Significant Predictors Of Dementia Research Articles

INFLAMMATORY CYTOKINE, SOCIAL SUPPORT, AND HEALTH DISPARITIES IN PERSONS WITH COGNITIVE IMPAIRMENT AND DEMENTIA

Abstract The protective role of social support on cognitive functioning is extensively documented. A pro-inflammatory cytokine, Tumor necrosis factor-alpha (Tnf-alpha), might have a role in the connection between social support and dementia as a marker of systemic inflammation. This study describes the influence of lack of friends’ support and Tnf-alpha on cognitive functioning. We conducted a cross-sectional study on Health and Retirement Study participants aged 65 and above, using datasets from the 2016 interviews. Of the 9,262 participants, 72.4% had normal cognition. 21.3% had cognitive impairment, and 6.3% had dementia. Our regression model controlled with depression scores revealed that participants with a lack of friends’ support were 51% more likely to have cognitive impairment and 54% more likely to have dementia. The effect of Tnf-alpha was comparably higher on participants with dementia and cognitive impairment than on participants with normal cognition. Compared to quartile-1 (lowest Tnf-alpha levels), Quartile-4 (highest Tnf-alpha levels) was significantly associated with cognitive impairment (OR=1.60) and dementia (OR=2.37). Quartile-3 was only a significant predictor of dementia (OR=2.08). The effect of Tnf-alpha was insignificant in quartile-2 for both groups. Hispanics were 65% more, and African Americans were 67% more likely to have cognitive impairment than non-Hispanic whites. The likelihood of having dementia was even higher in racial/ethnic minorities: Hispanics were 3.3 times more, and African Americans were 2.3 times more likely to have dementia than non-Hispanic whites. Future research can focus on racial and ethnic variations in pro-inflammatory cytokines and social support among people with dementia.

Education and Literacy as Risk Factors of Dementia after Stroke and Transient Ischemic Attack: NEDICES Study.

A protective effect of education on cognitive decline after stroke has been claimed, but evidence from prospective population-based cohorts is very limited. The differential role of literacy and education on dementia after stroke remains unexplored. This research addresses the role of education and literacy in dementia incidence after stroke and transient ischemic attack (TIA). 131 participants with stroke or TIA were identified within the population-based NEDICES study (N = 5,278 persons). Participants were fully assessed at baseline (1994-1995) and incident dementia diagnosis was made by expert neurologists (DSM-IV criteria) after a mean follow-up of 3.4 years. Adjusted Cox regression analyses were applied to test the association between education, literacy, and dementia risk. Within the 131 subjects with stroke or TIA, 19 (14%) developed dementia at follow-up. The Cox's regression model (age and sex adjusted) showed that low education (HR = 3.48, 95% CI = 1.28, 9.42, p = 0.014) and literacy (HR = 3.16, 95% CI = 1.08, 9.22, p = 0.035) were significantly associated with a higher dementia risk. Low education was also associated with dementia when main confounders (i.e., cognitive/functional performance) were considered in the Cox's model. However, after including stroke recurrence, only low/null literacy (versus education) remained as significant predictor of dementia. Finally, low/null literacy showed an effect over-and-above education on dementia risk when both factors were introduced in the adjusted Cox's regression. These findings underline the importance of literacy to estimate cognitive decline after stroke in low-educated populations.

Evaluating the Causal Effects of Gestational Diabetes Mellitus, Heart Disease, and High Body Mass Index on Maternal Alzheimer's Disease and Dementia: Multivariable Mendelian Randomization.

