Cognitive decline

About: Cognitive decline is a research topic. Over the lifetime, 29308 publications have been published within this topic receiving 1174689 citations.

The Decreasing Prevalence of Reversible Dementias: An Updated Meta-analysis

Abstract: Background In 1988, 2 meta-analyses suggested that the prevalence of reversible dementia was significantly lower than had been previously estimated. It was predicted that further work would indicate an even lower rate. The present study represents an updated meta-analysis of the true prevalence of reversible dementia. Methods MEDLINE was searched from 1987 through 2002. References were also gleaned from pertinent articles and relevant textbooks. Data were extracted on the nature and provenance of the studies, dementia etiology, and the proportion of cases that were potentially reversible and reversed. Results Fifty articles were identified of which 39 met the study criteria, representing 7042 patients of whom 5620 (87.2%) had dementia. Patients were classified according to etiology and, where possible (in 23 [59%] of 39 studies), whether the dementia partially or completely resolved. A much higher proportion of studies than was previously the case were either community-based (31%) or observed subjects from outpatient departments (54%). Alzheimer disease was still the commonest cause of dementia (56.3%) followed by a vascular etiology (20.3%). Conditions requiring neuroimaging made up only 2.2% of cases. Potentially reversible causes were seen in 9%, and only 0.6% of dementia cases actually reversed (0.29% partially, 0.31% fully). Conclusions The reported proportion of dementias that reverse is much lower than previously thought. While comorbidity should always be treated for its own sake and in the hope that cognitive decline may at least be delayed, the present findings have significant clinical and economic implications for the workup of dementia.

Montreal Cognitive Assessment (MoCA): normative study for the Portuguese population

Abstract: The Montreal Cognitive Assessment (MoCA) is a brief cognitive screening instrument with good psychometric features and an excellent sensitivity in the early detection of mild cognitive decline. The MoCA was applied to a community-based sample of cognitively healthy adults (n = 650), stratified according to sociodemographic variables (age, gender, educational level, geographic region, geographic localization, and residence area), with a distribution similar to that observed in the Portuguese population. The normative data were determined according to age and education as these were the sociodemographic variables that most significantly contributed to the prediction of the MoCA scores, explaining 49% of their variance.

Current and Remote Blood Pressure and Cognitive Decline

Abstract: ContextPrevious studies raise the possibility that blood pressure (BP) in middle age predicts later cognitive decline.ObjectiveTo examine prospectively the relationship of BP with level of and change in cognitive function in the elderly.DesignLongitudinal, population-based study comprising subjects enrolled in the East Boston component of the Established Populations for the Epidemiologic Study of the Elderly (EPESE) (1982-1983) and the Hypertension Detection and Follow-Up Program (HDFP) (1973-1974).SettingEast Boston, Mass.ParticipantsOf the 3657 participants in the EPESE with baseline BP measurements, 2068 also participated in the HDFP. Subjects were aged 65 to 102 years at baseline in the EPESE and had mental status and memory assessed at baseline and 3 and 6 years.Main Outcome MeasuresNumbers of errors on the Short Portable Mental Status Questionnaire and the East Boston Memory Test and rates of change in these numbers of errors. Subjects had BP measured both at baseline in the EPESE and 9 years before, as part of the HDFP.ResultsIn analyses adjusted for age, sex, and education, there was no strong linear association between BP and cognition. The associations found were fairly small in magnitude, and varied according to which test was used to measure cognition. There was little evidence for an effect of BP on change in cognitive function with either test, or for an effect on level of function on the memory test. In analyses of level of mental status questionnaire performance, however, elevated systolic BP (≥160 mm Hg) 9 years before baseline was associated with a 14% (95% confidence interval [CI], 4%-25%) increase in error rate, relative to the referent (130-139 mm Hg). Baseline systolic BP had a U-shaped association with the number of errors; error rates were 9% higher compared with the referent group among those with systolic BP lower than 130 mm Hg (95% CI, 1%-17%) and 7% greater (95% CI, 0%-15%) among those with elevated systolic BP. Diastolic BP 9 years before baseline also had a U-shaped association with errors on the mental status questionnaire.ConclusionThe findings do not suggest a linear association of BP with cognitive decline, but they are consistent with a more complex relationship between BP and cognition than previously appreciated.

Reducing HDAC6 ameliorates cognitive deficits in a mouse model for Alzheimer's disease.

Abstract: Histone deacetylases (HDACs) are currently being discussed as promising therapeutic targets to treat neurodegenerative diseases. However, the role of specific HDACs in cognition and neurodegeneration remains poorly understood. Here, we investigate the function of HDAC6, a class II member of the HDAC superfamily, in the adult mouse brain. We report that mice lacking HDAC6 are cognitively normal but reducing endogenous HDAC6 levels restores learning and memory and α-tubulin acetylation in a mouse model for Alzheimer's disease (AD). Our data suggest that this therapeutic effect is, at least in part, linked to the observation that loss of HDAC6 renders neurons resistant to amyloid-β-mediated impairment of mitochondrial trafficking. Thus, our study suggests that targeting HDAC6 could be a suitable strategy to ameliorate cognitive decline observed in AD.

Default mode network connectivity in stable vs progressive mild cognitive impairment

Abstract: Objective: Dysfunction of the default mode network (DMN) has been identified in prior cross-sectional fMRI studies of Alzheimer disease (AD) and mild cognitive impairment (MCI); however, no studies have examined its utility in predicting future cognitive decline. Methods: fMRI scans during a face–name memory task were acquired from a cohort of 68 subjects (25 normal control, 31 MCI, and 12 AD). Subjects with MCI were followed for 2.4 years (±0.8) to determine progression to AD. Maps of DMN connectivity were compared with a template DMN map constructed from elderly normal controls to obtain goodness-of-fit (GOF) indices of DMN expression. Indices were compared between groups and correlated with cognitive decline. Results: GOF indices were highest in normal controls, intermediate in MCI, and lowest in AD ( p r = −0.40, p Conclusions: fMRI connectivity indices distinguish patients with MCI who undergo cognitive decline and conversion to AD from those who remain stable over a 2- to 3-year follow-up period. Our data support the notion of different functional brain connectivity endophenotypes for “early” vs “late” MCI, which are associated with different baseline memory scores and different rates of progression and conversion.