Biomedical subjects

M Mitrushina

Publications and source records attributed to M Mitrushina.

27 records · Page 2Linked to original sources

PubMed1993

Left-handedness and old age: do left-handers die earlier?

Data are presented on the prevalence of current left-handedness and prior left-handedness (switched) in 2787 subjects from 21 to 101 years of age. In addition, data on sex differences, familial sinistrality, hand posture when writing, and education were recorded. Two hypotheses were tested. The elimination hypothesis states that reduced frequency of left-handers in old age is due to reduced longevity. The modification hypothesis states that differences in the number of left-handers between older and younger persons are due to changing patterns of social norms. The results showed a decreasing prevalence of left-handedness across the age span, with 15.22% in the youngest group (21-30 years), but only 1.67% in subjects older than 80 years. There was however a corresponding increase in the number of subjects who had switched hand for writing, 2.69% in the youngest group to 6.75% in subjects 80 years and above. This supports the modification hypothesis and questions the elimination hypothesis. However, the mean percent score was still lower in subjects above compared to below age 40 after correction for hand switching. Thus, although changes in social norms towards left-handers seem to be the most likely explanation, we have not empirically disproved the elimination hypothesis.

Adult↗

PubMed1991

Performance of four age groups of normal elderly on the Rey Auditory-Verbal Learning Test.

This study explored effect of age on encoding, retention, and retrieval components of memory functioning in a sample of 156 healthy, elderly subjects between the ages of 57 and 85, partitioned into four age groups. Memory assessment was based on subjects' performance on the RAVLT, which consisted of five free-recall trials, recall after interference, and recognition trial. Significant group differences in recall were found on all five learning trials, whereas rates of learning, forgetting, and recognition did not differ for four age groups. In addition, primacy/recency effect was equally strong for all groups. Results suggest faulty retrieval mechanisms, whereas encoding and retention processes did not prove to be affected by aging.

Aged↗

PubMed1991

Reliability and validity of the Mini-Mental State Exam in neurologically intact elderly.

Reliability and validity of MMSE were explored in a sample of 122 healthy, community-residing elderly volunteers between the ages of 57 and 85, who were tested with a battery of neuropsychological tests over three annual probes. Test-retest reliability ranged between .45 and .50 over a 1-year interval and was .38 over a 2-year period. Change on the MMSE of more than 5 points over a 2-year period was associated with a neurological disorder. Significant correlations were found with many neuropsychological measures, especially with a measure of verbal learning.

Aged↗

PubMed1991

Effect of repeated administration of a neuropsychological battery in the elderly.

Our study explored the magnitude of practice effect in repeated administration of NP measures that tap different cognitive domains in normal elderly subjects (N = 122) between ages 57 and 85, who were evaluated over three annual testing probes. Results revealed that WAIS-R PIQ, serial recall of words, WMS visual memory, and memory for logical passages (immediate and delayed) are likely to improve on the retest due to practice effect in individuals below age 75, whereas test-retest changes in older people show a different pattern. Implications of age-specific changes on retest for differential diagnosis of dementia in clinical practice were considered.

Aged↗

PubMed1991

Changes in cognitive functioning associated with normal aging.

The present study explores age-related changes in cognitive functioning in a cohort of 122 healthy elderly volunteer subjects over a 3-year period. The sample was partitioned into four age groups: 57-65, 66-70, 71-75, 76-85 years. The results suggested high stability of factor structure over three testing probes, as well as selective attrition effect with significantly lower performance in those subjects, who dropped out from the study on the tests of verbal memory and mental speed. The results of repeated measures MANOVA on raw scores and univariate ANOVAs on factor scores comparing four age groups at each testing probe revealed a differential pattern of changes in verbal and nonverbal perception/memory versus mental speed/mental flexibility. Implications of these findings in clinical diagnostics were considered.

Journal Article↗

PubMed1989

Some putative cognitive precursors in subjects hypothesized to be at-risk for dementia.

Virtually no data exists on the early cognitive precursors of dementia, primarily SDAT. This paper presents preliminary cross-sectional data on two elderly groups hypothesized to be at risk for SDAT and a well group matched individually on age, education and gender. The neuropsychological results, based on factor scores and individual t-test comparisons, revealed significant differences between the well group and the two at risk groups, each of which revealed a different pattern of cognitive impairment (specific vs. general). These results stimulated a number of hypotheses concerning the early precursors of SDAT that will be tested in the annual follow-up investigation of these subjects.

Journal Article↗

PubMed1987

WAIS-R marker for dementia of the Alzheimer type? An empirical and statistical induction test.

A specific WAIS subtest pattern has recently been shown to occur more frequently in cases of dementia of the Alzheimer's type (DAT) than in cases of multi-infarct dementia (Fuld, 1984; Brinkman & Braun, 1984). To date, only one study has examined the frequency of this WAIS pattern in a normal elderly sample and found it to be infrequent (Tuokko & Crocket, 1987). If replicated on a larger sample of normals, it would increase the potential of this pattern as a behavioral marker of DAT. WAIS-R scores (age-corrected) were analyzed on a sample of 149 healthy volunteers (ages 60-94) who were part of an ongoing aging study. Because only 12% of the sample revealed this WAIS pattern, its utility as a conditional marker of DAT in three different hypothetical clinical base rate settings was evaluated. Results provided cautious optimism for the application of this marker in certain clinical settings.

Aged↗

PubMedDate not supplied

Cognitive screening of psychiatric patients.

The goal of the present study was to explore characteristic cognitive profiles which distinguish between psychiatric patients with and without organic mental disorder (OMD), using Neurobehavioral Cognitive Status Examination (NCSE), a brief screening battery. A mild degree of cognitive deficits was found to be common in the Non-OMD psychiatric group. The deficit was especially pronounced in the Memory domain. Patients in the OMD group demonstrated a higher frequency of moderate and severe impairment. The best discriminator was the scale assessing visuospatial constructional ability and visual memory. Verbal memory deficit in OMD patients was more severe than in Non-OMD patients. Implications for improving diagnostic sensitivity of cognitive screening are discussed.

Adolescent↗

PubMedDate not supplied

Aspects of validity and reliability of the Neurobehavioral Cognitive Status Examination (NCSE) in assessment of psychiatric patients.

The validity and reliability of the NCSE were assessed on a sample of 192 psychiatric patients from a county general hospital with a mean age of 33.5 years and mean education of 12 years. The analyses revealed that demographic and general health factors need to be taken into consideration in interpreting the NCSE results. Predictive accuracy of the screening items for subsequent performance on metric items across different scales ranged from good to poor. A comparison of success versus failure on the screen for Construction scale with scores on metric items for this scale revealed a high number of false negative errors made using the screening item. Administration of both screen and metric items on this scale for all patients was recommended. Indices of internal consistency of the Orientation scale were adequate. A factor analysis on the scale scores extracted two factors. The second factor identified a subset of scales which assess the patients' functional capacity in dealing with the demands of everyday environment. Test-retest reliability of the NCSE assessed on a subsample of 28 subjects, was high for 7 scales, whereas low stability was demonstrated by Construction, Memory and Calculation scales (r = .79, .52 and .81, respectively). Practice effect and fluctuating attention might contribute to the low stability of these scales. These modifications in the test administration procedure would improve the accuracy of assessment of cognitive deficits in psychiatric patients.

Adolescent↗