Executive dyscontrol: an important factor affecting the level of care received by older retirees

Exploring behavioural and cognitive dysexecutive syndrome in patients with focal prefrontal cortex damage

This study's objectives were to characterize the frequency and profile of behavioral and cognitive dysexecutive syndromes in patients with focal prefrontal cortex damage and how these syndromes overlap. We also examined the contribution of the prefrontal brain regions to these syndromes. Therefore, thirty patients with prefrontal cortex damage and thirty control subjects were compared on their performances using the GREFEX battery assessing the dysexecutive syndromes. The results showed that combined behavioral and cognitive dysexecutive syndrome was observed in 53.33%, while pure cognitive dysexecutive syndrome was observed in 20% and behavioral in 26.67%. Also, almost all behavioral and cognitive dysexecutive disorders discriminated frontal patients from controls. Moreover, correlations and regression analyses between task scores in both domains of dysexecutive syndromes showed that the spectrum of behavioral disorders was differentially associated with cognitive impairment of initiation, inhibition, generation, deduction, coordination, flexibility and the planning process. Furthermore, the patterns of cognitive and behavioral dysexecutive syndrome were both predictors of impairment in daily living activities and loss of autonomy. Finally, frontal regions contributing to different dysexecutive syndromes assessed by MRI voxel lesion symptom analysis indicate several overlapping regions centered on the ventromedial and dorsomedial prefrontal cortex for both domains of dysexecutive syndrome. This study concludes that damage to the frontal structures may lead to a diverse set of changes in both cognitive and behavioral domains which both contribute to loss of autonomy. The association of the ventromedial and dorsomedial prefrontal regions to both domains of dysexecutive syndrome suggests a higher integrative role of these regions in processing cognition and behavior.

Aerobic Exercise Sustains Performance of Instrumental Activities of Daily Living in Early-Stage Alzheimer Disease

BACKGROUND AND PURPOSE

Individuals with Alzheimer disease (AD) experience progressive loss of independence-performing activities of daily living. Identifying interventions to support independence and reduce the economic and psychosocial burden of caregiving for individuals with AD is imperative. The purpose of this analysis was to examine functional disability and caregiver time in individuals with early-stage AD.

METHODS

This was a secondary analysis of a randomized controlled trial of 26 weeks of aerobic exercise (AEx) versus stretching and toning (ST). We measured functional dependence using the Disability Assessment for Dementia, informal caregiver time required using the Resources Utilization in Dementia Lite, and cognition using a standard cognitive battery.

RESULTS

We saw a stable function in the AEx group compared with a significant decline in the ST group (4%; F = 4.2, P = .04). This was especially evident in more complex, instrumental activities of daily living, with individuals in the AEx group increasing 1% compared with an 8% loss in the ST group over 26 weeks (F = 8.3, P = .006). Change in memory was a significant predictor of declining instrumental activities of daily living performance (r = 0.28, 95% confidence interval = 0.08 ∞, P = .01). Informal caregiver time was not different between the AEx and ST groups.

CONCLUSIONS

Our analysis extends recent work by revealing specific benefits for instrumental activities of daily living for individuals in the early stages of AD and supports the value of exercise for individuals with cognitive impairment.

Global Efficiency of Structural Networks Mediates Cognitive Control in Mild Cognitive Impairment

Background: Cognitive control has been linked to both the microstructure of individual tracts and the structure of whole-brain networks, but their relative contributions in health and disease remain unclear. Objective: To determine the contribution of both localized white matter tract damage and disruption of global network architecture to cognitive control, in older age and Mild Cognitive Impairment (MCI). Materials and Methods: Twenty-five patients with MCI and 20 age, sex, and intelligence-matched healthy volunteers were investigated with 3 Tesla structural magnetic resonance imaging (MRI). Cognitive control and episodic memory were evaluated with established tests. Structural network graphs were constructed from diffusion MRI-based whole-brain tractography. Their global measures were calculated using graph theory. Regression models utilized both global network metrics and microstructure of specific connections, known to be critical for each domain, to predict cognitive scores. Results: Global efficiency and the mean clustering coefficient of networks were reduced in MCI. Cognitive control was associated with global network topology. Episodic memory, in contrast, correlated with individual temporal tracts only. Relationships between cognitive control and network topology were attenuated by addition of single tract measures to regression models, consistent with a partial mediation effect. The mediation effect was stronger in MCI than healthy volunteers, explaining 23-36% of the effect of cingulum microstructure on cognitive control performance. Network clustering was a significant mediator in the relationship between tract microstructure and cognitive control in both groups. Conclusion: The status of critical connections and large-scale network topology are both important for maintenance of cognitive control in MCI. Mediation via large-scale networks is more important in patients with MCI than healthy volunteers. This effect is domain-specific, and true for cognitive control but not for episodic memory. Interventions to improve cognitive control will need to address both dysfunction of local circuitry and global network architecture to be maximally effective.

The Importance of Maintaining a Focus on Performance Components in Occupational Therapy Practice

Some authors have promoted the need for occupational therapists to prioritise occupation over performance components in their clinical work (Fisher 1992, Mathiowetz 1993, Trombly 1995, Baum and Law 1997, Fortune 2000, Molineux 2004). Nevertheless, there is a strong case to be made for maintaining concurrently a focus on performance components. This case is based on a review of relevant literature, which yielded three ways in which performance component functioning could be used to enhance a person's experience of occupational therapy. It is concluded that there is a sound rationale for maintaining a dual focus on occupational performance and performance components in occupational therapy practice.

A Description of a Functional Screening Assessment Developed for the Acute Physical Setting

This article provides a description of the development, process and introduction of the Structured Anchored Approach to Functional Assessment (SAAFA).1 The approach was designed to include a person-centred and time-efficient occupational therapy functional screening assessment that would meet the needs of patients and be appropriate for use in an acute physical inpatient setting. SAAFA assessments were developed to incorporate the strengths of both quantitative and qualitative occupational therapy assessments and research methods. Taken in the round, SAAFA assessments follow a process that corresponds with the four processes of qualitative research: data gathering, analysis, interpretation and reflexivity (Miller and Crabtree 2003).

The SAAFA is a dynamic approach that continues to evolve in response to developments in theory and practice. Information from occupational therapists' reports of their day-to-day practice indicate that SAAFA assessments reflect the complexity of individual patients' functioning and lead to the development of recommendations based on pragmatic consideration of a wide range of contextual influences. Research on the SAAFA commenced in 2002.

