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C Jonker

Publications and source records attributed to C Jonker.

At least 73 records · Page 4Linked to original sources
PubMed1997

Increased risk of mortality in Alzheimer's disease patients with higher education? A replication study.

The objective of this study was to replicate findings from an earlier study by Stern et al. of an increased risk of mortality in Alzheimer's disease (AD) patients with higher levels of education and to compare this risk with the risk of death in the elderly population. As part of a community-based follow-up study on dementia (Amsterdam Study of the Elderly [AMSTEL]) a cohort of 4,051 noninstitutionalized elderly age 65 to 84 years stratified in four 5-year strata of equal size was screened for dementia using the MMSE (Mini-Mental State Examination). Those suspected of dementia received diagnostic evaluation using the CAMDEX (Cambridge examination for mental disorders in the elderly). Clinical diagnoses of probable AD were made according to NINCDS-ADRDA criteria. Thirty-six prevalent patients were diagnosed as having AD. The suspected subcohort was followed up yearly over a period of 4 years. During the three yearly follow-ups, 30 incident patients received a diagnosis as well. After 6 years mortality data were obtained from municipality records. Cox proportional hazards models adjusted for age and sex were used to estimate the relative risk of death associated with the level of education. Relative risk of death decreased (although not statistically significant) in AD patients as level of education increased (RR = 0.86; 95% CI, 0.63 to 1.19). In the full baseline sample, relative risk of death decreased as level of education increased (RR = 0.93; 95% CI, 0.89 to 0.97). In this study we could not replicate the findings of Stern et al. of an increased risk of death in more highly educated AD patients. Several major differences between the two studies, among which difference in populations used is considered to be most important, are discussed that might explain the conflicting results. We conclude that higher education is not associated with increased risk of mortality in AD patients.

Age Factors↗
PubMed1997

[Dementia. Outlook on current developments].

The results of recent neuropathologic and genetic studies in Alzheimer's disease led to a renewed interest in differentiations within the dementia syndrome. New disease-entities can be distinguished (Lewy Body Dementia, Frontal Lobe Dementia) and other criteria have been put forward for vascular dementia. Hachinski's Ischemic Score, for many years the diagnostic criterium for vascular dementia, has been cancelled. Instead a CT- or MRI scan must demonstrate the vascular pathology in the brain. For clinical practice, the differentiation between cortical and subcortical dementia is still important. For reasons of management it appears useful to distinguish between early-onset and late-onset Alzheimer's disease. The amyloid cascade hypothesis for the pathogenesis of Alzheimer's disease is credible for the early-onset as well as the late-onset type, because results from epidemiological as well as from neurobiological studies might be fit in. Moreover, this hypothesis is promising from the point of view of developing specific therapies. Finally, the breakdown of the dementia syndrome in separate disease-entities stimulated interest in the psychiatric symptoms in these patients and activated the development of rational and symptomatic therapeutics.

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PubMed1996

Circadian rest-activity rhythm disturbances in Alzheimer's disease.

Previous studies showed circadian rhythm disturbances in patients with Alzheimer's disease. Rest-activity rhythm disturbances manifest themselves through a fragmentation of the rhythm, a weak coupling with Zeitgebers, and high levels of activity during the night. The aim of the present study was to investigate which factors contribute to the presence of these disturbances. Therefore, several rest-activity rhythm, constitutional, and environmental variables were assessed in a heterogeneous group of 34 patients with Alzheimer's disease, including presenile and senile patients living at home or in a nursing home, as well as in 11 healthy controls. Circadian rest-activity rhythm disturbances were most prominent in institutionalized patients. Regression analyses showed the involvement of the following variables. First stability of the rest-activity rhythm is associated with high levels of daytime activity and high levels of environmental light resulting from seasonal effects as well as from indoor illumination. Presenile onset contributed to instability of the rhythm. Second, fragmentation of periods of activity and rest is associated with low levels of daytime activity, and is most prominent in moderately severe dementia. Third, night-time activity level is higher during the times of the year when the days are getting shorter and lower when the days are growing longer. These findings indicate that rest-activity rhythm disturbances may improve by increasing environmental light and daytime activity, an assumption for which empirical evidence has recently been published.

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PubMed1996

Verbal and physical aggression against demented elderly by informal caregivers in The Netherlands.

