| 1. |
- Hibar, Derrek P., et al.
(författare)
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Novel genetic loci associated with hippocampal volume
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (r(g) = -0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness.
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| 2. |
- Satizabal, Claudia L., et al.
(författare)
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Genetic architecture of subcortical brain structures in 38,851 individuals
- 2019
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Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 51:11, s. 1624-
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Tidskriftsartikel (refereegranskat)abstract
- Subcortical brain structures are integral to motion, consciousness, emotions and learning. We identified common genetic variation related to the volumes of the nucleus accumbens, amygdala, brainstem, caudate nucleus, globus pallidus, putamen and thalamus, using genome-wide association analyses in almost 40,000 individuals from CHARGE, ENIGMA and UK Biobank. We show that variability in subcortical volumes is heritable, and identify 48 significantly associated loci (40 novel at the time of analysis). Annotation of these loci by utilizing gene expression, methylation and neuropathological data identified 199 genes putatively implicated in neurodevelopment, synaptic signaling, axonal transport, apoptosis, inflammation/infection and susceptibility to neurological disorders. This set of genes is significantly enriched for Drosophila orthologs associated with neurodevelopmental phenotypes, suggesting evolutionarily conserved mechanisms. Our findings uncover novel biology and potential drug targets underlying brain development and disease.
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| 3. |
- De Guio, François, et al.
(författare)
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Reproducibility and variability of quantitative magnetic resonance imaging markers in cerebral small vessel disease
- 2016
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - 0271-678X. ; 36:8, s. 1319-1337
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Forskningsöversikt (refereegranskat)abstract
- Brain imaging is essential for the diagnosis and characterization of cerebral small vessel disease. Several magnetic resonance imaging markers have therefore emerged, providing new information on the diagnosis, progression, and mechanisms of small vessel disease. Yet, the reproducibility of these small vessel disease markers has received little attention despite being widely used in cross-sectional and longitudinal studies. This review focuses on the main small vessel disease-related markers on magnetic resonance imaging including: white matter hyperintensities, lacunes, dilated perivascular spaces, microbleeds, and brain volume. The aim is to summarize, for each marker, what is currently known about: (1) its reproducibility in studies with a scan-rescan procedure either in single or multicenter settings; (2) the acquisition-related sources of variability; and, (3) the techniques used to minimize this variability. Based on the results, we discuss technical and other challenges that need to be overcome in order for these markers to be reliably used as outcome measures in future clinical trials. We also highlight the key points that need to be considered when designing multicenter magnetic resonance imaging studies of small vessel disease.
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| 4. |
- Dichgans, Martin, et al.
(författare)
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METACOHORTS for the study of vascular disease and its contribution to cognitive decline and neurodegeneration : An initiative of the Joint Programme for Neurodegenerative Disease Research
- 2016
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Ingår i: Alzheimer's and Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 12:12, s. 1235-1249
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Tidskriftsartikel (refereegranskat)abstract
- Dementia is a global problem and major target for health care providers. Although up to 45% of cases are primarily or partly due to cerebrovascular disease, little is known of these mechanisms or treatments because most dementia research still focuses on pure Alzheimer's disease. An improved understanding of the vascular contributions to neurodegeneration and dementia, particularly by small vessel disease, is hampered by imprecise data, including the incidence and prevalence of symptomatic and clinically “silent” cerebrovascular disease, long-term outcomes (cognitive, stroke, or functional), and risk factors. New large collaborative studies with long follow-up are expensive and time consuming, yet substantial data to advance the field are available. In an initiative funded by the Joint Programme for Neurodegenerative Disease Research, 55 international experts surveyed and assessed available data, starting with European cohorts, to promote data sharing to advance understanding of how vascular disease affects brain structure and function, optimize methods for cerebrovascular disease in neurodegeneration research, and focus future research on gaps in knowledge. Here, we summarize the results and recommendations from this initiative. We identified data from over 90 studies, including over 660,000 participants, many being additional to neurodegeneration data initiatives. The enthusiastic response means that cohorts from North America, Australasia, and the Asia Pacific Region are included, creating a truly global, collaborative, data sharing platform, linked to major national dementia initiatives. Furthermore, the revised World Health Organization International Classification of Diseases version 11 should facilitate recognition of vascular-related brain damage by creating one category for all cerebrovascular disease presentations and thus accelerate identification of targets for dementia prevention.