Executive Dysfunction Following Critical Illness: Exploring Risk Factors and Management Options in Geriatric Populations

Cognitive impairment is a common occurrence that has been shown to occur in over 50 % of patients following critical illness. This impairment occurs across a range of domains including attention, memory, processing speed, and executive dysfunction. In this article, we will discuss the pathophysiology behind cognitive impairment including hypoxemia and cytokines. Secondly, we will describe the risk factors for cognitive impairment including age, length of stay, and delirium. Lastly, we will review emerging data related to the use of cognitive rehabilitation, formation of postintensive care clinics in qualifying patients, and potential neuropharmacologic therapy. While our chapter focuses on cognitive impairment generally, it places a particular emphasis on executive dysfunction, not because impairment occurs solely in this domain but because impairments of an executive nature may be uniquely debilitating.

"Executive functions" cannot be distinguished from general intelligence: two variations on a single theme within a symphony of latent variance

The empirical foundation of executive control function (ECF) remains controversial. We have employed structural equation models (SEM) to explicitly distinguish domain-specific variance in executive function (EF) performance from memory (MEM) and shared cognitive performance variance, i.e., Spearman's “g.” EF does not survive adjustment for both MEM and g in a well fitting model of data obtained from non-demented older persons (N = 193). Instead, the variance in putative EF measures is attributable only to g, and related to functional status only through a fraction of that construct (i.e., “d”). d is a homolog of the latent variable δ, which we have previously associated specifically with the Default Mode Network (DMN). These findings undermine the validity of EF and its putative association with the frontal lobe. ECF may have no existence independent of general intelligence, and no functionally salient association with the frontal lobe outside of that structure's contribution to the DMN.

The Executive Interview (EXIT25) as a tool for assessing executive functioning in older medical and surgical inpatients referred to a psychiatry service: feasibility of creating a brief version

BACKGROUND

Most neuropsychological tests of executive function are time-consuming and otherwise unsuitable for routine bedside assessment, particularly in older people admitted to a general hospital. After introducing the Executive Interview (EXIT25) in our routine clinical practice, we hypothesized that it would be possible to shorten it for easier administration in our group of patients while maintaining or improving properties of the scale.

METHODS

The EXIT25 was applied in 122 clinically stable medical and surgical inpatients aged 65 years and over referred to the Liaison Psychiatry Service for Older People. Individual items were initially tested for floor and ceiling effects, inter-rater and test-retest reliability, and item-total correlations. Items were then selected for retention in the brief scale on the basis of adequate item-total correlation and inter-rater and test-retest reliability. The construct validity of the original and brief versions of the EXIT25 scale was assessed.

RESULTS

The original EXIT25 scale was found to lack desirable scaling properties either as a classical or hierarchical scale. The study confirmed a possibility to reduce the number of items to nine out of the original 25 while improving internal consistency, test-retest and inter-rater reliability, and maintaining high correlation with the original EXIT25 score, and moderate inverse correlation with the Mini-Mental State Examination score.

CONCLUSIONS

There is potential to abbreviate the original EXIT25, and improve internal consistency and hierarchical scaling properties. Future research is necessary to focus on piloting these brief measures of executive function in relevant clinical settings, when administered en bloc, rather than with items interspersed in the original longer version.

Optimism and Planning for Future Care Needs among Older Adults

Aging is associated with an increase in need for assistance. Preparation for future care (PFC) is related to improved coping ability as well as better mental and physical health outcomes among older adults. We examined the association of optimism with components of PFC among older adults. We also explored race differences in the relationship between optimism and PFC. In Study 1, multiple regression showed that optimism was positively related to concrete planning. In Study 2, optimism was related to gathering information. An exploratory analysis combining the samples yielded a race interaction: For Whites higher optimism, but for Blacks lower optimism was associated with more planning. High optimism may be a barrier to future planning in certain social and cultural contexts.

A multistate model of cognitive dynamics in relation to resistance training: the contribution of baseline function

PURPOSE

We investigated: (1) the effect of different targeted exercise training on an individual's overall probability for cognitive improvement, maintenance, or decline; and (2) the simultaneous effect of targeted exercise training and baseline function on the dynamics of executive functions when a multistate transition model is used.

METHODS

Analyses are based on a 12-month randomized clinical trial including 155 community-dwelling women 65-75 years of age who were randomly allocated to once-weekly resistance training (1x RT; n = 54), twice-weekly resistance training (2x RT; n = 52), or twice-weekly balance and tone training (BAT; n = 49). The primary outcome measure was performance on the Stroop test, an executive cognitive test of selective attention and conflict resolution. Secondary outcomes of executive functions were set shifting and working memory.

RESULTS

Individuals in the 1x RT or 2x RT group demonstrated a significantly greater probability for improved performance on the Stroop Test (0.49; 95% confidence interval, 0.41-0.57) compared with those in the BAT group (0.25; 95% confidence interval, 0.25-0.40). Resistance training had significant effects on transitions in selective attention and conflict resolution.

CONCLUSIONS

Resistance training is efficacious in improving a measure of selective attention and conflict resolution in older women, probably more so among those with greater baseline cognitive function.

Alzheimer disease alters the relationship of cardiorespiratory fitness with brain activity during the stroop task

BACKGROUND

Despite mounting evidence that physical activity has positive benefits for brain and cognitive health, there has been little characterization of the relationship between cardiorespiratory (CR) fitness and cognition-associated brain activity as measured by functional magnetic resonance imaging (fMRI). The lack of evidence is particularly glaring for diseases such as Alzheimer disease (AD) that degrade cognitive and functional performance.

OBJECTIVE

The aim of this study was to describe the relationship between regional brain activity during cognitive tasks and CR fitness level in people with and without AD.

DESIGN

A case-control, single-observation study design was used.

METHODS

Thirty-four individuals (18 without dementia and 16 in the earliest stages of AD) completed maximal exercise testing and performed a Stroop task during fMRI.

RESULTS

Cardiorespiratory fitness was inversely associated with anterior cingulate activity in the participants without dementia (r=-.48, P=.05) and unassociated with activation in those with AD (P>.7). Weak associations of CR fitness and middle frontal cortex were noted.

LIMITATIONS

The wide age range and the use of a single task in fMRI rather than multiple tasks challenging different cognitive capacities were limitations of the study.

CONCLUSIONS

The results offer further support of the relationship between CR fitness and regional brain activity. However, this relationship may be attenuated by disease. Future work in this area may provide clinicians and researchers with interpretable and dependable regional fMRI biomarker signatures responsive to exercise intervention. It also may shed light on mechanisms by which exercise can support cognitive function.

