Thromboprophylaxis in atrial fibrillation and association with cognitive decline: systematic review.

OBJECTIVE: atrial fibrillation (AF) is associated with dementia. If AF-related cognitive decline is driven by cerebral embolic events, thromboprophylaxis may impact on this. This systematic review assessed the association between cognitive impairment and AF thromboprophylaxis. METHODS: two independent reviewers searched CINAHL, EMBASE, MEDLINE, PsycINFO, Web of Science Core Collection and Cochrane Library from inception until 12 November 2014. Eligible studies compared AF thromboprophylaxis to control with an outcome measure of cognition or dementia. Where data allowed, meta-analyses describing between-group differences in cognitive test scores or rates of incident dementia were performed. RESULTS: nineteen studies were eligible. For two prospective studies (one randomised controlled trial, RCT) comparing anticoagulation against antiplatelet therapy, change in Mini-Mental Score Examination (MMSE) score from baseline to last follow-up (maximal duration: 5.9 years) suggested a difference favouring anticoagulation (mean difference: 0.90, 95% CI: 0.29-1.51), in keeping with a trend seen in the single RCT (mean difference MMSE: 0.80, 95% CI: -0.07 to 1.67). Pooled odds ratio (OR) suggested no association with incident dementia, comparing anticoagulant to antiplatelet therapy (two studies, OR: 1.23, 95% CI: 0.80-1.91) or no treatment (three studies, OR: 0.89, 95% CI: 0.47-1.69). CONCLUSION: our analyses show no definitive evidence of cognitive benefit or harm from anticoagulation. We demonstrated a potential benefit of anticoagulation in comparison to antiplatelet over time. Larger scale studies with longer follow-up are needed to determine the true cognitive impact of AF thromboprophylaxis.

Undergraduate radiology teaching from the student's perspective.

OBJECTIVES: To obtain medical students' evaluation of the quality of undergraduate radiology teaching received, preferred teaching methods and resources. This is a follow-up project to an earlier study of junior doctors who felt that radiology teaching left them ill prepared for medical practice. METHODS: A questionnaire to third and fifth year medical students undertaking clinical rotations at Newcastle University, UK. RESULTS: The questionnaire was completed by 57/60 (95 %) of third and 37/40 (93 %) of final year medical students. Students received minimal radiology teaching in pre-clinical years, feeling this was insufficient. The majority of students rated interactive case-based teaching as effective. Self-directed learning resources such as textbooks, journals and even online learning modules were perceived as less effective. Other types of web resources rated higher. Motivation for most students when studying radiology was to achieve learning objectives needed to pass their next exams and/or to improve as a doctor. CONCLUSIONS: Medical students criticise the lack of radiology teaching in pre-clinical undergraduate years. Radiology teaching should be represented in all undergraduate years, preferably delivered via interactive teaching sessions. Currently available e-learning modules do not meet the students' learning needs and there is a call for reliable, up-to-date open access electronic resources. MAIN MESSAGES: • Radiology teaching should be represented in all pre-clinical and clinical undergraduate years. • Medical students rate interactive case-based teaching sessions as very effective. • There is a call for reliable, up-to-date open access electronic resources for medical students.

Glucose-potassium-insulin infusions in the management of post-stroke hyperglycaemia: the UK Glucose Insulin in Stroke Trial (GIST-UK).

BACKGROUND: Hyperglycaemia after acute stroke is a common finding that has been associated with an increased risk of death. We sought to determine whether treatment with glucose-potassium-insulin (GKI) infusions to maintain euglycaemia immediately after the acute event reduces death at 90 days. METHODS: Patients presenting within 24 h of stroke onset and with admission plasma glucose concentration between 6.0-17.0 mmol/L were randomly assigned to receive variable-dose-insulin GKI (intervention) or saline (control) as a continuous intravenous infusion for 24 h. The purpose of GKI infusion was to maintain capillary glucose at 4-7 mmol/L, with no glucose intervention in the control group. The primary outcome was death at 90 days, and the secondary endpoint was avoidance of death or severe disability at 90 days. Additional planned analyses were done to determine any differences in residual disability or neurological and functional recovery. The trial was powered to detect a mortality difference of 6% (sample size 2355), with 83% power, at the 5% two-sided significance level. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN 31118803) FINDINGS: The trial was stopped due to slow enrolment after 933 patients were recruited. For the intention-to-treat data, there was no significant reduction in mortality at 90 days (GKI vs control: odds ratio 1.14, 95% CI 0.86-1.51, p=0.37). There were no significant differences for secondary outcomes. In the GKI group, overall mean plasma glucose and mean systolic blood pressure were significantly lower than in the control group (mean difference in glucose 0.57 mmol/L, p<0.001; mean difference in blood pressure 9.0 mmHg, p<0.0001). INTERPRETATION: GKI infusions significantly reduced plasma glucose concentrations and blood pressure. Treatment within the trial protocol was not associated with significant clinical benefit, although the study was underpowered and alternative results cannot be excluded.

Non-valvular atrial fibrillation and cognitive decline: a longitudinal cohort study.

