The guardian of intracranial vessels: Why the pericyte?

Intracranial atherosclerotic stenosis (ICAS) is a pathological condition characterized by progressive narrowing or complete blockage of intracranial blood vessels caused by plaque formation. This condition leads to reduced blood flow to the brain, resulting in cerebral ischemia and hypoxia. Ischemic stroke (IS) resulting from ICAS poses a significant global public health challenge, especially among East Asian populations. However, the underlying causes of the notable variations in prevalence among diverse populations, as well as the most effective strategies for preventing and treating the rupture and blockage of intracranial plaques, remain incompletely comprehended. Rupture of plaques, bleeding, and thrombosis serve as precipitating factors in the pathogenesis of luminal obstruction in intracranial arteries. Pericytes play a crucial role in the structure and function of blood vessels and face significant challenges in regulating the Vasa Vasorum (VV)and preventing intraplaque hemorrhage (IPH). This review aims to explore innovative therapeutic strategies that target the pathophysiological mechanisms of vulnerable plaques by modulating pericyte biological function. It also discusses the potential applications of pericytes in central nervous system (CNS) diseases and their prospects as a therapeutic intervention in the field of biological tissue engineering regeneration.

Ischaemic Stroke Occurring in a Patient Treated with Monoclonal Antibodies for COVID-19

Since the COVID-19 outbreak began, an association between COVID-19 and thrombotic diseases has been underlined. Although this association is more frequent with venous thromboembolism, ischaemic stroke has also been reported as a thrombotic complication in several cohorts of affected patients. Furthermore, the association between ischaemic stroke and COVID-19 has been considered a risk factor for early mortality. On the other hand, after the successful vaccination campaign, the incidence and the virulence of SARS-CoV-2 decreased, though it has been observed that COVID-19 may induce a severe infection in specific cohorts of frail subjects. For this reason, different drugs have been introduced of an antiviral action in order to improve the disease outcome of frail patients. In this field, with the arrival of a neutralizing monoclonal antibody against SARS-CoV-2, in particular, sotrovimab, a further chance to treat high-risk patients with mild-to-moderate COVID-19 arrived, achieving a concrete reduction in the risk of disease progression. We here report our clinical experience of an ischaemic stroke occurring a few minutes after the administration of sotrovimab for the treatment of moderate COVID-19 in a frail patient with chronic lymphocytic leukaemia. Other causes of ischaemic stroke were ruled out, and in order to evaluate the probability of a rare side effect, the Naranjo probability scale has also been utilized. In conclusion, among several side effects that have been described during the treatment of COVID-19 with sotrovimab, ischaemic stroke was not reported. Therefore, we here report a rare case of ischaemic stroke with early clinical manifestation after the administration of sotrovimab for the treatment of moderate COVID-19 in an immunocompromised patient for the first time.

Cardiac Troponin and Recurrent Major Vascular Events after Minor Stroke or Transient Ischemic Attack

OBJECTIVE

This study was undertaken to investigate whether high-sensitivity cardiac troponin T (hs-cTnT) is associated with major adverse cardiovascular events (MACE) in patients with minor stroke or transient ischemic attack (TIA), and whether this association differs after risk stratification based on the Age, Blood Pressure, Clinical Features, Duration of Symptoms, Diabetes (ABCD² ) score.

METHODS

INSPiRE-TMS was a randomized controlled trial allocating patients with minor stroke or TIA to an intensified support program or conventional care. In this post hoc analysis, participants were categorized using hs-cTnT levels (5th generation; Roche Diagnostics, Manheim, Germany; 99th percentile upper reference limit [URL] = 14ng/l). Vascular risk was stratified using the ABCD² score (lower risk = 0-5 vs higher risk = 6-7). Cox proportional hazard regression was performed using covariate adjustment and propensity score matching (PSM) for the association between hs-cTnT and MACE (stroke/nonfatal coronary event/vascular death).

RESULTS

Among 889 patients (mean age = 70 years, 37% female), MACE occurred in 153 patients (17.2%) during a mean follow-up of 3.2 years. hs-cTnT was associated with MACE (9.3%/yr, >URL vs 4.4%/yr, ≤URL, adjusted hazard ratio [HR] = 1.63 [95% confidence interval (CI) = 1.13-2.35], adjusted HR [Q₄ vs Q₁ ] = 2.57 [95% CI = 1.35-4.97], adjusted HR [log-transformed] = 2.31 [95% CI = 1.37-3.89]). This association remained after PSM (adjusted HR = 1.76 [95% CI = 1.14-2.72]). There was a significant interaction between hs-cTnT and ABCD² category for MACE occurrence (p_interaction  = 0.04). In the lower risk category, MACE rate was 9.5%/yr in patients with hs-cTnT > URL, which was higher than in those ≤URL (3.8%/yr) and similar to the overall rate in the higher risk category.