The epidemiology and clinical manifestations of dysexecutive syndrome in Parkinson's disease

This mini-review summarizes the evidence of the cognitive and behavioral features of dysexecutive syndrome in Parkinson’s disease (PD). Deficits in response inhibition, set-shifting, mental flexibility, and strategy have been frequently described from the earliest stages of PD, although there are inconsistencies in study findings due to the complexity of the executive function (EF) construct and methodological limitations. Behavioral disorders of PD, e.g., apathy, distractibility, perseverative behavior, and impulse-control disorders, may be viewed as the other side of dysexecutive syndrome. Despite the interrelationship between the cognitive and behavioral domains, some reports reveal that the two syndromes may be dissociated, suggesting that both aspects must be clinically assessed. EFs are widely associated with the prefrontal areas, although dysexecutive syndrome may be observed in patients with damage to other brain regions. EFs drive numerous abilities essential to daily life, such as prospective remembering and language comprehension, which may be impaired in PD subjects. Considering the impact of dysexecutive syndrome on independence and quality of life, early detection of executive impairment is crucial in the management of PD.

Cognitive impairment in acquired brain injury: a predictor of rehabilitation outcomes and an opportunity for novel interventions

Cognitive impairment is a common sequela in acquired brain injury and one that predicts rehabilitation outcomes. There is emerging evidence that impairments in cognitive functions can be manipulated by both pharmacologic and nonpharmacologic interventions to improve rehabilitation outcomes. By using stroke as a model for acquired brain injury, we review the evidence that links cognitive impairment to poor rehabilitation outcomes and discuss possible mechanisms to explain this association. Furthermore, we examine nascent promising research that suggests that interventions that target cognitive impairments can lead to better rehabilitation outcomes.

Biomarkers for cognitive aging part II: oxidative stress, cognitive assessments, and medication adherence

The purpose of this study was to further examine potential biomarkers of cognitive aging by looking at the associations among oxidative stress, cognitive abilities, and medication adherence in a community-based sample of middle-aged and older adults (n = 42; mean age = 69 years) prescribed at least one medication for hypertension. In addition to measures described in Part I, "Biomarkers for Cognitive Aging," a 12-hr urine collection for F(2)-isoprostanes served as an indicator of oxidative stress. Participants completed a battery of cognitive assessments and 8 weeks of electronic medication monitoring for adherence to one antihypertensive agent. Oxidative stress was significantly associated with logical memory, immediate (r = -.38, p < .01) and delayed recall (r = -.42, p < .01), and recognition memory (r = -.42, p < .01) from the Wechsler Memory Scale III, number of perseveration errors (r = .26, p < .05) and categories achieved (r = -.26, p < .01) on the Wisconsin Card Sorting Test (WSCT), and medication adherence (r = -.34, p <.05). Findings indicate that a biomarker of oxidative stress, F(2)-isoprostanes corrected for vitamin E, is significantly associated with cognitive measures and a functional outcome.

Independent association between preoperative cognitive status and discharge location after cardiac surgery

BACKGROUND

Among cardiac surgery patients, those with impaired cognitive status before surgery may have longer postoperative stays than do patients with normal status and may require additional care upon discharge.

OBJECTIVES

To determine if preoperative scores on a screening measure for cognitive status (the Clock-in-the-Box), were associated with postoperative length of stay and discharge to a location other than home in patients who had cardiac surgery.

METHODS

A total of 181 consecutive patients scheduled for cardiac surgery at a single site were administered the Clock-in-the-Box as part of the preoperative evaluation. Scores on the Clock-in-the-Box tool, demographic and operative information, postoperative length of stay, and discharge location were collected retrospectively from medical records.

RESULTS

The mean age of the patients was 68.1 years (SD, 0.7), and 99% were men. Mean postoperative length of stay was 10.5 days (SD, 8.2), and 35 patients (19%) were discharged to a facility. Scores on the Clock-in-the-Box assessment were not associated with postoperative length of stay. Increasing age, living alone before surgery, and duration of cardiopulmonary bypass were associated with discharge to a facility and were used as covariates in adjusted analyses. After adjustment, better preoperative cognitive status reduced the risk of being discharged to a facility (adjusted relative risk, 0.93; 95% confidence interval, 0.89-0.98) after cardiac surgery.

CONCLUSIONS

Cognitive screening before cardiac surgery can identify patients with impaired cognitive status who are less likely than patients with normal cognitive status to return home after cardiac surgery.

Measuring cognitive reserve based on the decomposition of episodic memory variance

In later adulthood brain pathology becomes common and trajectories of cognitive change are heterogeneous. Among the multiple determinants of late-life cognitive course, cognitive reserve has been proposed as an important factor that modifies or buffers the impact of brain pathology on cognitive function. This article presents and investigates a novel method for measuring and investigating such factors. The core concept is that in a population where pathology is common and variably present, 'reserve' may be defined as the difference between the cognitive performance predicted by an individual's level of pathology and that individual's actual performance. By this definition, people whose measured cognitive performance is better than predicted by pathology have high reserve, whereas those who perform worse than predicted have low reserve. To test this hypothesis, we applied a latent variable model to data from a diverse ageing cohort and decomposed the variance in a measure of episodic memory into three components, one predicted by demographics, one predicted by pathology as measured by structural MRI and a 'residual' or 'reserve' term that included all remaining variance. To investigate the plausibility of this approach, we then tested the residual component as an operational measure of reserve. Specific predictions about the effects of this putative reserve measure were generated from a general conceptual model of reserve. Each was borne from the results. The results show that the current level of reserve, as measured by this decomposition approach, modifies rates of conversion from mild cognitive impairment to dementia, modifies rates of longitudinal decline in executive function and, most importantly, attenuates the effect of brain atrophy on cognitive decline such that atrophy is more strongly associated with cognitive decline in subjects with low reserve than in those with high reserve. Decomposing the variance in cognitive function scores offers a promising new approach to the measure and study of cognitive reserve.

Rasch analysis of the Executive Interview (The EXIT-25) and introduction of an abridged version (The Quick EXIT)

OBJECTIVES

To evaluate the psychometric properties of the Executive Interview (EXIT-25) and to propose modifications that will improve those properties.

DESIGN

Rasch analysis of existing datasets contributed by 3 prior projects, all of which examined criterion-related validity of the EXIT-25.

SETTING

A large, urban, academic free-standing rehabilitation facility.

PARTICIPANTS

The sample of 147 was comprised of 109 adults diagnosed with stroke evaluated during inpatient rehabilitation and 38 adults with traumatic brain injury evaluated during inpatient (n=11) or outpatient rehabilitation (n=27).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The EXIT-25, Repeatable Battery for the Assessment of Neuropsychological Status, and Trails A and B.

RESULTS

Eleven of the 25 items correlated weakly with the total measure and misfit the rating scale model. Deleting these 11 items improved the internal consistency of the remaining 14 items and enhanced the measure's criterion-related validity.

