The relationship between age and cognitive impairment in HIV-1 infection: findings from the Multicenter AIDS Cohort Study and a clinical cohort.

Previous studies have identified age as a risk factor for many neurologic disorders, and a "cerebral reserve" factor has been postulated to explain these findings. This study examined whether age represents a risk factor for HIV-1-related neuropsychological dysfunction. Subjects for study 1 were primarily asymptomatic seropositive (n = 1,066) and seronegative (n = 1,004) nonelderly male community volunteers who completed neuropsychological and reaction time measures. Data analyses revealed a significant effect for age on reaction time and timed neuropsychological measures, but no interaction between age and serostatus. Study 2, employing a similar neuropsychological battery, consisted of 76 seropositive men (29 over age 55) recruited from community outpatient clinics and 47 seronegative controls. We found serostatus and age to have main effects on a number of measures, but a trend for an effect of age-serostatus interaction on only one measure.

Performance on motor tasks as an indication of increased behavioral asymmetry with advancing age.

Age-related asymmetrical functional decline was tested on a sample of 64 right-handed volunteers between 60 and 64 years of age who were free from neurological illnesses and physical handicaps. Increase in functional asymmetry was explored by examining performance indexes for each hand and superiority of the dominant hand on motor tasks of different complexities: the Finger Tapping Test, the Grooved Pegboard Test, and the Pin Test. Our study revealed an increase in superiority of the right hand with age on a highly demanding task (Pin Test). This finding is discussed in light of the hypothesis of a decline in callosal functioning with age and the alternative hypothesis of a greater vulnerability of the right hemisphere in the elderly.

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.

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.

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.

Task-induced differential cortical activation pattern.

Measures of task-dependent cortical activation were assessed by bilateral EEG recordings from frontal, temporal, parietal and occipital areas. Two pictorial tests, the Raven Advanced Progressive Matrices and the Space Relations Test were used for verbal and spatial conditions, respectively. Recordings were obtained for 20 trials of each task from 22 right-handed adult males and 16 s. trial epochs were subjected to Fast Fourier analyses. Averaged intensity values for the alpha band were compared between verbal and spatial tasks for all subjects and between subgroups of verbalizers and visualizers, allotted on the basis of subject's performance index, derived from response speed and accuracy on the two tasks. The results were as follows: (1) The most pronounced EEG discriminators between the two performance subgroups are the left and right parietal and the right frontal area; (2) The left parietal zone provides the most pronounced discrimination between two groups; (3) There were significant interactions between the left parietal and the right frontal region; (4) The two parietal areas show characteristic frequency shifts in opposite directions for the task conditions. The findings imply complex interplay among the two parietal and right frontal areas, associated with sequential and holistic strategies. The results urge researchers to take into consideration subjectively preferred cognitive strategy, which along with objective task demands influences the process of problem solving and accompanying physiological changes.

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.

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.

Frontal lobe functioning in geriatric and non-geriatric samples: an argument for multimodal analyses.

The present investigation examines specific aspects of frontal functioning across geriatric and nongeriatric cohorts. Subjects included 193 nongeriatric male pilots (mean age: 48.29 (SD = 6.79); mean education: 15.93 years (SD = 1.86)), and 68 geriatric males and females (mean age: 78.38 (SD = 5.07); mean education: 13.68 (SD = 2.53)). The results of a series of general linear model multivariate one-way analyses revealed poorer performance on frontal measures in the geriatric sample, although no differences were noted between the male and female samples. In contrast, variable interrelations, as assessed by a parametric statistic of betweengroup factor similarity, indicated a noteworthy similarity of factors between the geriatric and nongeriatric groups, and dissimilarities between the factor structures for males and geriatric females. These findings not only support the presence of age-related differences in frontal performance for the domains tested, they suggest the need to examine frontal functioning by multiple methods, as differences in frontal functioning may exist between groups that are undetected by analyses based on intergroup score differences or predictor-criterion correlations alone

Adolescent Multiphasic Personality Inventory and its utility in assessing suicidal and violent adolescents.

Adolescent Multiphasic Personality Inventory profiles of inpatient adolescents were examined to identify differences between suicidal (danger to self, n = 145) and violent (danger to others, n = 36) adolescents. Participants were 181 inpatients (12-17 years old, mean age, 14.7 years) admitted to an adolescent psychiatric unit of a southern California county hospital. Results indicate that the suicide group had significantly higher scores than the violent group on five scales (Hypochondriasis, Psychasthenia, Paranoia, Schizophrenia, and Social Introversion). This scales, singly or in combination, have been found to be indicative of psychotic process. This suggests the presence of psychotic process in suicidal, but not violent, adolescents.

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.

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.

Utility of mini-mental state examination in assessing cognition in the elderly.

The present study used a sample of 156 healthy elderly subjects between 57 and 85 years of age to examine concurrent validity of 3 MMSE components: serial seven subtractions, 3-word recall, and copying pentagons, which are most frequently used in clinical practice as indicators of specific cognitive deficits. Correlational analyses and examination of concordance rates were used to explore the relationship of 3 MMSE tasks with scores on neuropsychological tests. The results of this study indicated that performance on MMSE components by elderly individuals should be interpreted with caution due to the effect of education on individual task performance, questionable specificity of the tasks in assessing circumscribed cognitive domains, emphasis on verbal tasks and high misidentification rate.

