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C Jonker

Publications and source records attributed to C Jonker.

89 records · Page 5Linked to original sources
PubMed1990

Reliability, validity and follow-up of the EEG in senile dementia: sequelae of sequential measurement.

In a longitudinal study, slowing of the EEG in SDAT patients and elderly controls is investigated using both visual and power spectral analyses. For this a reliability study in 20 SDAT patients is performed and results for intra-rater, inter-rater and test-retest reliability (in 24 h) are used in the selection of parameters. Next, the diagnostic efficacy of the chosen parameters for SDAT is confirmed in a validity study in 43 SDAT patients, 41 elderly non-organic psychiatric patients and 51 elderly normals. In the longitudinal study 78 of these subjects could be retested after 20 months. The parameter for visual analysis appeared to be superior in actually showing a progress of slowing of the EEG in 20/21 SDAT patients over time. The parameter for power spectral analysis was superior in measuring the more subtle processes in the normal elderly. Results of these studies are used to discuss some problems in the measurement of EEG in SDAT over time.

Aged↗
PubMed1990

Loss of heterozygosity on 17p in human breast carcinomas: defining the smallest common region of deletion.

The marker D17S5, mapping to the short arm of chromosome 17, was recently reported by us and others to undergo frequent heterozygous deletion in human primary breast carcinomas, implicating the presence of a tumor suppressor gene in this region. To narrow down the location of this gene more precisely, we have performed a deletion-mapping study in an extended series of 78 breast carcinomas, using nine polymorphic markers for the short arm and two polymorphic markers for the long arm of chromosome 17. Partial allele losses on 17p were observed in nine cases, which, taken together, suggest that the target gene for the deletions maps to the region extending between the markers D17S5 (17p13.3) and D17S67 (17p12).

Breast Neoplasms↗
PubMed1990

The Amstel project: design and first findings. The course of mild cognitive impairment of the aged; a longitudinal 4-year study.

The AMSTEL-project is a longitudinal investigation to study the course of cognitive impairment in people aged 65 and over during a 4-year period. The study intends to contribute to the distinction between normal aging and early dementia, and should ultimately result in a diagnostic instrument enabling general practitioners to distinguish early dementia, in particular Alzheimer's disease, from normal aging. Another goal of the project is to elucidate the contribution of advanced biomedical methods (SPECT, MRI) to the early diagnosis of the main types (SDAT, MID) of dementia. This paper describes the design of the study, especially the recruitment of the study population and the sampling procedures. The investigation started in March 1990, and the first findings are presented. The procedure to approach the population resulted in a refusal rate of 45% for the screening phase. The reasons for this high non-response rate are discussed.

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PubMed1988

[A brief test for dementia screening: the ADS3].

The ADS3 is a short screening test, consisting of subtests for Visual Memory, Orientation and Fluency. Within the modest pretentions available to this type of test, the validity and reliability are satisfactory. Measures were taken to safeguard the test against misuse.

Age Factors↗
PubMed1987

Anterior temporal focal abnormalities in EEG in normal aged subjects; correlations with psychopathological and CT brain scan findings.

Normal aged subjects (65-83 years) were examined by EEG and CT brain scan; also a Geriatric Mental Scale (GMS) and Neuropsychologic Assessment Battery were administered. Based on the EEG findings 2 subgroups could be distinguished: one with focal abnormalities in the left fronto-temporal region and one without these focal abnormalities. The focal delta subgroup proved to perform poorly on the Fluency Test, a simple quick bedside, but very sensitive, test for word association productivity. Also this subgroup showed more ventricular dilatation than the non-focal group. Therefore slight left-sided antero-temporal abnormalities in normal aged subjects are not irrelevant but an early (subclinical) sign of temporal lobe pathology as expressed in deterioration of language function.

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PubMed1987

The influence of attention on visual evoked potentials in normal adults and dementias.

In normal subjects (n = 58, 22-71 y) the influence of the attention level on the VEP latency is studied, as is done in an additional small group of dementias (n = 14). The motor reaction time test (MRT) was selected to measure the attention level. The MRT was administered simultaneously with the VEP (checkerboard pattern reversal). By comparing VEP in test and non-test situations it proved that administration of MRT during VEP examination does not influence the VEP latencies. In dementias the motor reaction time is delayed but the degree of MRT delay did not correlate with the VEP latencies. This holds true for healthy volunteers as well as for demented patients. It is thus concluded that the latency increase of the late peaks of the VEP in dementias cannot be attributed to attentional deficits.

Adult↗
PubMed1985

Visual evoked potentials (VEPs) in senile dementia (Alzheimer type) and in non-organic behavioural disorders in the elderly; comparison with EEG parameters.

Forty-two patients with senile dementia of the Alzheimer type were compared with normal subjects (51) and with elderly patients with nonorganic psychiatric disorders (40). All were examined by EEG (routine visual inspection and power spectrum density analysis) and VEP (pattern reversal) testing. In dementia the late components (N130, P165, N220) of the VEP are delayed, but the EEG was abnormal more often than the VEP.