CONCLUSIONS

The EXIT-25 can be reduced from 25 to 14 items without reducing internal consistency. Convergent validity of the abbreviated measure is supported by moderate-size correlations with standard measures of cognitive deficits.

Executive function in self-neglecting adult protective services referrals compared with elder psychiatric outpatients

OBJECTIVE

Psychometric performance, with an emphasis on executive function, was compared between adult protective services (APS) clients referred for a decision-making capacity consultation and elders seen in an outpatient geriatric psychiatry clinic.

METHODS

The authors performed a retrospective medical records review extracting general, executive, and visuospatial cognitive performance and depression symptom burden in APS referrals (N = 63) and geriatric psychiatry outpatients (N = 58).

RESULTS

After adjusting for age and education, APS clients had worse mean executive performance as measured by the Executive Interview (24.3 [SD 6.4] versus 17.3 [SD 7.6], F[1, 87] 15.7, p <0.001) and CLOX1 (7.4 [SD 4.0] versus 9.3 [SD 4.2], F[1, 92] 4.79, p = 0.03). There were no differences in visuospatial or general cognitive abilities. The self-neglect subgroup had worse cognitive performance on each measure than other APS referrals.

CONCLUSIONS

Compared with routine geriatric psychiatry patients, APS referrals are more likely to be executively impaired but less depressed. General cognitive screens do not distinguish these two groups.

Selectivity of executive function deficits in mild cognitive impairment

Impairment in executive cognition (EC) is now recognized as relatively common among older persons with mild cognitive impairment (MCI) and may be predictive of the development of dementia. However, both MCI and executive functioning are broad and heterogeneous constructs. The present study sought to determine whether impairments in specific domains of EC are associated with specific subtypes of MCI. MCI patients (n = 124) were divided into 4 subgroups (amnestic vs. nonamnestic, and single- vs. multiple-domain) on the basis of their performance of widely used neuropsychological screening tests. These patients and 68 normal older persons were administered 18 clinical and experimental tests of executive function. Principal components analysis suggested 2 highly reliable EC components, planning/problem solving and working memory, and a less reliable 3rd component, judgment. Planning/problem solving and working memory, but not judgment, were impaired among the MCI patients. This was true even among those with "pure amnestic" MCI, the least impaired group overall. Multiple-domain MCI patients had more severe impairments in planning/problem solving and working memory than single-domain patients, leading to the supposition that they, not pure amnestic MCIs, are at highest risk of imminent dementia.

How are personality traits related to preparation for future care needs in older adults?

We investigated associations between personality and health cognitions and behaviors related to preparation for future care among 355 primary care patients who were 65 years of age and older. Path analyses examined the effects of the personality traits of neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness on health cognitions about future care (avoidance, awareness), health-planning behaviors (gathering information, decision making, and planning), and beliefs about planning, while covarying age, gender, education, medical burden, functional status, and depression-symptom severity. Higher levels of neuroticism, openness, and agreeableness were associated with greater awareness of care needs; higher openness was also associated with more gathering of information and less avoidance. Extraversion and conscientiousness were not related to future-oriented health cognitions. Depression was inversely associated with the gathering of information. Age and education were related to more positive beliefs about the planning. Neither concrete planning nor decision making were related to personality variables. Health professionals should consider the impact of individual differences when addressing preparation for future care with older adults.

Diagnostic Performance of Clock Drawing Test by CLOX in an Asian Chinese population

BACKGROUND/AIMS

Clock Drawing Tests are commonly used for cognitive screening, but their clinical utility has not yet been studied in Chinese Singaporeans. We examined the usefulness of a Clock Drawing Test, CLOX, in detecting dementia in our population and explored its performance in the dementia subtypes, Alzheimer's disease (AD), and the vascular composite group (VCG) of AD with cerebrovascular disease and vascular dementia.

METHOD

CLOX was administered to 73 subjects (49.3%) with dementia and 75 healthy controls (50.7%). Receiver operating characteristic analysis determined the diagnostic accuracy and optimal cut-off scores, stratified by education. Analysis of Variance was used to compare CLOX scores between AD and VCG.

RESULTS

The diagnostic accuracy (area under the curve) was 84 and 85% for CLOX1 and CLOX2, respectively. Cut-offs at 10 for CLOX1 and 12 for CLOX2 yielded sensitivities of 75.3 and 75%, and specificities of 76 and 80%, respectively. The mean CLOX1 but not CLOX2 scores for AD (8.1) and VCG (5.5) remained significantly different (p = 0.002) after adjustment for the covariates age, gender, education, MMSE and dementia stage.

CONCLUSION

Our results support CLOX as a valid cognitive screen in Singaporean Chinese with adequate psychometric properties. In addition, CLOX may aid as an adjunct in differentiating AD from dementia with a vascular element, e.g. AD with cerebrovascular disease and vascular dementia.

Cognitive predictors of mortality in elderly retirees: results from the Freedom House study

OBJECTIVE

The objective of this longitudinal cohort study was to study the cognitive domains associated with five-year longitudinal survival among healthy, well-educated, noninstitutionalized elderly.

METHODS

Survival curves were generated as a function of cross-sectional baseline cognitive test performance.

RESULTS

Nonverbal tests were significantly associated with survival. This finding was markedly consistent. Several nonverbal tasks were each significantly associated with survival independently of age, gender, baseline level of care, and healthcare utilization. In a multivariate model, copying a clock made the strongest, independent contribution to survival.

CONCLUSIONS

Right hemisphere integrity in general and nonverbal drawing tasks in particular have been associated with survival in conditions as diverse as Alzheimer disease, stroke, and epilepsy. This study extends this association to "normal" aging. The mechanism by which nonverbal cognitive function is related to mortality remains unclear but may be mediated by changes in right hemisphere cortical control of autonomic function. Nondemented older persons may be at risk. Clock drawing may provide a simple means of identifying them.

Neuropsychological predictors of self-neglect in cognitively impaired older people who live alone

OBJECTIVE

The authors examined the accuracy of certain neuropsychological tests in the prediction of harm resulting from self-neglect in cognitively impaired seniors who lived alone.

METHODS

The study included 130 participants, aged 65 and older, who scored less than 131 on the Dementia Rating Scale. Neuropsychological tests were administered at baseline, resulting in eight predictive scores. Informants and primary care physicians provided information about harm that occurred to the participants during the 18-month prospective follow up. An incident was defined as harmful if it occurred as the result of self-neglect or disorientation and resulted in physical injury or property loss or damage and required emergency interventions. Proportional hazard regression analysis was conducted to examine the predictive relationship between the eight neuropsychological tests and time to incident harm with age, sex, education, the Charlson Comorbidity Index, and the Mini-Mental State Examination included in the model as covariates.

