37 research outputs found

    Genetics of Sporadic Cerebral Amyloid Angiopathy

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    Transitoorne epileptiline amneesia

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    Mööduva mĂ€luhĂ€ire vĂ”imalikke pĂ”hjusi on palju. Isoleeritud transitoorse amneesia episoodid vĂ”ivad olla ka epilepsi kliiniliseks vĂ€ljenduseks. Kirjanduses on selle kohta kasutusel termin transitoorne epileptiline amneesia (TEA). TEA-le on iseloomulikud hilisemas eas algavad lĂŒhikese kestusega, sagedased ning tihti Ă€rkamisel tekkivad mööduvad mĂ€luhĂ€ired. Enamusel TEA-patsientidel (70%) esineb amneesiaatakkide kĂ”rval ka teisi temporaalsagara lĂ€htega epileptilisi avaldusi, kuid mööduv amneesia on ainsaks epilepsia kliiniliseks vĂ€ljenduseks umbes kolmandikul TEApatsientidel. TEA on kliiniliselt oluline probleem, kuna korrektse diagnoosi korral on esinevatele mĂ€luhĂ€iretele olemas tĂ”hus pĂ”hjuslik ravi. Artiklis on kirjeldatud TEA haigusjuhtu vanemal naisterahval, kelle probleemiks olid 2 aasta jooksul esinenud nn mĂ€lulĂŒngad, mis hĂ€irisid patsienti oluliselt ning millele ei oldud seni pĂ”hjust leitud. Eesti Arst 2009; 88(2):125−13

    Developing automated methods for disease subtyping in UK Biobank: an exemplar study on stroke.

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    Abstract Background Better phenotyping of routinely collected coded data would be useful for research and health improvement. For example, the precision of coded data for hemorrhagic stroke (intracerebral hemorrhage [ICH] and subarachnoid hemorrhage [SAH]) may be as poor as < 50%. This work aimed to investigate the feasibility and added value of automated methods applied to clinical radiology reports to improve stroke subtyping. Methods From a sub-population of 17,249 Scottish UK Biobank participants, we ascertained those with an incident stroke code in hospital, death record or primary care administrative data by September 2015, and ≄ 1 clinical brain scan report. We used a combination of natural language processing and clinical knowledge inference on brain scan reports to assign a stroke subtype (ischemic vs ICH vs SAH) for each participant and assessed performance by precision and recall at entity and patient levels. Results Of 225 participants with an incident stroke code, 207 had a relevant brain scan report and were included in this study. Entity level precision and recall ranged from 78 to 100%. Automated methods showed precision and recall at patient level that were very good for ICH (both 89%), good for SAH (both 82%), but, as expected, lower for ischemic stroke (73%, and 64%, respectively), suggesting coded data remains the preferred method for identifying the latter stroke subtype. Conclusions Our automated method applied to radiology reports provides a feasible, scalable and accurate solution to improve disease subtyping when used in conjunction with administrative coded health data. Future research should validate these findings in a different population setting

    Drug prescriptions and dementia incidence: a medication-wide association study of 17000 dementia cases among half a million participants

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    Previous studies have suggested that some medications may influence dementia risk. We conducted a hypothesis-generating medication-wide association study to investigate systematically the association between all prescription medications and incident dementia. We used a population-based cohort within the Secure Anonymised Information Linkage (SAIL) databank, comprising routinely-collected primary care, hospital admissions and mortality data from Wales, UK. We included all participants born after 1910 and registered with a SAIL general practice at ≀60 years old. Follow-up was from each participant's 60th birthday to the earliest of dementia diagnosis, deregistration from a SAIL general practice, death or the end of 2018. We considered participants exposed to a medication if they received ≄1 prescription for any of 744 medications before or during follow-up. We adjusted for sex, smoking and socioeconomic status. The outcome was any all-cause dementia code in primary care, hospital or mortality data during follow-up. We used Cox regression to calculate hazard ratios and Bonferroni-corrected p values. Of 551 344 participants, 16 998 (3%) developed dementia (median follow-up was 17 years for people who developed dementia, 10 years for those without dementia). Of 744 medications, 221 (30%) were associated with dementia. Of these, 217 (98%) were associated with increased dementia incidence, many clustering around certain indications. Four medications (all vaccines) were associated with a lower dementia incidence. Almost a third of medications were associated with dementia. The clustering of many drugs around certain indications may provide insights into early manifestations of dementia. We encourage further investigation of hypotheses generated by these results. [Abstract copyright: © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY. Published by BMJ.

