Montreal Cognitive Assessment for the diagnosis of Alzheimer's disease and other dementias.

BACKGROUND: Dementia is a progressive syndrome of global cognitive impairment with significant health and social care costs. Global prevalence is projected to increase, particularly in resource-limited settings. Recent policy changes in Western countries to increase detection mandates a careful examination of the diagnostic accuracy of neuropsychological tests for dementia. OBJECTIVES: To determine the diagnostic accuracy of the Montreal Cognitive Assessment (MoCA) at various thresholds for dementia and its subtypes. SEARCH METHODS: We searched MEDLINE, EMBASE, BIOSIS Previews, Science Citation Index, PsycINFO and LILACS databases to August 2012. In addition, we searched specialised sources containing diagnostic studies and reviews, including MEDION (Meta-analyses van Diagnostisch Onderzoek), DARE (Database of Abstracts of Reviews of Effects), HTA (Health Technology Assessment Database), ARIF (Aggressive Research Intelligence Facility) and C-EBLM (International Federation of Clinical Chemistry and Laboratory Medicine Committee for Evidence-based Laboratory Medicine) databases. We also searched ALOIS (Cochrane Dementia and Cognitive Improvement Group specialized register of diagnostic and intervention studies). We identified further relevant studies from the PubMed 'related articles' feature and by tracking key studies in Science Citation Index and Scopus. We also searched for relevant grey literature from the Web of Science Core Collection, including Science Citation Index and Conference Proceedings Citation Index (Thomson Reuters Web of Science), PhD theses and contacted researchers with potential relevant data. SELECTION CRITERIA: Cross-sectional designs where all participants were recruited from the same sample were sought; case-control studies were excluded due to high chance of bias. We searched for studies from memory clinics, hospital clinics, primary care and community populations. We excluded studies of early onset dementia, dementia from a secondary cause, or studies where participants were selected on the basis of a specific disease type such as Parkinson's disease or specific settings such as nursing homes. DATA COLLECTION AND ANALYSIS: We extracted dementia study prevalence and dichotomised test positive/test negative results with thresholds used to diagnose dementia. This allowed calculation of sensitivity and specificity if not already reported in the study. Study authors were contacted where there was insufficient information to complete the 2x2 tables. We performed quality assessment according to the QUADAS-2 criteria.Methodological variation in selected studies precluded quantitative meta-analysis, therefore results from individual studies were presented with a narrative synthesis. MAIN RESULTS: Seven studies were selected: three in memory clinics, two in hospital clinics, none in primary care and two in population-derived samples. There were 9422 participants in total, but most of studies recruited only small samples, with only one having more than 350 participants. The prevalence of dementia was 22% to 54% in the clinic-based studies, and 5% to 10% in population samples. In the four studies that used the recommended threshold score of 26 or over indicating normal cognition, the MoCA had high sensitivity of 0.94 or more but low specificity of 0.60 or less. AUTHORS' CONCLUSIONS: The overall quality and quantity of information is insufficient to make recommendations on the clinical utility of MoCA for detecting dementia in different settings. Further studies that do not recruit participants based on diagnoses already present (case-control design) but apply diagnostic tests and reference standards prospectively are required. Methodological clarity could be improved in subsequent DTA studies of MoCA by reporting findings using recommended guidelines (e.g. STARDdem). Thresholds lower than 26 are likely to be more useful for optimal diagnostic accuracy of MoCA in dementia, but this requires confirmation in further studies.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/14651858.CD010775.pub

Lifetime prevalence of novel psychoactive substances use among adults in the USA: Sociodemographic, mental health and illicit drug use correlates. Evidence from a population-based survey 2007–2014

