Florey Department of Neuroscience and Mental Health - Research Publications

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    Outcomes of endovascular thrombectomy with and without bridging thrombolysis for acute large vessel occlusion ischaemic stroke
    Maingard, J ; Shvarts, Y ; Motyer, R ; Thijs, V ; Brennan, P ; O'Hare, A ; Looby, S ; Thornton, J ; Hirsch, JA ; Barras, CD ; Chandra, R ; Brooks, M ; Asadi, H ; Kok, HK (WILEY, 2019-03)
    BACKGROUND: Endovascular thrombectomy (EVT) for management of large vessel occlusion (LVO) acute ischaemic stroke is now current best practice. AIM: To determine if bridging intravenous (i.v.) alteplase therapy confers any clinical benefit. METHODS: A retrospective study of patients treated with EVT for LVO was performed. Outcomes were compared between patients receiving thrombolysis and EVT with EVT alone. Primary end-points were reperfusion rate, 90-day functional outcome and mortality using the modified Rankin Scale (mRS) and symptomatic intracranial haemorrhage (sICH). RESULTS: A total of 355 patients who underwent EVT was included: 210 with thrombolysis (59%) and 145 without (41%). The reperfusion rate was higher in the group receiving i.v. tissue plasminogen activator (tPA) (unadjusted odds ratio (OR) 2.2, 95% confidence interval (CI): 1.29-3.73, P = 0.004), although this effect was attenuated when all variables were considered (adjusted OR (AOR) 1.22, 95% CI: 0.60-2.5, P = 0.580). The percentage achieving functional independence (mRS 0-2) at 90 days was higher in patients who received bridging i.v. tPA (AOR 2.17, 95% CI: 1.06-4.44, P = 0.033). There was no significant difference in major complications, including sICH (AOR 1.4, 95% CI: 0.51-3.83, P = 0.512). There was lower 90-day mortality in the bridging i.v. tPA group (AOR 0.79, 95% CI: 0.36-1.74, P = 0.551). Fewer thrombectomy passes (2 versus 3, P = 0.012) were required to achieve successful reperfusion in the i.v. tPA group. Successful reperfusion (modified thrombolysis in cerebral infarction ≥2b) was the strongest predictor for 90-day functional independence (AOR 10.4, 95% CI:3.6-29.7, P < 0.001). CONCLUSION: Our study supports the current practice of administering i.v. alteplase before endovascular therapy.
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    Carotid artery stenting: Current state of evidence and future directions
    Lamanna, A ; Maingard, J ; Barras, CD ; Kok, HK ; Handelman, G ; Chandra, RV ; Thijs, V ; Brooks, DM ; Asadi, H (WILEY, 2019-04)
    Both carotid endarterectomy (CEA) and carotid artery stenting (CAS) are common treatments for carotid artery stenosis. Several randomized controlled trials (RCTs) have compared CEA to CAS in the treatment of carotid artery stenosis. These studies have suggested that CAS is more strongly associated with periprocedural stroke; however, CEA is more strongly associated with myocardial infarction. Published long-term outcomes report that CAS and CEA are similar. A reduction in complications associated with CAS has also been demonstrated over time. The symptomatic status of the patient and history of previous CEA or cervical radiotherapy are significant factors when deciding between CEA or CAS. Numerous carotid artery stents are available, varying in material, shape and design but with minimal evidence comparing stent types. The role of cerebral protection devices is unclear. Dual antiplatelet therapy is typically prescribed to prevent in-stent thrombosis, and however, evidence comparing periprocedural and postprocedural antiplatelet therapy is scarce, resulting in inconsistent guidelines. Several RCTs are underway that will aim to clarify some of these uncertainties. In this review, we summarize the development of varying techniques of CAS and studies comparing CAS to CEA as treatment options for carotid artery stenosis.
