Recognition and management of stroke in young adults and adolescents.

Approximately 15% of all ischemic strokes (IS) occur in young adults and adolescents. To date, only limited prior public health and research efforts have specifically addressed stroke in the young. Early diagnosis remains challenging because of the lack of awareness and the relative infrequency of stroke compared with stroke mimics. Moreover, the causes of IS in the young are heterogeneous and can be relatively uncommon, resulting in uncertainties about diagnostic evaluation and cause-specific management. Emerging data have raised public health concerns about the increasing prevalence of traditional vascular risk factors in young individuals, and their potential role in increasing the risk of IS, stroke recurrence, and poststroke mortality. These issues make it important to formulate and enact strategies to increase both awareness and access to resources for young stroke patients, their caregivers and families, and health care professionals. The American Academy of Neurology recently convened an expert panel to develop a consensus document concerning the recognition, evaluation, and management of IS in young adults and adolescents. The report of the consensus panel is presented herein

Neural network-based integration of polygenic and clinical information: development and validation of a prediction model for 10-year risk of major adverse cardiac events in the UK Biobank cohort

Background: In primary cardiovascular disease prevention, early identification of high-risk individuals is crucial. Genetic information allows for the stratification of genetic predispositions and lifetime risk of cardiovascular disease. However, towards clinical application, the added value over clinical predictors later in life is crucial. Currently, this genotype–phenotype relationship and implications for overall cardiovascular risk are unclear. Methods: In this study, we developed and validated a neural network-based risk model (NeuralCVD) integrating polygenic and clinical predictors in 395 713 cardiovascular disease-free participants from the UK Biobank cohort. The primary outcome was the first record of a major adverse cardiac event (MACE) within 10 years. We compared the NeuralCVD model with both established clinical scores (SCORE, ASCVD, and QRISK3 recalibrated to the UK Biobank cohort) and a linear Cox-Model, assessing risk discrimination, net reclassification, and calibration over 22 spatially distinct recruitment centres. Findings: The NeuralCVD score was well calibrated and improved on the best clinical baseline, QRISK3 (ΔConcordance index [C-index] 0·01, 95% CI 0·009–0·011; net reclassification improvement (NRI) 0·0488, 95% CI 0·0442–0·0534) and a Cox model (ΔC-index 0·003, 95% CI 0·002–0·004; NRI 0·0469, 95% CI 0·0429–0·0511) in risk discrimination and net reclassification. After adding polygenic scores we found further improvements on population level (ΔC-index 0·006, 95% CI 0·005–0·007; NRI 0·0116, 95% CI 0·0066–0·0159). Additionally, we identified an interaction of genetic information with the pre-existing clinical phenotype, not captured by conventional models. Additional high polygenic risk increased overall risk most in individuals with low to intermediate clinical risk, and age younger than 50 years. Interpretation: Our results demonstrated that the NeuralCVD score can estimate cardiovascular risk trajectories for primary prevention. NeuralCVD learns the transition of predictive information from genotype to phenotype and identifies individuals with high genetic predisposition before developing a severe clinical phenotype. This finding could improve the reprioritisation of otherwise low-risk individuals with a high genetic cardiovascular predisposition for preventive interventions. Funding: Charité–Universitätsmedizin Berlin, Einstein Foundation Berlin, and the Medical Informatics Initiative

P2 receptors are involved in the mediation of motivation-related behavior

The importance of purinergic signaling in the intact mesolimbic–mesocortical circuit of the brain of freely moving rats is reviewed. In the rat, an endogenous ADP/ATPergic tone reinforces the release of dopamine from the axon terminals in the nucleus accumbens as well as from the somatodendritic region of these neurons in the ventral tegmental area, as well as the release of glutamate, probably via P2Y1 receptor stimulation. Similar mechanisms may regulate the release of glutamate in both areas of the brain. Dopamine and glutamate determine in concert the activity of the accumbal GABAergic, medium-size spiny neurons thought to act as an interface between the limbic cortex and the extrapyramidal motor system. These neurons project to the pallidal and mesencephalic areas, thereby mediating the behavioral reaction of the animal in response to a motivation-related stimulus. There is evidence that extracellular ADP/ATP promotes goal-directed behavior, e.g., intention and feeding, via dopamine, probably via P2Y1 receptor stimulation. Accumbal P2 receptor-mediated glutamatergic mechanisms seem to counteract the dopaminergic effects on behavior. Furthermore, adaptive changes of motivation-related behavior, e.g., by chronic succession of starvation and feeding or by repeated amphetamine administration, are accompanied by changes in the expression of the P2Y1 receptor, thought to modulate the sensitivity of the animal to respond to certain stimuli