INTRODUCTION: As Novel psychoactive substances (NPS) are conceived to mimic the effects of common illicit drugs, they represent a serious public health challenge due to the spike in intoxications and fatalities that have been linked to their use. This study aims to provide epidemiological data on NPS use in the USA, determining lifetime prevalence of use and defining demographic, socioeconomic, drug use patterns and mental health correlates. METHODS: This study uses secondary data from the US National Survey on Drug Use and Health (NSDUH), which is a large cross-sectional population-based survey carried out annually in the USA. We analysed data from 2007-14 (N = 307,935) using bivariate descriptive analysis and binary logistic regression to calculate prevalence and determine factors underlying NPS consumption. Adjusted odds ratios (OR) with 95% CI's were calculated for a set of selected independent variables. RESULTS AND DISCUSSION: Our analysis NSDUH from 2007-14 highlights an increase in NPS use among adults, especially among white young men aged 18 to 25. Although the level of education of NPS users was relatively higher as compared to non-users, NPS users seemed to have a less wealthy situation. However, socioeconomic vulnerability appeared to be less important than mental health issues as a correlate to NPS use. NPS users seem to have followed a pattern of polysubstance use throughout their life, which involves both traditional illicit drugs and classic synthetic drugs. As NPS use seemed to be more prevalent among people having mental health issues, the rise in their use may have a negative impact on population mental health outcomes. CONCLUSION: Further comparative research on trends in NPS use and potential public health responses would be instrumental for developing appropriate health interventions, including drug checking, education for users and training for healthcare professionals working both within emergency wards and in/outpatient addiction and mental health services

Relationships of brain cholesterol and cholesterol biosynthetic enzymes to Alzheimer’s pathology and dementia in the CFAS population-derived neuropathology cohort

Altered cholesterol metabolism is implicated in brain ageing and Alzheimer’s disease. We examined whether key genes regulating cholesterol metabolism and levels of brain cholesterol are altered in dementia and Alzheimer’s disease neuropathological change (ADNC). Temporal cortex (n = 99) was obtained from the Cognitive Function and Ageing Study. Expression of the cholesterol biosynthesis rate-limiting enzyme HMG-CoA reductase (HMGCR) and its regulator, SREBP2, were detected using immunohistochemistry. Expression of HMGCR, SREBP2, CYP46A1 and ABCA1 were quantified by qPCR in samples enriched for astrocyte and neuronal RNA following laser-capture microdissection. Total cortical cholesterol was measured using the Amplex Red assay. HMGCR and SREBP2 proteins were predominantly expressed in pyramidal neurones, and in glia. Neuronal HMGCR did not vary with ADNC, oxidative stress, neuroinflammation or dementia status. Expression of HMGCR neuronal mRNA decreased with ADNC (p = 0.022) and increased with neuronal DNA damage (p = 0.049), whilst SREBP2 increased with ADNC (p = 0.005). High or moderate tertiles for cholesterol levels were associated with increased dementia risk (OR 1.44, 1.58). APOE ε4 allele was not associated with cortical cholesterol levels. ADNC is associated with gene expression changes that may impair cholesterol biosynthesis in neurones but not astrocytes, whilst levels of cortical cholesterol show a weak relationship to dementia status

Neuropathological correlates of falling in the CC75C population-based sample of the older old.

BACKGROUND: Previous imaging studies have suggested links between brain pathologies and factors that are associated with falls such as gait, balance and daily function. Possible neuropathological correlates of older people's falls have been suggested based on brain imaging studies, but to date none have been examined in brain tissue. METHODS: Falls data collected from repeated surveys of a population-based cohort of individuals aged at least 75 years old at baseline were related to neuropathological data collected from post-mortem examination of the study's associated brain donor collection (n=212). RESULTS: Amongst people without dementia, most cerebrovascular neuropathological features examined, particularly white matter pallor, microinfarcts and microscopic atherosclerosis, were increasingly common across the subgroups categorised by no reports of falling, only one or at least two reports of falling. The overall burden of pathology was greater in those with dementia, but only microinfarcts showed a similar increase with respect to reported falling status. CONCLUSIONS: Subclinical pathologies sharing a common vascular origin are associated with increased falling amongst people with no dementia, as are microinfarcts in those with dementia. Although further research is needed to address the mechanisms of falls and their neuropathological correlates, the findings from the current study would suggest that if cerebrovascular disease prevention reduces vascular neuropathology changes this may have direct benefits in reducing falls amongst older people with or without dementia