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PubMed1983

[Do immunological factors play a role in the pathogenesis of Alzheimer's disease?].

Immunological injury is frequently thought to be a critical factor in Alzheimer's disease. In this review we discuss the immunological indices in serum and cerebrospinal fluid of patients with dementia of the Alzheimer type and subsequently the nature of cerebral amyloid. We conclude that the results of the immunopathological research program have not contributed to the understanding of the pathogenesis of Alzheimer's disease. Finally, we discuss the problems of neurobiological investigations concerning patients with dementia.

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PubMed1982

Immunological indices in the cerebrospinal fluid of patients with presenile dementia of the Alzheimer type.

In ten patients with presenile dementia of the Alzheimer type and in a control group the levels of the different immunoglobulins were determined in both serum and cerebrospinal fluid (CSF), and gel electrophoretic techniques used to determine possible oligoclonal bands in the gamma-globulin region. There is no indication that patients with Alzheimer disease produce immunoglobulins within the central nervous system.

Adult↗
PubMed1981

[Multidisciplinary diagnosis of dementia and non-dementia behavior disorders in the aged. Preliminary study for research on its course and prognosis].

The need to differentiate between dementia and the so-called functional psychiatric diseases of old age is of therapeutic as well as social importance. The main symptoms of dementia--lack of memory, disorientation and cognitive disturbances--are much less clearly defined than would be desirable, despite the neuropathological changes regarded as underlying senile dementia. The disease does not always have a progressive course. Confusion is also possible with other forms of dementia, while the symptoms of dementia can also be found in so-called functional psychiatric diseases. On the basis of the literature and/of our own research, it appears that a sharper definition of senile dementia is possible. Besides clinical criteria one can make use of--partly recently introduced--diagnostic techniques, specifically a structured psychiatric interview for old people, a neuropsychological testbattery, EEG, visual evoked response techniques and CT-brain scanning. The value of these diagnostic techniques for the diagnosis and the assessment of the prognosis of senile dementia can only be determined in a follow-up study. The set-up of such a follow-up study is described.

Aged↗
PubMed1975

Epidural haematoma. A retrospective study of 100 patients.

A retrospective study was made of 100 consecutive patients with an epidural haematoma in order to establish which clinically demonstrable factors had influenced the prognosis quoad vitam et sanationem. Operations were performed on 92 of these patients, 29 (32%) of whom died; 8 patients died without operation, and in 2 of these cases the diagnosis was not made during life. A lucid interval was observed in 57 patients; absence of a lucid interval in combination with a lowered sensory level indicated associated intradural lesions (cerebral contusion, acute subdural haematoma), with consequently a less good prognosis. The prognosis was also adversely affected by deeper coma, occurrence of extensor spasms, bilateral stiff pupils, bilateral pyramidal symptoms and an age over 50. Some 33% of the patients treated by operation showed marked symptoms of compression (extensor spasms and/or bilateral stiff pupils); although these symptoms are usually described as indicative of a hopeless prognosis, 40% of the patients in this catagory survived. Contrary to the data in the literature, the interval between accident and operation within the first 24 hours did not influence the mortality, which was 50%. All patients operated on more than 24 hours after the accident, survived. A cranial fracture was absent in 13 patients, 11 of whom were under 30; absence of a cranial fracture was prognostically favourable. A catamnestic study revealed that 7 of the 58 accessible survivors had residual neurological dysfunctions; all these patients were up and about. The residual morbidity after early operation (within 24 hours) was the same as that after later operation. The data obtained were compared with those on a number of series recently published in the literature.

Adolescent↗
PubMedDate not supplied

Immunological mechanisms and the spectrum of psychiatric syndromes in Alzheimer's disease.

Pathological, genetic and epidemiological studies support the opinion that inflammatory mechanisms are involved in the pathogenesis of Alzheimer's disease (AD). Recent pathological and neuroradiological (PET) data show that activation of microglia is an early pathogenic event that precedes the process of severe neuropil destruction in AD brains. In this paper we review the evidence that inflammatory mediators can play a pathogenic role in some behavioural disorders frequently encountered during the clinical course in AD patients. Motivational disturbances are the most striking of the depressive symptoms in AD and can be present in a preclinical stage of the disease. Experimental animal studies and clinical trials in humans have shown that cytokines can induce similar symptoms which were described as 'sickness behaviour' or 'depressive-like' state. Delirious states are frequently observed in more advanced stages of dementia. Delirium is generally considered the result of an imbalance in neurotransmitter systems with severe deficits of the cholinergic systems. Animal studies show that pro-inflammatory cytokines, such as interleukin-1, induce a reduced activity of the cholinergic system. In AD, the release of cytokines would exacerbate any already existing disturbances in the cholinergic neurotransmission. This could explain the susceptibility of demented patients to delirium provoked by a wide variety of trivial incidents that are accompanied by an acute phase response. The data reviewed in this paper suggest that it could be worthwhile employing a neuroimmunological approach to study at molecular level the pathogenesis of a broad spectrum of behavioural disturbances common in the clinical course of AD patients.

