scholarly journals Hippocampal Functional Connectivity and Memory Performance After Exercise Intervention in Older Adults with Mild Cognitive Impairment

2021 ◽  
pp. 1-17
Author(s):  
Junyeon Won ◽  
Daniel D. Callow ◽  
Gabriel S. Pena ◽  
Leslie S. Jordan ◽  
Naomi A. Arnold-Nedimala ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Memory Performance ◽  
Verbal Learning ◽  
Memory Task ◽  
Control Group ◽  
Age Related ◽  
Lm Test

Background: Exercise training (ET) has neuroprotective effects in the hippocampus, a key brain region for memory that is vulnerable to age-related dysfunction. Objective: We investigated the effects of ET on functional connectivity (FC) of the hippocampus in older adults with mild cognitive impairment (MCI) and a cognitively normal (CN) control group. We also assessed whether the ET-induced changes in hippocampal FC (Δhippocampal-FC) are associated with changes in memory task performance (Δmemory performance). Methods: 32 older adults (77.0±7.6 years; 16 MCI and 16 CN) participated in the present study. Cardiorespiratory fitness tests, memory tasks (Rey Auditory Verbal Learning Test (RAVLT) and Logical Memory Test (LM)), and resting-state fMRI were administered before and after a 12-week walking ET intervention. We utilized a seed-based correlation analysis using the bilateral anterior and posterior hippocampi as priori seed regions of interest. The associations of residualized ET-induced Δhippocampal-FC and Δmemory performance were assessed using linear regression. Results: There were significant improvements in RAVLT Trial 1 and LM test performance after ET across participants. At baseline, MCI, compared to CN, demonstrated significantly lower posterior hippocampal FC. ET was associated with increased hippocampal FC across groups. Greater ET-related anterior and posterior hippocampal FC with right posterior cingulate were associated with improved LM recognition performance in MCI participants. Conclusion: Our findings indicate that hippocampal FC is significantly increased following 12-weeks of ET in older adults and, moreover, suggest that increased hippocampal FC may reflect neural network plasticity associated with ET-related improvements in memory performance in individuals diagnosed with MCI.

Elevated Inflammatory Markers and Arterial Stiffening Exacerbate Tau but Not Amyloid Pathology in Older Adults with Mild Cognitive Impairment

2021 ◽  
pp. 1-13
Author(s):  
Alexandra L. Clark ◽  
Alexandra J. Weigand ◽  
Kelsey R. Thomas ◽  
Seraphina K. Solders ◽  
Lisa Delano-Wood ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Inflammatory Markers ◽  
Memory Performance ◽  
Cognitive Testing ◽  
Interactive Effects ◽  
Protein Biomarkers ◽  
Age Related ◽  
T Tau

Background: Age-related cerebrovascular and neuroinflammatory processes have been independently identified as key mechanisms of Alzheimer’s disease (AD), although their interactive effects have yet to be fully examined. Objective: The current study examined 1) the influence of pulse pressure (PP) and inflammatory markers on AD protein levels and 2) links between protein biomarkers and cognitive function in older adults with and without mild cognitive impairment (MCI). Methods: This study included 218 ADNI (81 cognitively normal [CN], 137 MCI) participants who underwent lumbar punctures, apolipoprotein E (APOE) genotyping, and cognitive testing. Cerebrospinal (CSF) levels of eight pro-inflammatory markers were used to create an inflammation composite, and amyloid-beta 1–42 (Aβ 42), phosphorylated tau (p-tau), and total tau (t-tau) were quantified. Results: Multiple regression analyses controlling for age, education, and APOE ɛ4 genotype revealed significant PP x inflammation interactions for t-tau (B = 0.88, p = 0.01) and p-tau (B = 0.84, p = 0.02); higher inflammation was associated with higher levels of tau within the MCI group. However, within the CN group, analyses revealed a significant PP x inflammation interaction for Aβ 42 (B = –1.01, p = 0.02); greater inflammation was associated with higher levels of Aβ 42 (indicative of lower cerebral amyloid burden) in those with lower PP. Finally, higher levels of tau were associated with poorer memory performance within the MCI group only (p s <  0.05). Conclusion: PP and inflammation exert differential effects on AD CSF proteins and provide evidence that vascular risk is associated with greater AD pathology across our sample of CN and MCI older adults.