Delirium is a strong risk factor for dementia in the oldest-old: a population-based cohort study

Recent studies suggest that delirium is associated with risk of dementia and also acceleration of decline in existing dementia. However, previous studies may have been confounded by incomplete ascertainment of cognitive status at baseline. Herein, we used a true population sample to determine if delirium is a risk factor for incident dementia and cognitive decline. We also examined the effect of delirium at the pathological level by determining associations between dementia and neuropathological markers of dementia in patients with and without a history of delirium. The Vantaa 85+ study examined 553 individuals (92% of those eligible) aged ≥85 years at baseline, 3, 5, 8 and 10 years. Brain autopsy was performed in 52%. Fixed and random-effects regression models were used to assess associations between (i) delirium and incident dementia and (ii) decline in Mini-Mental State Examination scores in the whole group. The relationship between dementia and common neuropathological markers (Alzheimer-type, infarcts and Lewy-body) was modelled, stratified by history of delirium. Delirium increased the risk of incident dementia (odds ratio 8.7, 95% confidence interval 2.1-35). Delirium was also associated with worsening dementia severity (odds ratio 3.1, 95% confidence interval 1.5-6.3) as well as deterioration in global function score (odds ratio 2.8, 95% confidence interval 1.4-5.5). In the whole study population, delirium was associated with loss of 1.0 more Mini-Mental State Examination points per year (95% confidence interval 0.11-1.89) than those with no history of delirium. In individuals with dementia and no history of delirium (n = 232), all pathologies were significantly associated with dementia. However, in individuals with delirium and dementia (n = 58), no relationship between dementia and these markers was found. For example, higher Braak stage was associated with dementia when no history of delirium (odds ratio 2.0, 95% confidence interval 1.1-3.5, P = 0.02), but in those with a history of delirium, there was no significant relationship (odds ratio 1.2, 95% confidence interval 0.2-6.7, P = 0.85). This trend for odds ratios to be closer to unity in the delirium and dementia group was observed for neuritic amyloid, apolipoprotein ε status, presence of infarcts, α-synucleinopathy and neuronal loss in substantia nigra. These findings are the first to demonstrate in a true population study that delirium is a strong risk factor for incident dementia and cognitive decline in the oldest-old. However, in this study, the relationship did not appear to be mediated by classical neuropathologies associated with dementia.Daniel H. J. Davis, Graciela Muniz Terrera, Hannah Keage, Terhi Rahkonen, Minna Oinas, Fiona E. Matthews ... et al

Improving Data Sharing in Research with Contect-free Encoded Missing Data

Lack of attention to missing data in research may result in biased results, loss of power and reduced generalizability. Registering reasons for missing values at the time of data collection, or — in the case of sharing existing data — before making data available to other teams, can save time and efforts, improve scientific value and help to prevent erroneous assumptions and biased results. To ensure that encoding of missing data is sufficient to understand the reason why data are missing, it should ideally be context-free. Therefore, 11 context-free codes of missing data were carefully designed based on three completed randomized controlled clinical trials and tested in a new randomized controlled clinical trial by an international team consisting of clinical researchers and epidemiologists with extended experience in designing and conducting trials and an Information System expert. These codes can be divided into missing due to participant and/or participation characteristics (n=6), missing by design (n=4), and due a procedural error (n=1). Broad implementation of context-free missing data encoding may enhance the possibilities of data sharing and pooling, thus allowing more powerful analyses using existing data. Keywords: missing data; data pooling; data sharing; context free encodingHATICE (www.hatice.eu) is a collaborative project co-funded by the European Union’s Seventh Framework Program (FP7, 2007-2013), under grant agreement No 305374. The research leading to these results has also been funded by the “Multimodal preventive trials for Alzheimer´s Disease: towards multinational strategies-programme: MIND-AD”, Academy of Finland (291803) and VTR, Kuopio University Hospital (5772815)

