417 research outputs found
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Exploring the Structure of a Neuropsychological Battery across Healthy Elders and Those with Questionable Dementia and Alzheimer's Disease
An exploratory factor analysis (EFA) and a series of confirmatory factor analyses were conducted on 17 variables designed to assess different cognitive abilities in a sample of healthy older adults. In the EFA, 4 factors emerged corresponding to language, memory, processing speed, and fluid ability constructs. The results of the confirmatory factor analyses suggested that a 5-factor model with an additional Attention factor improved the fit. The invariance of the 5-factor model was examined across 3 groups: a group of cognitively healthy older adults, a group of patients diagnosed with questionable dementia (QD), and a group of patients diagnosed with probable Alzheimer's disease (AD). Results of the invariance analysis suggest that the model may have configural invariance across the 3 groups but not metric invariance. Specifically, preliminary analyses suggest that the memory construct may represent something different in the QD and AD groups as compared to the healthy older adult group, consistent with the underlying pathology in early AD
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Neuropsychological Detection and Characterization of Preclinical Alzheimer's Disease
We attempted to characterize the changes in cognition associated with the earliest, or preclinical, stages of Alzheimer's disease (AD) by administering a comprehensive neuropsychological test battery to a group of initially nondemented older adults participating in a prospective epidemiologic study of dementia. Using Cox regression analyses, we examined the associations between baseline neuropsychological test scores and subsequent development of AD. Results confirmed preliminary findings that baseline scores on the Boston Naming Test, Immediate Recall on the Selective Reminding Test, and the Similarities subtest of the Wechsler Adult Intelligence Scale-Revised were significantly and independently associated with later diagnosis of AD. Analyses controlled for the effects of age, education, sex, and language of test administration. These results lend support to the notion of a preclinical phase of AD and indicate that this very early stage of AD is characterized by poor word-finding ability, abstract reasoning, and memory
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Interrater Reliability of Extrapyramidal Signs in a Group Assessed for Dementia
Extrapyramidal signs were rated by three neurologists in 20 patients who had either been diagnosed as having probable Alzheimer's disease or who were being evaluated for dementia. In general, good inter-rater reliability was found for the presence or absence of extrapyramidal signs, although agreement over the presence of some signs was reduced when distinctions between normality and slight departures from normality were required
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Safety and Efficacy of Oral Physostigmine in the Treatment of Alzheimer Disease
Results of therapeutic trials with physostigmine in the treatment of Alzheimer disease (AD) have been inconsistent and controversy persists concerning safety and efficacy. In a double-blind, placebo-controlled, crossover study, patients received 6 weeks of oral physostigmine (OP) and placebo in random order. Twenty-nine patients with AD received as much as 16 mg/day of OP and were assessed with neuropsychological and functional measures. No significant cardiac side effects were noted, though other systemic adverse effects were noted, requiring dose reduction in four patients. There was a slight but significant improvement (12%) in performance on the selective reminding test with physostigmine and the memory performance was correlated with dosage. This improvement compares favorably with the 15% decrease in scores seen in an untreated comparison cohort followed for an equivalent time period. There was a trend toward an improvement in communication and a reduction in memory complaint. These results suggest that oral physostigmine is safe and may improve memory in AD
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An Estimate of the Incidence of Depression in Idiopathic Parkinson's Disease
Estimates of the prevalence of depression in idiopathic Parkinson's disease vary, but have been greater than in most comparison groups. In a survey of patients with Parkinson's disease (N = 339), the prevalence of depression was 47%. A total of 326 cases were reviewed to estimate the incidence of depression from September 30, 1984, to July 31,1989. Assessments of depression during both the prevalent and the incident periods were noted in 258 cases. There was no history of depression in 129 cases, and nine new cases occurred. The incidence rate was 1.86% per year and the cumulative risk was 8.6%. Published estimates of the incidence of depression in the general population are few. In one study, the annual incidence of depression in individuals older than 40 years was 0.17%. In another, the incidence of depression in individuals older than 50 years was 0.14% for men and 0.29% for women. Although our retrospective study probably underdiagnoses depression, the incidence of depression is increased in Parkinson's disease
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Neuropsychologic Impairment in Early HIV Infection: A Risk Factor for Work Disability
Objective: To explore the functional significance of incident neuropsychologic impairment among initially asymptomatic subjects infected with human immunodeficiency virus. Design: Prospective, observational cohort study of homosexual and bisexual men to examine the incidence of work disability related to the onset of neuropsychologic impairment. Setting: A university clinical and behavioral research site in New York City. Participants: Sample of 207 homosexual and bisexual men; 123 were seropositive and 84 were seronegative. Principal Outcome Measures: Incident work disability in the course of 4.5 years of follow-up, with disability defined as a persistent (≥24 months) change in work hours (from 20 or more to less than 20 h/wk). Results: Compared with seronegative control subjects (n=72), the relative risk of work disability among initially asymptomatic seropositive men (n=44) was 2.76 (95% confidence interval, 1.2 to 6.5), nearly a threefold increase. Proportional hazards models show that this increased risk is attributable to the development of major neuropsychologic impairment in a subset (eight of 44) of the initially asymptomatic men, which is significantly associated with incident work disability (6/8 [75%]). Adjusting for symptom status and CD4+ cell count at the time of disability did not eliminate the increased risk associated with neuropsychologic impairment. Conclusions: In this cohort, the increased risk of work disability among initially asymptomatic human immunodeficiency virus—positive men was related to incident neuropsychologic impairment; such impairment predicted work disability independently of symptom status and CD4+ cell count over the follow-up period. Neuropsychologic impairment in the course of human immunodeficiency virus infection may indicate increased risk for poor outcomes over and above that associated with systemic disease