RESULTS

Twenty-seven participants experienced harm during the 18-month follow-up period. A proportional hazards model indicated that three neuropsychological tests, which measured recognition memory, executive functioning, and conceptualization, were independent risk factors for harm.

CONCLUSIONS

These findings provide insight into why harm occurred in these cognitively impaired elders who lived alone. They also support the ecologic validity of these tests and suggest directions for the development of intervention strategies for harm prevention.

Executive Control Function: A Clinically Practical Assessment

Intact executive control function is emerging as a determinant of functional status and independent living. Multiple causes of impaired executive control function including subclinical impairments exist. Integration of bedside executive control function assessment into routine nursing assessment and documentation provides a quantitative measure of an individual's ability to provide self-care.

The impact of medical illness on executive function

Executive function can be defined as one's ability to plan, initiate, sequence, monitor, and inhibit complex goal-directed behaviors. Although executive impairment is generally associated with dementia, recent studies have suggested that patients with chronic diseases, such as hypertension, chronic obstructive pulmonary disease, and diabetes, may also have executive deficits independent of psychiatric comorbidities. Because executive function is associated with functional outcomes, medication compliance, and the capacity to give informed consent, it is important that it be assessed. However, it is the authors' impression that executive function is not adequately assessed in medical settings, despite the availability of reliable measures. This article reviews the impact of medical illness on executive function and discusses practical diagnostic instruments and treatment strategies. The changes in functional status associated with executive impairment as well as pathophysiology and treatment strategies are also discussed.

Reading ability mediates the relationship between education and executive function tasks

Neuropsychological test results are affected by multiple factors, but usually age and education are the only variables by which norms are stratified. Some authors have questioned whether these variables alone are sufficient (e.g., Marcopulos et al., 1997; Manly et al., 2002), since such norms have lead to problems, such as poor specificity for African Americans on dementia screening devices (Fillenbaum et al., 1990). Recent research has shown that reading ability, a measure of educational quality, attenuated racial differences in test performance (Manly et al., 2002). We specifically examined whether reading ability would account for a greater amount of variance than education in executive function tests in a population traditionally subject to poor educational quality. Results determined that reading ability accounted for a significantly greater amount of variance than years of education for Letter-Number Sequencing, Similarities, COWA, Trail Making Test, and Coloured Progressive Matrices. Reading ability was found to significantly mediate the relationship between each of these tests and education. Animal naming appears to be least affected by educational quality or quantity. These findings hold implications for the interpretation of neuropsychological test results, especially in those exposed to substandard educational quality, and for the way that test norms are constructed.

Individualizing memory strategies to improve medication adherence

Changes in cognitive processes are well documented among even essentially healthy community-dwelling older adults. Although these changes do not produce the level of cognitive impairment associated with dementia, they do have the capacity to influence the degree to which elderly individuals self-manage chronic conditions. This pilot investigation tested the effect of an intervention to improve remembering to take medications and tracking if medications were taken as intended. Twenty-seven older adults (age range = 67-89 years, M = 78 years) all self-managing prescribed medications had one medication electronically monitored for 8 weeks preintervention and then 8 weeks postintervention. The percentage of days the correct number of doses was taken increased from a mean of 64.5% to that of 78%. With the use of Wilcoxon's signed ranks test, this improvement in adherence is significant. When participants with dementia or mild cognitive impairment were eliminated from the analysis (n = 6), the intervention continued to improve adherence (70.6% to 86%), suggesting that many older adults have the potential to improve adherence through individualized implementation of memory strategies.

Normal rates of cognitive change in successful aging: the freedom house study

We determined the rates of cognitive change associated with twenty individual measures. Participants included 547 noninstitutionalized septuagenarians and octogenarian residents of a comprehensive care retirement community who were studied over three years. Latent growth curves (LGC) of multiple cognitive measures were compared to a LGC model of the rates of change in Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL). All curves were standardized relative to each variable's baseline distribution. Baseline scores were within their expected normal age-specific ranges. Most measures showed significant rates of change over time. There was also significant variability about those rates, suggesting clinical heterogeneity. Many deteriorated over time, as did ADLs and IADLs. However, performance on some measures improved, consistent with learning effects. The rates of change in two measures, the Executive Interview and the Trail Making Test, were closely related to decline in IADLs. These results suggest that age-related cognitive decline is a dynamic longitudinal process affecting multiple cognitive domains. Heterogeneity in the rates of cognitive change may reflect the summed effects of age and comorbid conditions affecting cognition. Some measures may be ill-suited for measuring age-related changes in cognition, either because they are insensitive to change, or hindered by learning effects. Nonverbal measures appear to be particularly well suited for the prediction of age-related functional decline. These observations are relevant to the definition and diagnosis of "dementing" conditions.

An empiric approach to level of care determinations: the importance of executive measures

BACKGROUND

The ability to predict the level of care received by elderly retirees was compared in a discriminant model and using a classification tree derived from cognitive and noncognitive variables. Methods. Participants were 193 residents (mean age, 79.1+/-5.1 years) of a single, 1,500-bed, continuing care retirement community. They were given a battery of cognitive measures that included tests of general cognition, memory, and executive control function. A multivariate discriminant model of level of care was compared with a classification tree.

RESULTS

Residents in congregate high-rises (n=115) differed significantly from those in apartment settings (n=78) with respect to age, Executive Interview (EXIT 25), and the Executive Clock-Drawing Task (CLOX). Only age and executive control function measures (CLOX1, EXIT 25, and Trail Making Test Part B [Trails B]) contributed independently to a discriminant model of level of care (Wilke's lambda=0.92; F [df 4,170]=3.48; p <.01). Sixty-three percent of participants were correctly classified. A classification tree derived from the same variable set was more accurate (75% correctly classified). Age, CLOX1, and EXIT 25 made the most important contributions to the model. The EXIT 25 and CLOX1 thresholds empirically derived from this model coincide with the fifth percentiles for these instruments in a young adult sample.

CONCLUSIONS

Executive control function appears to be most responsible for the effect of cognition on level of care. Young adult norms may be most relevant when the effects of cognitive impairment on functional status are assessed.

