Thrombolysis and bridging therapy in patients with acute ischaemic stroke and Covid-19.

BACKGROUND AND PURPOSE: Comorbidity of acute ischaemic stroke with Covid-19 is a challenging condition, potentially influencing the decision of whether to administer intravenous thrombolysis (IVT). We aimed to assess the 1-month outcome in ischaemic stroke patients with Covid-19 infection who received IVT alone or before thrombectomy (bridging therapy). METHODS: As a collaboration initiative promoted by the Italian Stroke Organization, all Italian stroke units (n = 190) were contacted and invited to participate in data collection on stroke patients with Covid-19 who received IVT. RESULTS: Seventy-five invited centers agreed to participate. Thirty patients received IVT alone and 17 received bridging therapy between 21 February 2020 and 30 April 2020 in 20 centers (n = 18, Northern Italy; n = 2, Central Italy). At 1 month, 14 (30.4%) patients died and 20 (62.5%) survivors had a modified Rankin Scale (mRS) score of 3 to 5. At 24 to 36 hours, asymptomatic intracerebral hemorrhage (ICH) was reported in eight (17.4%) patients and symptomatic ICH (sICH) in two (4.3%) patients. Causes of death were severe ischaemic stroke (n = 8), a new ischaemic stroke (n = 2), acute respiratory failure (n = 1), acute renal failure (n = 1), acute myocardial infarction (n = 1), and endocarditis (n = 1). In survivors with a 1-month mRS score of 3 to 5, baseline glucose level was higher, whereas endovascular procedure time in cases of bridging therapy was longer. Baseline National Institutes of Health Stroke Scale glucose and creatinine levels were higher in patients who died. CONCLUSIONS: Intravenous thrombolysis for patients with stroke and Covid-19 was not a rare event in the most affected areas by pandemic, and rates of 1-month unfavorable outcomes were high compared to previous data from the pre-Covid-19 literature. However, risk of sICH was not increased.

Cerebral haemodynamics in early puerperium: A prospective study.

AIM: Prospective study on 900 consecutive puerperae to assess normal values and range of the blood flow velocity in the middle cerebral artery in both hemispheres. MATERIAL AND METHOD: M1 and M2 segments of both middle cerebral arteries were assessed in all subjects within 96 hours of delivery. Mean flow velocity was recorded after adjusting for insonation angle. Lindegaard index (LI = middle cerebral artery-Internal Carotid Artery mean flow velocity ratio) was calculated whenever the mean flow velocity exceeded 100 cm/second. Asymmetry indexes were calculated inter hemispherically for M1 and M2 segments separately. RESULTS: Mean flow velocities were 74 ± 17 and 72 ± 17 in right and 73 ± 17 and 72 ± 17 cm/second in the left M1 and M2, respectively. A total of 136 subjects (12.1%) exceeded the threshold of 100 cm/second, but LI was consistently <3 in all of them. Mean flow velocity was inversely and independently correlated to haemoglobin levels and to parity. Mean asymmetry indexes were 0.25 ± 23 in M1 and 0.45 ± 25 in M2. CONCLUSION: Mean flow velocity in the middle cerebral artery of healthy subjects in early puerperium is higher than in age-matched non-puerperal women and may exceed the threshold of 100 cm/second with no evidence of intracranial spasm, because of blood loss during delivery. Mean flow velocity is independently correlated with parity. Right-to-left mean flow velocity asymmetry may reach 50% as a consequence of a transient imbalance in vascular tone regulation.

Elevated peripheral leukocyte counts in acute cervical artery dissection.