Introduction: Gestational diabetes mellitus (GDM), heart disease (HD) and high body mass index (BMI) are strongly related to Alzheimer’s disease (AD) dementia in pregnant women. Therefore, we aimed to determine the total effects of GDM, heart disease, and high BMI on maternal AD dementia. Methods: We used data from the genome-wide association studies of European populations including more than 30,000 participants. We performed two-sample Mendelian randomization (MR) and multivariable MR (MVMR) to systematically estimate the direct effects of GDM, HD, and high BMI on maternal AD and dementia. Multiple sensitivity analyses involving classical MR approaches and expanded MR-pleiotropy residual sum and outlier analysis. Results: In two-sample MR analysis, the inverse-variance weighted method in our study demonstrated no significant causality between GDM and maternal dementia (β = −0.006 ± 0.0026, p = 0.82). This method also revealed no significant causality between high BMI and maternal dementia (β = 0.0024 ± 0.0043, p = 0.57), and it was supported by the MR-Egger regression results, which showed no causal effect of high BMI on maternal Alzheimer’s disease and dementia (β = 0.0027 ± 0.0096, p = 0.78). The IVW method showed no significant causal relationship between maternal HD and maternal Alzheimer’s disease and dementia (β = −0.05 ± 0.0042, p = 0.117) and MR-Egger regression analysis gave a similar result (β = −0.12 ± 0.0060, p = 0.079). In MVMR analysis, we found no significant causal relationship between GDM, high BMI, or HD and maternal Alzheimer’s disease and dementia (p = 0.94, 0.82, and 0.13, respectively). Thus, the MVMR estimates were consistent with our results from the two-sample MR analysis. We confirmed that these results showed no horizontal pleiotropy and enhanced the robustness of our results through multiple sensitivity analyses. Conclusion: In two-sample MR analysis, we found no significant causal relationship between GDM, HD, high BMI and maternal AD and dementia. These results differed from previous observational studies showing HD is a significant predictor of dementia. MVMR analysis supported no significant causal relationship between GDM, HD, high BMI and maternal AD and dementia. Sensitivity analysis broadly increased the robustness of two-sample MR and MVMR analysis results.

Low untreated systolic blood pressure over 18 years is associated with survival free of dementia age 90.

We hypothesized that lower untreated systolic blood pressure (SBP) would be associated with a lower risk of dementia and death up to age 95. SBP measured between 2000 and 2006 was evaluated in relationship to dementia risk and brain biomarkers from 2009-2020 (n=177) in the Gingko Evaluation of Memory Study (GEMS), mean age 95 in 2020. Participants had measurements of brain amyloid beta (Aβ) and repeat clinical-cognitive evaluations every 6 months. By 2020, only 9 of 177 patients (5%) were alive and cognitively unimpaired (CU). Mean SBP from 2000 to 2006 was 120mm Hg for nine alive/CU, 125mm Hg for alive/mild cognitive impairment (MCI), and 130mm Hg for alive/dementia (P=.03). The amount of Aβ was directly related to SBP levels. In multivariate analysis, Aβ+ in 2009 and thinner cortex were significant predictors of dementia. Excluding Aβ, SBP became a significant predictor of dementia. Low SBP untreated by antihypertensive medications was associated with significant decreased risk of dementia and less Aβ.

Immigrant Status Predicts Worse Subjective Memory Complaints

The “Immigrant Health Paradox” suggests that immigrants experience better health and lower mortality than the U.S.-born population despite their lower average socioeconomic status. However, it is unclear whether this health advantage extends to all areas of cognitive functioning. This study investigates cognitive functioning and Subjective Memory Complaints (SMCs) as a function of immigrant status and identifies predictors of cognitive decline as well as SMCs among the immigrant population. Data were drawn from the 2010 wave of the Health and Retirement Study. The sample consisted of 9,812 older adults aged 65 and older (8,873 U.S.-born and 939 foreign-born). Logistic regression was used to examine whether immigrant status was associated with cognitive functioning and SMCs, controlling for socio-demographic (age, gender, education, and marital status), health conditions (diabetes, depression, hypertension, and stroke), and functional limitations. Being foreign-born was not a significant predictor of dementia (OR:1.18, 95% CI: 0.83-1.67). However, immigrants were 41% more likely to report SMCs compared to U.S.-born respondents (OR:1.41, 95% CI: 1.17-1.69). Among the immigrant population, immigrants with less than a high school education showed four- and two-times higher odds of having dementia and reporting SMCs than those with more than high school. It is necessary to provide dementia education and screening to immigrants, especially those with low education, as this may contribute to reducing disparities in cognitive functioning within the older population.

