RÉSUMÉ
Introduction: There is a dearth of research on cognitive aging and dementia in Asian Americans, particularly in Vietnamese Americans, the fourth largest Asian subgroup in the United States. Methods: The Vietnamese Insights into Cognitive Aging Program (VIP) investigates early life adversity and war-related trauma and their associations with cognitive health in a community-based sample of older Vietnamese Americans in Northern California (i.e., Sacramento and Santa Clara counties). Baseline measurements include a comprehensive neuropsychological battery, including measures of global cognition along with executive function, semantic memory, and episodic memory. Data also include measures of functioning, early life adversity and trauma exposure, and psychosocial and traditional cardiovascular disease risk factors. Cognitive assessments will be repeated twice over the course of the data collection period, approximately 12- and 24- months post-baseline. Blood samples collected during Wave 2 will be assayed for biochemical risk factors. Results: Baseline assessments were conducted from January 2022 to November 2023, with N = 548 Vietnamese Americans; mean age ± SD was 73 ± 5.31 years and 55% of participants were women. There were significant differences in social factors by site, with Santa Clara participants having higher education (some college or higher: Sacramento, ≈25%; Santa Clara: ≈48%) and marginally higher incomes compared to Sacramento participants. A higher percentage of Santa Clara participants reported speaking English well or very well (24%) compared to Sacramento participants (13%), although the majority of the entire sample (81%) reported speaking some to no English (response options: not at all; some/a little bit; well/very well). Discussion: This longitudinal study providea a unique opportunity to more fully delineate psychosocial factors that contribute to dementia disparities in diverse and under-engaged populations. Future work will examine cognition, the prevalence of mild cognitive impairment and dementia, and other health outcomes, while controlling for site differences in all analyses. Highlights: Vietnamese Insights into Cognitive Aging Program (VIP) is a new study.VIP has detailed early life and health data on 548 older Vietnamese Americans.History of war and trauma may contribute to Alzheimer's disease and related dementias (ADRD)-related burden.VIP may provide insight into ADRD burden in other understudied groups.
RÉSUMÉ
Objective: Subjective cognitive decline (SCD) is an important part of the aging process and may be a sign of neurodegenerative disease. Current measures of SCD are subject to the limits of retrospective recall of symptoms over a long span of time, which might be addressed by using ecological momentary assessment (EMA) methods. However, there are no currently available measures of SCD validated for use in EMA. Thus, our goal was to develop and pilot test the mobile Everyday Cognition Scale (mECog). Method: 31 community-dwelling older adults completed in lab measures of cognition and mental health symptoms, followed by daily mECog ratings on a smart phone for 28 days. Results: Most participants completed at least 75% of mECog assessments (n = 27, 87%), and the average number of assessments completed was 22. Further, respondents rated the mobile assessment platform and measures as easy to use and non-interfering with daily life. Test-retest reliability of mECog scores was very strong (RKRN = .99), and within-person reliability was moderate (RCN = .41). mECog scores demonstrated strong positive associations with scores from the original ECog (ρ = .62-69, p < .001) and short form ECog (ρ = .63-.69, p < .001) and non-significant associations with demographics (ρ = -0.25-.04, p = .21-.94) and mental health symptoms (ρ = -0.06-.34, p = .08-.99). mECog scores also exhibited small-to-moderate negative correlations with objective cognitive test scores, though these relationships did not reach statistical significance (ρ = -0.32 to -0.22, p = .10-.27). Conclusions: Results suggest that mobile assessment of SCD via the mECog is feasible and acceptable. Further, mECog scores demonstrated good psychometric properties, including evidence of strong reliability, convergent validity, and divergent validity.
RÉSUMÉ
OBJECTIVE: Most prior research on physical activity (PA) and cognition is based on predominantly white cohorts and focused on associations of PA with mean (average) cognition versus the distribution of cognition. Quantile regression offers a novel way to quantify how PA affects cognition across the entire distribution. METHODS: The Kaiser Healthy Aging and Diverse Life Experiences study includes 30% white, 19% black, 25% Asian, and 26% Latinx adults age 65+ living in Northern California (n = 1600). The frequency of light or heavy PA was summarized as 2 continuous variables. Outcomes were z-scored executive function, semantic memory, and verbal episodic memory. We tested associations of PA with mean cognition using linear regression and used quantile regression to estimate the association of PA with the 10th-90th percentiles of cognitive scores. RESULTS: Higher levels of PA were associated with higher mean semantic memory (b = 0.10; 95% CI: 0.06, 0.14) and executive function (b = 0.05; 95% CI: 0.01, 0.09). Associations of PA across all 3 cognitive domains were stronger at low quantiles of cognition. CONCLUSION: PA is associated with cognition in this racially/ethnically diverse sample and may have larger benefits for individuals with low cognitive scores, who are most vulnerable to dementia.
