Ali Ezzati

Validation of the Perceived Stress Scale in a community sample of older adults

Three versions of Perceived Stress Scale (PSS‐14, PSS‐10, and PSS‐4) are among the most widely used measures of stress. The aim of the current study was to validate this instrument in a sample of nondemented older adults to facilitate studies of the impact of stress on health.

Topography of the motion aftereffect with and without eye movements.

Although a lot is known about various properties of the motion aftereffect (MAE), there is no systematic study of the topographic organization of MAE. In the current study, first we provided a topographic map of the MAE to investigate its spatial properties in detail. To provide a fine topographic map, we measured MAE with small test stimuli presented at different loci after adaptation to motion in a large region within the visual field. We found that strength of MAE is highest on the internal edge of the adapted area. Our results show a sharper aftereffect boundary for the shearing motion compared to compression and expansion boundaries. In the second experiment, using a similar paradigm, we investigated topographic deformation of the MAE area after a single saccadic eye movement. Surprisingly, we found that topographic map of MAE splits into two separate regions after the saccade: one corresponds to the retinal location of the adapted stimulus and the other matches the spatial location of the adapted region on the display screen. The effect was stronger at the retinotopic location. The third experiment is basically replication of the second experiment in a smaller zone that confirms the results of previous experiments in individual subjects. The eccentricity of spatiotopic area is different from retinotopic area in the second experiment; Experiment 3 controls the effect of eccentricity and confirms the major results of the second experiment.

Influence of Perceived Stress on Incident Amnestic Mild Cognitive Impairment: Results From the Einstein Aging Study

Stress is a potentially remediable risk factor for amnestic mild cognitive impairment (aMCI). Our objective is to determine whether perceived stress predicts incident aMCI and to determine if the influence of stress on aMCI is independent of known aMCI risk factors, particularly demographic variables, depression, and apolipoprotein genotype. The Einstein Aging Study is a longitudinal community-based study of older adults. The Perceived Stress Scale (PSS) was administered annually in the Einstein Aging Study to participants (N=507; 71 developed incident aMCI; mean follow-up time=3.6 y, SD=2.0) who were aged 70 years and older, free of aMCI and dementia at baseline PSS administration, and had at least 1 subsequent annual follow-up. Cox hazard models were used to examine time to aMCI onset adjusting for covariates. High levels of perceived stress are associated with a 30% greater risk of incident aMCI (per 5-point increase in PSS: hazard ratio=1.30; 95% confidence interval, 1.08-1.58) independent of covariates. The consistency of results after covariate adjustment and the lack of evidence for reverse causation in longitudinal analyses suggest that these findings are robust. Understanding of the effect of perceived stress on cognition may lead to intervention strategies that prevent the onset of aMCI and Alzheimer dementia.

Differential association of left and right hippocampal volumes with verbal episodic and spatial memory in older adults.

The hippocampus plays a critical role in verbal and spatial memory, thus any pathological damage to this formation may lead to cognitive impairment. It is suggested that right and left hippocampi are affected differentially in healthy or pathologic aging. The purpose of this study was to test the hypothesis that verbal episodic memory performance is associated with left hippocampal volume (HV) while spatial memory is associated with right HV. 115 non-demented adults over age 70 were drawn from the Einstein Aging Study. Verbal memory was measured using the free recall score from the Free and Cued Selective Reminding Test - immediate recall (FCSRT-IR), logical memory immediate and delayed subtests (LM-I and LM-II) from the Wechsler Memory Scale-Revised (WMS-R). Spatial Memory was measured using a computerized dot memory paradigm that has been validated for use in older adults. All participants underwent 3T MRI with subsequent automatized measurement of the volume of each hippocampus. The sample had a mean age of 78.7 years (SD=5.0); 57% were women, and 52% were white. Participants had a mean of 14.3 years (SD=3.5) of education. In regression models, two tests of verbal memory (FCSRT-IR free recall and LM-II) were positively associated with left HV, but not with right HV. Performance on the spatial memory task was associated with right HV, but not left HV. Our findings support the hypothesis that the left hippocampus plays a critical role in episodic verbal memory, while right hippocampus might be more important for spatial memory processing among non-demented older adults.

