scholarly journals Gray matter correlates of set-shifting among neurodegenerative disease, mild cognitive impairment, and healthy older adults

2010 ◽  
Vol 16 (4) ◽  
pp. 640-650 ◽  
Author(s):  
JUDY PA ◽  
KATHERINE L. POSSIN ◽  
STEPHEN M. WILSON ◽  
LOVINGLY C. QUITANIA ◽  
JOEL H. KRAMER ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Neurodegenerative Disease ◽  
Gray Matter ◽  
Parietal Lobe ◽  
Set Shifting ◽  
Healthy Older Adults ◽  
Component Processes ◽  
Posterior Parietal

AbstractThere is increasing recognition that set-shifting, a form of cognitive control, is mediated by different neural structures. However, these regions have not yet been carefully identified as many studies do not account for the influence of component processes (e.g., motor speed). We investigated gray matter correlates of set-shifting while controlling for component processes. Using the Design Fluency (DF), Trail Making Test (TMT), and Color Word Interference (CWI) subtests from the Delis-Kaplan Executive Function System (D-KEFS), we investigated the correlation between set-shifting performance and gray matter volume in 160 subjects with neurodegenerative disease, mild cognitive impairment, and healthy older adults using voxel-based morphometry. All three set-shifting tasks correlated with multiple, widespread gray matter regions. After controlling for the component processes, set-shifting performance correlated with focal regions in prefrontal and posterior parietal cortices. We also identified bilateral prefrontal cortex and the right posterior parietal lobe as common sites for set-shifting across the three tasks. There was a high degree of multicollinearity between the set-shifting conditions and the component processes of TMT and CWI, suggesting DF may better isolate set-shifting regions. Overall, these findings highlight the neuroanatomical correlates of set-shifting and the importance of controlling for component processes when investigating complex cognitive tasks. (JINS, 2010, 16, 640–650.)

scholarly journals Exercise Training-Related Changes in Cortical Gray Matter Diffusivity and Cognitive Function in Mild Cognitive Impairment and Healthy Older Adults

2021 ◽  
Vol 13 ◽  
Author(s):  
Daniel D. Callow ◽  
Junyeon Won ◽  
Gabriel S. Pena ◽  
Leslie S. Jordan ◽  
Naomi A. Arnold-Nedimala ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Exercise Training ◽  
Gray Matter ◽  
Verbal Fluency ◽  
Verbal Learning ◽  
Insular Cortex ◽  
Healthy Older Adults ◽  
Cortical Gray Matter

Individuals with Mild Cognitive Impairment (MCI) are at an elevated risk of dementia and exhibit deficits in cognition and cortical gray matter (GM) volume, thickness, and microstructure. Meanwhile, exercise training appears to preserve brain function and macrostructure may help delay or prevent the onset of dementia in individuals with MCI. Yet, our understanding of the neurophysiological effects of exercise training in individuals with MCI remains limited. Recent work suggests that the measures of gray matter microstructure using diffusion imaging may be sensitive to early cognitive and neurophysiological changes in the aging brain. Therefore, this study is aimed to determine the effects of exercise training in cognition and cortical gray matter microstructure in individuals with MCI vs. cognitively healthy older adults. Fifteen MCI participants and 17 cognitively intact controls (HC) volunteered for a 12-week supervised walking intervention. Following the intervention, MCI and HC saw improvements in cardiorespiratory fitness, performance on Trial 1 of the Rey Auditory Verbal Learning Test (RAVLT), a measure of verbal memory, and the Controlled Oral Word Association Test (COWAT), a measure of verbal fluency. After controlling for age, a voxel-wise analysis of cortical gray matter diffusivity showed individuals with MCI exhibited greater increases in mean diffusivity (MD) in the left insular cortex than HC. This increase in MD was positively associated with improvements in COWAT performance. Additionally, after controlling for age, the voxel-wise analysis indicated a main effect of Time with both groups experiencing an increase in left insular and left and right cerebellar MD. Increases in left insular diffusivity were similarly found to be positively associated with improvements in COWAT performance in both groups, while increases in cerebellar MD were related to gains in episodic memory performance. These findings suggest that exercise training may be related to improvements in neural circuits that govern verbal fluency performance in older adults through the microstructural remodeling of cortical gray matter. Furthermore, changes in left insular cortex microstructure may be particularly relevant to improvements in verbal fluency among individuals diagnosed with MCI.