Sujet(s)
Cognition , Exercice physique , Humains , Sujet âgé , Femelle , Mâle , Exercice physique/psychologie , Cognition/physiologie , Californie , Fonction exécutive/physiologie , Vieillissement en bonne santé/psychologie , Vieillissement en bonne santé/physiologie , Études de cohortes , Sujet âgé de 80 ans ou plus , Ethnies , Vieillissement/psychologieRÉSUMÉ
There is a dearth of research on cognitive aging and dementia in Asian Americans, particularly Vietnamese Americans, who are the fourth largest Asian subgroup in the United States. The National Institutes of Health is mandated to make certain that racially and ethnically diverse populations are included in clinical research. Despite the widespread recognition to ensure that research findings can be generalizable to all groups, there are no estimates of the prevalence or incidence of mild cognitive impairment and Alzheimer's disease and related dementias (ADRD) in Vietnamese Americans, nor do we understand ADRD risk and protective factors in this group. In this article, we posit that studying Vietnamese Americans contributes to a better understanding of ADRD in general and offers unique opportunities for elucidating life course and sociocultural factors that contribute to cognitive aging disparities. That is, the unique context of Vietnamese Americans may provide understanding in terms of within-group heterogeneity and key factors in ADRD and cognitive aging. Here, we provide a brief history of Vietnamese American immigration and describe the large but often ignored heterogeneity of Asian Americans in the United States, elucidate how early life adversity and stress might influence late-life cognitive aging, and provide a basis for the role of sociocultural and health factors in the study of Vietnamese cognitive aging disparities. Research with older Vietnamese Americans provides a unique and timely opportunity to more fully delineate the factors that contribute to ADRD disparities for all populations.
RÉSUMÉ
Introduction: Few longitudinal studies have examined the joint impact of neighborhood segregation and neighborhood socioeconomic status (NSES) in cognitive decline over time. Methods: This study included non-Hispanic White (NHW, n = 209) and Black participants (n = 118) whose cognition was evaluated as part of an ongoing longitudinal study. Four distinct categories of segregation and NSES were evaluated for their association with cognitive outcomes (episodic memory, semantic memory, executive function, and spatial ability) using race-specific mixed-effects models. Results: Compared to Black participants living in higher segregation-lower NSES areas, Black participants living in lower segregation-lower NSES areas or higher segregation-higher NSES areas experienced slower decline in episodic memory over time. Compared to NHW participants living in higher segregation-lower NSES areas, NHWs living in lower segregation-higher NSES areas experienced faster decline in spatial ability. Discussion: Segregation and NSES are differentially associated with cognition depending on participant race. Further research is needed to replicate study results.
RÉSUMÉ
This study examined the effectiveness of a 10-week cognitive rehabilitation and lifestyle modifying intervention that integrated compensation strategies, engagement in brain activities, and improving everyday function. The trial was registered with ClinicalTrials.gov (NCT03549078). Older adults with subjective cognitive concerns and normal performance on a cognitive screener were randomized into the intervention (n = 28) or waitlist control (n = 29) groups. The total sample comprised 57 individuals (age, mean = 74.8, SD = 6.5), mostly female (80.4% of the total sample), and well educated (education years: mean = 15.9, SD = 2.1). Outcome measures were completed at baseline, and immediately and 3- and 6-months post-intervention. Intervention participants reported significant improvements in aspects of everyday functioning and select compensation strategies and brain health activities. Increased compensation strategy use was maintained at 6-month follow up. This intervention has benefits for improving everyday functioning and increasing engagement with compensation strategies and brain health activities.