Impaired Odor Identification of Culturally Familiar Odorants Associated with Dementia in South Korean Older Adults.

Among olfactory functions, odor identification is the most studied predictor of dementia. We aimed to verify whether patients with dementia are less aware of specific odors than cognitively normal individuals using an odor identification test, which includes odorants that are culturally familiar to South Koreans. We divided 139 older adults aged 57–79 years into the dementia and normal cognition groups. Odor identification function was assessed in all participants. We conducted hierarchical logistic regression analyses with the diagnosis of dementia as a dependent variable and three demographic characteristics, as well as 12 odor identification items, as independent variables. Impaired odor identification for herbal medicine (odds ratio (OR) = 9.420; p = 0.012) and Korean grilled meat (OR = 5.361; p = 0.019) and older age (OR = 1.176; p = 0.005) were significant predictors of dementia. Impaired odor identification of culturally familiar odorants was associated with dementia risk. This may be explained by the fact that compared with culturally non-specific universal odorants, familiar odorants are more related to episodic memory, which is impaired in the early stages of dementia. Thus, an optimal combination of odor identification items should be used for screening individuals with cognitive decline requiring further neurocognitive function tests.

The Relationship Between Linguistic Ability, Multilingualism, and Dementia.

In a recent article of the Journal of Alzheimer's Disease, Hack et al. (2019) argue that linguistic ability rather than multilingualism is a significant predictor of dementia. In their longitudinal study, they investigated 325 religious sisters who were older than 75 years of age. Self-reports were used in order to determine multilingualism. They found that speaking two or three languages did not delay the onset of dementia. However, they did find that individuals speaking four or more languages were less likely to suffer from dementia than those speaking only one language and concluded that having linguistic ability was a more significant predictor of dementia than being multilingual. However, more research is needed in order to identify the characteristics of multilingualism most salient for the risk of dementia. In this commentary, we raise several important methodological and statistical issues that are likely to have affected the findings of Hack et al.'s study. As a result, although their study makes an important contribution to the research field, drawing a conclusion at this time that linguistic ability is more a predictor of dementia than multilingualism would be premature; moreover, their preliminary results cannot be generalized to the general population.

Multilingualism and Dementia Risk: Longitudinal Analysis of the Nun Study.

Multilingualism is associated with enhanced executive function and may thus prevent cognitive decline and reduce the risk of dementia. To determine whether multilingualism is associated with delayed onset or reduced risk of dementia. Dementia was diagnosed in the Nun Study, a longitudinal study of religious sisters aged 75+ years. Multilingualism was self-reported. Dementia likelihood was determined in 325 participants using discrete-time survival analysis; sensitivity analyses (n = 106) incorporated additional linguistic measures (idea density and grammatical complexity). Multilingualism did not delay the onset of dementia. However, participants speaking four or more languages (but not two or three) were significantly less likely to develop dementia than monolinguals (OR = 0.13; 95% CI = 0.01, 0.65, adjusted for age, apolipoprotein E, and transition period). This significant protective effect of speaking four or more languages weakened (OR = 0.53; 95% CI = 0.06, 4.91) in the presence of idea density in models adjusted for education and apolipoprotein E. Linguistic ability broadly was a significant predictor of dementia, although it was written linguistic ability (specifically idea density) rather than multilingualism that was the strongest predictor. The impact of language on dementia may extend beyond number of languages spoken to encompass other indicators of linguistic ability. Further research to identify the characteristics of multilingualism most salient for risk of dementia could clarify the value, target audience, and design of interventions to promote multilingualism and other linguistic training as a strategy to reduce the risk of dementia and its individual and societal impacts.

Maintained memory in aging is associated with young epigenetic age

Epigenetic alterations during aging have been proposed to contribute to decline in physical and cognitive functions, and accelerated epigenetic aging has been associated with disease and all-cause mortality later in life. In this study, we estimated epigenetic age dynamics in groups with different memory trajectories (maintained high performance, average decline, and accelerated decline) over a 15-year period. Epigenetic (DNA-methylation [DNAm]) age was assessed, and delta age (DNAm age − chronological age) was calculated in blood samples at baseline (age: 55–65 years) and 15 years later in 52 age- and gender-matched individuals from the Betula study in Sweden. A lower delta DNAm age was observed for those with maintained memory functions compared with those with average (p = 0.035) or accelerated decline (p = 0.037). Moreover, separate analyses revealed that DNAm age at follow-up, but not chronologic age, was a significant predictor of dementia (p = 0.019). Our findings suggest that young epigenetic age contributes to maintained memory in aging.