Evaluation of the effectiveness of treatment with erythropoietin on anemia, cognitive functioning and functions studied by comprehensive geriatric assessment in elderly cancer patients with anemia related to cancer chemotherapy

The primary aim of the present study was to examine the relationship of changes in hemoglobin levels following recombinant human erythropoietin (rHuEPO) treatment to changes in cognitive functioning studied by Mini Mental State Examination (MMSE) in elderly cancer patients undergoing chemotherapy treatment. The secondary aim was that to assess the relationship of changes in hemoglobin levels following rHuEPO treatment to changes in functions studied by Comprehensive Geriatic Assessment (CGA), such as Activity of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), Geriatric Depression Scale (GDS) and the Mini Nutritional Assessment (MNA). To this end, hemoglobin levels and cognitive functioning were evaluated in a sample of cancer patients prior to the start of chemotherapy treatment and again after 4, 8 and 12 weeks of treatment with chemotherapy plus rHuEPO. Ten elderly patients (mean age 71.4 years) were enrolled. At baseline, enrolled patients had a mean Hb value of 10.3g/dl. After 4 weeks of rHuEPO treatment, Hb values increased significantly (p<0.0001), with a mean increase of 1.2g/dl (range: 0.2-2.1). Remarkably, 8 out of 10 (80%) showed an increase of Hb levels >or=1g/dl in comparison to baseline and therefore were considered responders. At baseline, four patients (40%) showed a moderate cognitive impairment, whilst six patients (60%) showed a normal cognitive function. After 4 weeks of rHuEPO treatment nine patients (90%) showed a significant improvement of cognitive functions in comparison to baseline (p<0.005): eight of them were responders also to rHuEPO in terms of correction of anemia. The Spearman's rank correlation test showed a statistical significant correlation between Hb increase and increase in cognitive functioning assessed by MMSE after 4 weeks (p=0.049), 8 weeks (p=0.044) and 12 weeks (p=0.031) of rHuEPO treatment. Therefore, the findings of this study provide support for the hypothesis that significant increases in hemoglobin over the course of chemotherapy supplemented with rHuEPO administration would be accompanied by significant improvement in cognitive performance over the same interval.

The Executive Interview as a Screening Test for Executive Dysfunction in Patients with Mild Dementia

OBJECTIVES

To validate the Executive Interview (EXIT25) as a screening instrument for executive cognitive dysfunction in patients with mild dementia.

DESIGN

Validation using group comparison and correlation studies.

SETTING

The Copenhagen University Hospital Memory Clinic, a multidisciplinary outpatient clinic based in a neurological setting.

PARTICIPANTS

Thirty-three patients with mild dementia (MMSE score > or =20) and 30 healthy controls.

MEASUREMENTS

The EXIT25, a 25-item screening instrument for executive dysfunction, was administered to all participants. Global cognitive function was measured using the MMSE. Patients were evaluated using traditional neuropsychological tests for executive dysfunction (Wisconsin Card Sorting Test, Trail Making Part B, Stroop Test, verbal fluency, design fluency, and verbal abstraction). Changes in behavior and functional impairment in activities of daily living were assessed using the Frontal Behavioral Inventory (FBI) and the Disability Assessment for Dementia Scale.

RESULTS

EXIT25 scores were significantly higher in patients than in the healthy controls; MMSE scores could not account for the differences. Thirteen of the 25 items separated the two groups. EXIT25 was found to correlate significantly with the Stroop Test, the verbal fluency tests, and the FBI.

CONCLUSION

The EXIT25 is able to capture executive cognitive deficits not primarily related to the general level of intellectual reduction in patients with mild dementia. In clinical practice, the EXIT25 might be a valuable supplement to the MMSE.

The Clock Drawing Test Is an Independent Predictor of Incident Use of 24-Hour Care in a Retirement Community

BACKGROUND

It is unclear how early cognitive impairment affects future care needs. Furthermore, the Mini-Mental State Examination (MMSE), a commonly used screening tool in the clinical setting, tends to have a ceiling effect for early cognitive decline. One of the earliest changes in cognitive function is executive impairment. We examined the relationship between executive function, measured with a clock drawing protocol (CLOX1) designed to capture executive impairment, and incident need for increased level of care and total mortality.

METHODS

Residents (n = 230) in independent living at a continuing care retirement community were followed for incident need for 24-hour care (mean 2.5 years). Baseline assessment included health status and physical and cognitive function. Time to event analysis was performed to determine the association of the CLOX1 score with the outcomes.

RESULTS

Forty percent of residents had a CLOX1 score <12, and 10% had an MMSE score <26. The event rate for a CLOX1 score <12 was 30 per 100 person-years (p-y) and 13 per 100 p-y for a score > or =12. Similarly, the event rate was 34 per 100 p-y versus 17 per 100 p-y for MMSE <26 and MMSE > or =26, respectively. A CLOX1 score <12 was associated with a twofold higher risk of incident use of 24-hour care (hazard ratio 2.2; 95% confidence interval: 1.5-3.4) and death (hazard ratio 2.3; 95% confidence interval: 1.1-4.8) even after controlling for age, sex, comorbidity, and MMSE scores. The MMSE score was not an independent predictor of incident use of 24-hour care or mortality.

CONCLUSION

The clock drawing test, scored for executive impairment, but not the MMSE, predicted incident use of 24-hour care and mortality in this cohort of independent older adults.

Feasibility of Quantifying the Effects of Epoetin Alfa Therapy on Cognitive Function in Women with Breast Cancer Undergoing Adjuvant or Neoadjuvant Chemotherapy

Impaired cognition, fatigue, and diminished quality of life (QOL) are commonly associated with breast cancer chemotherapy. This randomized, double-blind, placebo-controlled pilot trial assessed the feasibility of quantifying the effects of epoetin alfa on cognitive function and mood, and evaluated its effects on fatigue and QOL in patients with breast cancer treated with anthracycline-based adjuvant or neoadjuvant chemotherapy. Patients were randomized to receive epoetin alfa 40,000 U subcutaneously once weekly or placebo at the beginning of 4 cycles of chemotherapy administered over 12 weeks. Cognitive function was assessed by Executive Interview (EXIT25) and Clock Drawing Tasks; mood by Profile of Mood States; anemia-related symptoms, including fatigue, by the Functional Assessment of Cancer Therapy-Anemia (FACT-An) subscale; and QOL by Linear Analog Scale Assessment. Ninety-four patients were evaluable for efficacy and safety. Mean change in EXIT25 scores from baseline to cycle 4 in the epoetin alfa group was 1.3 +/- 3.3; the mean change was 0.3 +/- 2.4 in the placebo group (a negative change indicates improved executive function). There was no difference between groups in mean change in EXIT25 score from baseline to 6-month follow-up assessment. Mean hemoglobin levels were higher in the epoetin alfa group compared with the placebo group after 4 cycles of chemotherapy. Epoetin alfa recipients had less of a decrease in FACT-An subscale scores from baseline to cycle 4 and improvement in FACT-An subscale scores at 6-month follow-up assessment compared with placebo. Epoetin alfa therapy was well tolerated. These data suggest that epoetin alfa may have attenuated the cognitive impairment and fatigue that occurred during adjuvant breast cancer chemotherapy.