Regional differences in multidimensional aspects of health: findings from the MRC cognitive function and ageing study

BACKGROUND: Differences in mortality and health experience across regions are well recognised and UK government policy aims to address this inequality. Methods combining life expectancy and health have concentrated on specific areas, such as self-perceived health and dementia. Few have looked within country or across different areas of health. Self-perceived health, self-perceived functional impairment and cognitive impairment are linked closely to survival, as well as quality of life. This paper aims to describe regional differences in healthy life expectancy using a variety of states of health and wellbeing within the MRC Cognitive Function and Ageing Study (MRC CFAS). METHODS: MRC CFAS is a population based study of health in 13,009 individuals aged 65 years and above in five centres using identical study methodology. The interviews included self-perceived health and measures of functional and cognitive impairment. Sullivan's method was used to combine prevalence rates for cognitive and functional impairment and life expectancy to produce expectation of life in various health states. RESULTS: The prevalence of both cognitive and functional impairment increases with age and was higher in women than men, with marked centre variation in functional impairment (Newcastle and Gwynedd highest impairment). Newcastle had the shortest life expectancy of all the sites, Cambridgeshire and Oxford the longest. Centre differences in self-perceived health tended to mimic differences in life expectancy but this did not hold for cognitive or functional impairment. CONCLUSION: Self-perceived health does not show marked variation with age or sex, but does across centre even after adjustment for impairment burden. There is considerable centre variation in self-reported functional impairment but not cognitive impairment. Only variation in self-perceived health relates to the ranking of life expectancy. These data confirm that quite considerable differences in life experience exist across regions of the UK beyond basic life expectancy

Neuropathological correlates of dementia in over-80-year-old brain donors from the population-based Cambridge city over-75s cohort (CC75C) study.

Key neuropathological changes associated with late-onset dementia are not fully understood. Population-based longitudinal studies offer an opportunity to step back and examine which pathological indices best link to clinical state. CC75C is a longitudinal study of the population aged 75 and over at baseline in Cambridge, UK. We report on the first 213 participants coming to autopsy with sufficient information for an end of life dementia diagnosis. Clinical diagnosis was ascertained by examining retrospective informant interviews, survey responses, and death certificates according to DSM-IV criteria. The neuropathological protocol was based on the Consortium to Establish a Registry of Alzheimer's Disease (CERAD). Clinical dementia was present in 113 participants (53%): 67% with Alzheimer's disease, 4% vascular dementia, 22% mixed dementia, and 1% dementia with Lewy bodies. As Alzheimer-type pathology was common, the mutually blinded clinical and neuropathological diagnoses were not strongly related. Multivariable analysis identified associations between dementia during life and entorhinal cortex neuritic plaques, hippocampal diffuse plaques, neocortical neurofibrillary tangles, white matter pallor, Lewy bodies, and hippocampal atrophy. These results were consistent in those with clinical Alzheimer's disease. Vascular pathologies, especially microinfarcts, were more common in those with clinical diagnoses including vascular dementia. Alzheimer-type and cerebrovascular pathology are both common in the very old. A greater burden of these pathologies, Lewy bodies, and hippocampal atrophy, are associated with a higher risk of, but do not define, clinical dementia in old age

Cognitive performance following stroke, transient ischaemic attack, myocardial infarction, and hospitalisation:an individual participant data meta-analysis of six randomised controlled trials