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| 5. |
- Mair, Grant, et al.
(författare)
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Arterial Obstruction on Computed Tomographic or Magnetic Resonance Angiography and Response to Intravenous Thrombolytics in Ischemic Stroke
- 2017
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Ingår i: Stroke. - 0039-2499 .- 1524-4628. ; 48:2, s. 353-360
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Computed tomographic angiography and magnetic resonance angiography are used increasingly to assess arterial patency in patients with ischemic stroke. We determined which baseline angiography features predict response to intravenous thrombolytics in ischemic stroke using randomized controlled trial data.METHODS: We analyzed angiograms from the IST-3 (Third International Stroke Trial), an international, multicenter, prospective, randomized controlled trial of intravenous alteplase. Readers, masked to clinical, treatment, and outcome data, assessed prerandomization computed tomographic angiography and magnetic resonance angiography for presence, extent, location, and completeness of obstruction and collaterals. We compared angiography findings to 6-month functional outcome (Oxford Handicap Scale) and tested for interactions with alteplase, using ordinal regression in adjusted analyses. We also meta-analyzed all available angiography data from other randomized controlled trials of intravenous thrombolytics.RESULTS: In IST-3, 300 patients had prerandomization angiography (computed tomographic angiography=271 and magnetic resonance angiography=29). On multivariable analysis, more extensive angiographic obstruction and poor collaterals independently predicted poor outcome (P<0.01). We identified no significant interaction between angiography findings and alteplase effect on Oxford Handicap Scale (P≥0.075) in IST-3. In meta-analysis (5 trials of alteplase or desmoteplase, including IST-3, n=591), there was a significantly increased benefit of thrombolytics on outcome (odds ratio>1 indicates benefit) in patients with (odds ratio, 2.07; 95% confidence interval, 1.18-3.64; P=0.011) versus without (odds ratio, 0.88; 95% confidence interval, 0.58-1.35; P=0.566) arterial obstruction (P for interaction 0.017).CONCLUSIONS: Intravenous thrombolytics provide benefit to stroke patients with computed tomographic angiography or magnetic resonance angiography evidence of arterial obstruction, but the sample was underpowered to demonstrate significant treatment benefit or harm among patients with apparently patent arteries.CLINICAL TRIAL REGISTRATION: URL: http://www.isrctn.com. Unique identifier: ISRCTN25765518.
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| 6. |
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| 7. |
- Berge, Eivind, et al.