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    Global Outcome Assessment Life-long after stroke in young adults initiative-the GOAL initiative: study protocol and rationale of a multicentre retrospective individual patient data meta-analysis
    Ekker, MS ; Jacob, MA ; van Dongen, MME ; Aarnio, K ; Annamalai, AK ; Arauz, A ; Arnold, M ; Barboza, MA ; Bolognese, M ; Brouns, R ; Chuluun, B ; Chuluunbaatar, E ; Dagvajantsan, B ; Debette, S ; Don, A ; Enzinger, C ; Ekizoglu, E ; Fandler-Hoefler, S ; Fazekas, F ; Fromm, A ; Gattringer, T ; Gulli, G ; Hoffmann, M ; Hora, TF ; Jern, C ; Jood, K ; Kamouchi, M ; Kim, YS ; Kitazono, T ; Kittner, SJ ; Kleinig, TJ ; Klijn, CJM ; Korv, J ; Lee, T-H ; Leys, D ; Maaijwee, NAM ; Martinez-Majander, N ; Marto, JP ; Mehndiratta, MM ; Mifsud, V ; Montanaro, VV ; Owolabi, MO ; Patel, VB ; Phillips, MC ; Piechowski-Iozwiak, B ; Pikula, A ; Luis Ruiz-Sandoval, J ; Sarnowski, B ; Schreuder, FHBM ; Swartz, RH ; Tan, KS ; Tanne, D ; Tatlisumak, T ; Thijs, V ; Tuladhar, AM ; Viana-Baptista, M ; Vibo, R ; Wu, TY ; Yesilot, N ; Waje-Andreassen, U ; Pezzini, A ; Putaala, J ; de Leeuw, F-E (BMJ PUBLISHING GROUP, 2019-11)
    INTRODUCTION: Worldwide, 2 million patients aged 18-50 years suffer a stroke each year, and this number is increasing. Knowledge about global distribution of risk factors and aetiologies, and information about prognosis and optimal secondary prevention in young stroke patients are limited. This limits evidence-based treatment and hampers the provision of appropriate information regarding the causes of stroke, risk factors and prognosis of young stroke patients. METHODS AND ANALYSIS: The Global Outcome Assessment Life-long after stroke in young adults (GOAL) initiative aims to perform a global individual patient data meta-analysis with existing data from young stroke cohorts worldwide. All patients aged 18-50 years with ischaemic stroke or intracerebral haemorrhage will be included. Outcomes will be the distribution of stroke aetiology and (vascular) risk factors, functional outcome after stroke, risk of recurrent vascular events and death and finally the use of secondary prevention. Subgroup analyses will be made based on age, gender, aetiology, ethnicity and climate of residence. ETHICS AND DISSEMINATION: Ethical approval for the GOAL study has already been obtained from the Medical Review Ethics Committee region Arnhem-Nijmegen. Additionally and when necessary, approval will also be obtained from national or local institutional review boards in the participating centres. When needed, a standardised data transfer agreement will be provided for participating centres. We plan dissemination of our results in peer-reviewed international scientific journals and through conference presentations. We expect that the results of this unique study will lead to better understanding of worldwide differences in risk factors, causes and outcome of young stroke patients.
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    Electrocardiographic RR Interval Dynamic Analysis to Identify Acute Stroke Patients at High Risk for Atrial Fibrillation Episodes During Stroke Unit Admission
    Adami, A ; Gentile, C ; Hepp, T ; Molon, G ; Gigli, GL ; Valente, M ; Thijs, V (SPRINGER, 2019-06)
    Patients at short-term risk of paroxysmal atrial fibrillation (PAF) often exhibit increased RR interval variability during sinus rhythm. We studied if RR dynamic analysis, applied in the first hours after stroke unit (SU) admission, identified acute ischemic stroke patients at higher risk for subsequent PAF episodes detected within the SU hospitalization. Acute ischemic stroke patients underwent continuous cardiac monitoring (CCM) using standard bedside monitors immediately after SU admission. The CCM tracks from the first 48 h were analyzed using a telemedicine service (SRA clinic, Apoplex Medical, Germany). Based on the RR dynamics, the stroke risk analysis (SRA) algorithm stratified the risk for PAF as follows: low risk for PAF, high risk for PAF, presence of manifest AF. The subsequent presence/absence of PAF during the whole SU hospitalization was ruled out using all available CCMs, standard ECGs, or 24-h Holter ECGs. Two hundred patients (40% females, mean age 71 ± 16 years) were included. According to the initial SRA analysis, 111 patients (56%) were considered as low risk for PAF, 52 (26%) as high risk while 37 patients (18%) had manifest AF. A low-risk level SRA was associated with a reduced probability for subsequent PAF detection (1/111, 0.9%, 95% CI 0-4.3%) while a high-risk level SRA predicted an increased probability (20/52, 38.5% (95% CI 25-52%). RR dynamic analysis performed in the first hours after ischemic stroke may stratify patients into categories at low or high risk for forthcoming paroxysmal AF episodes detected within the SU hospitalization.
