scholarly journals Hyposmia and Neuroimaging Signature in Community-Dwelling Older Adults

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 530-530
Author(s):  
Cynthia Felix ◽  
Lana Chahine ◽  
Honglei Chen ◽  
Zichun Cao ◽  
Caterina Rosano

Abstract Olfaction declines with aging, and hyposmia, or impaired sense of smell, is associated with neurodegenerative disorders including Alzheimer’s Disease (AD) and Parkinson’s Disease (PD). Neuroimaging studies of hyposmia in AD/PD patients have often examined pathology-specific brain regions. Our knowledge of neural correlates in regions that mediate olfaction in community-dwelling older adults, is limited. We quantified mean diffusivity (MD) of the gray matter (GM) using diffusion tensor imaging in a community-dwelling sample of 308 older adults (mean age: 82.9 years, 58% women, 40% black). We focused on total brain and these regions involved in olfaction- olfactory bulb, amygdala, entorhinal cortex, orbitofrontal cortex, and hippocampus. Smell was tested with a scratch-and-sniff validated odor identification test, the Brief Smell Identification Test (BSIT). Hyposmia was defined as BSIT score of ≤8, assessed about 7 years prior to neuroimaging. In our sample, 23% had hyposmia, more in in men (30%) than in women (19%). Hyposmia was not significantly associated with cardiovascular risk factors such as hypertension; diseases such as stroke; age; race; cognitive or mobility functions (all p>0.1). In linear regression models adjusted for demographics and brain atrophy (total brain gray matter volume divided by intracranial volume), hyposmia was significantly associated with higher GM MD (lower microstructural integrity) of the left orbitofrontal cortex (standardized beta: 0.142, t=2.56, p=0.011). Understanding the neural substrates involved in hyposmia in aging is an important step towards advancing research on hyposmia in non-clinic-based, community-dwelling populations.

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000013215
Author(s):  
Tiing Yee Siow ◽  
Cheng Hong Toh ◽  
Jung-Lung Hsu ◽  
Geng-Hao Liu ◽  
Shwu-Hua Lee ◽  
...  

Background and Objectives:The glymphatic system, which is robustly enabled during some stages of sleep, is a fluid-transport pathway that clears cerebral waste products. Most contemporary knowledge regarding glymphatic system is inferred from rodent experiments and human research is limited. The objective of the research is to explore the associations between human glymphatic function, sleep, neuropsychological performances, and cerebral gray matter volumes.Methods:This cross-sectional study included individuals 60 years or older who had participated in the Integrating Systemic Data of Geriatric Medicine to Explore the Solution for Health Aging study between September 2019 and October 2020. Community-dwelling older adults were enrolled at 2 different sites. Participants with dementia, major depressive disorders, and other major organ system abnormalities were excluded. Sleep profile was accessed using questionnaires and polysomnography. Administered neuropsychological test batteries included Everyday Cognition (ECog) and the Consortium to Establish a Registry for Alzheimer’s Disease Neuropsychological Battery (CERAD-NB). Gray matter volumes were estimated based on magnetic resonance imaging (MRI). Diffusion tensor imaging-analysis along the perivascular space (DTI-ALPS) index was used as the MRI marker of glymphatic function.Results:A total of 84 participants (mean [SD] age, 73.3 [7.1] years, 47 [56.0%] women) were analyzed. Multivariate linear regression model determined that age (unstandardized β, -0.0025 [SE, 0.0001]; P = 0.02), N2 sleep duration (unstandardized β, 0.0002 [SE, 0.0001]; P = 0.04), and the apnea-hypopnea index (unstandardized β, -0.0011 [SE, 0.0005]; P = 0.03) were independently associated with DTI-ALPS. Higher DTI-ALPS was associated with better ECog language scores (unstandardized β, -0.59 [SE, 0.28]; P = 0.04) and better CERAD-NB word-list-learning delayed recall subtest scores (unstandardized β, 6.17 [SE, 2.31]; P = 0.009) after co-varying for age and education. Higher DTI-ALPS was also associated with higher gray matter volume (unstandardized β, 107.00 [SE, 43.65]; P = 0.02) after controlling for age, gender, and total intracranial volume.Discussion:Significant associations were identified between glymphatic function and sleep stressing the importance of sleep for brain health. This study also revealed associations between DTI-ALPS, neuropsychological performances, and cerebral gray matter volumes suggesting the potential of DTI-ALPS as a biomarker for cognitive disorders.