scholarly journals Memory-Related Frontal Brainwaves Predict Transition to Mild Cognitive Impairment in Healthy Older Individuals Five Years Before Diagnosis

2020 ◽  
pp. 1-11
Author(s):  
Yang Jiang ◽  
Juan Li ◽  
Frederick A. Schmitt ◽  
Gregory A. Jicha ◽  
Nancy B. Munro ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Memory Performance ◽  
Memory Task ◽  
Cognitive Status ◽  
Older Individuals ◽  
Increased Risk ◽  
Differentiation Pattern

Background: Early prognosis of high-risk older adults for amnestic mild cognitive impairment (aMCI), using noninvasive and sensitive neuromarkers, is key for early prevention of Alzheimer’s disease. We have developed individualized measures in electrophysiological brain signals during working memory that distinguish patients with aMCI from age-matched cognitively intact older individuals. Objective: Here we test longitudinally the prognosis of the baseline neuromarkers for aMCI risk. We hypothesized that the older individuals diagnosed with incident aMCI already have aMCI-like brain signatures years before diagnosis. Methods: Electroencephalogram (EEG) and memory performance were recorded during a working memory task at baseline. The individualized baseline neuromarkers, annual cognitive status, and longitudinal changes in memory recall scores up to 10 years were analyzed. Results: Seven of the 19 cognitively normal older adults were diagnosed with incident aMCI for a median 5.2 years later. The seven converters’ frontal brainwaves were statistically identical to those patients with diagnosed aMCI (n = 14) at baseline. Importantly, the converters’ baseline memory-related brainwaves (reduced mean frontal responses to memory targets) were significantly different from those who remained normal. Furthermore, differentiation pattern of left frontal memory-related responses (targets versus nontargets) was associated with an increased risk hazard of aMCI (HR = 1.47, 95% CI 1.03, 2.08). Conclusion: The memory-related neuromarkers detect MCI-like brain signatures about five years before diagnosis. The individualized frontal neuromarkers index increased MCI risk at baseline. These noninvasive neuromarkers during our Bluegrass memory task have great potential to be used repeatedly for individualized prognosis of MCI risk and progression before clinical diagnosis.

scholarly journals Preserved functional connectivity in the default mode and salience networks is associated with youthful memory in superaging

2018 ◽  
Author(s):  
Jiahe Zhang ◽  
Joseph Andreano ◽  
Bradford C. Dickerson ◽  
Alexandra Touroutoglou ◽  
Lisa Feldman Barrett
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Functional Connectivity ◽  
Memory Performance ◽  
Verbal Learning ◽  
Memory Task ◽  
Recognition Task ◽  
Neural Basis ◽  
Default Mode ◽  
Intrinsic Connectivity