Sujet(s)
Dysfonctionnement cognitif , Entraînement cognitif , Humains , Femelle , Sujet âgé , Mâle , Activités de la vie quotidienne , Mode de vie , , Cognition , Dysfonctionnement cognitif/psychologieRÉSUMÉ
BACKGROUND: U.S. POINTER is a Phase 3, multicenter, randomized 2-year clinical trial of two multidomain lifestyle interventions in 2111 older adults who are at increased risk of cognitive decline and dementia due sedentary lifestyle, poor diet, and other factors such as family history of memory impairment and suboptimum cardiovascular health. METHOD: Enrollment took place at five geographically diverse sites, beginning in 2019 and completing in early 2023. Participants are randomly assigned to one of two lifestyle intervention groups that differ in format, intensity, and accountability. Those randomized to the Self-Guided Lifestyle Intervention receive annual medical monitoring and health education information, tools, and support to encourage increased physical and cognitive activity and a healthier diet through 2-3 annual group meetings. Those randomized to the Structured Lifestyle Intervention receive frequent medical monitoring of cardiovascular health and a structured program of exercise (primarily aerobic), nutritional counseling, cognitive training and social engagement initially through weekly and then monthly group meetings. U.S. POINTER includes partnerships with local chapters of the Alzheimer's Association and lifestyle specialists to assist with intervention delivery. The primary outcome is 2-year change in cognitive function measured with a global cognition composite score that permits harmonization with FINGER and other trials. Secondary and tertiary outcomes include measures of executive function and episodic memory, physical activity, diet, cognitive and physical activity, cardiometabolic disease risks, mood, quality of life, health care costs, and health care utilization. RESULT: U.S. POINTER is generating a richly phenotyped cohort that will provide a rigorous comparison of two lifestyle interventions designed to preserve cognitive function. It has nurtured 4 ancillary studies to assess intervention effects on outcomes related to sleep quality, brain structure and pathology, peripheral and neurovascular function, and the microbiome. It also partners with clinical trials within the World-Wide FINGERS international network. The study is generating an archive of biospecimens and de-identified public use data. Plans for a post-intervention observational study of the U.S. POINTER cohort are underway. CONCLUSION: U.S. POINTER provides an important national resource to advance the field in understanding the role of nonpharmacological interventions in reducing risk for cognitive decline and Alzheimer's disease and related dementia.
Sujet(s)
Dysfonctionnement cognitif , Humains , Dysfonctionnement cognitif/thérapie , Démence/prévention et contrôle , Exercice physique , Sujet âgé , Mode de vie , Mâle , Femelle , Mode de vie sédentaireRÉSUMÉ
OBJECTIVE: Cognitive functioning is associated with instrumental activity of daily living (IADL) performance among older adults. The present study examines potential differences in the prevalence of IADL difficulty and association with cognition across diverse groups. METHOD: Participants included 455 non-Hispanic Whites, 395 Blacks, 370 Asians, and 296 Latinos aged 65 years and older without a current dementia diagnosis from the Kaiser Healthy Aging and Diverse Life Experience cohort. Participants' self-reported IADL functioning and cognition was measured across episodic memory and executive functioning. RESULTS: Older age, male gender, and being Black were associated with more IADL difficulties. Executive functioning showed a stronger association with IADLs than memory, and it was independent of health status, whereas memory was not. In joint models including both cognitive domains, executive functioning remained a significant predictor of IADL difficulty, but memory did not. Results for both cognitive domains were attenuated with self-rated health added to the joint model. These relationships did not significantly differ across racial/ethnic groups. CONCLUSIONS: Our study supports previous work suggesting that Black older adults are at increased risk for IADL disability. This is the first study we are aware of that examined the association between specific cognitive domains and IADL performance across multiple racial/ethnic groups. Findings indicate that cognitive functioning has similar associations with self-reported IADL disability across diverse groups, and that executive functioning plays a particularly important role in IADL disability among older adults without dementia; however, health status largely attenuates the relationship between IADL difficulty and cognition.