2021 ◽  
Vol 13 ◽  
Author(s):  
Ai Iizuka ◽  
Hiroshi Murayama ◽  
Masaki Machida ◽  
Shiho Amagasa ◽  
Shigeru Inoue ◽  
...  

Background: Recent findings indicate that leisure activity (LA) delays cognitive decline and reduces the risk of dementia. However, the association between LA and brain volume remains unclear. This study aimed to examine the association between LA variety and brain volume with a focus on the hippocampus and gray matter.Methods: Data were obtained from the baseline survey of the Neuron to Environmental Impact across Generations study, which had targeted community-dwelling older adults living in Niigata, Japan. We divided LAs into 10 categories, and counted the number of categories of activities in which the participants engaged. We classified them as follows: 0 (i.e., no activity), 1, 2, or ≥ 3 types. Brain volume was assessed through magnetic resonance imaging, and hippocampal and gray matter volumes were ascertained.Results: The sample size was 482. Multiple linear regression analysis showed that hippocampal and gray matter volumes were significantly greater among participants with ≥ 3 types of LAs than among their no-activity counterparts. Hippocampal volume was significantly greater among those who engaged in one type of LA than among those who engaged in no such activity. Sex-stratified analysis revealed that hippocampal volumes were significantly greater among males who engaged in ≥ 3 types of LAs and one type of LA. However, no such association was found among females.Conclusion: The present findings suggest that engaging in a wide range of LAs is related to hippocampal and gray matter volumes. Furthermore, there was a sex difference in the association between LA variety and brain volume.


Author(s):  
Yannic van Gils ◽  
Erik Franck ◽  
Eva Dierckx ◽  
Sebastiaan P. J. van Alphen ◽  
John B. Saunders ◽  
...  

Background: One of the best-known tools in screening for hazardous drinking is the Alcohol Use Disorders Identification Test (AUDIT) and its abbreviated form, the AUDIT-C. The aim of the present study is to determine the cut-offs of both instruments in identifying hazardous drinking in older adults. Method: A sample of 1577 older adults completed a questionnaire regarding alcohol behavior. Hazardous drinking was defined as drinking >10 units/week. Receiver operating characteristics (ROC) curves of AUDIT and AUDIT-C were calculated and cut-off scores were derived. Results: Respectively 27.3% and 12.3% of older men and women drank >10 units/week. For the AUDIT the best trade-off between sensitivity and specificity was using a cut-off of ≥5 for men and ≥4 for women, which yielded in men sensitivity and specificity values respectively of 80.7% and 81.3% and in women 100% and 71.7%, respectively. We found the AUDIT-C to perform well with an optimal cut-off of ≥5 for men and ≥4 for women, which generated in men sensitivity and specificity values respectively of 76.5% and 85.3% and in women 100% and 74.1%, respectively. Conclusion: The AUDIT-C is accurate and sufficient in screening for hazardous drinking in community-dwelling older adults if the cut-offs are tailored by gender.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 209-209
Author(s):  
Fangyu Liu ◽  
Yang An ◽  
Amal Wanigatunga ◽  
Alden Gross ◽  
Eleanor Simonsick ◽  
...  

Abstract Perceived fatigability is linked to declining physical and cognitive performance, yet whether fatigability reflects early subclinical change in brain structure is unknown. Using mixed effects models, we assessed the longitudinal association of 3T MRI-derived brain volumes with perceived fatigability after a 5-min treadmill walk (0.67 m/s, 0% grade) using the Borg Rating of Perceived Exertion scale (range 6-20) in 802 BLSA participants (age 68.2+/-12.4 years, 45% men 66% White). In models adjusted for intracranial volume, demographics, chronic conditions, and CESD score, declining gray matter volumes in the frontal (β=-0.01) and temporal (β=-0.02) lobes, as well as the hippocampus (β=-0.25), precuneus (β=-0.10) and thalamus (β=-0.19) were associated with higher fatigability. Larger ventricular volumes were also associated with higher fatigability (β=0.02). Brain atrophy, particularly in gray matter and the hippocampal region, is longitudinally associated with increased fatigability in cognitively normal older adults, making it a potential marker of brain atrophy.


2019 ◽  
Vol 68 (5) ◽  
pp. 1023-1028 ◽  
Author(s):  
Nikki L. DiSalvio ◽  
Caterina Rosano ◽  
Howard J. Aizenstein ◽  
Mark S. Redfern ◽  
Joseph M. Furman ◽  
...  