(författare)
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Effects of alteplase on survival after ischaemic stroke (IST-3) : 3 year follow-up of a randomised, controlled, open-label trial
- 2016
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Ingår i: Lancet Neurology. - 1474-4422 .- 1474-4465. ; 15:10, s. 1028-34
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The effect of alteplase on patient survival after ischaemic stroke is the subject of debate. We report the effect of intravenous alteplase on long-term survival after ischaemic stroke of participants in the Third International Stroke Trial (IST-3).METHODS: In IST-3, done at 156 hospitals in 12 countries (Australia, Europe, and the UK), participants (aged >18 years) were randomly assigned with a telephone voice-activated or web-based system in a 1:1 ratio to treatment with intravenous 0·9 mg/kg alteplase plus standard care or standard care alone within 6 h of ischaemic stroke. We followed up participants in the UK and Scandinavia (Sweden and Norway) for survival up to 3 years after randomisation using data from national registries and compared survival in the two groups with proportional hazards survival analysis, adjusting for key prognostic variables. IST-3 is registered with the ISRCTN registry, number ISRCTN25765518.FINDINGS: Between May 5, 2000, and July 27, 2011, 3035 participants were enrolled in IST-3. Of these, 1948 (64%) of 3035 participants were scheduled for analysis of 3 year survival, and 1946 (>99%) of these were included in the analysis (967 [50%] in the alteplase plus standard care group and 979 [50%] in the standard care alone group). By 3 years after randomisation, 453 (47%) of 967 participants in the alteplase plus standard care group and 494 (50%) of 979 in the standard care alone group had died (risk difference 3·6% [95% CI -0·8 to 8·1]). Participants allocated to alteplase had a significantly higher hazard of death during the first 7 days (99 [10%] of 967 died in the alteplase plus standard care group vs 65 [7%] of 979 in the standard care alone group; hazard ratio 1·52 [95% CI 1·11-2·08]; p=0·004) and a significantly lower hazard of death between 8 days and 3 years (354 [41%] of 868 vs 429 [47%] of 914; 0·78 [0·68-0·90]; p=0·007).INTERPRETATION: Alteplase treatment within 6 h after ischaemic stroke was associated with a small, non-significant reduction in risk of death at 3 years, but among individuals who survived the acute phase, treatment was associated with a significant increase in long-term survival. These results are reassuring for clinicians who have expressed concerns about the effect of alteplase on survival.FUNDING: Heart and Stroke Scotland, UK Medical Research Council, Health Foundation UK, Stroke Association UK, Research Council of Norway, AFA Insurance, Swedish Heart Lung Fund, Foundation of Marianne and Marcus Wallenberg, Polish Ministry of Science and Education, Australian Heart Foundation, Australian National Health and Medical Research Council, Swiss National Research Foundation, Swiss Heart Foundation, Assessorato alla Sanita (Regione dell'Umbria), and Danube University.
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| 8. |
- Hachinski, Vladimir, et al.
(författare)
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Preventing dementia by preventing stroke : The Berlin Manifesto
- 2019
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Ingår i: Alzheimer's and Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 15:7, s. 961-984
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Forskningsöversikt (refereegranskat)abstract
- The incidence of stroke and dementia are diverging across the world, rising for those in low- and middle-income countries and falling in those in high-income countries. This suggests that whatever factors cause these trends are potentially modifiable. At the population level, neurological disorders as a group account for the largest proportion of disability-adjusted life years globally (10%). Among neurological disorders, stroke (42%) and dementia (10%) dominate. Stroke and dementia confer risks for each other and share some of the same, largely modifiable, risk and protective factors. In principle, 90% of strokes and 35% of dementias have been estimated to be preventable. Because a stroke doubles the chance of developing dementia and stroke is more common than dementia, more than a third of dementias could be prevented by preventing stroke. Developments at the pathological, pathophysiological, and clinical level also point to new directions. Growing understanding of brain pathophysiology has unveiled the reciprocal interaction of cerebrovascular disease and neurodegeneration identifying new therapeutic targets to include protection of the endothelium, the blood-brain barrier, and other components of the neurovascular unit. In addition, targeting amyloid angiopathy aspects of inflammation and genetic manipulation hold new testable promise. In the meantime, accumulating evidence suggests that whole populations experiencing improved education, and lower vascular risk factor profiles (e.g., reduced prevalence of smoking) and vascular disease, including stroke, have better cognitive function and lower dementia rates. At the individual levels, trials have demonstrated that anticoagulation of atrial fibrillation can reduce the risk of dementia by 48% and that systolic blood pressure lower than 140 mmHg may be better for the brain. Based on these considerations, the World Stroke Organization has issued a proclamation, endorsed by all the major international organizations focused on global brain and cardiovascular health, calling for the joint prevention of stroke and dementia. This article summarizes the evidence for translation into action.
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| 9. |
- Mair, Grant, et al.