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    The combined impact of dependency on caregivers, disability, and coping strategy on quality of life after ischemic stroke
    Dewilde, S ; Annemans, L ; Lloyd, A ; Peeters, A ; Hemelsoet, D ; Vandermeeren, Y ; Desfontaines, P ; Brouns, R ; Vanhooren, G ; Cras, P ; Michielsens, B ; Redondo, P ; Thijs, V (BMC, 2019-02-07)
    BACKGROUND: To estimate the additional impact of coping and of being dependent on caregivers, over and above the large effects of disability on utility after ischemic stroke. METHODS: A total of 539 patients were recruited into an observational, retrospective study when returning for a check-up between 3 and 36 months after an ischemic stroke. Patients' modified Rankin Scale (mRS), dependency on caregivers, the Brandtstädter and Renner Coping questionnaire (with summary scores: Tenacity of Goal Pursuit (TGP) and Flexible Goal Adjustment (FGA) coping styles), EQ-5D-3 L and co-morbidities were evaluated. RESULTS: In multivariable regression, greater disability (mRS) resulted in large utility losses, between 0.06 for mRS 1 to 0.65 for mRS 5 (p < 0.0001). Dependency on caregivers caused an additional dis-utility of 0.104 (p = 0.0006) which varied by mRS (0.044, 0.060, 0.083, 0.115, 0.150 and 0.173 for mRS 0-5). The effect of coping on utility varied by coping style, by the disability level of the patient and by his or her dependency on caregivers. FGA coping was associated with additional increases in utility (p < 0.0001) over and above the effect of disability and dependency, whereas TGA had no significant impact. FGA coping was associated with larger utility changes among more disabled patients (0.018 to 0.105 additional utility, for mRS 0 to mRS 5 respectively). Dependent patients had more to gain from FGA coping than patients who function independently of caregivers: utility gains were between 0.049 and 0.072 for moderate to high levels of FGA coping. In contrast, the same positive evolution in FGA coping resulted in 0.039 and 0.057 utility gain among independent patients. Finally, we found that important stroke risk factors and co-morbidities, such as diabetes and atrial fibrillation, were not predictors of EQ-5D utility in a multivariable setting. CONCLUSIONS: This study suggests that treatment strategies targeting flexible coping styles and decreasing dependency on caregivers may lead to significant gains in quality of life above and beyond treatment strategies that solely target disability.