BACKGROUND: Survivors of stroke are often concerned about cognitive problems, and information on the risk of cognitive problems often comes from small studies. We aimed to estimate years of cognitive ageing associated with stroke compared with transient ischaemic attack, myocardial infarction, and other hospitalisations in a large population.METHODS: Using data from six randomised controlled trials (ORIGIN, ONTARGET, TRANSCEND, COMPASS, HOPE-3, and NAVIGATE ESUS), we completed an individual participant data meta-analysis using data requested from the Public Health Research Institute to estimate the association of stroke (by type and severity), transient ischaemic attack, myocardial infarction, and other hospitalisations with cognitive performance measured at the end of each trial. We included participants in any of these randomised controlled trials with a cognitive assessment at baseline and at least one other timepoint. Cognitive performance was measured with the Mini-Mental State Examination or the Montreal Cognitive Assessment, transformed into Z scores. We estimated Z score differences in end of trial cognitive performance between people with and without events and calculated corresponding years of cognitive ageing in these trials, and additionally calculated using a population representative cohort-the Cognitive Function and Ageing Study.FINDINGS: In 64 106 participants from 55 countries, compared with no event, stroke was associated with 18 years of cognitive ageing (1487 strokes included in the model, 95% CI 10 to 28; p&lt;0·0001) and transient ischaemic attack with 3 years (660 transient ischaemic attacks included in the model, 0 to 6; p=0·021). Myocardial infarction (p=0·60) and other hospitalisations (p=0·26) were not associated with cognitive ageing. The mean difference in SD compared with people without an event was -0·84 (95% CI -0·91 to -0·76; p&lt;0·0001) for disabling stroke, and -0·12 (-0·19 to -0·05; p=0·0012) for non-disabling stroke. Haemorrhagic stroke was associated with worse cognition (-0·75, -0·95 to -0·55; p&lt;0·0001) than ischaemic stroke (-0·42, -0·48 to -0·36; p &lt;0·0001).INTERPRETATION: Stroke has a substantial effect on cognition. The effects of transient ischaemic attack were small, whereas myocardial infarction and hospitalisation had a neutral effect. Prevention of stroke could lead to a reduction in cognitive ageing in those at greatest risk.FUNDING: Population Health Research Institute and Chief Scientist Office of Scotland.</p

Behavioural and psychological symptoms in the older population without dementia - relationship with socio-demographics, health and cognition

<p>Abstract</p> <p>Background</p> <p>Behavioural and psychological symptoms are associated with dementia, but are also present in a significant number of the older population without dementia. Here we explore the distribution of behavioural and psychological symptoms in the population without dementia, and their relationship with domains and severity of health and cognitive impairment.</p> <p>Methods</p> <p>The Medical Research Council Cognitive Function and Ageing Study is a two-phase longitudinal study of ageing representative of the population aged 65 and over of England and Wales. A subsample of 1781 participants without a study diagnosis of dementia was included in this study. Information on symptoms including depression, apathy, anxiety, feelings of persecution, hallucination, agitated behaviour, elation, irritability, sleep problems, wandering, confabulation and misidentification, cognitive function, health related factors and socio-demographic information was extracted from interviews with participants and knowledgeable informants. Participants were classified according to the Mini-Mental State Examination and by criteria for subtypes of mild cognitive impairment (MCI). The prevalence of behavioural and psychological symptoms and associations with cognitive function, health and socio-demographics was examined. Co-occurrence of symptoms was tested using factor analysis.</p> <p>Results</p> <p>Most symptoms were reported more frequently in those with more severe cognitive impairment. Subjective memory complaints were the strongest independent predictor of reported symptoms, and most were reported more often in those classified as having MCI than in those with cognitive impairments that did not meet the MCI criteria. The pattern of co-occurrence of symptoms is similar to that seen in dementia.</p> <p>Conclusions</p> <p>Our results highlight that behavioural and psychological symptoms are prevalent in the cognitively impaired older population, and partly explain the variation observed in previous cohorts of individuals with MCI. Behavioural and psychological symptoms offer a target for intervention and so are an important consideration in the assessment of cognitively impaired older people.</p