BACKGROUND AND PURPOSE: It has been suggested that inflammation may play a role in the development of cervical artery dissection (CeAD), but evidence remains scarce. METHODS: A total of 172 patients were included with acute (< 24 h) CeAD and 348 patients with acute ischaemic stroke (IS) of other (non-CeAD) causes from the Cervical Artery Dissection and Ischemic Stroke Patients (CADISP) study, and 223 age- and sex-matched healthy control subjects. White blood cell (WBC) counts collected at admission were compared across the three groups. RESULTS: Compared with healthy control subjects, CeAD patients and non-CeAD stroke patients had higher WBC counts (P < 0.001). Patients with CeAD had higher WBC counts and were more likely to have WBC > 10 000/µl than non-CeAD stroke patients (38.4% vs. 23.0%, P < 0.001) and healthy controls (38.4% vs. 8.5%, P < 0.001). WBC counts were higher in CeAD (9.4 ± 3.3) than in IS of other causes (large artery atherosclerosis, 8.7 ± 2.3; cardioembolism, 8.2 ± 2.8; small vessel disease, 8.4 ± 2.4; undetermined cause, 8.8 ± 3.1; P = 0.022). After adjustment for age, sex, stroke severity and vascular risk factors in a multiple regression model, elevated WBC count remained associated with CeAD, as compared with non-CeAD stroke patients [odds ratio (OR) = 2.56; 95% CI 1.60-4.11; P < 0.001) and healthy controls (OR = 6.27; 95% CI 3.39-11.61; P < 0.001). CONCLUSIONS: Acute CeAD was associated with particularly high WBC counts. Leukocytosis may reflect a pre-existing inflammatory state, supporting the link between inflammation and CeAD.

Transforming growth factor ß signaling perturbation in the Loeys-Dietz syndrome.

The transforming growth factor ß (TGFß) superfamily consists of multipotential secreting cytokines that mediate many key events in normal cellular growth and development, including differentiation, proliferation, motility, organization and death. TGFßs act as ligand for 3 classes of cell surface receptors, the transmembrane serine-threonine kinase receptors, TGFß receptor type I (TGFßRI) and type 2 (TGFßRII), and TGFßRIII receptors which include an ubiquitous extracellular ß-glycan and the membrane glycoprotein endoglin (CD105). Binding of TGFßs to their receptors initiates diverse cellular responses resulting in the phosphorilation of Smad proteins, which then translocate to the nucleus and regulate the transcription of target genes. Perturbation of TGFß signaling has been implicated in various human disorders including cancer, fibrosis and auto-immune diseases. Recently, mutations in TGFßR1 and TGFßR2 genes have been found in association with a continuum of clinical features with widespread vascular involvement. The extreme of clinical severity is represented by the Loeys-Dietz syndrome (LDS), an autosomal dominant disorder characterized by hypertelorism, bifid uvula, and/or cleft palate, and aggressive arteriopathy causing arterial tortuosity as well as life-threatening complications such as vascular aneurysms and dissections. Elastin disarray, loss of elastic fibre architecture and increased collagen expression in the arterial wall are the pathologic hallmark of LDS. In the present review article we will provide details on the activation of TGFß cascade, on the clinical features of LDS, as well as on the mechanisms of TGFß signaling perturbation leading to this condition and the potential role of the antagonism of TGFß activity in disease management.

Advances in antiplatelet therapy for stroke prevention: the new P2Y12 antagonists.

Thrombus formation at a site of arterial injury (eg, rupture of an atherosclerotic plaque in a carotid artery), a crucial step in the pathogenesis of cerebral ischemia, is initiated by the adhesion of platelets to the arterial wall. In vivo, activated platelets release adenosine diphosphate (ADP), whose binding to the platelet P2Y12 receptor elicits progressive and sustained platelet aggregation. As a result, this receptor has been a target for the development of clinically effective antiplatelet agents, such as the thienopyridines ticlopidine and, more recently, clopidogrel, the only two currently FDA-approved P2Y12 antagonists. Clopidogrel has a well-established role as an antithrombotic agent in the setting of ischemic stroke. However, several challenges remain, including the relatively slow onset of action of this drug and the phenomenon of clopidogrel response variability or "resistance". A number of novel P2Y12 antagonists are therefore under investigation to determine whether they can result in better or more rapid antithrombotic effects than clopidogrel, without an unacceptable increase in hemorrhagic (or other) side effects. These include 1) prasugrel, an orally-administered thienopyridine prodrug, 2) ticagrelor (AZD6140), an ATP analog reversible P2Y12 antagonist, 3) cangrelor, an intravenously-administered reversible P2Y12 antagonist, and 4) PRT060128. Whether the promising pharmacological profile of these drugs will be translated into clinical benefit for stroke patients will be determined by the results of clinical trials.