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The Neuropsychological Profiles of Mild Alzheimer's Disease and Questionable Dementia as Compared to Age-Related Cognitive Decline
Test scores from a comprehensive neuropsychological battery administered to 1602 subjects consisting of 1347 subjects with probable Alzheimer's disease (AD), 100 subjects with questionable dementia (QD) and 155 non-demented elderly control subjects were cross-sectionally analyzed. Subjects with probable AD were categorized as mild (n = 244), moderate (n = 480), severe (n = 376), and very severe (n = 247) according to modified mini mental status exam (mMMSE) scores. Mean scores on individual neuropsychological tests are provided for each group of subjects. Stratified random sampling was performed to select a sample of mild AD subjects who were matched in age and education to non-demented elderly controls, and analyses focused on the performance of QD subjects and mild AD subjects, whose scores were compared to those of the elderly control subjects. Selected scores were organized by cognitive domain and logistic regressions were used to determine the domains and individual tests within each that were most predictive of group status. Results suggested a profile of scores associated with QD and mild AD including impaired recall of verbal information for both groups. Areas of lower functioning in QD subjects as compared to elderly controls included category fluency and visuospatial ability
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The Columbia University Scale for Psychopathology in Alzheimer's Disease
The Columbia University Scale for Psychopathology in Alzheimer's disease is a new screening instrument developed for use by clinicians or trained lay interviewers. Interrater reliability was established between a psychiatrist and a lay interviewer in 20 patients. In an independent sample of 91 outpatients with very mild to moderate probable Alzheimer's disease, caregiver informants reported that depressed mood was common (46.2%) but rarely persistent (2.2%), and that sleep disturbance occurred frequently (41.8%) but was never severe (0%). There were significant but weak associations between the presence of specific subtypes of delusions and severity of dementia. Although a variety of delusional symptoms were reported, they were frequently transient and patients often accepted the truth if corrected by the caregiver. As a result, few patients met broad or narrow operational criteria used to define delusions. Prior studies may have overestimated the prevalence of psychotic features in Alzheimer's disease by not employing standard definitional criteria. The findings also indicate that new methodology such as that employed in this instrument needs to be evaluated more widely
Examining the Multifactorial Nature of Cognitive Aging with Covariance Analysis of Positron Emission Tomography Data
Research has indicated that there may be age-related and Alzheimer's disease (AD) -related reductions in regional cerebral blood flow (rCBF) in the brain. This study explored differences in age- and AD-related rCBF patterns in the context of cognitive aging using a multivariate approach to the analysis of H215O PET data. First, an rCBF covariance pattern that distinguishes between a group of younger and older adults was identified. Individual subject's expression of the identified age-related pattern was significantly correlated with their performance on tests of memory, even after controlling for the effect of age. This finding suggests that subject expression of the covariance pattern explained additional variation in performance on the memory tasks. The age-related covariance pattern was then compared to an AD-related covariance pattern. There was little evidence that the two covariance patterns were similar, and the age-related pattern did a poor job of differentiating between cognitively-healthy older adults and those with probable AD. The findings from this study are consistent with the multifactorial nature of cognitive aging
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Impairment of Nonverbal Recognition in Alzheimer Disease: A Pet O-15 Study
OBJECTIVE: To characterize deficits in nonverbal recognition memory and functional brain changes associated with these deficits in Alzheimer disease (AD). METHODS: Using O-15 PET, we studied 11 patients with AD and 17 cognitively intact elders during the combined encoding and retrieval periods of a nonverbal recognition task. Both task conditions involved recognition of line drawings of abstract shapes. In both conditions, subjects were first presented a list of shapes as study items, and then a list as test items, containing items from the study list and foils. In the titrated demand condition, the shape study list size (SLS) was adjusted prior to imaging so that each subject performed at approximately 75% recognition accuracy; difficulty during PET scanning in this condition was approximately matched across subjects. A control task was used in which SLS = 1 shape. RESULTS: During performance of the titrated demand condition, SLS averaged 4.55 (+/-1.86) shapes for patients with AD and 7.53 (+/-4.81) for healthy elderly subjects (p = 0.031). However, both groups of subjects were closely matched on performance in the titrated demand condition during PET scanning with 72.17% (+/-7.98%) correct for patients with AD and 72.25% (+/-7.03%) for elders (p = 0.979). PET results demonstrated that patients with AD showed greater mean differences between the titrated demand condition and control in areas including the left fusiform and inferior frontal regions (Brodmann areas 19 and 45). CONCLUSIONS: Relative fusiform and inferior frontal differences may reflect the Alzheimer disease (AD) patients' compensatory engagement of alternate brain regions. The strategy used by patients with AD is likely to be a general mechanism of compensation, rather than task-specific
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