    Midlife vascular risk factors and risk of incident dementia:Longitudinal cohort and Mendelian randomization analyses in the UK Biobank

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    Introduction Midlife clustering of vascular risk factors has been associated with late-life dementia, but causal effects of individual biological and lifestyle factors remain largely unknown. Methods Among 229,976 individuals (mean follow-up 9 years), we explored whether midlife cardiovascular health measured by Life's Simple 7 (LS7) is associated with incident all-cause dementia and whether the individual components of the score are causally associated with dementia. Results Adherence to the biological metrics of LS7 (blood pressure, cholesterol, glycemic status) was associated with lower incident dementia risk (hazard ratio = 0.93 per 1-point increase, 95% confidence interval [CI;0.89-0.96]). In contrast, there was no association between the composite LS7 score and the lifestyle subscore (smoking, body mass index, diet, physical activity) and incident dementia. In Mendelian randomization analyses, genetically elevated blood pressure was associated with higher risk of dementia (odds ratio = 1.31 per one-standard deviation increase, 95% CI [1.05-1.60]). Discussion These findings underscore the importance of blood pressure control in midlife to mitigate dementia risk

    Phenotypes associated with genetic determinants of type I interferon regulation in the UK Biobank:a protocol

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    BACKGROUND: Type I interferons are cytokines involved in innate immunity against viruses. Genetic disorders of type I interferon regulation are associated with a range of autoimmune and cerebrovascular phenotypes. Carriers of pathogenic variants involved in genetic disorders of type I interferons are generally considered asymptomatic. Preliminary data suggests, however, that genetically determined dysregulation of type I interferon responses is associated with autoimmunity, and may also be relevant to sporadic cerebrovascular disease and dementia. We aim to determine whether functional variants in genes involved in type I interferon regulation and signalling are associated with the risk of autoimmunity, stroke, and dementia in a population cohort.METHODS: We will perform a hypothesis-driven candidate pathway association study of type I interferon-related genes using rare variants in the UK Biobank (UKB). We will manually curate type I interferon regulation and signalling genes from a literature review and Gene Ontology, followed by clinical and functional filtering. Variants of interest will be included based on pre-defined clinical relevance and functional annotations (using LOFTEE, M-CAP and a minor allele frequency &lt;0.1%). The association of variants with 15 clinical and three neuroradiological phenotypes will be assessed with a rare variant genetic risk score and gene-level tests, using a Bonferroni-corrected p-value threshold from the number of genetic units and phenotypes tested. We will explore the association of significant genetic units with 196 additional health-related outcomes to help interpret their relevance and explore the clinical spectrum of genetic perturbations of type I interferon.ETHICS AND DISSEMINATION: The UKB has received ethical approval from the North West Multicentre Research Ethics Committee, and all participants provided written informed consent at recruitment. This research will be conducted using the UKB Resource under application number 93160. We expect to disseminate our results in a peer-reviewed journal and at an international cardiovascular conference.</p

    Identifying dementia cases with routinely collected health data: A systematic review.

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    INTRODUCTION: Prospective, population-based studies can be rich resources for dementia research. Follow-up in many such studies is through linkage to routinely collected, coded health-care data sets. We evaluated the accuracy of these data sets for dementia case identification. METHODS: We systematically reviewed the literature for studies comparing dementia coding in routinely collected data sets to any expert-led reference standard. We recorded study characteristics and two accuracy measures-positive predictive value (PPV) and sensitivity. RESULTS: We identified 27 eligible studies with 25 estimating PPV and eight estimating sensitivity. Study settings and methods varied widely. For all-cause dementia, PPVs ranged from 33%-100%, but 16/27 were >75%. Sensitivities ranged from 21% to 86%. PPVs for Alzheimer's disease (range 57%-100%) were generally higher than those for vascular dementia (range 19%-91%). DISCUSSION: Linkage to routine health-care data can achieve a high PPV and reasonable sensitivity in certain settings. Given the heterogeneity in accuracy estimates, cohorts should ideally conduct their own setting-specific validation

