution (stroke progression, infarct volume at 72 h), and (c) stroke outcome [modified Rankin scale (mRS) score at month 3, mortality].

RESULTS

UA concentrations decreased significantly during the first 7 days after stroke onset before returning to baseline (p < 0.001). Mean plasma UA concentrations decreased from 336.66 +/- 113.01 micromol/L at admission to 300.37 +/- 110.04 micromol/L at day 7 (p < 0.001) in patients with stroke, but did not change significantly in patients with TIA. Changes in UA concentrations from admission to day 7 (DeltaUA(day 7)) correlated with the NIHSS score (rho = 0.32; p < 0.001), stroke progression (rho = 0.29; p = 0.001), infarct volume (rho = 0.37; p < 0.001), mRS score (rho = 0.28; p = 0.001) and mortality (p = 0.010).

CONCLUSIONS

Decreases in UA during the first week after onset of stroke correlates with more severe stroke, unfavorable stroke evolution, and poor long-term stroke outcome.

Neurobiochemical Markers of Brain Damage in Cerebrospinal Fluid of Acute Ischemic Stroke Patients

Background: Ischemic injury to the central nervous system causes cellular activation and disintegration, leading to release of cell-type–specific proteins into the cerebrospinal fluid (CSF). We investigated CSF concentrations of myelin basic protein (MBP), glial fibrillary astrocytic protein (GFAP), the calcium-binding protein S100B, and neuron-specific enolase (NSE) in acute ischemic stroke patients and their relation to initial stroke severity, stroke location, and long-term stroke outcome.

Methods: CSF concentrations of MBP, GFAP, S100B, and NSE were assessed in 89 stroke patients on admission (mean 8.7 h after stroke onset) and in 35 controls. We evaluated the relation between CSF concentrations and (a) stroke severity (NIH Stroke Scale [NIHSS] score on admission, infarct volume), (b) stroke location, and (c) stroke outcome (modified Rankin Scale [mRS] score at month 3).

Results: MBP concentration was significantly higher in subcortical than in cortical infarcts (median MBP, 1.18 vs 0.66 μg/L, P &lt; 0.001). GFAP and S100B concentrations correlated with the NIHSS score on admission (GFAP, R = 0.35, P = 0.001; S100B, R = 0.29, P = 0.006), infarct volume (GFAP, R = 0.34, P = 0.001; S100B, R = 0.28, P = 0.008), and mRS score at month 3 (R = 0.42, P &lt; 0.001 and R = 0.28, P = 0.007). Concentrations of NSE did not correlate with stroke characteristics.

Conclusions: MBP, GFAP, S100B, and NSE display relevant differences in cellular and subcellular origins, which are reflected in their relation to stroke characteristics. MBP is a marker for infarct location. GFAP and S100B correlate with stroke severity and outcome.

Bioinformatics for protein biomarker panel classification: what is needed to bring biomarker panels into in vitro diagnostics?

A large number of biomarkers have been discovered over the past few years using proteomics techniques. Unfortunately, most of them are neither specific nor sensitive enough to be translated into in vitro diagnostics and routine clinical practice. From this observation, the idea of combining several markers into panels to improve clinical performances has emerged. In this article, we present a discussion of the bioinformatics aspects of biomarker panels and the concomitant challenges, including high dimensionality and low patient number and reproducibility.