Vascular cognitive disorder: a new diagnostic category updating vascular cognitive impairment and vascular dementia

Vascular cognitive impairment (VCI) was proposed as an umbrella term to include subjects affected with any degree of cognitive impairment resulting from cerebrovascular disease (CVD), ranging from mild cognitive impairment (MCI) to vascular dementia. VCI may or may not exclude the host of "focal" circumscribed impairments of specialized functions such as language (aphasia), intentional gesture (apraxia), or categorical recognition (agnosia), among others, that may result from a stroke. Therefore, there are no universally accepted diagnostic criteria for VCI. We conclude that this concept could be more useful if it were to be limited to cases of vascular MCI without dementia, by analogy with the concept of amnestic MCI, currently considered the earliest clinically diagnosable stage of Alzheimer disease (AD). In agreement with our view,the Canadian Study on Health and Aging successfully implemented a restricted definition of VCI, excluding cases of dementia (i.e., vascular cognitive impairment no dementia, VCI-ND). The Canadian definition and diagnostic criteria could be utilized for future studies of VCI. This definition excludes isolated impairments of specialized cognitive functions. Vascular dementia (VaD): The main problem of this diagnostic category stems from the currently accepted definition of dementia that requires memory loss as the sine qua non for the diagnosis. This may result in over-sampling of patients with AD worsened by stroke (AD+CVD). This problem was minimized in controlled clinical trials of VaD by excluding patients with a prior diagnosis of AD, those with pre-existing memory loss before the index stroke, and those with amnestic MCI. We propose a definition of dementia in VaD based on presence of abnormal executive control function, severe enough to interfere with social or occupational functioning. Vascular cognitive disorder (VCD): This term, proposed by Sachdev [P. Sachdev, Vascular cognitive disorder. Int J Geriat Psychiatry 14 (1999)402-403.] would become the global diagnostic category for cognitive impairment of vascular origin, ranging from VCI to VaD. It would include specific disease entities such as post-stroke VCI, post-stroke VaD, CADASIL, Binswanger disease, and AD plus CVD. This category explicitly excludes isolated cognitive dysfunctions such as those mentioned above.

Facts, myths, and controversies in vascular dementia

Significant progress in the field of VaD resulted from publication of the NINIDS-AIREN Diagnostic Criteria for VaD (G.C. Roman, T.K. Tatemichi, T. Erkinjuntti, et al., Vascular dementia (VaD): diagnostic criteria for research studies. Report of the NINDS-AIREN International Workshop. Neurology 43 (1993) 250-260). Epidemiological studies confirmed the importance of VaD as the second most common cause of dementia in the elderly, representing 15-20% of all cases of dementia. In Europe and North America, Alzheimer's disease (AD) predominates over VaD in a 2:1 ratio; in contrast, in Japan and China VaD accounts for almost 50% of all dementias. Case-control studies have identified risk factors for VaD including ageing, hypertension, diabetes mellitus, hyperlipidemia, recurrent stroke, cardiac disease, smoking, sleep apnea, and more recently, hyperhomocysteinemia, among others. Hypertension treatment may prevent VaD and AD. This finding has enormous importance from the Public Health viewpoint to decrease the future number of patients with dementia in the elderly. Along with advances in the field of VaD came a number of controversies and damaging misconceptions and myths. Myth no. 1--Vascular dementia is a non-entity: The false idea that VaD does not exist is particularly destructive because it creates the perspective that VaD is unworthy of study or research. A condition that either does not exist or represents only a minute proportion of all cases of dementia in the elderly, lacks public health relevance and becomes a low priority for research by funding agencies and industry. In fact, vascular brain lesions are the commonest and most important component of dementia in the elderly. Myth no. 2--Vascular dementia is so difficult to diagnose that only experts can recognize and identify it accurately: VaD does exist and the diagnosis of post-stroke VaD, in particular is straightforward. Most cases fulfill NINDS-AIREN criteria for probable VaD; i.e., (1) there is acute onset of dementia demonstrated by impairment of memory and two other cognitive domains, such as orientation, praxis or executive dysfunction; (2) relevant cerebrovascular lesions are demonstrated by neuroimaging; and (3) a temporal relation between stroke and cognitive loss is evident. In the donepezil trials on VaD, post-stroke dementia represented about 75% of the >1,200 patients enrolled. Myth no. 3--Improvement in clinical trials of cholinergics in VaD is due to underlying AD, not to the vascular lesions. Experimental, clinical and pathological evidence has demonstrated cholinesterase deficits in VaD (independently of any concomitant AD pathology), including low acetylcholine in cerebrospinal fluid, and reduced choline acetyltransferase (ChAT) in the brain.

Relationship of hemoglobin levels to fatigue and cognitive functioning among cancer patients receiving chemotherapy

The aim of this study was to examine the relationship of changes in hemoglobin levels to changes in fatigue and cognitive functioning in cancer patients undergoing chemotherapy treatment. Seventy-seven (77) patients completed a self-administered measure of fatigue and a battery of psychometrician-administered measures of cognitive performance before the start of chemotherapy and again before the start of the fourth treatment cycle. Hemoglobin levels were measured at corresponding timepoints. Findings partially supported the hypothesis that greater declines in hemoglobin over the course of repeated chemotherapy administrations would be accompanied by greater increases in fatigue and greater declines in cognitive performance over the same interval. Among the subset of 49 patients who demonstrated a decline in hemoglobin to a final value < or =12 g/dL, greater declines in hemoglobin were significantly (P<0.05) related to greater increases in fatigue duration and disruptiveness and more negative changes in performance on three cognitive tasks. These findings suggest that, in addition to previously reported relationships with fatigue, declines in hemoglobin levels during chemotherapy treatment are associated with adverse changes in cognitive functioning.

The executive clock drawing task (CLOX) is a poor screening test for executive dysfunction in Chinese elderly patients with subcortical ischemic vascular disease

Executive dysfunction (ED) is a prominent feature of subcortical ischemic vascular disease. A screening test for ED is lacking among Chinese. The objective of the study is to investigate the validity and reliability of a Chinese version of the Executive clock drawing task (CLOX) in screening ED among Chinese elderly patients with small subcortical infarct (SSI). The Chinese version of CLOX correlated with MMSE, CDRS I/P, and WCST perseverative errors. However, multivariate regression analysis showed that only education (R(2) change=0.22, p < 0.001 ) and MMSE (R(2) change=0.35, p < 0.001), but none of the standard executive function tests, significantly accounted for the variance in the CLOX. Test-retest (r=0.84) and inter-rater reliability (r=0.84) were high for the CLOX. Conclusions. Although the CLOX is reliable, it is not valid in detecting ED in Chinese elderly patients with SSI.