OBJECTIVES: non-valvular atrial fibrillation (NVAF) is an established risk factor for thromboembolism and stroke. Small cross-sectional studies suggest associations between NVAF, silent cerebral infarction and decreased cognitive function. We compared change in cognitive function between patients with recent onset NVAF and controls 12 and 36 months after baseline assessment, and examined the impact of anti-thrombotic therapy. DESIGN: prospective longitudinal cohort study with follow-up at 12 and 36 months. SETTING: Sunderland and South Tyneside, North East of England. PARTICIPANTS: community-dwelling men and women aged over 60 with recently identified NVAF or in sinus rhythm, matched for age, sex and general practice (N = 362, 174 NVAF, 188 sinus rhythm). PARTICIPANTS were stratified for use of anti-thrombotic therapy. MEASUREMENTS: assessment included stroke risk factors and a comprehensive battery of neuropsychological tests. RESULTS: at 3 years, 74 cases and 86 controls remained, giving an attrition rate for cases (59%) versus controls (52%); p = 0.15. Analysis of change in cognitive function between baseline and follow-up at 12 and 36 months revealed no clinically important differences between cases and controls, nor between subgroups on aspirin, warfarin or neither. Age and other confounders did not influence the results. CONCLUSIONS: there was no association between overall cognitive decline and NVAF after 3 years' follow-up, nor any apparent effect of anti-thrombotic therapy. This is consistent with our baseline results, but conflicts with previous studies. Cognitive decline is probably multifactorial and any influence of NVAF was not identified in this study.

Escherichia coli O157:H7 in feral swine near spinach fields and cattle, central California coast.

We investigated involvement of feral swine in contamination of agricultural fields and surface waterways with Escherichia coli O157:H7 after a nationwide outbreak traced to bagged spinach from California. Isolates from feral swine, cattle, surface water, sediment, and soil at 1 ranch were matched to the outbreak strain.

Rapid laboratory detection of meningococcal disease outbreaks caused by serogroup C Neisseria meningitidis.

Molecular subtyping is of significant importance to the recognition of outbreaks of meningococcal disease caused by serogroup C Neisseria meningitidis. We describe the application of multilocus variable number tandem repeat analysis (MLVA) for the molecular subtyping of N. meningitidis and compare its performance to that of pulsed-field gel electrophoresis (PFGE). For MLVA, a multiplex PCR assay targeting five variable number tandem repeat regions was developed and evaluated using a panel of sporadic and outbreak-associated serogroup C N. meningitidis isolates. MLVA was highly reproducible and provided results within 6 h. Overall, the discriminatory power of MLVA was equivalent to that of PFGE. The utilization of MLVA for subtyping N. meningitidis isolates provides a rapid and safer alternative to PFGE for identifying outbreaks of meningococcal disease. As such, it may provide public health officials with timely information that may minimize the spread of outbreak-related cases through prophylaxis.

Recovery of visual and functional disability following cataract surgery in older people: Sunderland Cataract Study.

PURPOSE: To examine changes in visual, psychological, and functional disability in older people waiting for cataract extraction and 6 months after surgery. SETTING: Community-based study in Northeast England. METHODS: Participants were 92 patients (mean age 78.1 years +/- 6.5 [SD], 79% female) with age-related cataract. Questionnaires were administered at time of listing for cataract extraction, 2 weeks preoperatively, and 2 and 6 months after surgery to assess visual symptoms and function, anxiety and depression, perceived health status, cognition, and activities of daily living. RESULTS: Mean waiting time was 265 +/- 64.4 days. Forty-six patients had first-eye surgery, 39 had second-eye surgery, and 7 had sequential-eye surgery (both eyes operated on during follow-up). During the waiting period, there were no significant changes in visual symptoms, cognition, or functional abilities. However, perceived health status, anxiety, and depression improved significantly during this time. For first- and second-eye patients, surgery resulted in significant improvements in all questionnaire scores, except activities of daily living. CONCLUSIONS: Despite waiting 9 months for cataract surgery, patients did not decline in visual symptoms, social functioning, or cognition. In first- and second-eye patients, successful cataract extraction resulted in significant gains in visual function, cognition, and emotional and general well-being. The benefits of cataract surgery in older people extended beyond simple measures of visual acuity.

Poststroke hyperglycemia: natural history and immediate management.

BACKGROUND AND PURPOSE: Poststroke hyperglycemia (PSH) is a frequent finding for which there is currently no evidence to justify routine treatment. The United Kingdom Glucose Insulin in Stroke Trial (GIST-UK) is the only trial of glucose modulation in acute stroke from which evidence can be derived for the immediate management of PSH. Using safety-monitoring data from the trial we aimed to describe the immediate recovery of PSH in treated and control patients, thus providing evidence for the use of glucose/potassium/insulin (GKI) infusions as a means of maintaining euglycemia. METHODS: GIST-UK is a multicenter randomized controlled trial of GKI or saline infusions in acute stroke patients presenting with mild to moderate hyperglycemia (admission plasma glucose, 6.0 to 17 mmol). We analyzed the capillary BM and plasma glucose values in the 2 treatment groups to describe the recovery of PSH and the effectiveness of the GIST treatment regimen in maintaining euglycemia. RESULTS: The majority of patients have only moderate PSH (mean plasma glucose, 8.37+/-SD 2.13). Without specific intervention, mean plasma glucose levels decline spontaneously. Treatment with the GIST GKI regimen rapidly achieved euglycemia at significantly lower levels than with saline hydration alone. Euglycemia was achieved with a median of 2 changes to the GKI regimen and a low risk of hypoglycemia. CONCLUSIONS: GKI infusions as described in the GIST trial are a safe and effective means of correcting PSH and maintaining euglycemia in the acute phase of stroke. The clinical benefits of routine management of hyperglycemia remain to be determined.