Sujet(s)
Activités de la vie quotidienne , Démence , Activités de la vie quotidienne/psychologie , Sujet âgé , Cognition , Démence/diagnostic , Ethnies , Humains , Mâle , Tests neuropsychologiques , PrévalenceRÉSUMÉ
Social determinants of health, including neighborhood factors, play a key role in the health of diverse older adults. However, few longitudinal studies have examined the role of neighborhood racial/ethnic segregation on cognitive decline in diverse samples. We examined older non-Hispanic White (NHW), Black, and Latino participants evaluated at an Alzheimer's Disease Research Center. Neighborhood racial/ethnic segregation was measured using the Getis-Ord Gi* statistic, a spatial measure of clustering that was created for Latino and Black clustering separately. Cognitive outcomes included episodic memory, semantic memory, and executive function. We used mixed effects multivariable regression models to evaluate associations between segregation and cognitive function and decline. We had 452 individuals: 46% NHW, 26% Black, and 21% Latino in 309 census tracts with an average of 5.2 years of follow-up data (range 0.6-15.0). In analyses that adjusted for a variety of covariates (including neighborhood SES), individuals in neighborhoods with a higher clustering of Latino residents (higher Gi* statistic) had slower declines over time on semantic memory and those in neighborhoods with a higher clustering of Black residents had slower declines over time on episodic memory. In race/ethnicity-stratified adjusted analyses: for Black participants, the association between clustering and cognition was present for episodic memory and executive function, showing lower baseline scores in highly clustered Black and Latino neighborhoods, respectively. There was no association with cognitive change. Among Latino participants, highly clustered Latino neighborhoods were associated with lower baseline scores in semantic memory, but slower declines in episodic memory; Latinos living in neighborhoods with a greater clustering of Black residents also had slower declines in episodic memory. Among NHWs, residing in neighborhoods with a higher clustering of Latino residents was associated with slower declines over time on semantic memory. Segregated neighborhoods may be differentially associated with cognitive outcomes depending on individual race/ethnicity.
Sujet(s)
Dysfonctionnement cognitif , Ségrégation sociale , , Sujet âgé , Dysfonctionnement cognitif/épidémiologie , Ethnies , Humains , Caractéristiques de l'habitatRÉSUMÉ
INTRODUCTION: The Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study enrolled Asian, Black, Latino, and White adults ages 65+ without prior dementia diagnosis (N = 1709). We evaluated the prevalence of cognitive impairment (mild cognitive impairment or dementia) accounting for potential biases. METHODS: A random subgroup (N = 541) received clinical evaluation and others were evaluated if they failed a cognitive screen. Diagnoses were made under two conditions: (1) demographics-blind, based on clinical exam and demographically adjusted neuropsychological test scores; and (2) all available information (clinical exam, demographics, and adjusted and unadjusted test scores). RESULTS: Cognitive impairment prevalence was 28% for blinded-adjusted diagnosis and 25% using all available information. Black participants had higher impairment rates than White (both conditions) and Latino (blinded-adjusted diagnosis) participants. Incomplete assessments negatively biased prevalence estimates for White participants. DISCUSSION: Racial/ethnic disparities in cognitive impairment were amplified by attrition bias in White participants but were unaffected by type of test norms and diagnosticians' knowledge of demographics.
RÉSUMÉ
Objective: Subtle changes in functional abilities are an early indicator of cognitive impairment. Early intervention may be key to prolonging independence. This study describes the development and program evaluation of an intervention designed to (1) bolster the use of compensation strategies that support everyday executive and memory functioning and (2) utilize these strategies to promote engagement in brain health activities.Method: Older adults (n = 35) with subjective cognitive complaints completed an eight-week group program targeting compensation strategies (e.g., calendars) and brain health activities (e.g., physical exercise). Participants completed outcome measures at first, last, and 3 month follow-up sessions.Results: Compensation strategy use can be successfully taught to and implemented by older adults, and increasing engagement in brain health behaviors is possible, although particular lifestyle changes are challenging to implement.Conclusion: Findings support the use of interventions aimed at increased engagement in compensation strategies to aid everyday memory and executive functioning.Clinical Implications: Early intervention may help to promote prolonged functional independence.