This study describes the extent of verbal and/or physical aggression as reported by caregivers and correlates of each type of aggression against the demented care recipient. The extent of verbal aggression alone was 30.2% and of physical aggression, 10.7%. Verbal and physical aggression were associated with sharing the same household with the care recipient, caring for a male and caring for an elderly person more severely impaired in cognitive functioning and more dependent in Instrumental Activities of Daily Living. Verbal aggression was also associated with proving more care, and physical aggression with caring for a spouse and more psychological complaints of the caregiver. Accordingly, physical aggression does not seem to be a mere extension of verbal aggression, and different intervention strategies may be required for verbally and physically aggressive caregivers.

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PubMed1996

Effects of adjustment on the case-finding potential of cognitive tests.

Adjustment of a cognitive test for an expected level of performance improves the discrimination between brain-diseased and healthy subjects. However, this improvement is subject to severe limitations and may be worthwhile only in clinical settings, where test results tend to be low regardless of disease status. The objective of this study was to provide an empirical demonstration of these principles, applied to the detection of dementia with the Mini-Mental State Examination (MMSE). The subjects, derived from a population-based sample, consisted of 36 cases of dementia (23 diagnosed shortly after testing and 13 at follow-up 1 year later) and 301 nondemented subjects defined by a negative follow-up diagnosis. A simulated group of 179 clinically suspect normals was obtained by selecting all cases with an MMSE score below 27. Adjustment was based on the Dutch version (DART) of the National Adult Reading Test (NART), which was highly correlated (0.53) with the MMSE score of nondemented subjects. The results were in accordance with the predictions. We conclude that adjustment is unlikely to improve case finding in representative samples, but can be profitable in clinical practice, where it will be especially helpful in ruling out cerebral disease.

Adult↗
PubMed1996

Memory complaints and memory impairment in older individuals.

OBJECTIVE: To examine whether subjective memory complaints, measured with a series of four questions, are associated with performance on cognitive tests. DESIGN: Cross-sectional study of individuals, 65 to 85 years of age, who lived in the community of Amsterdam. PARTICIPANTS: Individuals were selected randomly within 5-year age strata from the patient lists of 30 general practitioners. Of the 4051 participants, 2537 nondepressed and nondemented respondents were included in the analysis. MEASURES: Four categories of subjective memory complaints were developed on the basis of answers to questions about the presence or absence of memory complaints and memory-related problems in daily functioning. Tests of cognitive function were derived from the subscales of the CAMCOG. MAIN RESULTS: Individuals with complaints and memory-related problems performed more poorly on tests of memory and memory-related functions. This relationship was strengthened after adjusting for age, sex, and premorbid verbal intelligence, all of which were related to complaint status and to performance on cognitive tests. CONCLUSION: Simple questions about memory function are related to memory performance in nondepressed, nondemented community-dwelling older people. Subjective memory complaints may be a promising indicator of memory impairment that signals the need for follow-up.

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PubMed1996

Subjective memory complaints may announce dementia.

Whether subjective memory complaints in the absence of objective memory decline can predict future dementia has been investigated only in highly selected clinical and volunteer cohorts. Our study examines this question in a subsample of AMSTEL (Amsterdam Study of the Elderly), a longitudinal population study on cognitive decline and dementia. Subjects (aged 65 to 84 years; n = 357) without dementia or other psychiatric disorders at baseline were followed for 3 years. After this interval, 16 of 203 re-examined patients developed a dementia. Logistic regression analyses indicated that memory complaints at baseline contributed a small but significant amount of diagnostic information. However, the most powerful predictor of future dementia was deficient memory performance. We conclude that subjective memory complaints may predict dementia within 3 years, particularly when there are objective signs of memory deterioration.

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PubMed1996

Cross-national interrater reliability of dementia diagnosis in the elderly and factors associated with disagreement.

Thirteen researchers from five centers in Australia, Germany, the Netherlands, United Kingdom, and United States applied DSM-III-R and Clinical Dementia Rating (CDR) syndrome-level dementia criteria to written vignettes of 100 elderly people identified in clinics or community surveys. Subjects ranged in type from cognitively intact to severely demented and many were also frail, partially sighted, or deaf. This paper concerns reliability within and between centers, and the relationship between reliability and factors such as diagnostic criteria, dementia severity, and respondents' clinical characteristics. Within-center interrater reliability was high, more so for "yes-no" DSM-III-R diagnoses than the multi-level CDR. Between-center rates were lower but still moderate to good. Concordance was lower for intermediate dementia levels than for no dementia and severe dementia. Physical disability made an additional contribution to uncertainty but deafness, poor vision, anxiety, and depression had no discernible effects. Reliability levels are likely to be lower in representative aged populations than in carefully selected clinical groups.

