Biomedical subjects

Roee Holtzer

Publications and source records attributed to Roee Holtzer.

9 recordsLinked to original sources

PubMed2007

Walking while talking: effect of task prioritization in the elderly.

OBJECTIVE: To examine the effect of 2 instructions on the same walking while talking (WWT) task on task prioritization by nondisabled subjects. DESIGN: Cross-sectional survey with within subject comparisons. SETTING: Community-based sample. PARTICIPANTS: Older adults (N=189; mean age, 80.2+/-4.9y), who did not meet criteria from the Diagnostic and Statistical Manual, Fourth Edition, for dementia and were able to independently perform activities of daily living. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Verbal and gait measures on the same WWT task with 2 different instructions: paying attention to both talking and walking (WWT-C) and paying attention only to talking (WWT-T). RESULTS: Task prioritization effects were seen on walking but not on talking. Compared with their baseline normal walking velocity (without talking), subjects slowed down more on WWT-T (median change, 28.3%) than WWT-C (median change, 26.4%). Comparing the 2 WWT conditions, velocity and cadence was slower during WWT-T compared with WWT-C, with longer stride length. Verbal output was not significantly different on the 2 conditions. CONCLUSIONS: Changing instructions while maintaining the same cognitive and motor tasks on WWT in older adults result in task prioritization effects.

Activities of Daily Living↗

PubMed2006

Relation of quantitative indexes of concurrent alpha-synuclein abnormalities to clinical outcome in autopsy-proven Alzheimer disease.

BACKGROUND: Lewy bodies (LBs) and Lewy neurites are frequent concomitant neuropathologic observations in clinical and neuropathologically defined Alzheimer disease (AD), but their relation to clinical features in AD is uncertain. Most studies used semiquantitative measures to determine the presence or absence of LB abnormalities. OBJECTIVE: To determine the clinical consequences of LB abnormalities in the setting of AD. DESIGN: Prospective study. SETTING: Three outpatient research and treatment centers. PARTICIPANTS: Fourteen autopsy cases with a pathologic diagnosis of AD abnormalities and concomitant LBs followed semiannually for up to 8 years (mean age at intake, 72 years; mean age at death, 77 years; mean education, 15 years; 12 women). MAIN OUTCOME MEASURES: The modified Mini-Mental State Examination was used to assess cognitive function. The Unified Parkinson Disease Rating Scale was used to rate extrapyramidal motor signs. Hallucinations were evaluated using the Columbia University Scale for Psychopathology in Alzheimer's Disease. Time from the first evaluation in which diagnostic criteria for probable AD were met to death was used to determine illness duration. Quantitative measures of LB abnormalities were obtained for the frontal cortex, entorhinal cortex, substantia nigra, and hippocampus. RESULTS: Independent-samples t tests were used to assess whether the degree of LB abnormality varied as a function of the presence or absence of hallucinations and extrapyramidal signs. Pearson r correlations were run to examine whether there was a relation among LB abnormalities, cognitive function, and illness duration. There was no relation between quantitative neuropathologic indexes of LB abnormalities and clinical outcome. CONCLUSION: The variability of clinical features in AD was not related to the presence or degree of LB abnormalities.

Aged↗

PubMed2006

Cognitive processes related to gait velocity: results from the Einstein Aging Study.

The authors examined the relationship between cognition and gait velocity, performed with and without interference, in elderly participants. Neuropsychological test scores from 186 cognitively normal elders were submitted to factor analysis that yielded 3 factors: Verbal IQ, Speed/Executive Attention, and Memory. Regression analyses revealed that these factors were significant predictors of variance in gait velocity, but the relationship varied as a function of task condition. All 3 factors predicted gait velocity without interference. However, the Speed/Executive Attention and Memory factors but not Verbal IQ predicted gait velocity in the interference condition. These findings suggest that gait velocity and cognitive function may have both shared and independent brain substrates. Future studies should explore gait velocity and cognitive function as predictors of dementia and falls.