Genetic risk factors for ischaemic stroke and its subtypes (the METASTROKE Collaboration): a meta-analysis of genome-wide association studies

<p>Background - Various genome-wide association studies (GWAS) have been done in ischaemic stroke, identifying a few loci associated with the disease, but sample sizes have been 3500 cases or less. We established the METASTROKE collaboration with the aim of validating associations from previous GWAS and identifying novel genetic associations through meta-analysis of GWAS datasets for ischaemic stroke and its subtypes.</p> <p>Methods - We meta-analysed data from 15 ischaemic stroke cohorts with a total of 12 389 individuals with ischaemic stroke and 62 004 controls, all of European ancestry. For the associations reaching genome-wide significance in METASTROKE, we did a further analysis, conditioning on the lead single nucleotide polymorphism in every associated region. Replication of novel suggestive signals was done in 13 347 cases and 29 083 controls.</p> <p>Findings - We verified previous associations for cardioembolic stroke near PITX2 (p=2·8×10−16) and ZFHX3 (p=2·28×10−8), and for large-vessel stroke at a 9p21 locus (p=3·32×10−5) and HDAC9 (p=2·03×10−12). Additionally, we verified that all associations were subtype specific. Conditional analysis in the three regions for which the associations reached genome-wide significance (PITX2, ZFHX3, and HDAC9) indicated that all the signal in each region could be attributed to one risk haplotype. We also identified 12 potentially novel loci at p<5×10−6. However, we were unable to replicate any of these novel associations in the replication cohort.</p> <p>Interpretation - Our results show that, although genetic variants can be detected in patients with ischaemic stroke when compared with controls, all associations we were able to confirm are specific to a stroke subtype. This finding has two implications. First, to maximise success of genetic studies in ischaemic stroke, detailed stroke subtyping is required. Second, different genetic pathophysiological mechanisms seem to be associated with different stroke subtypes.</p&gt

Genome-wide association study identifies a variant in HDAC9 associated with large vessel ischemic stroke

Genetic factors have been implicated in stroke risk but few replicated associations have been reported. We conducted a genome-wide association study (GWAS) in ischemic stroke and its subtypes in 3,548 cases and 5,972 controls, all of European ancestry. Replication of potential signals was performed in 5,859 cases and 6,281 controls. We replicated reported associations between variants close to PITX2 and ZFHX3 with cardioembolic stroke, and a 9p21 locus with large vessel stroke. We identified a novel association for a SNP within the histone deacetylase 9(HDAC9) gene on chromosome 7p21.1 which was associated with large vessel stroke including additional replication in a further 735 cases and 28583 controls (rs11984041, combined P = 1.87×10−11, OR=1.42 (95% CI) 1.28-1.57). All four loci exhibit evidence for heterogeneity of effect across the stroke subtypes, with some, and possibly all, affecting risk for only one subtype. This suggests differing genetic architectures for different stroke subtypes

