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Biomedical subjects

E Koss

Publications and source records attributed to E Koss.

44 records · Page 3Linked to original sources

Processes of verbal memory failure in Alzheimer-type dementia.

Multiple aspects of verbal learning and memory performance in mild as compared to moderate Alzheimer-type dementia (ATD) were studied with the Buschke selective reminding paradigm. Results show that (1) both groups of ATD subjects depend less on long-term memory (LTM) and more on short-term memory (STM) relative to elderly control subjects, (2) mild ATD subjects show less LTM encoding than moderate ATD subjects, (3) moderate ATD subjects retrieve a smaller portion of the items presumed to be encoded into LTM than do mild ATD subjects, and (4) high-imagery words increase LTM encoding and retrieval as compared to low-imagery words for moderate ATD subjects only. These results are explained by the inability of ATD subjects to attend to more than one component of the list-learning task, in conjunction with differences in the deployment of attention between mild and moderate ATD subjects.

Alzheimer Disease↗

The Stroop color-word test: indicator of dementia severity.

The Stroop color-word test was used to examine patterns of cognitive decline in Alzheimer-type dementia (ATD) and non-Alzheimer dementia. Slowing on color naming and word reading was observed, and was greater in moderate than in mild dementia subjects. However, error scores were unrelated to dementia type and severity. The Stroop interference effect, measured with reaction time, was high in individuals with mild ATD and mild non-Alzheimer dementia. In contrast, the more severely impaired ATD subjects showed less Stroop interference effect than mildly impaired subjects when the reaction time was adjusted for color naming performance. These findings are attributed to variation in speed-accuracy tradeoff for the patient groups due to differences in information processing deficits, linguistic impairment, and attitudes to errors. This study demonstrates the importance of partialling out underlying deficits for the understanding of complex cognitive processes in dementia.

Aged↗

A comparison of the Cohen-Mansfield agitation inventory with the CERAD behavioral rating scale for dementia in community-dwelling persons with Alzheimer's disease.

In a group of 242 community-dwelling patients with Alzheimer's disease (AD), a longitudinal comparison was made of two caregiver-administered instruments for assessment of behavioral disturbance; the Cohen-Mansfield Agitation Inventory (CMAI) and the CERAD Behavioral Rating Scale for Dementia (BRSD). We examined records of the 206 patients with baseline and 12-month follow-up data for the CMAI and the BRSD who also had tests of cognitive (Mini-mental State; MMSE) and global function (Clinical Dementia Rating; CDR and Functional Assessment Staging; FAST). Among 114 AD subjects, the correlation between total CMAI at baseline and 1 month readministration was 0.83 (p < 0.0001). In the same subjects, stratified into 5 groups by MMSE scores, the correlations between BRSD baseline and 1-month scores ranged from 0.70-0.89 (p < 0.0001). There was high correlation between total scores of both instruments at baseline and 12 months. In addition, all CMAI subscales except Verbally Aggressive correlated significantly with total BRSD score at both time points. At baseline, BRSD subscales for irritability/aggression, behavioral dysregulation and psychotic symptoms and at 12 months, irritability/aggression and behavioral dysregulation correlated with total CMAI scores. Neither scale changed significantly over 1 year, but there was wide individual variation. CMAI and BRSD scores correlated with 1-year change in the FAST, but not with MMSE or CDR (which weighs cognition heavily), suggesting that behavioral disturbance may be more strongly related to ability to manage activities of daily living (executive function) than to other aspects of cognition. The CMAI and BRSD appear to be interchangeable as measures of agitation, with the CMAI possibly more useful for patients who lack language and the BRSD more sensitive to apathy and depression.

Activities of Daily Living↗

Measurement of disease progression in Alzheimer's disease.

Riege and Metter's comprehensive review deals with many issues pertaining to Alzheimer's disease research. We agree with the authors that early diagnosis and evaluation of disease progression represent key points that must be addressed in an integrated manner. Brain imaging holds great promise for the resolution of both issues.

Alzheimer Disease↗

Determinants of attrition in a natural history study of Alzheimer disease.

The aim of the present study was to identify determinants of attrition in a natural history study of a tertiary care sample of patients with Alzheimer disease (AD) and control subjects. A longitudinal study was performed with 978 patients with AD and 466 control subjects age 50 years and older enrolled at 25 sites of the Consortium to Establish a Registry for Alzheimer's Disease between January 1987 and January 1992; subjects were followed annually for up to 78 months. Both descriptive statistics and polytomous logistic regressions were run to identify determinants of attrition. Of the 1,444 subjects enrolled, 10.5% dropped out after initial evaluation, 31.0% provided at least two waves of data, and 58.4% provided complete follow-up. Inadequate involvement by the site, non-white status, and patient's spouse not enrolled in the study were predictive of dropout; cessation of participation because of death (which may have precluded dropout) predicted continuation in the study. Age, level of education, severity of dementia, and rapidity of progression of disease did not predict dropout. Level-of-site commitment was the most significant determinant of continued participation in this natural history study of AD, followed by white race, and the inclusion of both husband and wife where one is a patient and the other a control subject.

Aged↗

Functional imaging, the frontal lobes, and dementia.

A 58-year-old man developed progressive difficulty with comprehension and verbal output with dementia. Positron emission tomography with 18F 2-fluoro-2-deoxy-D-glucose demonstrated asymmetrical frontal and anterior temporal lobe loss of glucose use. Scopolamine infusion (0.3 mg) did not influence memory. Postmortem studies revealed evidence of Pick's disease, with Pick bodies, loss of somatostatin, preservation of choline acetyltransferase and immunostaining with neurofilament antibodies. Pharmacological challenge and positron imaging offer valuable means for the noninvasive assessment of dementing illness. The contributions of functional imaging to our knowledge of frontal involvement in dementing illness are reviewed.

Brain Chemistry↗

The factor structure of the Brief Psychiatric Rating Scale in Alzheimer's disease.

The factor structure of the Brief Psychiatric Rating Scale (BPRS) is well established with young psychiatric patients. A study by Overall and Beller showed, however, that its factor structure was different with geropsychiatric patients. Although the BPRS has been used in assessing the behavioral characteristics of patients with probable Alzheimer's disease (AD), its factor structure has not been established with these patients. The present study investigated the factor structure of the BPRS among patients with clinically diagnosed AD by (NINCDS/ADRDA) criteria. The scale had limited usefulness with outpatients with mild AD. The factor structure obtained was similar to that found with other patient groups, but a unique factor, including the items Tension and Uncooperativeness, probably reflects the behavioral and psychological agitation characteristic of some AD patients. We recommend caution be taken in generalizing data from younger psychiatric samples to older adult patients with dementia.

Adult↗