Declining Executive Control in Normal Aging Predicts Change in Functional Status: The Freedom House Study

OBJECTIVES

To assess the contribution of executive control function (ECF) to functional status.

DESIGN

Three-year longitudinal cohort study.

SETTING

A comprehensive-care retirement community.

PARTICIPANTS

Five hundred forty-seven noninstitutionalized septuagenarians.

MEASUREMENTS

The Mini-Mental State Examination (MMSE) and Executive Interview (EXIT25). Functional status was assessed using instrumental activities of daily living (IADLs). Latent growth curves of MMSE, EXIT25, and IADL were modeled. The rate of change in IADLs (DeltaIADL), adjusted for baseline IADLs and cognition, was regressed on the rate of change in each cognitive measure (adjusted for baseline cognition). Models were also adjusted for baseline age, level of care, and comorbid illnesses.

RESULTS

Baseline test scores were within normal ranges, but mean EXIT25 scores reached the impaired range by the second follow-up. There was significant variability around the baseline means and slopes for all variables. The rate of change in EXIT25 was strongly correlated with DeltaIADL (r=-0.57, P<.001). This remained significant after adjusting for baseline EXIT25 scores, IADLs, age, comorbid disease, and level of care. The effect of the EXIT25 on DeltaIADL was stronger than those of age, baseline IADLs, comorbid disease, or level of care. The rate of change in MMSE scores was not significantly associated with DeltaIADL.

CONCLUSION

ECF is a significant and independent correlate of functional status in normal aging. Traditional dementia case finding is likely to underestimate cognition-related disability. Neither a normal baseline MMSE score nor stable MMSE scores over time preclude functionally significant changes in ECF.

Executive dyscontrol in normal aging: normative data, factor structure, and clinical correlates

Although there is ample evidence of frontal system dysfunction in old age, the clinical significance of these impairments has not been well studied. In this article, we examine the factor structure of putative executive measures in a sample of well elderly subjects. Three stable factors emerged, but only one was associated with measures of functional status. This factor was most strongly associated with relatively simple bedside executive measures that might prove useful in dementia screening. In contrast, a second factor, dominated by the Wisconsin Card Sorting Task, was weakly associated with disability. These data suggest that certain executive measures may be more relevant to functional outcomes, and hence dementia case finding, than others. Moreover, associations with functional status should not be casually extrapolated from regional frontal clinical correlations, particularly with the dorsolateral prefrontal cortex.

Chemotherapy-related cognitive dysfunction in breast cancer

OBJECTIVES

To provide an overview of chemotherapy-related cognitive dysfunction in breast cancer survivors, focusing on its pathophysiology, risk factors, assessment, and management.

DATA SOURCES

Published biomedical literature.

CONCLUSION

Chemotherapy-related cognitive dysfunction in patients with breast cancer is multifactorial and possibly related to anemia or a direct effect of chemotherapy on brain function. Clinical observation and subjective reports are useful assessments. Therapies directed at alleviating or preventing cognitive deficits are being investigated.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses are important in monitoring cognitive function in patients with breast cancer receiving chemotherapy. Nurses who are aware of the risks, assessment, and management of cognitive impairment are better able to discuss these issues with patients and caregivers.

Decline in learning ability best predicts future dementia type: the Freedom House Study

The authors studied longitudinal change in learning efficiency as a predictor of future dementia type among healthy, well-educated, noninstitutionalized elderly retirees. Serial assessments of memory were obtained using the California Verbal Learning Test (CVLT). Latent growth (LG) models were developed from the slopes of the subjects' performance over the first five CVLT learning trials at each of three serial administrations (e.g., cohort inception [i.e., baseline] [CVLT1], 18 months [CVLT2] and 36 months [CVLT3]). The resulting growth curves were incorporated into a higher order LG model representing the dynamic change in learning efficiency over time (DeltaCVLT). DeltaCVLT was used to predict each subject's "dementia type" (i.e., clinical state) at 36 months (e.g., no dementia, Type 1 [Alzheimer type] dementia or Type 2 [non-Alzheimer type] dementia), after adjusting for CVLT1, baseline age, and baseline dementia type. Nonlinear (logarithmic) LG models of CVLT1-CVLT3 and DeltaCVLT best fit the data. There was significant variability about both CVLT1 and DeltaCVLT, suggesting subgroups in the sample with significantly different baseline memory function, and different rates of deterioration in learning efficiency. Age, baseline dementia type, and DeltaCVLT made significant independent contributions to final dementia type. CVLT1 did not predict final dementia type independently of the other covariates. These data suggest that baseline memory performance in noninstitutionalized elderly retirees does not predict future dementia type independently of the dynamic rate of change in memory measures. Serial administrations of memory tests may help identify nondemented persons at greater or lesser risk for conversion to frank dementia in the near-term.

Selective impairment of frontal-executive cognitive function in african americans with cardiovascular risk factors

OBJECTIVES

To determine whether a summary cardiovascular risk score is associated with an increased risk of frontal-executive cognitive impairment.

DESIGN

Cross-sectional study.

SETTING

Subjects were recruited from senior centers, senior housing complexes, and communities in the Boston metropolitan area.

PARTICIPANTS

Forty-three predominantly female elderly African Americans.

MEASUREMENTS

Cardiovascular risk factors were assessed during an interview and clinical examination. For each subject, the total number of cardiovascular (CV) risk factors was summed to compute a CV risk score. A battery of neuropsychological tests was administered that examined memory, visuospatial abilities, and frontal-executive functions. Cognitive test scores were transformed into domain-specific (memory, visuospatial, frontal-executive) composite z scores. Cognitive impairment for each composite z score was defined as performance less than the median for the study group. Multivariate logistic regression was used to examine the relationship between the CV risk score and the risk for cognitive impairment in the three cognitive domains of interest.

RESULTS

After controlling for age and education, the CV risk score was associated only with frontal-executive cognitive impairment (odds ratio (OR)=2.44, 95% confidence interval (CI)=1.06-5.65). The CV risk score was not associated with the risk of memory (OR=1.30, 95% CI=0.64-2.67) or visuospatial impairment (OR=1.49, 95% CI=0.66-3.36). Greater CV risk scores were associated with an increased likelihood of having frontal-executive cognitive impairment.

CONCLUSION

CV risk factors may exert a specific deleterious effect on frontal-executive cognitive abilities as opposed to memory or visuospatial functions. Associated executive dysfunction may compromise the ability of patients with CV risk factors to comply with recommendations for risk reduction.