Acquired immunodeficiency syndrome and the risk of stroke

BACKGROUND AND PURPOSE: Although acquired immunodeficiency syndrome (AIDS) is thought to increase the risk of stroke, few data exist to quantify this risk. This is the first population-based study to quantify the AIDS-associated risk of stroke. METHODS: We identified all incident ischemic stroke (IS) and intracerebral hemorrhage (ICH) cases among young adults 15 to 44 years of age in central Maryland and Washington, DC, who were discharged from any of the 46 hospitals in the study area in 1988 and 1991. Using data from the medical records, 2 neurologists reviewed each case to confirm the diagnosis. Cases of AIDS among these patients with stroke were defined using Centers for Disease Control and Prevention criteria (1987). The number of cases of AIDS in the central Maryland and Washington population during 1988 and 1991 was determined from regional health departments working with the Centers for Disease Control and Prevention. Poisson regression was used to estimate the age-, race-, and sex-adjusted relative risk of stroke associated with AIDS. RESULTS: There were 385 IS cases (6 with AIDS) and 171 ICH cases (6 with AIDS). The incidences of IS and ICH among persons with AIDS were both 0.2% per year. AIDS conferred an adjusted relative risk of 13.7 (95% confidence interval [CI], 6.1 to 30.8) for IS and 25.5 (95% CI, 11.2 to 58.0) for ICH. After exclusion of 5 cases of stroke in AIDS patients in whom other potential causes were identified, AIDS patients continued to have an increased risk of stroke with an adjusted relative risk of 9.1 (95% CI, 3.4 to 24.6) for IS and 12.7 (95% CI, 4.0 to 40.0) for ICH. CONCLUSIONS: This population-based study found that AIDS is strongly associated with both IS and ICH

Home-based subcutaneous immunoglobulin G replacement therapy under real-life conditions in children and adults with antibody deficiency

Background: Subcutaneous immunoglobulin (SCIG) therapy is an alternative to intravenous immunoglobulin (WIG) therapy.Methods: We evaluated the efficacy and safety of the SCIG Vivaglobin (R) (formerly known as Beriglobin (R) SC) under real-life conditions in a post-marketing observational study in 82 patients with primary or secondary antibody deficiencies. Health-related quality of life (HRQoL) was evaluated in a subset of 30 patients previously treated with WIG (including 11 children <14 years) using the Short Form 36 (SF-36) for patients >= 14 years of age (adults) and the Child Health Questionnaire - Parental Form 50 (CHQ-PF50) for children <14 years of age. Treatment preferences were assessed in adults.Results: The mean serum immunoglobulin G (IgG) trough level during SCIG treatment (7.5 g/L) was higher than during previous IVIG treatment (6.6 g/L; p<0.01). The investigators assessed the efficacy of SCIG therapy as "excellent" in 89% of patients. No systemic adverse drug reactions were observed. Improvements by >= 5 points were observed in 5 of 8 SF-36 subscales and in 6 of 12 CHQ-PF50 subscales. Statistically significant improvements (p <= 0.05) were observed for the SF-36 subscales of bodily pain, general health perceptions, and vitality (adults), and for the CHQ-PF50 subscales of general health perceptions, parental impact - time, parental impact - emotional, and family activities (children). Patients preferred SCIG over WIG therapy (92%) and home therapy over therapy at the clinic/physician (83%).Conclusion: This study confirms that therapy with Vivaglobin (R) at home is effective, safe, well tolerated, and improves quality of life in patients with antibody deficiency

The P2Y1 receptor is involved in the maintenance of glucose homeostasis and in insulin secretion in mice

Pancreatic β cells express several P2 receptors including P2Y1 and the modulation of insulin secretion by extracellular nucleotides has suggested that these receptors may contribute to the regulation of glucose homeostasis. To determine whether the P2Y1 receptor is involved in this process, we performed studies in P2Y1 mice. In baseline conditions, P2Y1-mice exhibited a 15% increase in glycemia and a 40% increase in insulinemia, associated with a 10% increase in body weight, pointing to a role of the P2Y1 receptor in the control of glucose metabolism. Dynamic experiments further showed that P2Y1-mice exhibited a tendency to glucose intolerance. These features were associated with a decrease in the plasma levels of free fatty acid and triglycerides. When fed a lipids and sucrose enriched diet for 15 weeks, the two genotypes no longer displayed any significant differences. To determine whether the P2Y1 receptor was directly involved in the control of insulin secretion, experiments were carried out in isolated Langerhans islets. In the presence of high concentrations of glucose, insulin secretion was significantly greater in islets from P2Y1-mice. Altogether, these results show that the P2Y1 receptor plays a physiological role in the maintenance of glucose homeostasis at least in part by regulating insulin secretion