scholarly journals Repetition Priming in Individuals with Amnestic Mild Cognitive Impairment and Alzheimer’s Dementia: a Systematic Review and Meta-Analysis

2021 ◽  
Author(s):  
Liselotte De Wit ◽  
Vitoria Piai ◽  
Pilar Thangwaritorn ◽  
Brynn Johnson ◽  
Deirdre O’Shea ◽  
...  
Keyword(s):  
Systematic Review ◽  
Older Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Repetition Priming ◽  
Meta Analysis ◽  
Healthy Older Adults ◽  
Amnestic Mci ◽  
Standard Mean Difference ◽  
Priming Paradigm

AbstractThe literature on repetition priming in Alzheimer’s disease (AD) is inconsistent, with some findings supporting spared priming while others do not. Several factors may explain these inconsistencies, including AD severity (e.g., dementia vs. Mild Cognitive Impairment; MCI) and priming paradigm-related characteristics. This systematic review and meta-analysis provides a quantitative summary of repetition priming in AD. We examined the between-group standard mean difference comparing repetition priming in AD dementia or amnestic MCI (aMCI; presumably due to AD) to controls. Thirty-two studies were selected, including 590 individuals with AD dementia, 267 individuals with amnestic MCI, and 703 controls. Our results indicated that both individuals with aMCI and AD dementia perform worse on repetition priming tasks than cognitively older adults. Paradigm-related moderators suggested that the effect size between studies comparing the combined aMCI or AD dementia group to cognitively healthy older adults was the highest for paradigms that required participants to produce, rather than identify, primes during the test phase. Our results further suggested that priming in AD is impaired for both conceptual and perceptual priming tasks. Lastly, while our results suggested that priming in AD is impaired for priming tasks that require deep processing, we were unable to draw firm conclusions about whether priming is less impaired in aMCI or AD dementia for paradigms that require shallow processing.

scholarly journals Five-Year Change in Body Mass Index Predicts Conversion to Mild Cognitive Impairment or Dementia Only in APOE ɛ4 Allele Carriers

2021 ◽  
pp. 1-11
Author(s):  
Kylie R. Kadey ◽  
John L. Woodard ◽  
Allison C. Moll ◽  
Kristy A. Nielson ◽  
J. Carson Smith ◽  
...  
Keyword(s):  
Older Adults ◽  
Body Mass Index ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Body Mass ◽  
Carrier Status ◽  
Healthy Older Adults ◽  
E4 Allele ◽  
Lifestyle Risk

Background: Body mass index (BMI) has been identified as an important modifiable lifestyle risk factor for dementia, but less is known about how BMI might interact with Apolipoprotein E ɛ4 (APOE ɛ4) carrier status to predict conversion to mild cognitive impairment (MCI) and dementia. Objective: The aim of this study was to investigate the interaction between APOE ɛ4 status and baseline (bBMI) and five-year BMI change (ΔBMI) on conversion to MCI or dementia in initially cognitively healthy older adults. Methods: The associations between bBMI, ΔBMI, APOE ɛ4 status, and conversion to MCI or dementia were investigated among 1,289 cognitively healthy elders from the National Alzheimer’s Coordinating Center (NACC) database. Results: After five years, significantly more carriers (30.6%) converted to MCI or dementia than noncarriers (17.6%), p <  0.001, OR = 2.06. Neither bBMI (OR = 0.99, 95%CI = 0.96–1.02) nor the bBMI by APOE interaction (OR = 1.02, 95%CI = 0.96–1.08) predicted conversion. Although ΔBMI also did not significantly predict conversion (OR = 0.90, 95%CI = 0.78–1.04), the interaction between ΔBMI and carrier status was significant (OR = 0.72, 95%CI = 0.53–0.98). For carriers only, each one-unit decline in BMI over five years was associated with a 27%increase in the odds of conversion (OR = 0.73, 95%CI = 0.57–0.94). Conclusion: A decline in BMI over five years, but not bBMI, was strongly associated with conversion to MCI or dementia only for APOE ɛ4 carriers. Interventions and behaviors aimed at maintaining body mass may be important for long term cognitive health in older adults at genetic risk for AD.