Sujet(s)
Activités de la vie quotidienne/psychologie , Dysfonctionnement cognitif/thérapie , Fonction exécutive , Mémoire , Sujet âgé , Sujet âgé de 80 ans ou plus , Exercice physique , Femelle , Humains , Mâle , Adulte d'âge moyen , Projets pilotes , Auto-efficacitéRÉSUMÉ
The Alzheimer's Association's Research Roundtable met in November 2016 to explore how best to measure changes in cognition and function in the preclinical stage of Alzheimer's disease. This review will cover the tools and instruments currently available to identify populations for prevention trials, and measure subtle disease progression in the earliest stages of Alzheimer's disease, and will include discussions of suitable cognitive, behavioral, functional, composite, and biological endpoints for prevention trials. Current prevention trials are reviewed including TOMMOROW, Alzheimer's Prevention Initiative Autosomal Dominant Alzheimer's Disease Trial, the Alzheimer's Prevention Initiative Generation Study, and the Anti-Amyloid Treatment in Asymptomatic Alzheimer's to compare current approaches and tools that are being developed.
RÉSUMÉ
Level of education is often regarded as a proxy for cognitive reserve in older adults. This implies that brain degeneration has a smaller effect on cognitive decline in those with more education, but this has not been directly tested in previous research. We examined how education, quantitative magnetic resonance imaging-based measurement of brain degeneration, and their interaction affect cognitive decline in diverse older adults spanning the spectrum from normal cognition to dementia. Gray matter atrophy was strongly related to cognitive decline. While education was not related to cognitive decline, brain atrophy had a stronger effect on cognitive decline in those with more education. Importantly, high education was associated with slower decline in individuals with lesser atrophy but with faster decline in those with greater atrophy. This moderation effect was observed in Hispanics (who had high heterogeneity of education) but not in African-Americans or Caucasians. These results suggest that education is an indicator of cognitive reserve in individuals with low levels of brain degeneration, but the protective effect of higher education is rapidly depleted as brain degeneration progresses.
Sujet(s)
Encéphale/anatomopathologie , Dysfonctionnement cognitif/anatomopathologie , Dysfonctionnement cognitif/psychologie , Réserve cognitive/physiologie , Niveau d'instruction , Sujet âgé , Sujet âgé de 80 ans ou plus , Atrophie , Encéphale/imagerie diagnostique , Femelle , Substance grise/imagerie diagnostique , Substance grise/anatomopathologie , Humains , Imagerie par résonance magnétique , Mâle , Neuroimagerie ,RÉSUMÉ
OBJECTIVE: The purpose of this study was to examine longitudinal associations between structural MRI and cognition in a diverse sample. METHOD: Older adults (n = 444; Mage = 74.5)-121 African Americans, 212 Whites, and 111 Hispanics-underwent an average of 5.3 annual study visits. Approximately half were cognitively normal at baseline (global Clinical Dementia Rating M = 0.5). Of the patients with dementia, most (79%) were diagnosed with Alzheimer's disease (AD). MRI measures of gray matter volume (baseline and change), and hippocampal and white matter hyperintensity (WMH) volumes (baseline), were used to predict change in global cognition. Multilevel latent variable modeling was used to test the hypothesis that brain effects on cognitive change differed across ethnoracial groups. RESULTS: In a multivariable model, global gray matter change was the strongest predictor of cognitive decline in Whites and African Americans and specific temporal lobe change added incremental explanatory power in Whites. Baseline WMH volume was the strongest predictor of cognitive decline in Hispanics and made an incremental contribution in Whites. CONCLUSIONS: We found ethnoracial group differences in associations of brain variables with cognitive decline. The unique patterns in Whites appeared to suggest a greater influence of AD in this group. In contrast, cognitive decline in African Americans and Hispanics was most uniquely attributable to global gray matter change and baseline WMH, respectively. Brain changes underlying cognitive decline in older adults are heterogeneous and depend on fixed and modifiable risk factors that differ based on ethnicity and race. (PsycINFO Database Record
Sujet(s)