Hippocampal subfields differentially correlate with chronic pain in older adults

Although previous studies have demonstrated that the hippocampus plays a role in pain processing, the role of hippocampal subfields is uncertain. The goal of this study was to examine the relationship between hippocampal subfield volumes and chronic pain in nondemented older adults. The study sample included 86 community-residing adults age 70 or older who were free of dementia and recruited from the Einstein Aging Study. Chronic pain was defined as pain over the last 3 months, that was moderate or severe (minimum rating of 4 out of 10) most, or all of the time. Hippocampal subfield volumes were estimated using FreeSurfer software. We modeled the association between chronic pain and hippocampal and subfield volume using linear regression. The sample had a mean age of 80 and was 58% female. Chronic pain, present in 55% of the sample, was associated with smaller right and total hippocampal volumes, particularly in women, after adjusting for age, education, and intracranial volume (eTICV). In addition, in women, volume was significantly reduced in participants with chronic pain in right CA2-3 (β=-0.35, p=0.010), right CA4-DG (β=-0.35, p=0.011), left presubiculum (β=-0.29, p=0.030), and left fimbria (β=-0.30, p=0.023). In men, chronic pain was not associated with the volume of any of the hippocampal subfield volumes. Chronic pain in women is associated with a reduction in the volume of right hippocampus and also selected hippocampal subfields. Future studies should clarify the mechanisms underlying the association between regional hippocampal volumes and chronic pain, particularly in women.

Roles of hippocampal subfields in verbal and visual episodic memory

HighlightsNeurocognitive tests tapping specific HC subfields can help target at‐risk individuals.Subiculum was associated with verbal and visual episodic memory.CA1 was associated with verbal and visual episodic memory.No other subfields were associated with verbal or visual episodic memory.Our results suggest that CA1 and subiculum are responsible for retrieval. Introduction: Selective hippocampal (HC) subfield atrophy has been reported in older adults with mild cognitive impairment and Alzheimer’s disease. The goal of this study was to investigate the associations between the volume of hippocampal subfields and visual and verbal episodic memory in cognitively normal older adults. Methods: This study was conducted on a subset of 133 participants from the Einstein Aging Study (EAS), a community‐based study of non‐demented older adults systematically recruited from the Bronx, N.Y. All participants completed comprehensive EAS neuropsychological assessment. Visual episodic memory was assessed using the Complex Figure Delayed Recall subtest from the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Verbal episodic memory was assessed using Delayed Recall from the Free and Cued Selective Reminding Test (FCSRT). All participants underwent 3T MRI brain scanning with subsequent automatic measurement of the hemispheric hippocampal subfield volumes (CA1, CA2‐CA3, CA4‐dente gyrus, presubiculum, and subiculum). We used linear regressions to model the association between hippocampal subfield volumes and visual and verbal episodic memory tests while adjusting for age, sex, education, and total intracranial volume. Results: Participants had a mean age of 78.9 (SD = 5.1) and 60.2% were female. Total hippocampal volume was associated with Complex Figure Delayed Recall (&bgr; = 0.31, p = 0.001) and FCSRT Delayed Recall (&bgr; = 0.27, p = 0.007); subiculum volume was associated with Complex Figure Delayed Recall (&bgr; = 0.27, p = 0.002) and FCSRT Delayed Recall (&bgr; = 0.24, p = 0.010); CA1 was associated with Complex Figure Delayed Recall (&bgr; = 0.26, p < 0.002) and FCSRT Delayed Recall (&bgr; = 0.20, p = 0.025). Conclusions: Our findings confirm previous research on the specific roles of CA1 and subiculum in episodic memory. Our results suggest that hippocampal subfields have sensitive roles in the process of visual and verbal episodic memory.

Perceived Stress Is Differentially Related to Hippocampal Subfield Volumes among Older Adults

Introduction Chronic exposure to stress has been shown to impact a wide range of health-related outcomes in older adults. Despite extensive animal literature revealing deleterious effects of biological markers of stress on the dentate gyrus subfield of the hippocampus, links between hippocampal subfields and psychological stress have not been studied in humans. This study examined the relationship between perceived stress and hippocampal subfield volumes among racially/ethnically diverse older adults. Methods and Materials Between July 2011 and March 2014, 116 nondemented participants were consecutively drawn from the Einstein Aging Study, an ongoing community-based sample of individuals over the age of 70 residing in Bronx, New York. All participants completed the Perceived Stress Scale, Geriatric Depression Scale, and underwent 3.0 T MRI. FreeSurfer was used to derive total hippocampal volume, hippocampal subfield volumes (CA1, CA2/CA3, CA4/Dentate Gyrus (CA4/DG), and subiculum), entorhinal cortex volume, whole brain volume, and total intracranial volume. Results Linear regression analyses revealed that higher levels of perceived stress were associated with smaller total hippocampal volume (β = -0.20, t = -2.40, p = 0.02), smaller CA2/CA3 volumes (β = -0.18, t = -2.24, p = 0.03) and smaller CA4/DG volumes (β = -0.19, t = -2.28, p = 0.03) after controlling for total intracranial volume, age, gender, and race. These findings remained unchanged after removal of individuals with clinically significant symptoms of depression. Discussion Our findings provide evidence of a relationship between a direct indicator of psychological stress and specific hippocampal subfield volumes in elderly individuals. These results highlight the importance of clinical screening for chronic stress in otherwise healthy older adults.