ABSTRACT“Superagers” are older adults who, despite their advanced age, maintain youthful memory. Previous morphometry studies revealed multiple default mode network (DMN) and salience network (SN) regions whose cortical thickness is preserved in superagers and correlates with memory performance. In this study, we examined the intrinsic functional connectivity within DMN and SN in 41 young (24.5 ± 3.6 years old) and 40 elderly adults (66.9 ± 5.5 years old). As in prior studies, superaging was defined as youthful performance on a memory recall task, the California Verbal Learning Test (CVLT). Participants underwent a resting state fMRI scan and performed a separate visual-verbal recognition memory task. As predicted, within both DMN and SN, superagers had stronger connectivity compared to typical older adults and similar connectivity compared to young adults. Superagers also performed similarly to young adults and better than typical older adults on the recognition task, demonstrating youthful episodic memory that generalized across memory tasks. Stronger connectivity within each network independently predicted better performance on both the CVLT and recognition task in older adults. Variation in intrinsic connectivity explained unique variance in memory performance, above and beyond preserved neuroanatomy. A post-hoc analysis revealed that DMN and SN nodes were more strongly inversely correlated in superagers than in typical older adults but were similarly correlated in superagers and young adults. Stronger between-network inverse correlations also predicted better memory performance in the entire sample of older adults. These results extend our understanding of the neural basis of superaging as a model of successful aging.SIGNIFICANCE STATEMENTMemory capacity generally declines with age, but a unique group of older adults – ‘superagers’ – have memory capacities rivaling those of younger adults, as well as preserved neuroanatomy in an ensemble of regions contained in two core intrinsic brain networks – the default mode and salience networks. In this study, we assessed the strength of intrinsic connectivity within these networks in superagers and typical older adults compared to young adults. We also expanded the behavioral assessment of memory. As predicted, superagers have intrinsic connectivity within the default mode and salience networks that is stronger than typical older adults and similar to that of young adults. Within older adults, preserved intrinsic connectivity within each network was uniquely associated with better memory performance.

scholarly journals Stronger Functional Connectivity in the Default Mode and Salience Networks Is Associated With Youthful Memory in Superaging

2019 ◽  
Vol 30 (1) ◽  
pp. 72-84 ◽  
Author(s):  
Jiahe Zhang ◽  
Joseph M Andreano ◽  
Bradford C Dickerson ◽  
Alexandra Touroutoglou ◽  
Lisa Feldman Barrett
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Functional Connectivity ◽  
Successful Aging ◽  
Memory Performance ◽  
Verbal Learning ◽  
Memory Task ◽  
Recognition Task ◽  
Neural Basis ◽  
Default Mode

Abstract “Superagers” are older adults who, despite their advanced age, maintain youthful memory. Previous morphometry studies revealed multiple default mode network (DMN) and salience network (SN) regions whose cortical thickness is greater in superagers and correlates with memory performance. In this study, we examined the intrinsic functional connectivity within DMN and SN in 41 young (24.5 ± 3.6 years old) and 40 older adults (66.9 ± 5.5 years old). Superaging was defined as youthful performance on a memory recall task, the California Verbal Learning Test (CVLT). Participants underwent a resting-state functional magnetic resonance imaging (fMRI) scan and performed a separate visual–verbal recognition memory task. As predicted, within both DMN and SN, superagers had stronger connectivity compared with typical older adults and similar connectivity compared with young adults. Superagers also performed similarly to young adults and better than typical older adults on the recognition task, demonstrating youthful episodic memory that generalized across memory tasks. Stronger connectivity within each network independently predicted better performance on both the CVLT and recognition task in older adults. Variation in intrinsic connectivity explained unique variance in memory performance, above and beyond youthful neuroanatomy. These results extend our understanding of the neural basis of superaging as a model of successful aging.

Proactive and retroactive interference in young adults, healthy older adults, and older adults with amnestic mild cognitive impairment

2009 ◽  
Vol 15 (1) ◽  
pp. 83-93 ◽  
Author(s):  
PATRICIA L. EBERT ◽  
NICOLE D. ANDERSON
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Retroactive Interference ◽  
Memory Performance ◽  
Verbal Learning ◽  
Amnestic Mild Cognitive Impairment ◽  
Healthy Older Adults ◽  
Memory Interference