/psychologie , Encéphale/imagerie diagnostique , Troubles de la cognition/imagerie diagnostique , Cognition/physiologie , Démence/imagerie diagnostique , Hispanique ou Latino/psychologie , /psychologie , Sujet âgé , Sujet âgé de 80 ans ou plus , Troubles de la cognition/psychologie , Démence/psychologie , Femelle , Humains , Imagerie par résonance magnétique , Mâle , Tests neuropsychologiquesRÉSUMÉ
OBJECTIVE: Examine how longitudinal cognitive trajectories relate to brain baseline measures and change in lobar volumes in a racially/ethnically and cognitively diverse sample of older adults. METHOD: Participants were 460 older adults enrolled in a longitudinal aging study. Cognitive outcomes were measures of episodic memory, semantic memory, executive function, and spatial ability derived from the Spanish and English Neuropsychological Assessment Scales (SENAS). Latent variable multilevel modeling of the four cognitive outcomes as parallel longitudinal processes identified intercepts for each outcome and a second order global change factor explaining covariance among the highly correlated slopes. We examined how baseline brain volumes (lobar gray matter, hippocampus, and white matter hyperintensity) and change in brain volumes (lobar gray matter) were associated with cognitive intercepts and global cognitive change. Lobar volumes were dissociated into global and specific components using latent variable methods. RESULTS: Cognitive change was most strongly associated with brain gray matter volume change, with strong independent effects of global gray matter change and specific temporal lobe gray matter change. Baseline white matter hyperintensity and hippocampal volumes had significant incremental effects on cognitive decline beyond gray matter change. Baseline lobar gray matter was related to cognitive decline, but did not contribute beyond gray matter change. CONCLUSION: Cognitive decline was strongly influenced by gray matter volume change and, especially, temporal lobe change. The strong influence of temporal lobe gray matter change on cognitive decline may reflect involvement of temporal lobe structures that are critical for late life cognitive health but also are vulnerable to diseases of aging. (PsycINFO Database Record
Sujet(s)
Vieillissement/psychologie , Encéphale/imagerie diagnostique , Cognition/physiologie , Dysfonctionnement cognitif/imagerie diagnostique , Sujet âgé , Sujet âgé de 80 ans ou plus , Dysfonctionnement cognitif/psychologie , Fonction exécutive , Femelle , Substance grise/imagerie diagnostique , Humains , Études longitudinales , Imagerie par résonance magnétique , Mâle , Mémoire épisodique , Adulte d'âge moyen , Tests neuropsychologiquesRÉSUMÉ
OBJECTIVES: To examine whether specific types of early functional limitations in cognitively normal older adults are associated with subsequent development of mild cognitive impairment (MCI), as well as the relative predictive value of self versus informant report in predicting diagnostic conversion to MCI. DESIGN: As a part of a longitudinal study design, participants underwent baseline and annual multidisciplinary clinical evaluations, including a physical and neurological examination, imaging, laboratory work, and neuropsychological testing. SETTING: Data used in this study were collected as part of longitudinal research at the University of California, Davis Alzheimer's Disease Center. PARTICIPANTS: Individuals diagnosed as having normal cognition at study baseline who had an informant who could complete informant-based ratings and at least one follow-up visit (N = 324). MEASUREMENTS: Participants and informants each completed the Everyday Cognition Scale (ECog), an instrument designed to measure everyday function in six cognitively relevant domains. RESULTS: Self- and informant-reported functional limitations on the ECog were associated with significantly greater risk of diagnostic conversion to MCI (informant: hazard ratio (HR) = 2.0, 95% confidence interval (CI) = 1.3-3.2, P = .002), with self-report having a slightly higher hazard (HR = 2.3, 95% CI = 1.4-3.6, P < .001). When controlling for baseline cognitive abilities, the effect remained significant for self- and informant-reported functional limitations. CONCLUSION: Deficits in everyday memory and executive function domains were the strongest predictors of diagnostic conversion to MCI. Detection of early functional limitations may be clinically useful in assessing the future risk of developing cognitive impairment in cognitively normal older adults.