    Physician-Confirmed and Administrative Definitions of Stroke in UK Biobank Reflect the Same Underlying Genetic Trait

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    BACKGROUND: Stroke in UK Biobank (UKB) is ascertained via linkages to coded administrative datasets and self-report. We studied the accuracy of these codes using genetic validation. METHODS: We compiled stroke-specific and broad cerebrovascular disease (CVD) code lists (Read V2/V3, ICD-9/-10) for medical settings (hospital, death record, primary care) and self-report. Among 408,210 UKB participants, we identified all with a relevant code, creating 12 stroke definitions based on the code type and source. We performed genome-wide association studies (GWASs) for each definition, comparing summary results against the largest published stroke GWAS (MEGASTROKE), assessing genetic correlations, and replicating 32 stroke-associated loci. RESULTS: The stroke case numbers identified varied widely from 3,976 (primary care stroke-specific codes) to 19,449 (all codes, all sources). All 12 UKB stroke definitions were significantly correlated with the MEGASTROKE summary GWAS results (rg.81-1) and each other (rg.4-1). However, Bonferroni-corrected confidence intervals were wide, suggesting limited precision of some results. Six previously reported stroke-associated loci were replicated using ≄1 UKB stroke definition. CONCLUSIONS: Stroke case numbers in UKB depend on the code source and type used, with a 5-fold difference in the maximum case-sample size. All stroke definitions are significantly genetically correlated with the largest stroke GWAS to date

    Epilepsia partialis continua complicated by disseminated tuberculosis and hemophagocytic lymphohistiocytosis: a case report.

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    BACKGROUND: We describe a patient copresenting with epilepsia partialis continua, tuberculosis, and hemophagocytic lymphohistiocytosis. To our knowledge, this is the first documented case of this triad. CASE PRESENTATION: A 54-year-old black South African woman presented to a hospital in Scotland with an acute history of right-sided facial twitching, breathlessness, and several months of episodic night sweats. Clinical examination revealed pyrexia and continuous, stereotyped, right-sided facial contractions. These worsened with speech and continued through sleep. A clinical diagnosis of epilepsia partialis continua was made, and we provide a video of her seizures. Computed tomographic imaging of the chest and serous fluid analyses were consistent with a diagnosis of disseminated Mycobacterium tuberculosis. An additional diagnosis of hemophagocytic lymphohistiocytosis was made following the identification of pancytopenia and hyperferritinemia in peripheral blood, with hemophagocytosis evident in bone marrow investigation. We provide images of her hematopathology. The patient was extremely unwell and was hospitalized for 6 months, including two admissions to the intensive care unit for ventilatory support. She was treated successfully with high doses of antiepileptic drugs (benzodiazepines, levetiracetam, and phenytoin) and 12 months of oral antituberculosis therapy, and she underwent chemotherapy with 8 weeks of etoposide and dexamethasone for hemophagocytic lymphohistiocytosis, followed by 12 months of cyclosporine and prednisolone. CONCLUSIONS: This combination of pathologies is unusual, and this case report helps educate clinicians on how such a patient may present and be managed. A lack of evidence surrounding the coexpression of this triad may represent absolute rarity, underdiagnosis, or incomplete case ascertainment due to early death caused by untreated tuberculosis or hemophagocytic lymphohistiocytosis. Further research is needed

    Genome-Wide Meta-analysis identifies three novel loci associated with stroke

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    We conducted a European‐only and transancestral genome‐wide association meta‐analysis in 72,147 stroke patients and 823,869 controls using data from UK Biobank (UKB) and the MEGASTROKE consortium. We identified an exonic polymorphism in NOS3 (rs1799983, p.Glu298Asp; p = 2.2E‐8, odds ratio [OR] = 1.05, 95% confidence interval [CI] = 1.04–1.07) and variants in an intron of COL4A1 (rs9521634; p = 3.8E‐8, OR = 1.04, 95% CI = 1.03–1.06) and near DYRK1A (rs720470; p = 6.1E‐9, OR = 1.05, 95% CI = 1.03–1.07) at genome‐wide significance for stroke. Effect sizes of known stroke loci were highly correlated between UKB and MEGASTROKE. Using Mendelian randomization, we further show that genetic variation in the nitric oxide synthase–nitric oxide pathway in part affects stroke risk via variation in blood pressure
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