INTERPRETATION

hs-cTnT levels are associated with incident MACE within 3 years after minor stroke or TIA and may help to identify high-risk individuals otherwise deemed at lower risk based on the ABCD² score. If confirmed in independent validation studies, this might warrant intensified secondary prevention measures and cardiac diagnostics in stroke patients with elevated hs-cTnT. ANN NEUROL 2021;90:901-912.

[Cerebrovascular diseases: matching ICD-10 and ICD-11 codes]

A comparison of the codes and wording of the ICD-11 with the previous version of the classification was carried out. It seems necessary to develop a new revision of the domestic classification of cerebrovascular pathology, consistent with the ICD-11 codes.

Challenges and opportunities in stroke genetics

Stroke, ischaemic stroke and subtypes of ischaemic stroke display substantial heritability. When compared with related vascular conditions, the number of established risk loci reaching genome-wide significance for association with stroke is still in the lower range, particularly for aetiological stroke subtypes such as large artery atherosclerotic stroke or small vessel stroke. Nevertheless, for individual loci substantial progress has been made in determining the specific mechanisms mediating stroke risk. In this review, we present a roadmap for functional follow-up of common risk variants associated with stroke. First, we discuss in silico strategies for characterizing signals in non-coding regions and highlight databases providing information on quantitative trait loci for mRNA and protein expression, as well as methylation, focussing on those with presumed relevance for stroke. Next, we discuss experimental strategies for following up on non-coding risk variants and regions such as massively parallel reporter assays, proteome-wide association studies, and chromatin conformation capture (3C) assays. These and other approaches are relevant for gaining insight into the specific variants and mechanisms mediating genetic stroke risk. Finally, we discuss how genetic findings could influence clinical practice by adding to diagnostic algorithms and eventually improve treatment options for stroke.

Etiological classification of ischemic stroke in young patients: a comparative study of TOAST, CCS, and ASCO

Analysis of stroke subtypes is important for making treatment decisions and prognostic evaluations. The TOAST classification system is most commonly used, but the CCS and ASCO classification systems might be more useful to identify stroke etiologies in young patients whose strokes have a wide range of different causes. In this manuscript, we aim to compare the differences in subtype classification between TOAST, CCS, and ASCO in young stroke patients. The TOAST, CCS, and ASCO classification schemes were applied to 151 patients with ischemic stroke aged 18-49 years old and the proportion of subtypes classified by each scheme was compared. For comparison, determined etiologies were defined as cases with evident and probable subtypes when using the CCS scheme and cases with grade 1 and 2 subtypes but no other grade 1 subtype when using the ASCO scheme. The McNemar test with Bonferroni correction was used to assess significance. By TOAST, 41.1% of patients' stroke etiology was classified as undetermined etiology, 19.2% as cardioembolic, 13.2% as large artery atherosclerosis, 11.3% as small vessel occlusion, and 15.2% as other causes. Compared with TOAST, both CCS and ASCO assigned fewer patients to the undetermined etiology group (30.5% p < 0.001 and 26.5% p < 0.001, respectively) and assigned more patients to the small vessel occlusion category (19.9%, p < 0.001, and 21.9%, p < 0.001, respectively). Additionally, both schemes assigned more patients to the large artery atherosclerosis group (15.9 and 16.6%, respectively). The proportion of patients assigned to either the cardioembolic or the other causes etiology did not differ significantly between the three schemes. Application of the CCS and ASCO classification schemes in young stroke patients seems feasible, and using both schemes may result in fewer patients being classified as undetermined etiology. New studies with more patients and a prospective design are needed to explore this topic further.

The value of transesophageal echocardiography for embolic strokes of undetermined source

OBJECTIVE

Our aim was to evaluate the diagnostic yield of transesophageal echocardiography (TEE) in consecutive patients with ischemic stroke (IS) fulfilling the diagnostic criteria of embolic strokes of undetermined source (ESUS).

METHODS

We prospectively evaluated consecutive patients with acute IS satisfying ESUS criteria who underwent in-hospital TEE examination in 3 tertiary care stroke centers during a 12-month period. We also performed a systematic review and meta-analysis estimating the cumulative effect of TEE findings on therapeutic management for secondary stroke prevention among different IS subgroups.

