Amsterdam Short-Term Memory test: a new procedure for the detection of feigned memory deficits

The validity of two malingering tests, the newly developed Amsterdam Short-Term Memory (ASTM) test and the Distraction test (Baker, Hanley, Jackson, Kimmance, & Slade, 1993) was examined in a group of patients with closed-head injury (CHI), a normal control group, and a control group with instruction to feign memory deficits. Both control groups consisted of first-degree relatives of the patients. The ASTM test is a forced-choice verbal memory test, based on the technique of symptom validity testing. Stimulus material was chosen from category norms and chance level is not transparent. The CHI and normal control groups scored near ceiling on the ASTM test, whereas the feigned deficit group scored significantly worse. The ASTM test classified all subjects correctly. Contrary to expectation, the Distraction test appeared to be invalid. The score profiles of the CHI and feigning groups on conventional memory and concentration tests were indistinguishable from each other. Thus, the ASTM test may be very useful for the detection of malingering and other kinds of less than optimal performance. The test may readily be constructed in any language for which category norms are available.

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.

[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.

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.

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.

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.

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.

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.

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.

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.

[Differentiation between dementia and functional psychiatric disorders in a geriatric ward of a general psychiatric hospital using the 'Amsterdam Dementia-Screening Test']

OBJECTIVE

Investigating the discriminative power of the Amsterdam Dementia Screening Test (ADS) in a heterogeneous elderly psychiatric population.

SETTING

Observation clinic for the elderly MFC Duinoord, Psychiatric Centre Vogelenzang, Bennebroek, Holland.

DESIGN

Retrospective comparison of test results and clinical diagnosis.

METHOD

Patients referred for neuropsychological evaluation in 1991-1992 were selected on the basis of DSM-III-R discharge diagnosis 'dementia' or 'psychiatric syndrome'. The ADS, MMSE and SPMSQ scores of 30 male and 74 female patients were compared with diagnostic classification.

RESULTS

The ADS appeared to be highly sensitive and specific. Only 10% of the psychiatric patients were incorrectly classified by the ADS, as against 55% using the MMSE, some MMSE items not differentiating at all. A significant correlation was found in the demented group between ADS and MMSE total scores on the one hand and demographic variables such as age and level of education on the other. The latter appears to be related to better performance on visuo-constructive tasks by more highly educated subjects.

CONCLUSION

Normative data for the ADS come from an inpatient population. This study shows that the ADS discriminates well in a mixed in/outpatient group with dementia syndromes or psychiatric disorders. The visuo-constructive tasks appear to be related to the level of education.

Cognitive functions and quality of life in patients with low-grade gliomas: the impact of radiotherapy

The role of early radiotherapy in the treatment of low-grade gliomas is controversial. For this reason the impact of radiotherapy on quality of life was studied in long-term survivors of biopsy-proved low-grade gliomas without signs of tumor recurrence. Twenty patients (age range, 18-66 years) had been treated with early radiotherapy; the other 21 patients (age range, 19-65 years) had undergone surgery or biopsy only. The interval from diagnosis to testing ranged from 1 to 12 years (mean, 3.5 years). Nineteen patients with low-grade hematological malignancies, surviving 1 to 15 years without central nervous system involvement, served as control subjects. Apart from the neurological and functional status, the patients' cognitive, affective, and psychological status was determined. None of the survivors had significant neurological impairment and the Karnofsky index for them was at least 70. However, more specific examinations of cognitive functions and the affective status (Profile of Mood States) indicated that, compared to the control subjects, the patients with low-grade gliomas had significantly more cognitive disturbances and suffered more frequently from fatigue and depressed moods. The two groups with low-grade gliomas, on the other hand, did not differ significantly on any of these measures. It is concluded that radiotherapy did not cause these disturbances and had no negative impact on quality of life in these patients.

[Digit series and Knox cubes as concentration tests for elderly subjects]

We studied psychometric properties of the Digit Span test and its nonverbal counterpart, the Knox Cube test, with reference to their utility in the clinical assessment of the elderly. Subjects were 100 residents of residential homes and semi-independent housing projects, aged 68 to 94. An administration of Digit Span with three trials per sequence length provides high reliability and minimizes floor effects, allowing separate interpretation of the Forward and Backward conditions. Due to its low internal consistency, the Knox Cube test cannot reliably distinguish differences among normal subjects, but may still be useful to detect impairment. Using regression equations, the Forward Digit Span score can be corrected for education level and both Digit Backward and Knox Cubes can be compared with Digit Span Forward.