Individuals With Mild Cognitive Impairment and Alzheimer's Disease Benefit From Audiovisual Speech Cues and Supportive Sentence Context

2021 ◽  
pp. 1-10
Author(s):  
Alexandre Chauvin ◽  
Shari Baum ◽  
Natalie A. Phillips
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Speech Perception ◽  
Sentence Context ◽  
Speech Perception In Noise ◽  
Healthy Older Adults ◽  
Speech Cues

Purpose Speech perception in noise becomes difficult with age but can be facilitated by audiovisual (AV) speech cues and sentence context in healthy older adults. However, individuals with Alzheimer's disease (AD) may present with deficits in AV integration, potentially limiting the extent to which they can benefit from AV cues. This study investigated the benefit of these cues in individuals with mild cognitive impairment (MCI), individuals with AD, and healthy older adult controls. Method This study compared auditory-only and AV speech perception of sentences presented in noise. These sentences had one of two levels of context: high (e.g., “Stir your coffee with a spoon”) and low (e.g., “Bob didn't think about the spoon”). Fourteen older controls ( M age = 72.71 years, SD = 9.39), 13 individuals with MCI ( M age = 79.92 years, SD = 5.52), and nine individuals with probable Alzheimer's-type dementia ( M age = 79.38 years, SD = 3.40) completed the speech perception task and were asked to repeat the terminal word of each sentence. Results All three groups benefited (i.e., identified more terminal words) from AV and sentence context. Individuals with MCI showed a smaller AV benefit compared to controls in low-context conditions, suggesting difficulties with AV integration. Individuals with AD showed a smaller benefit in high-context conditions compared to controls, indicating difficulties with AV integration and context use in AD. Conclusions Individuals with MCI and individuals with AD do benefit from AV speech and semantic context during speech perception in noise (albeit to a lower extent than healthy older adults). This suggests that engaging in face-to-face communication and providing ample context will likely foster more effective communication between patients and caregivers, professionals, and loved ones.

scholarly journals Magnetic Resonance Hippocampal Subfield Volumetric Analysis for Differentiating among Healthy Older Adults and Older Adults with Mild Cognitive Impairment or Major Depressive Disorder

2021 ◽  
Vol 73 (12) ◽  
pp. 786-792
Author(s):  
Doonyaporn Wongsawaeng ◽  
Orasa Chawalparit ◽  
Siriwan Piyapittayanan ◽  
Tanyaluck Thientunyakit ◽  
Weerasak Muangpaisan ◽  
...  
Keyword(s):  
Older Adults ◽  
Major Depressive Disorder ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Depressive Disorder ◽  
Subgroup Analysis ◽  
Amyloid Pet ◽  
Major Depressive ◽  
Healthy Older Adults ◽  
Valuable Adjunct

Objective: Depression among older adults is frequently an early symptom of cognitive decline, and is believed to be a risk factor for Alzheimer’s disease (AD). Hippocampal subfield volume loss is found in both mild cognitive impairment (MCI) and major depressive disorder (MDD). We aimed to investigate the potential of MR hippocampal subfield volumetry for discriminating among healthy older adults (HOA) and older adults with MCI or MDD. Materials and Methods: Seventy age-matched subjects (29 non-depressed MCI, 12 MDD, and 29 HOA) underwent 3-Tesla MR imaging (MRI) with high-resolution 3D-T1W-TFE whole brain. Hippocampal subfield volumetric measurements were performed using FreeSurfer software to distinguish among MCI, MDD, and HOA. Subgroup analysis with amyloid PET result was also performed.Results: Significantly smaller bilateral hippocampal tail volume was observed in MCI compared to HOA (p=0.004 and p=0.04 on the left and right side, respectively). The same comparative finding was observed at left HATA (hippocampus-amygdala-transition-area) of MCI (p=0.046). Other regions showed non-significantly smaller size in MCI than in HOA [left molecular layer HP (p=0.06), left whole hippocampus (p=0.06), and left CA1 (p=0.07)]. There was a non-significant trend toward smaller size in almost all 13 subfield hippocampal regions of MCI compared to MDD, even in subgroup analysis with amyloid PET result.Conclusion: MR hippocampal subfield volumetry may have value in routine clinical practice for screening individuals with MCI, and may be a valuable adjunct to amyloid PET study for very early-stage diagnosis of AD.

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