RESULTS

We identified 61 patients with ESUS who underwent investigation with TEE (mean age 44 ± 12 years, 49% men, median NIH Stroke Scale score = 5 points [interquartile range: 3-8]). TEE revealed additional findings in 52% (95% confidence interval [CI]: 40%-65%) of the study population. TEE findings changed management (initiation of anticoagulation therapy, administration of IV antibiotic therapy, and patent foramen ovale closure) in 10 (16% [95% CI: 9%-28%]) patients. The pooled rate of reported anticoagulation therapy attributed to abnormal TEE findings among 3,562 acute IS patients included in the meta-analysis (12 studies) was 8.7% (95% CI: 7.3%-10.4%). In subgroup analysis, the rates of initiation of anticoagulation therapy on the basis of TEE investigation did not differ (p = 0.315) among patients with cryptogenic stroke (6.9% [95% CI: 4.9%-9.6%]), ESUS (8.1% [95% CI: 3.4%-18.1%]), and IS (9.4% [95% CI: 7.5%-11.8%]).

CONCLUSIONS

Abnormal TEE findings may decisively affect the selection of appropriate therapeutic strategy in approximately 1 of 7 patients with ESUS.

Symptomatic carotid stenosis and stroke risk in patients with transient ischemic attack according to the tissue-based definition

BACKGROUND AND PURPOSE

Symptomatic carotid stenosis (sCS), a common cause of transient ischemic attack (TIA), is correlated with higher stroke risk. We investigated the frequency and associated factors of sCS in patients with TIA and the association between sCS and stroke risk following TIA.

METHODS

Over a three-year period (2011-2013), 861 consecutive patients with TIA, who were admitted to the Department of Neurology at the University of Lübeck, Germany, were included in a monocenter study and prospectively evaluated. Diagnosis of TIA was in accordance with the tissue-based definition (transient neurological symptoms without evidence of infarction by brain imaging).

RESULTS

Of 827 patients (mean age, 70 ± 13.2 years; 49.7% women), 64 patients (7.7%; 95% confidence interval [CI], 5.9%-9.7%) exhibited sCS and 3 patients (0.3%) showed an occlusion of the corresponding internal carotid artery. Logistic regression revealed that sCS was associated with male sex (odds ratio [OR], 2.7; 95% CI, 1.2-3.6; p = 0.012), amaurosis fugax (OR, 8.1; 95% CI, 3.4-19-4; p < 0.001), unilateral weakness (OR, 3.4; 95% CI, 1.9-6.1; p < 0.001), symptom duration less than 1 h (OR, 2.0; 95% CI, 1.1-3.4; p = 0.019) and previous stroke (OR, 2.7; 95% CI, 1.5-4.7; p = 0.001). During hospitalization (mean, 6.6 days), five patients (0.6%; 95% CI, 0.1%-1.2%) suffered from stroke. The stroke risk was higher in patients with sCS than in those without sCS (6.3% vs. 0.1%; p < 0.001), whereas the recurrent TIA risk (2.6%) did not differ between the groups (4.7% vs. 2.5%; p = 0.29).

CONCLUSION

SCS appears to be associated with a higher risk of stroke in patients with TIA defined according to the tissue-based definition.

Hospital-Based Prospective Registration of Acute Transient Ischemic Attack and Noncerebrovascular Events in Korea

BACKGROUND

There have been no prospective studies on the clinical features, etiologies, and outcome of transient ischemic attack (TIA) in Korea. The aim of this study was to identify variables that can discriminate TIA from TIA mimics. Also we evaluated the characteristic of TIA patients according to the presence of diffusion-weighted imaging (DWI) lesion.

METHODS

Patients were categorized into TIA and TIA mimics according to the result of an initial workup. TIA patients were divided according to the presence of DWI lesions. Baseline demographics, risk factors, laboratory results, initial blood pressure, imaging findings, recurrence rate of TIA or stroke at 3 months, and initial neurologic manifestations were prospectively collected and compared.

RESULTS

We evaluated a total of 252 patients (212 with TIA and 40 with TIA mimics). Steno-occlusion of the relevant artery (odds ratio [OR], 22.39; 95% confidence interval [CI], 2.03-246.73) and cardioembolic risk (OR, 32.15; 95% CI, 1.12-922.97) were significantly associated with TIA. Amnesia (OR, .001; 95% CI, .00-.05) and consciousness disturbance (OR, .003; 95% CI, .00-.06) favored TIA mimics. Perfusion defect (OR, 5.56; 95% CI, 2.90-10.68) and cardioembolic risk (OR, 2.68; 95% CI, 1.14-6.32) were significantly associated with DWI lesion. Recurrence did not significantly differ according to the presence of a lesion on DWI (positive, 4.9%; negative, 7.8%; P = .41).

CONCLUSION

Steno-occlusive disease and cardioembolic risk were independently associated with TIA. Perfusion defect and cardioembolic risk predicted positive DWI lesion. The value of various imaging modalities for predicting TIA etiology needs further evaluation.