Role of COL4A1 in basement-membrane integrity and cerebral small-vessel disease. The COL4A1 stroke syndrome.

Type IV collagens are basement membrane (BM) proteins expressed in all tissues including the vasculature. COL4A1 and COL4A2, the most abundant type IV collagens, form heterotrimers with a 2:1 stoichiometry and each heterotrimer forms a triple helix along the length of the collagenous domains. Recently, mutations in COL4A1 on chromosome 13q34, encoding the alpha1 chain of type IV collagen, have been linked to a spectrum of cerebral small-vessel disease in humans, including perinatal intracerebral hemorrhage (ICH) with consequent porencephaly, adult-onset ICH, microbleeds, lacunar strokes, and leukoaraiosis, which follows an autosomal dominant pattern of inheritance. This variable phenotype has been named the "COL4A1 stroke syndrome". In COL4A1 stroke syndrome most mutations are missense mutations involving a glycine residue, including G562E, G749S, G805R, G1130D, G1236R, G1423R, G720D, G1580R, and G755R. Mutations replacing a highly conserved hydrophobic glycine residue likely lead to synthesis of an abnormal protein with abnormal structure and inhibit heterotrimer secretion into the vascular BM, modify its structural properties (when imaged with electron microscopy BM is uneven, with inconsistent density and focal disruptions), and, thus, increase the fragility of the vessel wall when exposed to environmental factors. Although pathological changes in BM also occur in other tissues (mostly retina and kidney), the major site of vessel damage is the brain. In the present review article we will focus on the molecular basis of the COL4A1 stroke syndrome, summarize data on its variable phenotype, and explore additional questions concerning the possible genotype-phenotype correlations and the mechanisms leading to cerebral small-vessel disease in this clinically heterogeneous condition.

Common genetic markers and prediction of recurrent events after ischemic stroke in young adults.

BACKGROUND: Scarce information is available on the usefulness of new prediction markers for identifying young ischemic stroke patients at highest risk of recurrence. METHODS: The predictive effect of traditional risk factors as well as of the 20210A variant of prothrombin gene, the 1691A variant of factor V gene, and the TT677 genotype of the methylenetetrahydrofolate reductase (MTHFR) gene on the risk of recurrence was investigated in a hospital-based cohort study of 511 ischemic stroke patients younger than 45 years followed up for a mean of 43.4 months. Outcome measures were fatal/nonfatal myocardial infarction, ischemic stroke, or TIA. Risk prediction was assessed with the use of the concordance c (c index), and the Net Reclassification Improvement (NRI). RESULTS: The risk of recurrence increased with increasing number of traditional factors (hazard ratio [HR] 2.29, 95% confidence interval [CI] 1.57-3.35 for subjects with 1 factor: HR 5.25, 95% CI 2.45-11.2 for subjects with 2), as well as with that of predisposing genotypes (HR 1.96, 95% CI 1.33-2.89 for subjects carrying 1 at-risk genotype; HR 3.83, 95% CI 1.76-8.34 for those carrying 2). The c statistics increased significantly when the genotypes were included into a model with traditional risk factors (0.696 vs 0.635, test z = 2.41). The NRI was also significant (NRI = 0.172, test z = 2.17). CONCLUSIONS: Addition of common genetic variants to traditional risk factors may be an effective method for discriminating young stroke patients at different risk of future ischemic events.

Cerebral amyloid angiopathy: a common cause of cerebral hemorrhage.

