Lorna M Gibson

UK Biobank is a population-based cohort of half a million participants aged 40-69 years recruited between 2006 and 2010. In 2014, UK Biobank started the world's largest multi-modal imaging study, with the aim of re-inviting 100,000 participants to undergo brain, cardiac and abdominal magnetic resonance imaging, dual-energy X-ray absorptiometry and carotid ultrasound. The combination of large-scale multi-modal imaging with extensive phenotypic and genetic data offers an unprecedented resource for scientists to conduct health-related research. This article provides an in-depth overview of the imaging enhancement, including the data collected, how it is managed and processed, and future directions.

BACKGROUND: We aimed to determine the proportion of patients who had suffered a stroke and compare this to those patients with suspected stroke, and the range of differential diagnosis for suspected stroke. METHODS: We searched for prospective studies of suspected stroke in electronic databases and our personal files. We undertook a meta-analysis of these studies, aimed at determining the proportions of patients with confirmed stroke in different settings. RESULTS: We identified 29 studies involving 8,839 patients: 13 studies were from emergency departments, five from stroke units or transient ischaemic attack (TIA) clinics, three from primary care, three from ambulance services and five were unspecified. About three-quarters (74% [95% confidence interval (CI): 66 to 83%]) of patients had a diagnosis of stroke, though there was significant heterogeneity in this estimate. The five most frequent non-stroke diagnoses were seizure, syncope, sepsis, migraine and brain tumours. CONCLUSION: Patients who had not had a stroke accounted for a significant proportion of people referred to stroke services. Expertise in the differential diagnoses of stroke is needed in order to manage the patients at the point of referral.

OBJECTIVES: To determine prevalence and types of potentially serious incidental findings on magnetic resonance imaging (MRI) in apparently asymptomatic adults, describe factors associated with potentially serious incidental findings, and summarise information on follow-up and final diagnoses. DESIGN: Systematic review and meta-analyses. DATA SOURCES: Citation searches of relevant articles and authors' files in Medline and Embase (from inception to 25 April 2017). REVIEW METHODS: statistics. MAIN OUTCOME MEASURES: Prevalence of potentially serious incidental findings on MRI of the brain, thorax, abdomen, and brain and body. RESULTS: Of 5905 retrieved studies, 32 (0.5%) met the inclusion criteria (n=27 643 participants). Pooled prevalence of potentially serious incidental findings was 3.9% (95% confidence interval 0.4% to 27.1%) on brain and body MRI, 1.4% (1.0% to 2.1%) on brain MRI, 1.3% (0.2% to 8.1%) on thoracic MRI, and 1.9% (0.3% to 12.0%) on abdominal MRI. Pooled prevalence rose after including incidental findings of uncertain potential seriousness (12.8% (3.9% to 34.3%), 1.7% (1.1% to 2.6%), 3.0% (0.8% to 11.3%), and 4.5% (1.5% to 12.9%), respectively). There was generally substantial heterogeneity among included studies. About half the potentially serious incidental findings were suspected malignancies (brain, 0.6% (95% confidence interval 0.4% to 0.9%); thorax, 0.6% (0.1% to 3.1%); abdomen, 1.3% (0.2% to 9.3%); brain and body, 2.3% (0.3% to 15.4%)). There were few informative data on potential sources of between-study variation or factors associated with potentially serious incidental findings. Limited data suggested that relatively few potentially serious incidental findings had serious final diagnoses (48/234, 20.5%). CONCLUSIONS: A substantial proportion of apparently asymptomatic adults will have potentially serious incidental findings on MRI, but little is known of their health consequences. Systematic, long term follow-up studies are needed to better inform on these consequences and the implications for policies on feedback of potentially serious incidental findings. SYSTEMATIC REVIEW REGISTRATION: Prospero CRD42016029472.

BACKGROUND: After a first ischaemic stroke, further vascular events due to thromboembolism are common and often fatal. Anticoagulants could potentially reduce the risk of such events, but any benefits could be offset by an increased risk of fatal or disabling haemorrhages. OBJECTIVES: To assess the effect of prolonged anticoagulant therapy compared with placebo or open control following presumed non-cardioembolic ischaemic stroke or transient ischaemic attack. SEARCH STRATEGY: We searched the Cochrane Stroke Group Trials Register in May 2008. In June 2008 we searched three online trial registers, used Web of Science Cited Reference Search to identify new citations of previously included studies, contacted a pharmaceutical company, and also contacted authors for additional information on included trials. SELECTION CRITERIA: Randomised and quasi-randomised trials comparing at least one month of anticoagulant therapy with control in people with previous, presumed non-cardioembolic, ischaemic stroke or transient ischaemic attack. DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials for inclusion, assessed trial quality and extracted the data. MAIN RESULTS: Eleven trials involving 2487 participants were included. The quality of the nine trials which predated routine computerised tomography (CT) scanning and the use of the International Normalised Ratio to monitor anticoagulation was poor. There was no evidence of an effect of anticoagulant therapy on either the odds of death or dependency (two trials, odds ratio (OR) 0.83, 95% confidence interval (CI) 0.52 to 1.34) or of 'non-fatal stroke, myocardial infarction, or vascular death' (four trials, OR 0.96, 95% CI 0.68 to 1.37). Death from any cause (OR 0.95, 95% CI 0.73 to 1.24) and death from vascular causes (OR 0.86, 95% CI 0.66 to 1.13) were not significantly different between treatment and control. The inclusion of two recently completed trials did not alter these conclusions. There was no evidence of an effect of anticoagulant therapy on the risk of recurrent ischaemic stroke (OR 0.85, 95% CI 0.66 to 1.09). However, anticoagulants increased fatal intracranial haemorrhage (OR 2.54, 95% CI 1.19 to 5.45), and major extracranial haemorrhage (OR 3.43, 95% CI 1.94 to 6.08). This is equivalent to anticoagulant therapy causing about 11 additional fatal intracranial haemorrhages and 25 additional major extracranial haemorrhages per year for every 1000 patients given anticoagulant therapy. AUTHORS' CONCLUSIONS: Compared with control, there was no evidence of benefit from long-term anticoagulant therapy in people with presumed non-cardioembolic ischaemic stroke or transient ischaemic attack, but there was a significant bleeding risk.

The interface between cerebrovascular disease (CVD) and epilepsy is complex and multifaceted. Late-onset epilepsy (LOE) is increasingly common and is often attributed to CVD, and is indeed associated with an increased risk of stroke. This relationship is easily recognizable where there is a history of stroke, particularly involving the cerebral cortex. However, the relationship with otherwise occult, subcortical CVD is currently less well established yet causality is often invoked. In this review, we consider the diagnosis of LOE in clinical practice--including its behaviour as a potential mimic of acute ischemic stroke and transient ischemic attack; evidence for an association between occult CVD and LOE; and potential mechanisms of epileptogenesis in occult CVD, including potential interrelationships between disordered cerebral metabolism and perfusion, disrupted neurovascular unit integrity, blood-brain barrier dysfunction, and inflammation. We also discuss recently recognized issues concerning antiepileptic drug treatment and vascular risk and consider a variety of less common CVD entities associated with seizures.