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PubMed1996

[Item series of the cognitive screening test compared to those of the mini-mental status examination].

The items of the ¿mini-mental state examination' (MMSE) and a Dutch dementia screening instrument, the ¿cognitive screening test' (CST), as well as the ¿geriatric mental status schedule' (GMS) and the ¿Dutch adult reading test' (DART), were administered to 4051 elderly people aged 65 to 84 years. This study was part of the Amsterdam Study of the Elderly (AMSTEL-project), which is a population survey of cognitive decline and dementia. Based on the item-pool, CST and MMSE scores were calculated. Both tests were comparable as far as their validity as dementia screeners is concerned (dementia criterion was GMS Organic syndrome, cut-point 2/3). The abbreviated version of the CST (CST-14) has a somewhat lower validity. The reliabilities of the unabbreviated CST (CST-20) and the MMSE are also comparable. The influence of age, education, depression, and premorbid intelligence (DART-IQ) was most notable in the MMSE. Thus, the CST-20 item set has slightly better psychometric properties than the MMSE. A figure is presented by which CST scores can be transformed into MMSE scores.

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PubMed1995

Late-life depressive disorder in the community, early onset and the decrease of vulnerability with increasing age.

This study examined reports of a history of psychiatric illness related to age and depression in 4051 community residents aged 65-84. Depression was twice as common among subjects with a history of psychiatric illness before age 65. 78% of depressed subjects reported no history. The rate of reported history was inversely proportionate to the subjects actual age. This did not appear to be due to recollection bias but it did match the proportions previously reported to result from excess mortality of individuals with a psychiatric history. A psychiatric history may be an important risk factor for late-life depression but in the aging process after age 65 it may become increasingly uncommon.

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PubMed1995

Relation between education and dementia: the role of test bias revisited.

Several authors have suggested that dementia screening tests may be biased against low levels of education, whereas others find that a low level of education is a genuine risk factor for dementia. The present paper attempts to reconcile these conflicting views by examining item bias and test bias indices of the mini mental state examination (MMSE). Psychometric calculations and receiver operating characteristics (ROC) analyses of sensitivity and specificity as performed by earlier studies were replicated and extended from the database of the Amsterdam Study of the Elderly. This is a population survey on cognitive decline and dementia (age range 65-84). Subjects with a low level of education (primary school) were compared with better educated subjects (at least some secondary education). Cases were matched by age and sex. The results indicate that the MMSE is not educationally biased as far as item characteristics, reliability, and construct validity are concerned. Yet its predictive validity as a screening test for dementia is educationally biased. This bias will effectively be eliminated with a two point higher cut off score for the subjects whose education extends beyond primary school. Even after such score correction, a low level of education probably remains a genuine risk factor for dementia.

Activities of Daily Living↗
PubMed1995

Late-life depressive disorder in the community. I. The relationship between MMSE score and depression in subjects with and without psychiatric history.

BACKGROUND: In previous studies cognitive impairment in depressed elderly in-patients tends to be associated with a late onset of depression. This study tests the hypothesis that cognitive impairment is associated with depression only in elderly individuals with no history of psychiatric illness. METHOD: We investigated an age-stratified sample of 4051 elderly people living in the community, aged between 65 and 84 (AMSTEL). The relationship between depression (GMS-AGECAT diagnosis) and scores on the Mini Mental State Examination was studied in subjects with and without a reported psychiatric history (CAMDEX questionnaire). RESULTS: Low MMSE scores (MMSE < or = 25) were only associated with depression in subjects with no psychiatric history (young/old: OR = 2.75, 95% CI = 1.83, 4.19; old/old: OR = 2.21, 95% CI = 1.61, 3.03). CONCLUSIONS: We concluded that the combination of cognitive impairment and first-episode depression in elderly individuals may indicate cerebral deterioration. Depression as such may not be associated with cognitive impairment.

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PubMed1995

Late-life depressive disorder in the community. II. The relationship between psychiatric history, MMSE and family history.