Amyloid is a term used to describe protein deposits with circumscript physical characteristics: beta-pleated sheet configuration, apple green birefringence under polarized light after Congo red staining, fibrillary structure and high insolubility. Cerebral amyloid angiopathy (CAA) defines a clinicopathological phenomenon characterized by amyloid deposition in the walls of leptomeningeal and cortical arteries, arterioles, and, less often capillaries and veins of the central nervous system. CAAs are currently classified according to the protein deposited including amyloid beta peptide (Abeta), cystatin C (ACys C), prion protein (PrP(Sc)), ABri/ADan, transthyretin (ATTR), and gelsolin (AGel). Most often amyloid deposition occurs in sporadic forms. In less common hereditary forms, a mutated variant protein or precursor protein is abnormally metabolized by proteolytic pathways in consequence of specific gene mutations, and accumulates as amyloid. The spectrum of clinical phenotypes associated with CAA-related vasculopathic changes includes both ischemic and hemorrhagic presentations, primary intracerebral hemorrhage (PICH) being probably the most well-recognized. However, in spite of accumulating data and recent progress in understanding the pathogenesis of CAA-related hemorrhage, the exact mechanisms leading to vessel rupture in these cases are yet to be established. This represents, at present, a major limitation to the identification of reliable biomarkers and the development of disease-specific treatment options. The present paper summarizes epidemiologic and clinical aspects of CAA, and highlights the presumed pathomechanisms of amyloid deposition in both sporadic and hereditary forms.

No association of the -105 promoter polymorphism of the selenoprotein S encoding gene SEPS1 with cerebrovascular disease.

A common pro-inflammatory promoter variant of the selenoprotein S encoding gene (SEPS1) was studied in young stroke patients from Italy and Germany and in healthy control subjects. The -105A-allele was found in 56 of 205 (27.3%) patients with ischemic stroke IS because of a spontaneous cervical artery dissection (CAD), and in 69 of 295 (23.4%) patients <50 years with IS of non-CAD origin. The SEPS -105A promoter variant was detected in 87 of 393 healthy control subjects (22.1%) and in 11 of 55 CAD patients without IS (20%). The non-significant differences of SEPS1 allele frequencies between disease groups and healthy controls suggest that the SEPS1 -105A allele is not a major-risk factor for stroke.

Inherited thrombophilia and stratification of ischaemic stroke risk among users of oral contraceptives.

BACKGROUND: Whether use of oral contraceptives is a risk factor for arterial ischaemic stroke is controversial. In particular, few data are available on what criteria should be adopted to establish an individual profile of risk before the start of oral contraceptives. PATIENTS AND METHODS: The effects of oral contraceptives and their interaction with the G1691A polymorphisms of the factor V gene, the G20210A polymorphisms of the prothrombin gene and the C677T polymorphisms of the MTHFR gene on the risk of cerebral ischaemia were determined in a series of 108 consecutive women aged <45 years with ischaemic stroke and 216 controls, in a hospital-based case-control study design. RESULTS: Use of oral contraceptives was associated with an increased risk of cerebral ischaemia (odds ratio (OR) 3.95; 95% confidence interval (CI) 2.29 to 6.78). ORs for stroke were 2.25 (95% CI 1.15 to 4.40), 3.94 (95% CI 2.28 to 6.81) and 8.87 (95% CI 3.72 to 21.1) for non-oral contraceptive users with the TT MTHFR genotype, oral contraceptive users without the TT MTHFR genotype and oral contraceptive users with the TT MTHFR genotype, respectively, when compared with non-oral contraceptive users without the TT MTHFR genotype, with a multiplicative independent effect. Compared with non-oral contraceptive users, ORs for stroke were 2.65 (95% CI 1.46 to 4.81) for oral contraceptive users with none of the studied polymorphisms and 22.8 (95% CI 4.46 to 116.00) for oral contraceptive users with at least one of the studied polymorphisms, with a synergistic effect. CONCLUSIONS: Exposure to the effects of oral contraceptives may increase the risk of ischaemic stroke in women with an inherited prothrombotic background. Testing for these genetic variants may allow more accurate stratification of the population at risk before long-term use of oral contraceptives is prescribed.