COGNITIVE RESERVE AS INDEXED BY EDUCATIONAL AND OCCUPATIONAL ATTAINMENT MODERATES THE ASSOCIATION BETWEEN CARDIOVASCULAR DISEASE AND DEMENTIA

Cognitive reserve (CR) hypothesis suggests that those with higher levels of reserve can tolerate risk factors of dementia better than those with lower levels of reserve. We tested if higher CR, as indexed by higher educational and occupational attainments, helps to withstand deteriorative effects of cardiovascular disease on cognition. We studied CR, history of cardiovascular disease (CVD) and old age cognition in a sample of 2284 individuals from a population-based Finnish Twin Cohort study. Summary score of middle age CR was based on five questions on educational and occupational status at a mean age of 47 years. Old age cognitive status at a mean age of 74 years was determined with two validated instruments: a self-report interview for cognitive status (TELE) and the Telephone Interview for Cognitive Status (TICS). We used Finnish dementia cutoff scores of <16 and <22.5 for TELE and TICS, respectively. CVD was obtained from hospital discharge registry data. Both CR and CVD were significant predictors of dementia after a mean follow-up of 28 years. There was also a significant CR-CVD interaction indicating that CVD was more strongly associated with dementia in those with low CR compared to those with high CR. In individuals with high CR, 2.6% (TELE) / 1.3% (TICS) of those without CVD and 0% (TELE) / 0% (TICS) of those with CVD were demented. In individuals with low CR, 30.6% (TELE) / 25% (TICS) of those without CVD and 40.5% (TELE) / 37.1% (TICS) of those with CVD were demented. Moreover, the level of CR was more strongly (B = 1.24 [95%CI 1.03; 1.44]) associated with total TELE/TICS score in those with a history of CVD compared to those without a history of CVD (B= 1.00 [95%CI 0.89; 1.11]). Our results support the CR hypothesis whereby those with higher levels of reserve tolerate risk factors of dementia better than those with low levels of reserve. Our results also demonstrate that there may be subgroups who are at elevated risk for dementia due to cardiovascular disease. Detecting high risk subgroups is important for early detection of cognitive impairment and dementia.

Risk of dementia and death in the long-term follow-up of the Pittsburgh Cardiovascular Health Study–Cognition Study

IntroductionIncreasing life expectancy has resulted in a larger population of older individuals at risk of dementia. MethodsThe Cardiovascular Health Study–Cognition Study followed 532 participants from 1998–99 (mean age 79) to 2013 (mean age 93) for death and dementia. ResultsRisk of death was determined by extent of coronary artery calcium, high-sensitivity cardiac troponin, brain natriuretic peptide, and white matter grade. Significant predictors of dementia were age, apolipoprotein-E4, vocabulary raw score, hippocampal volume, ventricular size, cognitive performance, and number of blocks walked. By 2013, 160 of 532 were alive, including 19 cognitively normal. Those with normal cognition had higher grade education, better cognition test scores, greater hippocampal volume, faster gait speed, and number of blocks walked as compared with survivors who were demented. DiscussionFew survived free of dementia and disability. Prevention and delay of cognitive decline for this older population is an imperative.