Hippocampal correlates of depression in healthy elderly adults.

Mixed findings have been reported on the relationship between hippocampal integrity and major depression in clinical populations. Few neuroimaging studies have investigated associations between hippocampal measures and depressive symptoms in nondemented older adults. Here, we address this issue by imaging 36 nondemented adults over age 70 from the Einstein Aging Study, a community‐based sample from the Bronx, NY. Depressive symptoms were assessed using the 15‐item Geriatric Depression scale (GDS). Clinically significant depression was defined using a cut‐off score of 5 or greater. Hippocampal data included MRI‐derived volume data normalized to midsagittal area and MRS‐derived N‐acetylaspartate to creatine ratios (NAA/Cr). Our result indicates that smaller total hippocampal volume was associated with higher GDS scores, but there were no significant association between hippocampal NAA/Cr and GDS score. These effects were consistent after controlling for age, education, and gender. Reduction in hippocampal volume could represent a risk factor or a consequence of depression in older adults. Further studies are needed to better understand the role of the hippocampus in the development and experience of depression in older adults.

Pain Intensity and Pain Interference in Older Adults: Role of Gender, Obesity and High-Sensitivity C-Reactive Protein

Background: Among older adults, pain intensity and pain interference are more common in women than men and associated with obesity and inflammatory markers. Objective: We examined whether the obesity and pain relationship is mediated by the high-sensitivity C-reactive protein (hsCRP), a nonspecific marker of systemic inflammation, and whether this relationship differs by sex. Methods: Items from Medical Outcomes Study Short Form-36 were used to measure pain intensity and pain interference in daily life. Ordinal logistic regression was used to assess the cross-sectional association among body mass index (BMI), hsCRP levels, pain intensity and pain interference using gender-stratified models adjusted for demographic variables. Results: Participants included 667 community-residing adults over the age of 70 years, free of dementia, enrolled in the Einstein Aging Study (EAS). In women (n = 410), pain intensity was associated with obesity [BMI ≥30 vs. normal, odds ratio (OR) = 2.29, 95% confidence interval (CI) 1.43-3.68] and higher hsCRP (OR = 1.28, 95% CI 1.08-1.51). In a model with obesity and hsCRP, both remained significant, but the association between hsCRP and pain intensity was somewhat attenuated. Obesity (OR = 3.04, 95% CI 1.81-5.11) and higher hsCRP levels (OR = 1.30, 95% CI 1.08-1.56) were also independently associated with greater pain interference in women. After adjustment for pain intensity and BMI, hsCRP was no longer associated with pain interference in women. Greater pain intensity and being overweight or obese continued to be significantly associated with pain interference in women. In men (n = 257), obesity and hsCRP were not associated with pain intensity or pain interference. Conclusions: In women, the relationship between obesity and higher levels of pain intensity or interference may be accounted for by factors related to hsCRP.

Validation of the Perceived Stress Scale in a community sample of older adults: Results from the Einstein Aging Study

reliability and validity of the SRVersion.Methods:TheHABC-Monitor has three patient symptom domains (cognitive, functional, and behavioral/psychological) with parallel items for both the CG Version and the SRVersion. The Caregiver Quality of Life domain is included on the CGVersion but not the SRVersion. Patients (n1⁄4 291) were consecutively approached and consented during a patient’s routine visit to their primary care provider. The SR Version was administered to each patient during a subsequent phone interview. Results: The HABC-Monitor demonstrated excellent fit for the confirmatory factor analysis model (RMSEA 1⁄4 0.020, CFI 1⁄4 0.974, WRMR 1⁄4 0.837); good internal consistency (0.78-0.92); and adequate knowngroups validity, indicated by significant separation of TICSm severity groups.Conclusions:The SRVersion demonstrates good reliability and validity as a clinically practical multidimensional tool for measuring symptoms of dementia. The tool can be used with the CG Version to provide useful feedback (via monitoring of symptoms) for modifying care plans for dementia patients and their informal caregivers.