Cognitive decline

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

Mini-Mental State Examination (MMSE) and the Modified MMSE (3MS): A psychometric comparison and normative data.

Abstract: study, 525 community-dwelling participants, aged 65-89, were divided into 2 groups: no cognitive impairment (NCI; n - 406) and Alzheimer's disease (n = 119). Both tests yielded comparable reliability estimates. Fewer years of education decreased specificity and increased sensitivity, whereas increasing age primarily decreased specificity. It is concluded that although the 2 tests produce comparable effects, the inclusion of a verbal fluency test would increase the sensitivity of the MMSE. Normative data for the NCI group, stratified for 2 age levels (65-79 and 80-89) and 2 educational levels (0-8 and 9+ years), are presented. Folstein, Folstein, and McHugh (1975) introduced the MiniMental State Examination (MMSE) as a brief, objective assessment of cognitive functioning and as a measure of changes in cognitive status. The MMSE usually can be administered in 510 min and has been employed extensively in clinical settings, community surveys, and epidemiological studies. In a recent review of the literature, Tombaugh and Mclntyre (1992) concluded that the MMSE possessed moderate to high reliability coefficients, demonstrated high levels of sensitivity for cognitive deficits in patients suffering from moderate to severe Alzheimer's disease, and reflected the cognitive decline typical of dementia patients. Criticisms of the MMSE included (a) its failure to discriminate between people with mild dementia and those who are not demented, (b) a limited ability to detect impairment caused by focal lesions, particularly those in the right hemisphere, (c) overly simple language items that reduce sensitivity to mild linguistic deficits, and (d) a large number of false-positive errors because of its bias against individuals with low education. In response to these problems, several attempts have been made to improve the MMSE. Of these, the Modified Mini-Mental State Examination (3MS; Teng & Chui, 1987) represents the most extensive revision. Teng and Chui (1987) added four additional subtests (date and place of birth, word fluency, similarities, and delayed recall of words). The maximum score was

Role of the immune system in HIV-associated neuroinflammation and neurocognitive implications

Abstract: Individuals living with HIV who are optimally treated with combination antiretroviral therapy (cART) can now lead an extended life. In spite of this remarkable survival benefit from viral suppression achieved by cART in peripheral blood, the rate of mild to moderate cognitive impairment remains high. A cognitive decline that includes impairments in attention, learning and executive function is accompanied by increased rates of mood disorders that together adversely impact the daily life of those with chronic HIV infection. The evidence is clear that cells in the brain are infected with HIV that has crossed the blood-brain barrier both as cell-free virus and within infected monocytes and T cells. Viral proteins that circulate in blood can induce brain endothelial cells to release cytokines, invoking another source of neuroinflammation. The difficulty of efficient delivery of cART to the central nervous system (CNS) contributes to elevated viral load in the CNS, resulting in a persistent HIV-associated neurocognitive disorders (HAND). The pathogenesis of HAND is multifaceted, and mounting evidence indicates that immune cells play a major role. HIV-infected monocytes and T cells not only infect brain resident cells upon migration into the CNS but also produce proinflammatory cytokines such as TNF and IL-1s, which in turn, further activate microglia and astrocytes. These activated brain resident cells, along with perivascular macrophages, are the main contributors to neuroinflammation in HIV infection and release neurotoxic factors such as excitatory amino acids and inflammatory mediators, resulting in neuronal dysfunction and death. Cytokines, which are elevated in the blood of patients with HIV infection, may also contribute to brain inflammation by entering the brain from the blood. Host factors such as aging and co-morbid conditions such as cytomegalovirus co-infection and vascular pathology are important factors that affect the HIV-host immune interactions in HAND pathogenesis. By these diverse mechanisms, HIV-1 induces a neuroinflammatory response that is likely to be a major contributor to the cognitive and behavior changes seen in HIV infection.

Motoric cognitive risk syndrome: Multicountry prevalence and dementia risk

Abstract: Objectives: Our objective is to report prevalence of motoric cognitive risk syndrome (MCR), a newly described predementia syndrome characterized by slow gait and cognitive complaints, in multiple countries, and its association with dementia risk. Methods: Pooled MCR prevalence analysis of individual data from 26,802 adults without dementia and disability aged 60 years and older from 22 cohorts from 17 countries. We also examined risk of incident cognitive impairment (Mini-Mental State Examination decline ≥4 points) and dementia associated with MCR in 4,812 individuals without dementia with baseline Mini-Mental State Examination scores ≥25 from 4 prospective cohort studies using Cox models adjusted for potential confounders. Results: At baseline, 2,808 of the 26,802 participants met MCR criteria. Pooled MCR prevalence was 9.7% (95% confidence interval [CI] 8.2%–11.2%). MCR prevalence was higher with older age but there were no sex differences. MCR predicted risk of developing incident cognitive impairment in the pooled sample (adjusted hazard ratio [aHR] 2.0, 95% CI 1.7–2.4); aHRs were 1.5 to 2.7 in the individual cohorts. MCR also predicted dementia in the pooled sample (aHR 1.9, 95% CI 1.5–2.3). The results persisted even after excluding participants with possible cognitive impairment, accounting for early dementia, and diagnostic overlap with other predementia syndromes. Conclusion: MCR is common in older adults, and is a strong and early risk factor for cognitive decline. This clinical approach can be easily applied to identify high-risk seniors in a wide variety of settings.

A Voxel-based Morphometric Study to Determine Individual Differences in Gray Matter Density Associated with Age and Cognitive Change Over Time

Abstract: Voxel-based morphometry (VBM) was used to examine the relation between age and gray matter density cross-sectionally and to study the association between gray matter density and longitudinal decline in performance on cognitive tests in healthy, non-demented elderly individuals. Participants were neuropsychologically tested at baseline and again after 3 years. Thirty-seven subjects (mean age 72.5 years) who showed a decline in cognitive test performance at follow-up were compared with 38 individually matched control subjects (mean age 71.8 years) whose performance did not change over time. Magnetic resonance imaging scans were acquired at follow-up and individual differences in regional gray matter density were examined with VBM. The largest age effects were found in various regions in the prefrontal cortex, the (medial) temporal lobes and the striate cortex. Longitudinal cognitive decline was associated with decreased gray matter density in prefrontal areas, the (medial) temporal lobes and the posterior parietal cortex. These findings suggest that prefrontal and temporal cortical regions are of particular relevance both in aging and age-related cognitive decline in healthy elderly individuals.