Risk and prediction of dementia in patients with atrial fibrillation — A nationwide population-based cohort study

BackgroundAtrial fibrillation (AF) is associated with an increased risk of cognitive impairment and functional decline, and may contribute to development of dementia. ObjectivesData from a nationwide large-scale population-based cohort study are lacking. Besides, how best to predict the occurrence of incident dementia among AF subjects remains uncertain. MethodsA total of 332,665 AF subjects without dementia were identified as the study group from the “National Health Insurance Research Database” in Taiwan. For each study patient, one age- and sex-matched subject without AF and dementia was selected as the control group. The study end point was occurrence of dementia, and the usefulness of CHADS2 and CHA2DS2-VASc scores in predicting dementia was analyzed. ResultsDuring the follow-up, 29,012 AF patients experienced dementia with an annual incidence of 2.12%, higher than non-AF subjects (1.50%). Patients with AF possessed a higher risk of dementia with a hazard ratio (HR) of 1.420 after adjustments for age, gender, baseline differences and medication use. Among AF patients, the CHADS2 and CHA2DS2-VASc scores were significant predictors of dementia with an adjusted HR of 1.520 and 1.497 per 1 increment of the CHADS2 and CHA2DS2-VASc scores, respectively. The c-index for CHA2DS2-VASc in predicting dementia (0.611, 95% confidence interval [CI]=0.608–0.614) was significantly higher than the CHADS2 score (0.589, 95% CI=0.586–0.592) (DeLong test p<0.001). ConclusionsIn this nationwide cohort study, AF was independently associated with a higher risk of dementia. The CHA2DS2-VASc score can be used to estimate the risk of dementia in AF patients.

Cerebral basis of visual hallucinations in Parkinson's disease: Structural and functional MRI studies

The presence of visual hallucinations (VH) is a significant predictor of dementia in Parkinson's disease (PD) and it is associated with a more rapid cognitive decline. Non-demented PD patients with VH present greater neuropsychological impairment than those without VH in domains such as verbal and visual memory, language comprehension, and visuospatial and visuoperceptive functions. Frontal dysfunction has also been described in PD with VH, including deficits in verbal fluency, sustained attention, and inhibition. In PD with VH, structural and functional abnormalities within the primary visual system and visual association areas, including ventral and dorsal pathways, have been reported. Structural MRI studies have shown that non-demented PD patients with VH present grey matter reduction in parieto-occipital areas and the hippocampal head. A follow-up study performed at a mean of 30months revealed that unlike PD patients without VH, PD patients with VH frequently develop dementia associated with progressive atrophy in limbic, paralimbic and neocortical areas. Functional MRI (fMRI) studies have revealed altered activation in occipito-temporal and frontal areas in response to simple and complex visual stimuli in PD patients with VH, suggesting a marked impairment in bottom-up visual processing, as well as an attentional deficit in the pathophysiology of VH in PD.

P01-486 - White matter hyperintensities predict dementia in poststroke patients with cognitive impairment no dementia (CIND)

IntroductionLongitudinal studies of predicting dementia conversion of poststroke cognitive impairment no dementia (CIND) are limited.ObjectiveTo investigate the clinical and imaging predictors of dementia conversion in poststroke patients with CIND.AimTo understand dementia conversion of CIND.Methods143 patients with CIND (defined as impairment in at least one cognitive domain without meeting the criteria of dementia) at three months after stroke were recruited and followed up for one year. Dementia was diagnosed using the criteria of Diagnostic and Statistical Manual of Mental Disorders (4th edition, DSM-IV). MRI measurements including infarction, microbleeds, white matter hyperintensities (WMHs) and hippocampal volume were conducted. Logistic regression was performed to find the predictors of dementia at follow-up.Results16 (11.2%) out of the 143 patients developed dementia 15 months after stroke. In univariate comparisons, subjects with dementia at follow-up had older age (78.0 ± 5.3 vs.71.5 ± 8.5 years, p = 0.003) and higher NIHSS score (7.1 ± 3.5 vs.4.7 ± 3.3, p = 0.005) on admission. They also had higher frequency of old infarcts in the thalamus (31.3% vs. 11.0%, p = 0.025), larger volume of old infarcts (4.2 ± 11.2 vs. 0.7 ± 2.6 cm3, p &lt; 0.001) and WMHs volume (33.2 ± 34.0 vs. 14.2 ± 14.1 cm3, p = 0.016). In logistic regression, age (odds ratio [OR] =1.203, 95%C.I.=1.054-1.373, p = 0.006), NIHSS score on admission (OR = 1.324, 95%C.I.=1.082-1.619, p = 0.006) and WMHs volume (OR = 1.045, 95%C.I.=1.007-1.084, p = 0.019) were significant predictors of dementia at follow-up.ConclusionsWMHs volume predicts dementia in poststroke patients with CIND, suggesting subcortical ischemic vascular disease was an important origin of poststroke delayed dementia.