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.

[The diagnostic value of tests for mental control]

Designated as Mental Control, the recitation of word lists and arithmetic progressions is often used for a cursory examination of attention and concentration in elderly patients. We studied the psychometric properties of the EMCT (Expanded Mental Control Test), which consists of 12 mental control tasks. The test was given to 174 residents of rest homes and semi-independent housing projects (aged 68 to 94) and 74 neurologic patients (aged 65 to 87) who had been referred for neuropsychological assessment. The reliability of the EMCT was satisfactory. Performance was related to education level but not to sex or age. In healthy subjects the EMCT score was associated with the backward digit span score. The correlations between the EMCT and subtests of the Amsterdam Dementia Screening (Ads6) in patients appeared to depend on the complexity of the target behavior. Performance on the EMCT may reflect the functioning of the Supervisory Attentional System postulated by Shallice.

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.

[Paced addition. A neuropsychological test for assessment of divided attention]

The Pasat (Paced auditory serial addition task) is a test requiring addition of simple digits presented auditorily in several series of a successively higher pace of presentation. The task reflects the capacity for divided attention, is a measure of information processing speed and has appeared to be sensitive to minor attention deficits. We made a Dutch version characterized by longer time intervals between digits, for use in a study among (altogether 130) middle-aged and elderly persons. This modified version was evaluated with respect to feasibility. It appeared to be fairly feasible, provided sufficient opportunity for practice is given. Two series with inter-stimulus intervals of 4 and 3 seconds respectively were then evaluated with respect to validity and reliability in subjects of 48 to 74 years. Both Pasat series correlated well with two tests of attention: Digit Symbol (WAIS) and d2-test (r = 0.53-0.67), the relation with reaction decision speed being generally weak (r = 0.29-0.33) and weak to absent with a number of memory tests (r = -0.04-0.29). The Pasat performance shows a positive relationship with educational level and intelligence (inter-stimulus interval 4 seconds: r = 0.28 and 0.33 resp.; inter-stimulus interval 3 seconds: r = 0.40, 0.57 resp.). The stability of test performance over a period of about two months is moderate (r = 0.54, 0.61 resp.). In view of the excellent inter-observer reliability (r = 0.99) and the good parallel-test reliability (r = 0.79, 0.68 resp.), this might be explained by fluctuations in the capacity measured, rather than measurement error.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of quality of life in patients treated for low-grade glioma: a preliminary report

In this pilot study quality of life was assessed in fourteen adult patients who were treated for a low-grade glioma with surgery and radiotherapy at least one year previously. Apart from widely used parameters, such as the neurological and functional status, the patients' cognitive functioning and actual affective status were determined. In addition the patients were interviewed to evaluate various aspects of quality of life. Generally no serious focal neurological deficits were found, although psychological examination showed serious cognitive and affective disturbances in most cases. Self report measures concerning cognitive functioning were not in all cases in accordance with objective test results. When the results of treatment in glioma patients are evaluated assessment of quality of life, including neuropsychological functioning, should be performed, especially as new therapeutic strategies are being developed.

A case of progressive aphasia without dementia: "temporal" Pick's disease?

We report a patient who suffered from progressive aphasia for nine years, before developing mild behavioural disturbances. Sequential computed tomography (CT) scanning and magnetic resonance (MRI) imaging showed progressive bilateral temporal atrophy. The case is thought to be a temporal form of Pick's disease, in which isolated progressive aphasia was the only symptom over many years.

Who needs cutting points?

Individual scores of discriminative tests can be connected to an estimate of the confidence of classification, which obviates the need for cutting points. Such estimates can be corrected for base rate conditions. It is suggested that, while base rates are largely imponderable, the prior probabilities of individual cases are not.

Interhemispheric disconnection effects in multiple sclerosis

Patients with multiple sclerosis reported less left ear numbers but more right ear numbers than controls in a dichotic listening test. The multiple sclerosis patients were also relatively impaired on three learning tasks; one of these, a test for paired-associate learning of names and faces, correlated with left ear findings; the results are interpreted as supporting a hypothesised disconnection mechanism.