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Biomedical subjects

Cees Jonker

Publications and source records attributed to Cees Jonker.

26 records · Page 2Linked to original sources

Early life physical activity and cognition at old age.

Physical activity has shown to be inversely associated with cognitive decline in older people. Whether this association is already present in early life has not been investigated previously. The association between early life physical activity and cognition was studied in 1,241 subjects aged 62-85 years, in a prospective population-based study. Physical activity between ages 15 and 25 years was asked retrospectively. The findings suggest a positive association between regular physical activity early in life and level of information processing speed at older age in men, not in women. The association could not be explained by current physical activity or other lifestyle factors. This finding supports the cognitive reserve hypothesis, and might suggest that early life physical activity may delay late-life cognitive deficits.

Aged↗

Medial temporal lobe activity during semantic classification using a flexible fMRI design.

In this study, we evaluated the use of a self-paced fMRI design, to allow a flexible speed of responding with only four alternating stimulus blocks to minimize the influence of task switching on a group of young subjects. This was done in view of our intention to use such a design on groups of elderly and demented subjects in the near future. In addition, the hypothesis was tested that the medial temporal lobe is involved in semantic memory similar to episodic memory using a semantic retrieval task. In line with previous imaging studies that compared a semantic (living/nonliving) to a perceptual (alphabetically ascending/descending) classification condition, activity was seen in lateral temporal and inferior frontal regions, indicating the applicability of our design. Additional activity was seen in the right, and, at a slightly lower threshold, also in the left MTL, providing support for the involvement of the MTL in retrieval from semantic memory.

Adolescent↗

Course of minimal dementia and predictors of outcome.

BACKGROUND: Previous studies have indicated that not all subjects who meet the CAMDEX criteria of 'minimal dementia' progress to dementia. In the present study, predictors of outcome in minimally demented subjects were tested. METHODS: Forty-five subjects with minimal dementia who were participating in a population-based study were followed-up for on average 2.3 years. Variables tested as predictors of outcome were age, the apolipoprotein E (APOE) genotype, and the baseline scores on the MMSE, CAMCOG memory subscale, and fluency. Depression at baseline was tested as a predictor of reversible minimal dementia. RESULTS: At follow-up, minimal dementia turned out to be reversible in 11 subjects (24%), and persistent in ten subjects (22%). Twenty-four subjects (53%) had become demented. Predictors of outcome in multivariate analyses were age, score on the CAMCOG memory subscale, and the APOE genotype. Depression was not associated with reversible minimal dementia. CONCLUSIONS: Subjects who meet the CAMDEX criteria of minimal dementia form a heterogenous group with respect to clinical outcome. Age, the score on the CAMCOG memory subscale, and the APOE genotype can improve predictive accuracy in these subjects.

Aged↗

Different cognitive functions in relation to falls among older persons. Immediate memory as an independent risk factor for falls.

It is not clear which specific cognitive function is strongest related to falls. To investigate this, not only "general cognitive functioning," but also "nonverbal and abstract reasoning," "information processing speed," and "immediate memory" were related to falls. Furthermore, relevant effect modifiers, confounders, and mediators were identified. This study was performed within the Longitudinal Aging Study Amsterdam (LASA), a multidisciplinary, prospective cohort study. In this study (n = 1437), an interaction between "immediate memory" and age was found. In persons aged 75 years and over, "immediate memory," as measured by the 15 Words Test, showed to be an independent risk factor for falls. Part of this relationship was explained by the mediating effects of activity, mobility, and grip strength. The association between the other cognitive functions and falls was only statistically significant in univariate analysis. We conclude that "immediate memory" is an independent risk factor for recurrent falls in persons aged 75 years and older.

Accidental Falls↗

[The assessment of competence in cognitively impaired elderly persons: a closer look at the vignette method].

This article focuses on the assessment of competence of elderly persons both with and without cognitive impairment. In total 113 patients of a geriatric clinic were interviewed. Competence was assessed by using two clinical vignettes, representing respectively a hypothetical treatment situation with mild consequences (endoscopy) and one with severe consequences (operation for colon cancer). Competence was evaluated using the following standards: the ability to evidence a choice, the ability to understand a situation, the ability to reason about a choice, and the ability to appreciate a situation. In the vignette with mild consequences, elderly persons with cognitive impairment performed significantly worse on understanding, reasoning and appreciation than elderly persons without cognitive impairment. In the vignette with severe consequences, elderly persons with cognitive impairment performed significantly worse only on understanding as compared to elderly persons without cognitive impairment. No differences were found for reasoning and appreciation between the cognitively impaired and non-impaired elderly persons. We conclude that competence is less limited by cognitive impairment when assessed in a treatment situation with severe consequences. Therefore, the use of hypothetical vignettes should be carefully reconsidered.

Aged↗

Insulin-like growth factor I (IGF-I) and cognitive decline in older persons.

Insulin-like growth factor I (IGF-I) deficiency may be involved in cognitive deficits seen with aging, and in neurodegenerative diseases such as Alzheimer's disease. The objective of this study was to investigate whether IGF-I is associated with cognitive performance and 3-year cognitive decline in 1318 subjects, aged 65-88 years. Cross-sectionally, IGF-I was directly related to information processing speed, memory, fluid intelligence, and Mini-Mental State Examination (MMSE) score, but these associations did not remain significant after adjustment for age and other factors. Analysis in quintiles of IGF-I revealed a threshold effect of low IGF-I on information processing speed, with lower speed in subjects in the lowest quintile of IGF-I (<9.4 nmol/l)(1) versus those in the other four quintiles (fully adjusted B=-0.89; 95% CI, -1.72 to -0.05). This threshold of low IGF-I was also observed for 3-year decline in information processing speed (adjusted RR=1.78; 95% CI, 1.19-2.68). In summary, this study suggests that IGF-I levels below 9.4 nmol/l are negatively associated with both the level and decline of information processing speed.

Aged↗

The emotional impact of psychiatric symptoms in dementia on partner caregivers: do caregiver, patient, and situation characteristics make a difference?

This study aims to investigate the emotional impact of psychiatric symptoms of patients with dementia on their caregiving partners, and to explore if caregiver, patient, and situation factors predict this emotional impact on caregivers. A cross-sectional design was used. Partners of patients with slight to moderately severe dementia who live in the community (n = 85) were interviewed. In a subgroup (n = 58) potential predictors of emotional impact of psychiatric symptoms on caregivers were studied. Agitation, irritability, apathy, and disinhibition produced the highest mean emotional impact scores in caregivers. Besides the neuropsychiatric symptoms themselves, the emotional impact of these symptoms on caregivers was predicted by sense of competence, degree of care needed by the patient, and financial expenditure due to the caregiving situation. The emotional impact of psychiatric symptoms on caregivers is predicted by several patient, caregiver, and situation factors. Interventions aimed at decreasing the experienced burden of caregivers should therefore not only focus on the psychiatric symptoms of the patient, but also on the sense of competence of the caregiver and the financial burden due to the caregiving situation.

Adaptation, Psychological↗