Prediction of All-Cause Dementia Using Neuropsychological Tests within 10 and 5 Years of Diagnosis in a Community-Based Sample

While neuropsychological tests have been identified for the early prediction of Alzheimer's disease, this has not been established for prediction of all-cause dementia. This would be helpful for clinicians concerned about the risk of progression to dementia in patients who may present with a variety of medical and neurological conditions. We wanted to determine whether neuropsychological tests could accurately predict incident dementia within 10 and five years of diagnosis in a community-based sample. The Canadian Study of Health and Aging was conducted in three waves over a 10-year period (1991-2002). We studied 1472 non-demented participants who completed neuropsychological testing in 1991 and received a diagnostic assessment for dementia in 2001 (n = 284). We also studied 1231 non-demented participants who completed neuropsychological testing in 1996 and received a diagnostic assessment in 2001 (n = 634). Diagnosticians were blinded to performance on the predictive tests. Age, education, and sex were included as covariates in all regression analysis. Ten-year prediction: 2 tests, Rey Auditory Verbal Learning Test (RAVLT) short delayed verbal recall and Wechsler Adult Intelligence Test Revised (WAIS-R) Digit Symbol, were significant predictors of dementia (sensitivity = 78%, specificity = 72%, positive likelihood ratio = 2.81). Five-year prediction: 4 tests, Wechsler Memory Scale Information, RAVLT short delayed verbal recall, animal fluency, and WAIS-R Digit Symbol, significantly predicted incident dementia (sensitivity = 75%, specificity = 74%, positive likelihood ratio = 2.90). Regression models were supported with bootstrapping estimates. Neuropsychological tests can accurately predict progression to all-cause dementia within 10 years of diagnosis in a large community-based sample of non-demented participants.

B-type natriuretic peptide as a predictor of declining cognitive function and dementia—a cohort study of an elderly general population with a 5-year follow-up

Background. Several traditional cardiovascular risk factors assessed in the middle-aged are associated with the risk of dementia, but they are known to lose much of their prognostic value when measured in the elderly. The aim of the study was to compare B-type natriuretic peptide (BNP) with previously known risk markers for dementia in their association with cognitive decline and dementia during a follow-up.Methods. A total of 464 subjects free of dementia aged 75 years or more were examined and followed up for 5 years in a prospective population-based stratified cohort study. The association of clinical variables to base-line Mini Mental State Examination score (MMSE), the decline of MMSE, and onset of dementia during the follow-up were examined.Results. The only variable to significantly associate with the decline of MMSE was BNP (beta 0.140; P = 0.019). A total of 59 new cases of dementia were diagnosed after the follow-up. Significant predictors of the occurrence of dementia over the study period were BNP (adjusted odds ratio (OR) 1.53; 95% confidence interval (CI) 1.09–2.16; P = 0.013), length of education (OR 0.50; 95% CI 0.33–0.77; P = 0.001), and diagnosis of hypertension (OR 0.53; 95% CI 0.27–0.95; P = 0.036). BNP remained as a significant predictor of dementia and the decline of MMSE even after adjustment to the base-line MMSE.Conclusions. BNP is an independent harbinger of the cognitive decline and incidence of new onset of dementia in an elderly general population. This is a ground for testing the impact of antihypertensive treatment in the prevention of cognitive impairment in those with elevated BNP.