Sujet(s)
Activités de la vie quotidienne/psychologie , Cognition , Dysfonctionnement cognitif/diagnostic , Sujet âgé , Vieillissement/psychologie , Maladie d'Alzheimer , Femelle , Humains , Études longitudinales , Mâle , Tests neuropsychologiques/statistiques et données numériques , AutorapportRÉSUMÉ
INTRODUCTION: Investigation of the conversion rates from normal cognition (NC) to mild cognitive impairment (MCI) is important, as effective early intervention could potentially prevent or substantially delay the onset of dementia. However, reported conversion rates differ across studies and recruitment source. Our study examined predictors of conversion from NC to MCI in a racially and ethnically diverse sample drawn both from community and clinic recruitment sources. METHODS: Rates and predictors of conversion were assessed in an ongoing prospective longitudinal study at University of California, Davis, Alzheimer's Disease Center from 2000 to 2015. Participants (n = 254) were recruited through a clinic (5%) and community sample (95%). They were clinically confirmed as cognitively normal at baseline and followed up to seven years. Recruitment source, demographic factors (age, gender, race/ethnicity, year of education, APOE ε4 positive), cognitive measures (SENAS test scores), functional assessments (CDR sum of boxes), and neuroimaging measures (total brain volume, total hippocampal volume, white hyperintensity volume) were assessed as predictors of conversion from cognitively normal to mild cognitive impairment using proportional hazards models. RESULTS: Of 254 participants, 62 (11 clinic, 51 community) progressed to MCI. The clinic-based sample showed an annual conversion rate of 30% (95% CI 17%-54%) per person-year, whereas the community-based sample showed a conversion rate of 5% (95% CI 3%-6%) per person-year. Risk factors for conversion include clinic-based recruitment, being older, lower executive function and worse functional assessment at baseline, and smaller total brain volume. DISCUSSION: Older adults who sought out a clinical evaluation, even when they are found to have normal cognition, have increased risk of subsequent development of MCI. Results are consistent with other studies showing subjective cognitive complaints are a risk for future cognitive impairment, but extend such findings to show that those who seek evaluation for their complaints are at particularly high risk. Moreover, these individuals have subtle, but significant differences in functional and cognitive abilities that, in the presence of concerns and evidence of atrophy on by brain imaging, warrant continued clinical follow-up. These risk factors could also be used as stratification variables for dementia prevention clinical trial design.
Sujet(s)
Dysfonctionnement cognitif/épidémiologie , Facteurs âges , Sujet âgé , Apolipoprotéine E4/génétique , Encéphale/imagerie diagnostique , Dysfonctionnement cognitif/imagerie diagnostique , Dysfonctionnement cognitif/génétique , Dysfonctionnement cognitif/physiopathologie , Évolution de la maladie , Femelle , Humains , Estimation de Kaplan-Meier , Études longitudinales , Mâle , Tests neuropsychologiques , Taille d'organe , Études prospectives , Facteurs de risqueRÉSUMÉ
Low-frequency (delta/theta band) hippocampal neural oscillations play prominent roles in computational models of spatial navigation, but their exact function remains unknown. Some theories propose they are primarily generated in response to sensorimotor processing, while others suggest a role in memory-related processing. We directly recorded hippocampal EEG activity in patients undergoing seizure monitoring while they explored a virtual environment containing teleporters. Critically, this manipulation allowed patients to experience movement through space in the absence of visual and self-motion cues. The prevalence and duration of low-frequency hippocampal oscillations were unchanged by this manipulation, indicating that sensorimotor processing was not required to elicit them during navigation. Furthermore, the frequency-wise pattern of oscillation prevalence during teleportation contained spatial information capable of classifying the distance teleported. These results demonstrate that movement-related sensory information is not required to drive spatially informative low-frequency hippocampal oscillations during navigation and suggest a specific function in memory-related spatial updating.
Sujet(s)
Ondes du cerveau/physiologie , Signaux , Hippocampe/physiopathologie , Perception de l'espace/physiologie , Mémoire spatiale/physiologie , Navigation spatiale/physiologie , Adulte , Épilepsie pharmacorésistante/anatomopathologie , Électroencéphalographie , Femelle , Humains , Mâle , Mouvement , Stimulation lumineuse , Interface utilisateurRÉSUMÉ
OBJECTIVE: This review examines the evidence that deep brain stimulation (DBS) has extensive impact on nonmotor symptoms (NMSs) of patients with Parkinson's disease (PD). DATA SOURCES: We retrieved information from the PubMed database up to September, 2015, using various search terms and their combinations including PD, NMSs, DBS, globus pallidus internus (GPi), subthalamic nucleus (STN), and ventral intermediate thalamic nucleus. STUDY SELECTION: We included data from peer-reviewed journals on impacts of DBS on neuropsychological profiles, sensory function, autonomic symptoms, weight changes, and sleep disturbances. For psychological symptoms and cognitive impairment, we tried to use more reliable proofs: Random, control, multicenter, large sample sizes, and long period follow-up clinical studies. We categorized the NMSs into four groups: those that would improve definitively following DBS; those that are not significantly affected by DBS; those that remain controversial on their surgical benefit; and those that can be worsened by DBS. RESULTS: In general, it seems to be an overall beneficial effect of DBS on NMSs, such as sensory, sleep, gastrointestinal, sweating, cardiovascular, odor, urological symptoms, and sexual dysfunction, GPi-DBS may produce similar results; Both STN and Gpi-DBS are safe with regard to cognition and psychology over long-term follow-up, though verbal fluency decline is related to DBS; The impact of DBS on behavioral addictions and dysphagia is still uncertain. CONCLUSIONS: As the motor effects of STN-DBS and GPi-DBS are similar, NMSs may determine the target choice in surgery of future patients.