Prevalence and prediction of unrecognised diabetes mellitus and impaired glucose tolerance following acute stroke.

BACKGROUND: diabetes mellitus not only increases the risk of ischaemic stroke two- to four-fold but also adversely inXuences prognosis. The prevalence of recognised diabetes mellitus in acute stroke patients is between 8 and 20%, but between 6 and 42% of patients may have undiagnosed diabetes mellitus before presentation. Post-stroke hyperglycaemia is frequent and of limited diagnostic value and the oral glucose tolerance test assumes that the patient is clinically stable and eating normally. There is a need for a simple and reliable method to predict new diabetes mellitus in acute stroke patients. OBJECTIVES: to determine the prevalence of unrecognised diabetes mellitus and impaired glucose tolerance on hospital admission and 12 weeks later in acute stroke patients with post-stroke hyperglycaemia > or = 6.1 mmol/l. To measure the accuracy of hyperglycaemia and elevated glycosylated haemoglobin concentration in predicting the presence of unrecognised diabetes mellitus at 12 weeks. DESIGN: acute (<24 hours) stroke patients (cerebral infarction and primary intracerebral haemorrhage) with admission hyperglycaemia between 6.0 and 17 mmol/l and without a previous history of insulin-treated diabetes mellitus who were randomised into the Glucose Insulin in Stroke Trial between October 1997 and May 1999 were studied. The Glucose Insulin in Stroke Trial is a randomised controlled trial investigating the benefits of maintaining euglycaemia in acute stroke patients with mild to moderate hyperglycaemia. At 12 weeks, survivors underwent a 75 g oral glucose tolerance test. The positive predictive value and negative predictive value of admission plasma glucose > or = 6.1 mmol/l and elevated glycosylated haemoglobin concentration in predicting the presence of diabetes mellitus were used to estimate the prevalence of unrecognised diabetes mellitus in a consecutive series of 582 acute stroke admissions. RESULTS: 582 consecutive acute stroke patients were assessed for eligibility for the Glucose Insulin Stroke Trial, of whom 83 (14%) had recognised diabetes mellitus. One hundred and forty-two patients were randomised and 62 underwent a 3-month oral glucose tolerance test, of whom 26 (42%) had normal glucose tolerance, 23 (37%) had impaired glucose tolerance and 13 (21%) had diabetes mellitus. Admission plasma glucose > or = 6.1 mmol/l and glycosylated haemoglobin > or = 6.2% predicted the presence of previously unrecognised diabetes mellitus at 12 weeks with a positive predictive value of 80% and negative predictive value of 96%. The estimated prevalence of unrecognised diabetes mellitus in the total series of acute stroke admissions was 16-24%. CONCLUSIONS: one-third of all acute stroke patients may have diabetes mellitus. For patients presenting with post-stroke hyperglycaemia, impaired glucose tolerance or diabetes mellitus is present in two-thirds of survivors at 12 weeks. Admission plasma glucose > or = 6.1 mmol/l combined with glycosylated haemoglobin > or = 6.2% are good predictors of the presence of diabetes mellitus following stroke.

A systematic review of cognitive decline in the general elderly population.

BACKGROUND: The public health impact of cognitive decline and dementia is increasing as the population ages. Studies exploring therapies or risk factors for cognitive impairment require understanding of expected age-related decline. OBJECTIVE: To establish the rate of age-related cognitive decline in the general elderly population. DESIGN: Systematic review of studies of cognitive decline in the general elderly population. Medline, Embase and PsycINFO databases were searched using an adapted version of McMaster's aetiology, causation and harm strategies and the Cochrane Dementia and Cognitive Impairment Group strategy. Grey literature was explored and experts contacted. A second observer was involved at all stages and quality appraisal of included studies was performed. Included studies were representative, community-based, cohort studies of people aged over 60, incorporating individuals with dementia. RESULTS: Identification of 5990 abstracts and retrieval of 163 full texts led to inclusion of 19 papers. Heterogeneity made narrative review the appropriate method of data synthesis. Some degree of cognitive impairment with increasing age was found in all studies, although the extent varied. The prevalence of cognitive impairment and the rate of decline increased with age. Studies were of variable quality. CONCLUSIONS: Cognitive decline is almost universal in the general elderly population and increases with age. Improved communication between researchers and between clinicians to identify a core minimum data set of neuropsychological tests that could be used in different populations would support consistent study design and meta-analysis, helping to quantify the true rate of cognitive decline in the elderly and assisting diagnosis in clinical practice.