BACKGROUND: In previous studies, dementia was linked to a family history of dementia and Down's syndrome. This study tested the hypothesis that late-life depression accompanied by cognitive impairment in elderly individuals with no history of psychiatric illness is also associated with these family histories. METHOD: We investigated an age-stratified sample of 4051 elderly people in the community aged 65-84 (AMSTEL). The relationship between family history (CAMDEX questionnaire) and depression (GMS-AGECAT diagnosis) was studied. RESULTS: A family history of mental health problems was associated with all subtypes of depression. Family history of dementia was associated with depression in subjects with a psychiatric history, but a family history of Down's syndrome was only associated with the combination of depression and cognitive impairment in subjects with no history of psychiatric illness. CONCLUSIONS: The heritability pattern confirms the concept of a dementia-related subtype of late-life depression.

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PubMed1995

Medial temporal lobe atrophy in an open population of very old persons: cognitive, brain atrophy, and sociomedical correlates.

Medial temporal lobe structures may be important for memory. We examined the cognitive, brain atrophy, and sociomedical correlates of medial temporal lobe atrophy (MTA) in 59 individuals (79.2 +/- 4.6 years old) randomly selected from a population-based study within strata of age and severity of clinically assessed DSM-III-R dementia (45 clinically normal and 14 mild/severely demented). MTA was qualitatively assessed on coronal T-1-weighted MRI. Thirty-three percent of the sample showed MTA, which was associated with dementia severity (p < 0.01), and cortical and white matter atrophy. MTA was not associated with age, education, sex, depressive symptoms, or presence of infarction. Controlling for age, education, and associated brain atrophy, those with MTA performed more poorly on a general test of cognitive function (the neuropsychological test component of the Cambridge Examination for Mental Disorders of the Elderly; p < 0.04) and its subtests of memory function (p < 0.02) and memory-related functions, including perception, fluency, and orientation (p < 0.05). In the clinically normal subsample, those with MTA performed more poorly on the memory function (p < 0.05) subtests. We conclude that MTA is common among very old persons, is associated with other brain abnormalities implicated in cognitive function, but may specifically contribute to memory dysfunction in the general population of very old persons.

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PubMed1993

Some psychometric properties of the CAMCOG.

The CAMCOG, the cognitive section of the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX), was administered twice to 53 patients with a clinical diagnosis ranging from no dementia to severe dementia. The stability of the total CAMCOG score was high (0.97). Patients with less than moderate dementia were differentiated well by the total score and by subscales with a range of more than 8 points, except when education was low or age was higher than 78. Because performance on most (sub)scales is modified by age and education level, stratified norms are desirable. Only the Praxis subscale, and specifically performance on drawing tasks, appeared to be influenced by depression.

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PubMed1993

Are age and education independent correlates of the Mini-Mental State Exam performance of community-dwelling elderly?

We examined the effects of selected health conditions and sensory functions, socioeconomic status, age, and education on cognitive functioning in 3,974 community-dwelling individuals aged 65-84 years. Logistic regression analysis was used to examine the independent and joint effects of these variables on borderline (Mini-Mental State Exam [MMSE] of 22-25) and poor (MMSE of < or = 21) functioning relative to adequate functioning (MMSE of 26-30). The effect of age and of education on MMSE performance was relatively stable, even after adjusting for age- and education-related health conditions and sensory impairments that also influenced level of cognitive functioning. These conditions included poor vision, Parkinson's disease, diabetes, depression, stroke (in 65-74-year-olds), and low socioeconomic status (in 75-84-year-olds). Education did not modify the effect of these variables on MMSE performance. Additional studies elucidating further the mechanisms that relate these sociodemographic factors to cognitive performance are warranted, as are studies of the relationship between these factors and the incidence of cognitive impairment.

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PubMed1991

SPECT in early- and late-onset Alzheimer's disease.

We assessed with SPECT the influence of age of onset in Alzheimer's disease in patients who were matched for severity of disease with early and late onset of the disease. Twenty-six patients, severity-matched according to scores on Mini-Mental State Examination, were compared to nine controls. Comparison of the temporoparietal cerebellar ratio (TPC) revealed a statistically significantly lower ratio in the early-onset group compared to the late-onset group of patients. These results are in agreement with other imaging, structural, and neurochemical studies, supporting the view of heterogeneity of Alzheimer's disease according to age of onset.

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