Aged↗

PubMed2005

Predicting age-related dual-task effects with individual differences on neuropsychological tests.

This study examined the relation of dual-task performance to individual differences on neuropsychological tests. Neuropsychological test scores from 16 young and 16 older participants were simultaneously submitted to a factor analysis that yielded 2 factors (Attention/Executive and Memory) that differed by age and 2 (Motor Speed and Cognitive Status) that did not. Regression analyses revealed that these factors were significant predictors of performance on a delayed visual recognition task, but the relationship varied as a function of task condition. The Memory and Motor Speed factors were the strongest predictors of single-task performance, but the Attention/Executive factor was the most important predictor of dual-task performance. The authors conclude that compromised central executive may underlie age-related decline in dual-task performance.

Adult↗

PubMed2005

Depressive symptoms in Alzheimer's disease: natural course and temporal relation to function and cognitive status.

OBJECTIVES: To examine the natural course of depressive symptoms in patients with probable Alzheimer's disease (AD), specifically, the temporal relationship between depressive symptoms, function, and cognitive status. DESIGN: Multicenter cohort study with follow-up of up to 14 years. SETTING: Patients from the two Multicenter Study of Predictors of Disease Course in Alzheimer's Disease (Predictors Study) cohorts were recruited at five sites in the United States and Europe. PARTICIPANTS: Patients diagnosed with probable AD (n=536) enrolled in a longitudinal study (Predictors Study). MEASUREMENTS: Depressive symptoms were evaluated at 6-month intervals using the Columbia Scale for Psychopathology in Alzheimer's Disease. The Modified Mini-Mental State (3MS) and Blessed Dementia Rating Scale (BDRS) were used to assess cognitive status and functional activity, respectively. RESULTS: The prevalence of depressive symptoms was stable over the first 3 years of follow-up, at approximately 40%. There was a significant drop to 28% and 24% in the fourth and fifth years of follow-up, respectively. Time-dependent Cox analysis revealed that functional activity (BDRS) but not cognitive status (3MS) was a significant predictor of the first episode of depressive symptoms during follow-up. Generalized estimating equation analyses showed that AD duration and functional activity but not cognitive status were significantly related to depressive symptoms over the entire follow-up period. CONCLUSION: Depressive symptoms are common in AD, but their prevalence decreases over time. Examination of the temporal relationship between depressive symptoms and risk factors suggests that decline in function but not in cognition precedes the first episode of depressive symptoms in patients with probable AD.

Activities of Daily Living↗

PubMed2004

The sensitivity of dual-task performance to cognitive status in aging.

The present study examined dual-task performance in elders with cognitive impairments and normal controls. The participants (N = 60; M age = 84.6) were recruited from residential facilities and the community. They were assigned to one of three groups: (1) cognitive impairment; (2) residential facility control; (3) community control. Two different dual-task conditions were comprised of simple tests that are presumably processed via separate perceptual modalities: 1 visual-manual and 1 auditory-verbal. The first condition consisted of a visual cancellation test and an auditory digit span. The second condition was comprised of an alternate form of the visual cancellation test and letter fluency. MANOVA examined the effect of cognitive status (3-level independent variable) on 3 indices of dual-task performance (letter fluency, digit span, visual cancellation). Analyses controlled for age, education and performance on each test when performed alone. The results revealed that the cognitive impairment group incurred significantly greater dual-task costs compared to both control groups. Furthermore, as was evident from discriminant function analyses, the dual-task measures were very accurate and better than the traditional neuropsychological measures at discriminating elders with cognitive impairments from normal controls. (JINS, 2004, 10, 230-238.)

Aged↗

PubMed2004

Age-related differences in executive control of working memory.