Severity of CIND and MCI predict incidence of dementia in an ischemic stroke cohort

The utility of poststroke cognitive status, namely dementia, cognitive impairment no dementia (CIND), mild cognitive impairment (MCI), and no cognitive impairment (NCI), in predicting dementia has been previously examined. However, no studies to date have compared the ability of subtypes of MCI and CIND to predict dementia in a poststroke population. A cohort of ischemic stroke patients underwent neuropsychological assessment annually for up to 5 years. Dementia was defined using the DSM-IV criteria. Univariate and multivariable Cox proportional regression was performed to determine the ability of MCI subtypes, CIND severity, and individual domains of impairment to predict dementia. A total of 362 patients without dementia were followed up for a mean of 3.4 years (17% drop out), with 24 developing incident dementia. Older age, previous and recurrent stroke, and CIND and MCI subtypes were significant predictors of dementia. In multivariable analysis controlling for treatment allocation, patients who were older, had previous or recurrent stroke, and had either CIND moderate or multiple domain MCI with amnestic component were at elevated risk for dementia. In multivariable domain analysis, recurrent strokes, age, and previous strokes, verbal memory, and visual memory were significant predictors of dementia. Receiver operating characteristic curve analysis showed that CIND moderate (area under the curve: 0.893) and multiple domain MCI with amnestic component (area under the curve: 0.832) were significant predictors of conversion to dementia. All other classifications of cognitive impairment had areas under the curve less than 0.7. Stroke patients with cognitive impairment no dementia (CIND) moderate are at higher risk of developing dementia, while CIND mild patients are not at increased risk of developing dementia.

Risk Factors for Dementia in the Cardiovascular Health Cognition Study

Background: The Cardiovascular Health Cognition Study has evaluated the determinants of dementia among 3,608 participants that had a magnetic resonance imaging (MRI) of the brain in 1991 and were followed to 1998–1999. Methods: There were 480 incident dementia cases, 330 (69%) were classified as Alzheimer’s disease (AD). Results: In univariate analysis, low scores on the Modified Mini-Mental State Examination (3MSE) and on the Digit Symbol Substitution Test as well as declines in scores over time prior to the development of dementia were significant predictors of dementia. A high ventricular grade on the MRI (atrophy) as well as high white matter grade, a number of brain infarcts on the MRI were all determinants of dementia. Apolipoprotein E Ε4 (Apo_E-4) was also a powerful predictor of dementia. In a multivariate Cox proportional hazards model controlling for race, gender and grade, the hazard ratios for age (1.1), 3MSE score (0.9), ventricular size (1.4), white matter grade (1.8), presence of large infarcts >3 mm (1.3) and Apo_E-4 (2.1) were significant predictors of dementia. The combination of an Apo_E-4 genotype, 3MSE score <90, ≧5 ventricular grade, ≧3 white matter grade at the time of the MRI were associated with a 17-fold increased risk (95% CI: 8.6–34.9) of dementia as compared to individuals with none of the above attributes. Conclusions: Measures of cognition, Apo_E-4 and MRI of the brain are strong predictors of both dementia and of AD.

Preclinical syndromes predict dementia: the Sydney older persons study

OBJECTIVESTo identify if preclinical syndromes for Alzheimer's disease, vascular dementia, and Parkinson's disease and related dementias exist. Identification of dementia at early or even preclinical stages has important implications for...

A 10-year study of the incidence of and factors predicting dementia in Parkinson's disease.

To compare the incidence of dementia in PD with that of a control group without PD, and to assess the relationship between dementia and other features of PD. The authors recruited 83 patients with PD and 50 controls, all without dementia at initial assessment, and assessed them at regular intervals over a maximum period of 122 months. Dementia was diagnosed according to objective criteria, and included a judgment by researchers masked to subject group and to variables putatively associated with dementia. Seventeen patients fulfilled dementia criteria; no controls did so. The cumulative proportion of PD patients becoming demented by 112 months was 0.38 (95% CI 0.20 to 0.55), or 42.6 cases per 1000 years of observation. Univariate analyses showed that incident dementia in patients with PD was associated with older age at entry into the study, greater severity of neurologic symptoms, longer duration of PD, greater disability, and male sex. The association of age at onset of PD with incident dementia was of only borderline significance. Multivariate analysis found that age at entry into the study and severity of motor symptoms were significant predictors of dementia but duration of PD and age at onset of PD were not. Dementia in PD is likely to reflect interaction of the neuropathology of the basal ganglia and age-related pathology. The findings do not support the division of PD into early and late-onset cases.