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    Small obliquely oriented cortical cerebellar infarctions are associated with cardioembolic stroke
    Ter Schiphorst, A ; Tatu, L ; Thijs, V ; Demattei, C ; Thouvenot, E ; Renard, D (BMC, 2019-05-18)
    BACKGROUND: A revised classification of cerebellar infarctions (CI) may uncover unrecognized associations with etiologic stroke subtypes. We hypothesized that obliquely oriented small cortical cerebellar infarction (SCCI) representing end zone infarctions on MRI would be associated with cardiac embolism. METHODS: We retrospectively analyzed consecutive stroke patients recruited between January-December 2016 in our center. Analyzed baseline characteristics: sex, age, cardiovascular risk factors, history of stroke or atrial fibrillation (AF). TOAST classification was used for determining stroke subtype. Acute infarction location (anterior/posterior/mixed anterior-posterior circulation), acute uni- or multiterritorial infarction, and acute or chronic CI/SCCI/non-SCCI were assessed by MRI, and vertebrobasilar stenosis/occlusion by vessel imaging. Pre-specified analysis was also performed in patients without known high cardioembolic risk (known AF history or acute multiterritorial infarction). RESULTS: We included 452 patients (CI in 154, isolated SCCI in 55, isolated non-SCCI in 50, and mixed SCCI/non-SCCI in 49). Both SCCI and non-SCCI were associated with AF history (SCCI, p = 0.021; non-SCCI, p = 0.004), additional acute posterior circulation infarction (p < 0.001 both CI-subtypes), multiterritorial infarctions (SCCI, p = 0.003; non-SCCI, p < 0.001) and cardioembolic more frequent than large-artery atherosclerosis origin (p < 0.001 for both CI-subtypes). SCCI was associated with older age (p < 0.001), whereas non-SCCI was associated with stroke history (p = 0.036) and vertebrobasilar stenosis/occlusion (p = 0.002). SCCI were older (p = 0.046) than non-SCCI patients, had less frequently prior stroke (p < 0.001), and more frequent cardioembolic infarction (p = 0.025). In patients without known high cardioembolic risk (n = 348), SCCI was strongly associated with subsequent cardioembolism diagnosis (OR 3.00 [CI 1.58-5.73, p < 0.001]). No such association was present in non-SCCI. CONCLUSIONS: Acute or chronic SCCI are strongly associated with a cardioembolic origin.
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    Variation in neurosurgical management of traumatic brain injury: a survey in 68 centers participating in the CENTER-TBI study
    van Essen, TA ; den Boogert, HF ; Cnossen, MC ; de Ruiter, GCW ; Haitsma, I ; Polinder, S ; Steyerberg, EW ; Menon, D ; Maas, AIR ; Lingsma, HF ; Peul, WC ; Cecilia, A ; Hadie, A ; Vanni, A ; Judith, A ; Krisztina, A ; Norberto, A ; Nada, A ; Lasse, A ; Azasevac, A ; Audny, A ; Anna, A ; Hilko, A ; Gerard, A ; Kaspars, A ; Philippe, A ; Luisa, AM ; Camelia, B ; Rafael, B ; Ronald, B ; Pal, B ; Ursula, B ; Romuald, B ; Ronny, B ; Francisco Javier, B ; Bo-Michael, B ; Antonio, B ; Remy, B ; Habib, B ; Thierry, B ; Maurizio, B ; Luigi, B ; Christopher, B ; Federico, B ; Harald, B ; Erta, B ; Morten, B ; Hugo, DB ; Pierre, B ; Peter, B ; Alexandra, B ; Vibeke, B ; Joanne, B ; Camilla, B ; Andras, B ; Monika, B ; Emiliana, C ; Rosa, CM ; Peter, C ; Lozano Guillermo, C ; Marco, C ; Elsa, C ; Carpenter, K ; Ana M, C-L ; Francesco, C ; Giorgio, C ; Arturo, C ; Giuseppe, C ; Maryse, C ; Mark, C ; Jonathan, C ; Lizzie, C-K ; Johnny, C ; Jamie, CD ; Marta, C ; Amra, C ; Nicola, C ; Endre, C ; Marek, C ; Claire, D-F ; Francois, D ; Pierre, D ; Helen, D ; Veronique, DK ; Francesco, DC ; Bart, D ; Godard, DRCW ; Dula, D ; Ding, S ; Diederik, D ; Abhishek, D ; Emma, D ; Jens, D ; Guy-Loup, D ; George, E ; Heiko, E ; Ari, E ; Patrick, E ; Erzsebet, E ; Martin, F ; Valery, FL ; Feng, J ; Kelly, F ; Francesca, F ; Gilles, F ; Ulderico, F ; Shirin, F ; Alex, F ; Pablo, G ; Damien, G ; Dashiell, G ; Gao, G ; Karin, G ; Pradeep, G ; Alexandre, G ; Lelde, G ; Benoit, G ; Ben, G ; Jagos, G ; Pedro, GA ; Francesca, G ; Russell, GL ; Deepak, G ; Juanita, HA ; Iain, H ; Jed, HA ; Raimund, H ; Eirik, H ; Daniel, H ; Astrid, H ; Stefan, H ; Lindsay, H ; Jilske, H ; Peter, HJ ; Kristine, HA ; Bram, J ; Stefan, J ; Mike, J ; Bojan, J ; Jiang, J-Y ; Kelly, J ; Konstantinos, K ; Mladen, K ; Ari, K ; Maija, K ; Thomas, K ; Riku, K ; Angelos, KG ; Balint, K ; Erwin, K ; Ksenija, K ; Daniel, K ; Lars-Owe, K ; Noemi, K ; Alfonso, L ; Linda, L ; Steven, L ; Fiona, L ; Christian, L ; Rolf, L ; Valerie, L ; Jin, L ; Leon, L ; Roger, L ; Hester, L ; Dirk, L ; Angels, L ; Andrew, MIR ; Stephen, M ; Marc, M ; Marek, M ; Sebastian, M ; Alex, M ; Geoffrey, M ; Didier, M ; Francisco, ML ; Costanza, M ; Armando, M ; Hugues, M ; Alessandro, M ; Julia, M ; Charles, M ; Catherine, M ; Bela, M ; David, M ; Tomas, M ; Cristina, M-K ; Davide, M ; Visakh, M ; Lynnette, M ; Holger, M ; Nandesh, N ; Ancuta, N ; David, N ; Virginia, N ; Daan, N ; Quentin, N ; Jozsef, N ; Mauro, O ; Annemarie, O ; Matej, O ; Fabrizio, O ; Aarno, P ; Paul, PM ; Adriana, P ; Jean-Francois, P ; Natascha, P ; Vincent, P ; Paolo, P ; PeulWilco, ; Anna, P-K ; Sebastien, PF ; Matti, P ; Horia, P ; Maria Antonia, P ; Suzanne, P ; Inigo, P ; Jussi, P ; Louis, P ; Andreea, R ; Arminas, R ; Rahul, R ; Malinka, R ; Ruben, R ; Veronika, R ; Jonathan, R ; Samuli, R ; Saulius, R ; Cecilie, R ; Olav, R ; Gerwin, R ; Jonathan, R ; Jeffrey, R ; Christina, R ; Guy, R ; Rolf, R ; Sandra, R ; Daniel, R ; Martin, R ; Marco, S ; Barbara, S ; Juan, S ; Oliver, S ; Francesca, S ; Renan, S-P ; Janos, S ; Edgar, S ; Luminita, S ; Davide, S ; Nadine, S ; Inger, S ; Barbara, S ; Silke, S ; Herbert, S ; Guus, S ; Frederik, SR ; Elisabeth, S ; Michael, S ; Ozcan, S ; Toril, S ; Lidwien, S ; Dirk, S ; Peter, S ; Abayomi, S ; Emmanuel, S ; Simon, S ; Nicole, S ; Ana, S ; Robert, S ; William, S ; Ewout, SW ; Nino, S ; Nina, S ; Anneliese, S ; Fabio Silvio, T ; Riikka, T ; Viktoria, T ; Paivi, T ; Steven, TM ; Braden, TA ; Olli, T ; Ralph, T ; Guido, T ; Alice, T ; Matt, T ; Dick, T ; Christos, T ; Luaba, TJ-F ; Tony, T ; Maria, TC ; Peter, V ; Shirley, V ; Egils, V ; Gregory, VDS ; Mathieu, VDJ ; Joukje, VDN ; Jeroen, VDTJM ; Thomas, VEA ; Wim, VH ; Caroline, VH ; Dominique, VP ; Thijs, VV ; Julia, VW ; Audrey, V ; Alessia, V ; Emmanuel, V ; Kimberley, V ; Jan, V ; Paul, VM ; Anne, V ; Rimantas, V ; Giacinta, V ; Carmen, V-L ; Victor, V ; Daphne, V ; Peter, V ; Zoltan, V ; Derick, W ; Kevin, WKW ; Lei, W ; Lars, W ; Eno, W ; Guy, W ; Lindsay, W ; Maren, WKL ; Stefan, W ; Peter, Y ; Alexander, Y ; Menashe, Z ; Yang, Z ; Agate, Z ; Fabrizio, Z (SPRINGER WIEN, 2019-03)
    BACKGROUND: Neurosurgical management of traumatic brain injury (TBI) is challenging, with only low-quality evidence. We aimed to explore differences in neurosurgical strategies for TBI across Europe. METHODS: A survey was sent to 68 centers participating in the Collaborative European Neurotrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. The questionnaire contained 21 questions, including the decision when to operate (or not) on traumatic acute subdural hematoma (ASDH) and intracerebral hematoma (ICH), and when to perform a decompressive craniectomy (DC) in raised intracranial pressure (ICP). RESULTS: The survey was completed by 68 centers (100%). On average, 10 neurosurgeons work in each trauma center. In all centers, a neurosurgeon was available within 30 min. Forty percent of responders reported a thickness or volume threshold for evacuation of an ASDH. Most responders (78%) decide on a primary DC in evacuating an ASDH during the operation, when swelling is present. For ICH, 3% would perform an evacuation directly to prevent secondary deterioration and 66% only in case of clinical deterioration. Most respondents (91%) reported to consider a DC for refractory high ICP. The reported cut-off ICP for DC in refractory high ICP, however, differed: 60% uses 25 mmHg, 18% 30 mmHg, and 17% 20 mmHg. Treatment strategies varied substantially between regions, specifically for the threshold for ASDH surgery and DC for refractory raised ICP. Also within center variation was present: 31% reported variation within the hospital for inserting an ICP monitor and 43% for evacuating mass lesions. CONCLUSION: Despite a homogeneous organization, considerable practice variation exists of neurosurgical strategies for TBI in Europe. These results provide an incentive for comparative effectiveness research to determine elements of effective neurosurgical care.
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    Genome-wide association meta-analysis of functional outcome after ischemic stroke
    Soderholm, M ; Pedersen, A ; Lorentzen, E ; Stanne, TM ; Bevan, S ; Olsson, M ; Cole, JW ; Fernandez-Cadenas, I ; Hankey, GJ ; Jimenez-Conde, J ; Jood, K ; Lee, J-M ; Lemmens, R ; Levi, C ; Mitchell, BD ; Norrving, B ; Rannikmaee, K ; Rost, NS ; Rosand, J ; Rothwell, PM ; Scott, R ; Strbian, D ; Sturm, JW ; Sudlow, C ; Traylor, M ; Thijs, V ; Tatlisumak, T ; Woo, D ; Worrall, BB ; Maguire, JM ; Lindgren, A ; Jern, C (LIPPINCOTT WILLIAMS & WILKINS, 2019-03-19)
    OBJECTIVE: To discover common genetic variants associated with poststroke outcomes using a genome-wide association (GWA) study. METHODS: The study comprised 6,165 patients with ischemic stroke from 12 studies in Europe, the United States, and Australia included in the GISCOME (Genetics of Ischaemic Stroke Functional Outcome) network. The primary outcome was modified Rankin Scale score after 60 to 190 days, evaluated as 2 dichotomous variables (0-2 vs 3-6 and 0-1 vs 2-6) and subsequently as an ordinal variable. GWA analyses were performed in each study independently and results were meta-analyzed. Analyses were adjusted for age, sex, stroke severity (baseline NIH Stroke Scale score), and ancestry. The significance level was p < 5 × 10-8. RESULTS: We identified one genetic variant associated with functional outcome with genome-wide significance (modified Rankin Scale scores 0-2 vs 3-6, p = 5.3 × 10-9). This intronic variant (rs1842681) in the LOC105372028 gene is a previously reported trans-expression quantitative trait locus for PPP1R21, which encodes a regulatory subunit of protein phosphatase 1. This ubiquitous phosphatase is implicated in brain functions such as brain plasticity. Several variants detected in this study demonstrated suggestive association with outcome (p < 10-5), some of which are within or near genes with experimental evidence of influence on ischemic stroke volume and/or brain recovery (e.g., NTN4, TEK, and PTCH1). CONCLUSIONS: In this large GWA study on functional outcome after ischemic stroke, we report one significant variant and several variants with suggestive association to outcome 3 months after stroke onset with plausible mechanistic links to poststroke recovery. Future replication studies and exploration of potential functional mechanisms for identified genetic variants are warranted.