Aged↗
PubMedDate not supplied

Does aspirin or other NSAIDs reduce the risk of cognitive decline in elderly persons? Results from a population-based study.

OBJECTIVE: To investigate the protective effect of NSAIDs and aspirin separately on cognitive decline in elderly subjects, controlling for consistent use of these agents over a prolonged period of time. METHODS: The study sample consisted of 1007 subjects, drawn from a population-based random sample of elderly individuals, 62-85 years old, who participated in a 3-year follow-up study. From this sample subjects were selected, who did use NSAIDs and completed all cognitive tests at both measurements (n=137), and subjects who did not use NSAIDs and completed all cognitive tests (n=475). Cognitive tests included the Mini-Mental State Examination (MMSE), tests for episodic memory (Auditory Verbal Learning Test) and information processing speed (coding task). Cognitive decline was computed using Edwards-Nunnally method. Multiple logistic regression analyses were performed to examine the association between NSAID (with and without aspirin) and decline in cognitive performance. Besides, the interaction of NSAIDs with age on cognitive decline was determined. RESULTS: The relative risk estimates of decline in episodic memory (immediate recall) adjusted for age, gender, education, baseline MMSE, vascular diseases, diabetes mellitus and (rheumatoid) arthritis for aspirin users only was more than three times reduced (OR: 0.30, 95% CI: 0.09-0.82). The odds ratio for decline in memory of NSAID use without aspirin, adjusted for age, gender, education, baseline MMSE, vascular diseases, diabetes mellitus and (rheumatoid) arthritis was not significant (OR: 1.00, 95% CI: 0.39-2.93). The effect of aspirin was significant only in persons of 75 years and over (OR: 0.10, 95% CI: 0.01-0.81), not in subjects younger than 75 years (OR: 0.52, 95% CI: 0.14-1.96). NSAIDs did not have benefit on information processing speed. In 92% of aspirin users a low dose of 100mg daily or less was used. CONCLUSION: Low-dose aspirin might be protective for decline in memory in individuals of 75 years and over. The benefit of a low-dose aspirin does not support an anti-inflammatory effect, but suggests an antiplatelet effect. Therefore, a possible protective effect of low-dose aspirin on cognitive decline is likely only in subjects with aspirin use over a prolonged period of time.

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PubMedDate not supplied

Assessment of mental competency in community-dwelling elderly.

We studied the utility of a "vignette method" to assess mental competency for decision making on medical treatment and research participation. A vignette is a description of an imaginary situation in which the subject is asked to decide on a proposed treatment or on participation in research. His or her understanding of the situation and the quality of the reasoning underlying that choice are tested by a short series of questions. Subjects were participants in the Amsterdam Study of the Elderly (AMSTEL), a population-based study on cognitive decline and dementia. The sample consisted of elderly people (70-90 years), who were cognitively intact (n = 176) or had a dementia syndrome (n = 64; mostly Alzheimer disease). Dementia was diagnosed using the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX) schedule. Two vignettes were used as competency assessment instruments. The answers to the vignette questions were summed to form a competency score. The reliability (internal consistency) of this score was 0.82 for both vignettes combined. After dichotomization into competent/incompetent (cutoff at the fifth centile of the control group), the agreement between the vignette method and a physician's judgment of competency was poor (kappa = 0.36) in the demented group. There was no agreement whatsoever when subjects with "minimal dementia" (n = 14) were left out of this analysis (kappa = 0.04). As expected, mean competency scores declined with increasing dementia severity. A multiple regression analysis showed that mental competency as measured by the vignette method was determined mainly by recent memory, expressive language, and abstract thinking. In the control group the competency score was only slightly related to education (r = 0.12) and verbal intelligence (r = 0.27). We conclude that the vignette method is a reliable and valid method for the assessment of mental competency in elderly people with cognitive decline. The vignette method is preferred over a physician's judgment, especially in patients with early dementia.

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PubMedDate not supplied

Diagnosing Alzheimer's disease in community-dwelling elderly: a comparison of EEG and MRI.

In a study on the course of cognitive impairment in people over 65 years of age, 58 randomly selected community dwelling elderly underwent EEG and MRI studies. The EEG was visually and quantitatively (qEEG) assessed. Nine out of 58 subjects appeared to have Alzheimer dementia (AD) according to CAMDEX criteria. In this group medial temporal lobe atrophy on MRI, as an objective criterium for AD, showed a total accuracy of 72%, visually assessed EEG 81% and qEEG 81-84%. There was an incomplete overlap in subjects regarding MRI and EEG abnormalities, implying that both methods may be complementary.

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