Biomedical subjects

Celeste A de Jager

Publications and source records attributed to Celeste A de Jager.

5 recordsLinked to original sources

PubMed2006

Cases with mild cognitive impairment and Alzheimer's disease fail to benefit from repeated exposure to episodic memory tests as compared with controls.

Memory tests may be predictive for cognitive decline. We investigated the sensitivity and change in performance over time of the Hopkins Verbal Learning Test (HVLT) and the Mini-Mental Status Examination (MMSE) for Mild Cognitive Impairment (MCI) and Alzheimer's Disease (AD) when compared to cognitively healthy controls. Participants included elderly controls (n = 54), MCI (n = 19) and AD cases (n = 28) from OPTIMA. The MMSE and the HVLT (version 1) were administered twice to all subjects with an interval of 2-3 years.MCI and AD cases had poorer performance than controls on the HVLT and MMSE at both testing episodes (p < 0.05). The HVLT profile over time showed a learning effect in the control group (P < 0.0001), a trend to decline in the AD group (p = 0.09) and no change in the MCI group (P = 0.8). A subgroup of MCI subjects had lower HVLT scores at follow-up. The MMSE profile showed no significant change over time for all three groups (P > 0.05). The HVLT had better sensitivity and specificity compared to the MMSE for detecting MCI and AD. The HVLT is not only valuable for cross-sectional designs but has also proved to be valuable in a longitudinal design. Cognitively healthy controls showed evidence of learning strategies on the HVLT after a 2-3 year interval, with improved scores at the second testing episode. By contrast, an MCI group showed no benefits of previous exposure to this test. Lack of use of learning strategies on the HVLT may be an important marker of the likelihood of cognitive decline to MCI or dementia.

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PubMed2006

The Placing Test: preliminary investigations of a quick and simple memory test designed to be sensitive to pre-dementia Alzheimer's disease but not to normal ageing.

The medial temporal lobe (MTL) memory system is damaged early in Alzheimer's disease. Cognitive tests designed to help diagnose the disease must detect dysfunction in this system, but must also be insensitive to the cognitive slowing that characterizes normal ageing. On the assumption that the MTL system forms new memories by binding together the many informational aspects of events into units, The Placing Test was designed to index this function by measuring the ability to remember associations between faces and their locations. The influence of normal ageing was minimized by using procedures that compensate for the difficulties in learning and retrieval caused by the cognitive slowing of normal ageing. In two experiments The Placing Test was administered as part of a battery of neuropsychological tests to a group of healthy older people. In both studies, performance in The Placing Test correlated significantly with other measures of memory, but had weaker associations than standard memory measures with other types of cognitive function. The Placing Test appeared not to be biased by age, education or gender, although a larger sample is needed to verify this. A final study examined the performance of 16 patients with suspected Alzheimer's disease. These patients showed clear impairment in The Placing Test, with 81% scoring below the 5th percentile, despite the majority having normal MMSE scores. It is concluded that The Placing Test provides a quick, simple and sensitive measure of memory that has potential to be useful in routine diagnostic investigations for Alzheimer's disease.

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PubMed2005

Stability and predictability of the classification of mild cognitive impairment as assessed by episodic memory test performance over time.

This study aimed to address the criteria and the stability of the classification of MCI. The Foresight Challenge cohort of 157 community-dwelling volunteers was assessed on 3 visits at 2-year intervals with episodic, semantic and working memory tests. Subjective memory complaints were assessed with the CAMDEX. Of the cohort, 2% had dementia and 31% were classified with MCI at visit 3, 43% with stable impairment from Time 1. Thirteen percent of those with objective memory impairment at Time 1 or 2 improved to control status by Time 3. Episodic memory tests were predictive for MCI at all timepoints, as were tests for praxis and Graded Naming, while at Time 3 spatial span lost predictive value, but processing speed became predictive. Decline in processing speed was seen in control and MCI groups, while memory performance and MMSE decline occurred only in the MCI group. The use of combined memory test scores gave better sensitivity to MCI than single tests. Subjective memory complaints were positive for 79% of the MCI group and 62.5% of controls. These findings would suggest consideration of modification of current MCI criteria.

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PubMed2004

Changes over time in memory, processing speed and clock drawing tests help to discriminate between vascular cognitive impairment, mild cognitive impairment and Alzheimer's disease.

Measures of cognitive change over time may help to better discriminate between mild cognitive impairment, Alzheimer's disease and vascular cognitive impairment than single assessments. Our hypothesis was that performance in processing speed and executive function would decline with mild cognitive impairment and Alzheimer's disease. Subjects included 36 controls, 18 cases with mild cognitive impairment, eight with vascular cognitive impairment and 24 with Alzheimer's disease who were tested on a cognitive battery at two episodes with a 12-month interval. Changes in performance were determined for each group with paired means tests. Controls improved in pattern comparison speed and the CLOX, a clock-drawing task to detect dysexecutive function. Those with vascular cognitive impairment declined in letter comparison speed, but improved in paragraph recall. Alzheimer's disease patients declined in CLOX and the Hopkins Verbal Learning Test. The mild cognitive impairment group showed no significant changes. Alzheimer's disease patients on treatment declined in Hopkins Verbal Learning Test, while those without treatment declined in The Placing Test and CLOX. Processing speed decline may be a marker of cerebrovascular disease, while decline in memory and executive function was more evident with Alzheimer's disease.

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PubMed2003

Utility of TICS-M for the assessment of cognitive function in older adults.

BACKGROUND: Routine screening of high-risk elderly people for early cognitive impairment is constrained by the limitations of currently available cognitive function tests. The Telephone Interview of Cognitive Status is a novel instrument for assessment of cognitive function that can be administered in person or by telephone. OBJECTIVE: To evaluate the determinants and utility of TICS-M (13-item modified version) for assessment of cognitive function in healthy elderly people. METHODS: The utility of TICS-M was compared with more widely used MMSE and CAMCOG in a cross-sectional survey of 120 older (62 to 89 years) UK adults. RESULTS: The TICS-M cognitive test scores (27.97, SD 4.15) were normally distributed in contrast with those for MMSE and CAMCOG that had a negatively skewed distribution. TICS-M scores were inversely correlated with age (r = -0.21) and with the NART fullscale IQ (r = -0.35), but were independent of years of education in this cohort. TICS-M was highly correlated with MMSE (r = 0.57) and with CAMCOG (r = 0.62) scores. The time required to complete the test is comparable to MMSE and substantially less than CAMCOG. CONCLUSIONS: The normal distribution of TICS-M test scores suggest that this test is less constrained by the ceiling effect which limits the utility of MMSE and CAMCOG test scores in detecting early cognitive impairment. TICS-M is an appropriate instrument to assess cognitive function in both research and in clinical practice.

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