(författare)
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Effect of alteplase on the CT hyperdense artery sign and outcome after ischemic stroke.
- 2016
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Ingår i: Neurology. - 0028-3878 .- 1526-632X. ; 86:2, s. 118-25
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To investigate whether the location and extent of the CT hyperdense artery sign (HAS) at presentation affects response to IV alteplase in the randomized controlled Third International Stroke Trial (IST-3).METHODS: All prerandomization and follow-up (24-48 hours) CT brain scans in IST-3 were assessed for HAS presence, location, and extent by masked raters. We assessed whether HAS grew, persisted, shrank, or disappeared at follow-up, the association with 6-month functional outcome, and effect of alteplase. IST-3 is registered (ISRCTN25765518).RESULTS: HAS presence (vs absence) independently predicted poor 6-month outcome (increased Oxford Handicap Scale [OHS]) on adjusted ordinal regression analysis (odds ratio [OR] 0.66, p < 0.001). Outcome was worse in patients with more (vs less) extensive HAS (OR 0.61, p = 0.027) but not in proximal (vs distal) HAS (p = 0.420). Increasing age was associated with more HAS growth at follow-up (OR 1.01, p = 0.013). Treatment with alteplase increased HAS shrinkage/disappearance at follow-up (OR 0.77, p = 0.006). There was no significant difference in HAS shrinkage with alteplase in proximal (vs distal) or more (vs less) extensive HAS (p = 0.516 and p = 0.580, respectively). There was no interaction between presence vs absence of HAS and benefit of alteplase on 6-month OHS (p = 0.167).CONCLUSIONS: IV alteplase promotes measurable reduction in HAS regardless of HAS location or extent. Alteplase increased independence at 6 months in patients with and without HAS.CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for patients within 6 hours of ischemic stroke with a CT hyperdense artery sign, IV alteplase reduced intra-arterial hyperdense thrombus.
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| 10. |
- Mair, Grant, et al.
(författare)
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Effect of IV alteplase on the ischemic brain lesion at 24-48 hours after ischemic stroke.
- 2018
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Ingår i: Neurology. - 0028-3878 .- 1526-632X. ; 91:22, s. e2067-e2077
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine whether alteplase alters the development of ischemic lesions on brain imaging after stroke.METHODS: The Third International Stroke Trial (IST-3) was a randomized controlled trial of IV alteplase for ischemic stroke. We assessed CT or brain MRI at baseline (pretreatment) and 24 to 48 hours posttreatment for acute lesion visibility, extent, and swelling, masked to all other data. We analyzed associations between treatment allocation, change in brain tissue appearances between baseline and follow-up imaging, and 6-month functional outcome in IST-3. We performed a meta-analysis of randomized trials of alteplase vs control with pre- and postrandomization imaging.RESULTS: Of 3,035 patients recruited in IST-3, 2,916 had baseline and follow-up brain imaging. Progression in either lesion extent or swelling independently predicted poorer 6-month outcome (adjusted odds ratio [OR] = 0.92, 95% confidence interval [CI] 0.88-0.96, p < 0.001; OR = 0.73, 95% CI 0.66-0.79, p < 0.001, respectively). Patients allocated alteplase were less likely than controls to develop increased lesion visibility at follow-up (OR = 0.77, 95% CI 0.67-0.89, p < 0.001), but there was no evidence that alteplase reduced progression of lesion extent or swelling. In meta-analysis of 6 trials including IST-3 (n = 4,757), allocation to alteplase was associated with a reduction in ischemic lesion extent on follow-up imaging (OR = 0.85, 95% CI 0.76-0.95, p = 0.004).CONCLUSION: Alteplase was associated with reduced short-term progression in lesion visibility. In meta-analysis, alteplase reduced lesion extent. These findings may indicate that alteplase improves functional outcome by reducing tissue damage.CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that IV alteplase impedes the progression of ischemic brain lesions on imaging after stroke.
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