Author(s):  
Cynthia Felix ◽  
Caterina Rosano ◽  
Xiaonan Zhu ◽  
Jason D Flatt ◽  
Andrea L Rosso

Abstract Objective Social engagement (SE) may protect against cognitive decline in older adults. We estimate associations of SE with gray matter (GM) microstructure in regions of interest (ROI) relevant to social cognition, among community-dwelling older adults. Method Cross-sectional analysis of 293 Health ABC study participants who underwent 3 Tesla magnetic resonance imaging with diffusion tensor and free from cognitive impairment was conducted. Linear regression models tested associations between SE index (marital status, not living alone, social activities, work, and volunteering) and mean diffusivity (MD) of GM ROIs, adjusted for age, race, gender, and education. Hearing and activities of daily living (ADL) difficulties were tested as confounders. Effect modification by gender was tested with interaction terms and stratification by gender. Results Higher SE was significantly related to lower MD (greater GM microstructural integrity) (shown as standardized estimate [p-value]) in left middle frontal gyrus-orbital part: −.168 (.005), left caudate nucleus: −.141 (.02), left temporal pole-middle temporal gyrus: −.136 (.03), right middle frontal gyrus: −.160 (.006), right superior frontal gyrus-orbital part: −.187 (.002), and right middle frontal gyrus-orbital part: −.124 (.04), when adjusted for demographic attributes. Associations were robust to adjustments for hearing or ADL difficulty. There was significant effect modification by gender for some ROIs, with associations only for females. Discussion SE is related to greater microstructural integrity of specific GM regions relevant to social cognition, that have described roles in dementia. SE may therefore be a useful preventive mechanism against loss of GM integrity in older adults.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 176-177
Author(s):  
Qu Tian ◽  
Susan Resnick ◽  
Bennett Landman ◽  
Luigi Ferrucci

Abstract Physical frailty is an age-related clinical syndrome that is related to adverse health outcomes, including cognitive impairment and dementia. Recent studies have shown structural neuroimaging correlates with frailty. However, most existing evidence relies on brain volumetric measures. Whether brain microstructure is associated with frailty and its spatial distribution have not been explored. In the Baltimore Longitudinal Study of Aging, we identified 776 cognitively normal participants aged 50 and older who had concurrent data on frailty and brain microstructure by diffusion tensor imaging (DTI), including mean diffusivity (MD) of gray matter and fractional anisotropy (FA) of white matter. We first identified neuroimaging markers that were associated with frailty score (0-5) and further examined their relationships with frailty status (0: non-frail, 1-2: pre-frail, 3+: frail) using multivariate linear regression. Models were adjusted for age, sex, race, years of education, and Apolipoprotein E e4 carrier status. DTI-based neuroimaging markers that were associated with frailty status were localized in the supplementary motor area of the frontal lobe, several subcortical regions (putamen, caudate), and body and splenium of corpus callosum. This study demonstrates for the first time that microstructure of both gray and white matter differs by frailty levels in cognitively normal older adults. Brain areas were not widespread, but mostly localized in gray matter subcortical motor areas and white matter corpus callosum. Whether changes in brain microstructure precede future frailty development warrants further investigation.


2021 ◽  
pp. 0271678X2110652
Author(s):  
Zi-Yue Liu ◽  
Fei-Fei Zhai ◽  
Dong-Hui Ao ◽  
Fei Han ◽  
Ming-Li Li ◽  
...  

Our aim is to investigate the association of cerebral deep medullary veins (DMVs) with white matter microstructural integrity and regional brain atrophy in MRI. In a community-based cohort of 979 participants (mean age 55.4 years), DMVs were identified on susceptibility-weighted imaging. Brain structural measurements including gray matter and hippocampus volumes, as well as diffusion tensor metrics, were evaluated. The mean (SD)number of DMVs was 19.0 (1.7). A fewer number of DMVs was related to lower fractional anisotropy and higher mean diffusivity in multiple voxels on the white matter skeleton (threshold-free cluster enhancement corrected p < 0.05, adjusted for age and sex). Also, fewer DMVs were significantly related to a lower gray matter fraction and a hippocampal fraction (0.10 and 0.11 per DMV, respectively; SE, 0.03 for both; p < 0.001 for both). A significant correlation between DMVs’ reduction and cortical atrophy was observed in the bilateral occipital lobes, temporal lobes, hippocampus, and frontal lobes (p < 0.001, adjusted for age, sex, and total intracranial volume). Our results provided evidence that cerebral small venules disease play a role in brain parenchymal lesions and neurodegenerative processes.


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