Test-retest reliability of the WAIS-R Satz-Mogel short form in a normal elderly sample.

Test-retest reliability of the WAIS-R Satz-Mogel short form was tested on a sample of 122 normal elderly volunteer subjects with mean age of 70.4. Subjects' performance was assessed over 3 annual probes. Reliability coefficients for sums of scaled scores on Verbal subscale and Full Scale ranged between 0.79 and 0.83. Corresponding coefficients for Performance subscale ranged between 0.70 and 0.72. The percentage of subjects who showed change between two probes of more than 1 SD was the highest for the Performance subscale. Implications for clinical use, particularly for the purpose of estimation of premorbid intellectual functioning are discussed.

Repeated testing of normal elderly with the Boston Naming Test.

The Boston Naming Test is commonly viewed as a measure of language ability, particularly, confrontational naming. Its utility in detecting word-retrieval problems in clinical populations is well documented. However, studies which would explore information-processing mechanisms involved in BNT performance are not available. Results of our repeated testing of 122 subjects between the ages of 57 and 85 with the 60-item version of BNT and other measures over three annual probes revealed high stability of the BNT scores over time, which suggests a lack of the practice effect, whereas cross-sectional analysis demonstrated some decline in the BNT scores in subjects over 70 years of age. In spite of the high stability in BNT scores on repeated testing, the pattern of correlations between the BNT and measures tapping different cognitive domains shifted over time. Results suggest predominantly the verbal mode of information processing in BNT performance on the first probe, as opposed to visuo-spatial mode on the third probe in our sample of elderly individuals.

Base rates of the WAIS-R intersubtest scatter and VIQ-PIQ discrepancy in normal elderly.

This study provides base rates for WAIS-R VIQ-PIQ discrepancy and for 3 indices of intersubtest scatter in a sample of high functioning normal elderly. High correlations between indices of scatter, such as (1) range of scatter; (2) Profile Variability Index; and (3) number of subtest scores that significantly deviated from the individual's own mean, indicate that easy-to-compute range can be used as an adequate measure of scatter in many clinical settings. The results suggest that bright elderly individuals display a large degree of scatter. The clinician should base judgment regarding abnormality of the WAIS-R indices on the rarity of the value demonstrated by the individual with respect to the sample of comparable age and intelligence level.

Correlates of self-rated health in the elderly.

The relationship between self-rated health status and age group, gender, self-reported number of physical symptoms, functional capacity and level of activity was explored in a group of 133 elderly subjects ranging in age from 57 to 85 years. Self-rating of health was found to be a useful measure of health status, which is highly related to a number of physical symptoms and evidence of disruption in everyday functioning due to health problems. Women's overall ratings of health were interpreted as reflecting a more optimistic appraisal of their self-ratings of health.

The neurobehavioral cognitive status examination as a screening tool for organicity in psychiatric patients.

OBJECTIVE: The study explored the efficiency of the Neurobehavioral Cognitive Status Examination (NCSE) in predicting organic pathology in psychiatric patients. METHODS: Based on history of neurological disorders, 192 psychiatric patients at a country hospital were assigned to one of two groups according to whether they did or did not have organic mental disorder. Fifty patients were determined to have the disorder, and 136 were determined not to have the disorder. The patient's performance on each of the NCSE's ten scales was rated from 1, indicating average performance, to 4, indicating severe impairment. The scores were added together to form a composite index score, with a range from 10 to 40. Composite scores for the two groups were compared. RESULTS: A composite index score of 13 was optimal for discriminating between patients with organic mental disorder and those without the disorder. At this cutoff level, the test had a sensitivity of .72 and specificity of .73. CONCLUSIONS: The NCSE can be useful in screening for organicity in a psychiatric population. However, psychiatric patients without organic mental disorder can be expected to demonstrate some impairment on one or more of the NCSE's ten scales.

Heterogeneity of cognitive profiles in normal aging: implications for early manifestations of Alzheimer's disease.

This study explores the presence of homogeneous subgroups among 156 normal elderly subjects based on their performance on a battery of neuropsychological tests. Subjects ranged in age between 57 and 85 years and included 62 males and 94 females with a mean age 70.7 years, mean education 14.1 years, and mean Full Scale IQ of 117.2. Six clusters were extracted, three of which are likely to represent preclinical stages of the dementing process with distinct patterns of cognitive deficits. The results are discussed in light of different models of cognitive deterioration in DAT.

A comparison of cognitive profiles in schizophrenia and other psychiatric disorders.

This study compared patients across 5 psychiatric diagnostic groups: Depression, Mania, Schizophrenia, Schizoaffective Disorder, and Psychosis NOS, all of whom are psychotic. Differences in overall cognitive profiles and in dysfunctional memory mechanisms, as well as the effect of psychosis on cognitive functioning were explored using the Neurobehavioral Cognitive Status Examination (NCSE), a brief screening instrument. Results indicated pronounced deficit in memory and abstract reasoning associated with schizophrenic illness, which is not secondary to psychosis and points to localized brain dysfunction. Both encoding and postencoding memory mechanisms were affected. Results support a hypothesis of progressive dysfunction associated with the severity and chronicity of the illness. Implications of findings in aiding diagnostic determination, patient management and rehabilitation are discussed.