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    Genetic variation in PLEKHG1 is associated with white matter hyperintensities (n=11,226)
    Traylor, M ; Tozer, DJ ; Croall, ID ; Ford, DML ; Olorunda, AO ; Boncoraglio, G ; Dichgans, M ; Lemmens, R ; Rosand, J ; Rost, NS ; Rothwell, PM ; Sudlow, CLM ; Thijs, V ; Rutten-Jacobs, L ; Markus, HS (LIPPINCOTT WILLIAMS & WILKINS, 2019-02-19)
    OBJECTIVE: To identify novel genetic associations with white matter hyperintensities (WMH). METHODS: We performed a genome-wide association meta-analysis of WMH volumes in 11,226 individuals, including 8,429 population-based individuals from UK Biobank and 2,797 stroke patients. Replication of novel loci was performed in an independent dataset of 1,202 individuals. In all studies, WMH were quantified using validated automated or semi-automated methods. Imputation was to either the Haplotype Reference Consortium or 1,000 Genomes Phase 3 panels. RESULTS: We identified a locus at genome-wide significance in an intron of PLEKHG1 (rs275350, β [SE] = 0.071 [0.013]; p = 1.6 × 10-8), a Rho guanine nucleotide exchange factor that is involved in reorientation of cells in the vascular endothelium. This association was validated in an independent sample (overall p value, 2.4 × 10-9). The same single nucleotide polymorphism was associated with all ischemic stroke (odds ratio [OR] [95% confidence interval (CI)] 1.07 [1.03-1.12], p = 0.00051), most strongly with the small vessel subtype (OR [95% CI] 1.09 [1.00-1.19], p = 0.044). Previous associations at 17q25 and 2p16 reached genome-wide significance in this analysis (rs3744020; β [SE] = 0.106 [0.016]; p = 1.2 × 10-11 and rs7596872; β [SE] = 0.143 [0.021]; p = 3.4 × 10-12). All identified associations with WMH to date explained 1.16% of the trait variance in UK Biobank, equivalent to 6.4% of the narrow-sense heritability. CONCLUSIONS: Genetic variation in PLEKHG1 is associated with WMH and ischemic stroke, most strongly with the small vessel subtype, suggesting it acts by promoting small vessel arteriopathy.
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    Genetic and lifestyle risk factors for MRI-defined brain infarcts in a population-based setting
    Chauhan, G ; Adams, HHH ; Satizabal, CL ; Bis, JC ; Teumer, A ; Sargurupremraj, M ; Hofer, E ; Trompet, S ; Hilal, S ; Smith, AV ; Jian, X ; Malik, R ; Traylor, M ; Pulit, SL ; Amouyel, P ; Mazoyer, B ; Zhu, Y-C ; Kaffashian, S ; Schilling, S ; Beecham, GW ; Montine, TJ ; Schellenberg, GD ; Kjartansson, O ; Gudnason, V ; Knopman, DS ; Griswold, ME ; Windham, BG ; Gottesman, RF ; Mosley, TH ; Schmidt, R ; Saba, Y ; Schmidt, H ; Takeuchi, F ; Yamaguchi, S ; Nabika, T ; Kato, N ; Rajan, KB ; Aggarwal, NT ; De Jager, PL ; Evans, DA ; Psaty, BM ; Rotter, JI ; Rice, K ; Lopez, OL ; Liao, J ; Chen, C ; Cheng, C-Y ; Wong, TY ; Ikram, MK ; van der Lee, SJ ; Amin, N ; Chouraki, V ; DeStefano, AL ; Aparicio, HJ ; Romero, JR ; Maillard, P ; DeCarli, C ; Wardlaw, JM ; Hernandez, MDCV ; Luciano, M ; Liewald, D ; Deary, IJ ; Starr, JM ; Bastin, ME ; Maniega, SM ; Slagboom, PE ; Beekman, M ; Deelen, J ; Uh, H-W ; Lemmens, R ; Brodaty, H ; Wright, MJ ; Ames, D ; Boncoraglio, GB ; Hopewell, JC ; Beecham, AH ; Blanton, SH ; Wright, CB ; Sacco, RL ; Wen, W ; Thalamuthu, A ; Armstrong, NJ ; Chong, E ; Schofield, PR ; Kwok, JB ; van der Grond, J ; Stott, DJ ; Ford, I ; Jukema, JW ; Vernooij, MW ; Hofman, A ; Uitterlinden, AG ; van der Lugt, A ; Wittfeld, K ; Grabe, HJ ; Hosten, N ; von Sarnowski, B ; Voelker, U ; Levi, C ; Jimenez-Conde, J ; Sharma, P ; Sudlow, CLM ; Rosand, J ; Woo, D ; Cole, JW ; Meschia, JF ; Slowik, A ; Thijs, V ; Lindgren, A ; Melander, O ; Grewal, RP ; Rundek, T ; Rexrode, K ; Rothwell, PM ; Arnett, DK ; Jern, C ; Johnson, JA ; Benavente, OR ; Wasssertheil-Smoller, S ; Lee, J-M ; Wong, Q ; Mitchell, BD ; Rich, SS ; McArdle, PF ; Geerlings, MI ; van der Graaf, Y ; de Bakker, PIW ; Asselbergs, FW ; Srikanth, V ; Thomson, R ; McWhirter, R ; Moran, C ; Callisaya, M ; Thanh, P ; Rutten-Jacobs, LCA ; Bevan, S ; Tzourio, C ; Mather, KA ; Sachdev, PS ; van Duijn, CM ; Worrall, BB ; Dichgans, M ; Kittner, SJ ; Markus, HS ; Ikram, MA ; Fornage, M ; Launer, LJ ; Seshadri, S ; Longstreth, WT ; Debette, S (LIPPINCOTT WILLIAMS & WILKINS, 2019-01-29)
    OBJECTIVE: To explore genetic and lifestyle risk factors of MRI-defined brain infarcts (BI) in large population-based cohorts. METHODS: We performed meta-analyses of genome-wide association studies (GWAS) and examined associations of vascular risk factors and their genetic risk scores (GRS) with MRI-defined BI and a subset of BI, namely, small subcortical BI (SSBI), in 18 population-based cohorts (n = 20,949) from 5 ethnicities (3,726 with BI, 2,021 with SSBI). Top loci were followed up in 7 population-based cohorts (n = 6,862; 1,483 with BI, 630 with SBBI), and we tested associations with related phenotypes including ischemic stroke and pathologically defined BI. RESULTS: The mean prevalence was 17.7% for BI and 10.5% for SSBI, steeply rising after age 65. Two loci showed genome-wide significant association with BI: FBN2, p = 1.77 × 10-8; and LINC00539/ZDHHC20, p = 5.82 × 10-9. Both have been associated with blood pressure (BP)-related phenotypes, but did not replicate in the smaller follow-up sample or show associations with related phenotypes. Age- and sex-adjusted associations with BI and SSBI were observed for BP traits (p value for BI, p [BI] = 9.38 × 10-25; p [SSBI] = 5.23 × 10-14 for hypertension), smoking (p [BI] = 4.4 × 10-10; p [SSBI] = 1.2 × 10-4), diabetes (p [BI] = 1.7 × 10-8; p [SSBI] = 2.8 × 10-3), previous cardiovascular disease (p [BI] = 1.0 × 10-18; p [SSBI] = 2.3 × 10-7), stroke (p [BI] = 3.9 × 10-69; p [SSBI] = 3.2 × 10-24), and MRI-defined white matter hyperintensity burden (p [BI] = 1.43 × 10-157; p [SSBI] = 3.16 × 10-106), but not with body mass index or cholesterol. GRS of BP traits were associated with BI and SSBI (p ≤ 0.0022), without indication of directional pleiotropy. CONCLUSION: In this multiethnic GWAS meta-analysis, including over 20,000 population-based participants, we identified genetic risk loci for BI requiring validation once additional large datasets become available. High BP, including genetically determined, was the most significant modifiable, causal risk factor for BI.