In two experiments, we used dual-task methodology to assess the effect of aging on executive control of working memory. We hypothesized that (1) age-related dual-task costs would be observed even when individual tasks represent different perceptual modalities; (2) age would modulate the effect of increased temporal overlap on dual-task performance; and (3) the vulnerability of specific memory mechanisms to interference would be age related. We found that aging was associated with disproportionate dual-task costs that increased when extending the overlap between individual tasks. The effect of interference with encoding, and arguably output, was disproportionately larger in old than in young individuals. Ensuring that individual tasks represent different perceptual modalities is important but insufficient when using dual-task methodology to assess the effect of aging on executive function. The degree of temporal overlap between individual tasks and the sensitivity of specific memory operations to interference should be considered, as well.

Adult↗

PubMed2003

The rate of cognitive decline and risk of reaching clinical milestones in Alzheimer disease.

BACKGROUND: Previous studies revealed that cognitive test scores were related to functional outcome in Alzheimer disease (AD). However, the relationship between the rate of cognitive decline at the initial disease phase and the risk of reaching clinical milestones in subsequent years has not yet been examined. OBJECTIVE: To examine whether the rate of cognitive decline predicts the risk of reaching functional milestones in patients with probable AD. DESIGN: A 5-year prospective study was conducted at 3 sites. SETTING: Outpatient research and treatment centers. PARTICIPANTS: Patients diagnosed with probable AD (N = 236; mean age, 73 years; 59% women; mean years of education, 13). MAIN OUTCOME MEASURES: Modified Mini-Mental State Examination (mMMSE) scores were used to assess the rate of cognitive decline over time. Total dependence score and 2 clinical milestones: (1) the need to be dressed, groomed, and washed and (2) receiving a level of care equivalent to a placement in a health-related facility, were derived from the Dependence Scale. RESULTS: General estimating equation analyses revealed that the rate of cognitive decline during the entire follow-up period was positively related to an increase in total dependence scores. Cox analyses showed that a fast rate of decline during the first year was related to an increase in the risk of reaching clinical milestones in subsequent years. Analyses controlled for age, sex, education, and baseline mMMSE scores. CONCLUSION: A fast rate of cognitive decline was associated with increasing risk of reaching clinical milestones in AD.

Activities of Daily Living↗

PubMed2003

Psychopathological features in Alzheimer's disease: course and relationship with cognitive status.

OBJECTIVES: To examine the course, clinical correlates, and relationship between cognitive status and psychopathological features in patients with probable Alzheimer's disease (AD) followed over a 5-year period. DESIGN: Cohort study with follow-up of 5 years. SETTING: Patients were recruited at three sites: 91 patients at Columbia Medical Center, 84 at Johns Hopkins School of Medicine, and 61 at Massachusetts General Hospital. PARTICIPANTS: Patients diagnosed with probable AD (n = 236) enrolled in a longitudinal study (Predictors study). MEASUREMENTS: Wandering/agitation, physical aggression, hallucinations, and delusions were evaluated at 6-month intervals using the Columbia Scale for Psychopathology in Alzheimer's Disease. Descriptive analyses were used to provide estimates of prevalence and course of psychopathological features. General estimating equations determined the odds of having any of the four psychopathological behaviors as a function of cognitive status. Markov analyses provided 6-month transition probabilities for psychopathological behaviors given patients' cognitive status and the presence or absence of such behaviors in the previous evaluation. RESULTS: For wandering/agitation, prevalence (39-57%) and persistence increased as a function of time and decrement in cognitive status. Physical aggression was less prevalent (6-22%) and increased as a function of cognitive decline but tended to persist only in the more severely impaired patients. Delusions (34-49%) reached a peak at the second year and then declined. The odds of delusions were maximal with intermediate decline but remained persistent regardless of cognitive status. Hallucinations, despite some fluctuations, were relatively stable during the follow-up period (8-17%) and moderately persistent. CONCLUSION: Psychopathological features, particularly wandering/agitation and delusions, in AD were common throughout the disease course. The natural history and persistence of the four psychopathological features varied. These findings provide important information to clinicians and caregivers regarding the course, predictability, and possible treatment of psychopathological behaviors in patients with probable AD.

Aged↗