Sujet(s)
Stimulation cérébrale profonde , Maladie de Parkinson/chirurgie , Maladie de Parkinson/thérapie , Globus pallidus/chirurgie , Humains , Mâle , Noyau subthalamique/chirurgieRÉSUMÉ
IMPORTANCE: Vitamin D (VitD) deficiency is associated with brain structural abnormalities, cognitive decline, and incident dementia. OBJECTIVE: To assess associations between VitD status and trajectories of change in subdomains of cognitive function in a cohort of ethnically diverse older adults. DESIGN, SETTING, AND PARTICIPANTS: Longitudinal multiethnic cohort study of 382 participants in an outpatient clinic enrolled between February 2002 and August 2010 with baseline assessment and yearly follow-up visits. Serum 25-hydroxyvitamin D (25-OHD) was measured, with VitD status defined as the following: deficient, less than 12 ng/mL (to convert to nanomoles per liter, multiply by 2.496); insufficient, 12 to less than 20 ng/mL; adequate, 20 to less than 50 ng/mL; or high, 50 ng/mL or higher. Subdomains of cognitive function were assessed using the Spanish and English Neuropsychological Assessment Scales. Associations were evaluated between 25-OHD levels (as continuous and categorical [deficient, insufficient, or adequate]) and trajectories of cognitive decline. MAIN OUTCOMES AND MEASURES: Serum 25-OHD levels, cognitive function, and associations between 25-OHD levels and trajectories of cognitive decline. RESULTS: Participants (N = 382 at baseline) had a mean (SD) age of 75.5 (7.0) years; 61.8% were women; and 41.4% were white, 29.6% African American, 25.1% Hispanic, and 3.9% other race/ethnicity. Diagnosis at enrollment included 17.5% with dementia, 32.7% with mild cognitive impairment, and 49.5% cognitively normal. The mean (SD) 25-OHD level was 19.2 (11.7) ng/mL, with 26.2% of participants being VitD deficient and 35.1% insufficient. The mean (SD) 25-OHD levels were significantly lower for African American and Hispanic participants compared with white participants (17.9 [15.8] and 17.2 [8.4] vs 21.7 [10.0] ng/mL, respectively; P < .001 for both). The mean (SD) 25-OHD levels were similarly lower in the dementia group compared with the mild cognitive impairment and cognitively normal groups (16.2 [9.4] vs 20.0 [10.3] and 19.7 [13.1] ng/mL, respectively; P = .006). The mean (SD) follow-up was 4.8 (2.5) years. Rates of decline in episodic memory and executive function among VitD-deficient (episodic memory: ß = -0.04 [SE = 0.02], P = .049; executive function: ß = -0.05 [SE = 0.02], P = .01) and VitD-insufficient (episodic memory: ß = -0.06 [SE = 0.02], P < .001; executive function: ß = -0.04 [SE = 0.02], P = .008) participants were greater than those with adequate status after controlling for age, sex, education, ethnicity, body mass index, season of blood draw, vascular risk, and apolipoprotein E4 genotype. Vitamin D status was not significantly associated with decline in semantic memory or visuospatial ability. Exclusion of participants with dementia did not substantially affect the associations between VitD status and rates of cognitive decline. CONCLUSIONS AND RELEVANCE: Low VitD status was associated with accelerated decline in cognitive function domains in ethnically diverse older adults, including African American and Hispanic individuals who exhibited a high prevalence of VitD insufficiency or deficiency. It remains to be determined whether VitD supplementation slows cognitive decline.