AbstractThis study investigated memory interference in amnestic mild cognitive impairment (aMCI) and normal aging. Participants were 27 young adults, 44 healthy older adults, and 15 older adults with aMCI. Memory interference was examined on the California Verbal Learning Test (CVLT) and on a modified AB-AC paradigm. Despite significant differences in memory performance on the CVLT, interference measures on this test did not distinguish individuals with aMCI and healthy older adults. The AB-AC task involved first learning a list (AB list) of 12 semantically related word pairs (e.g., knee-bone). Twenty minutes later, a second list (AC list) was learned in which the same stimulus words were paired with new response words (e.g., knee-bend). Both lists were repeated until 100% accurate recall was achieved. Finally, participants recalled the first (AB) list. Proactive interference (PI) was greater among older than younger adults, and greater still among individuals with aMCI, but the older and aMCI groups showed similar levels of retroactive interference. This study suggests that PI contributes to the memory deficits seen in aMCI and that tests sensitive to PI may assist in the early identification of aMCI. Memory interventions aimed at alleviating PI may improve memory functioning in individuals with aMCI. (JINS, 2009, 15, 83–93.)

Neurocognitive Plasticity Is Associated with Cardiorespiratory Fitness Following Physical Exercise in Older Adults with Amnestic Mild Cognitive Impairment

2021 ◽  
pp. 1-22
Author(s):  
Galit Yogev-Seligmann ◽  
Tamir Eisenstein ◽  
Elissa Ash ◽  
Nir Giladi ◽  
Haggai Sharon ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Aerobic Exercise ◽  
Cardiorespiratory Fitness ◽  
Neuropsychological Tests ◽  
Aerobic Training ◽  
Amnestic Mild Cognitive Impairment ◽  
Control Group ◽  
Memory Encoding

Background: Aerobic training has been shown to promote structural and functional neurocognitive plasticity in cognitively intact older adults. However, little is known about the neuroplastic potential of aerobic exercise in individuals at risk of Alzheimer’s disease (AD) and dementia. Objective: We aimed to explore the effect of aerobic exercise intervention and cardiorespiratory fitness improvement on brain and cognitive functions in older adults with amnestic mild cognitive impairment (aMCI). Methods: 27 participants with aMCI were randomized to either aerobic training (n = 13) or balance and toning (BAT) control group (n = 14) for a 16-week intervention. Pre- and post-assessments included functional MRI experiments of brain activation during associative memory encoding and neural synchronization during complex information processing, cognitive evaluation using neuropsychological tests, and cardiorespiratory fitness assessment. Results: The aerobic group demonstrated increased frontal activity during memory encoding and increased neural synchronization in higher-order cognitive regions such as the frontal cortex and temporo-parietal junction (TPJ) following the intervention. In contrast, the BAT control group demonstrated decreased brain activity during memory encoding, primarily in occipital, temporal, and parietal areas. Increases in cardiorespiratory fitness were associated with increases in brain activation in both the left inferior frontal and precentral gyri. Furthermore, changes in cardiorespiratory fitness were also correlated with changes in performance on several neuropsychological tests. Conclusion: Aerobic exercise training may result in functional plasticity of high-order cognitive areas, especially, frontal regions, among older adults at risk of AD and dementia. Furthermore, cardiorespiratory fitness may be an important mediating factor of the observed changes in neurocognitive functions.

scholarly journals Sex-dependent Pathological Aging Effect on Caudate Functional Connectivity in Mild Cognitive Impairment

2021 ◽  
Author(s):  
Zhengshi Yang ◽  
Jessica Z.K. Caldwell ◽  
Jeffrey L. Cummings ◽  
Aaron Ritter ◽  
Jefferson W. Kinney ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Aging Effect ◽  
Analysis Of Covariance ◽  
Aging Effects ◽  
Mixed Effect ◽  
Effect Analysis ◽  
Pathological Aging ◽  
Age Related

Abstract Purpose To assess the pathological aging effect on caudate functional connectivity among mild cognitive impairment (MCI) participants and examine whether and how sex and amyloid contribute to this process. Materials and Methods 277 functional magnetic resonance imaging (fMRI) sessions from 163 cognitive normal (CN) older adults and 309 sessions from 139 participants with MCI were included as the main sample in our analysis. Pearson’s correlation was used to characterize the functional connectivity (FC) between caudate and each brain region, then caudate nodal strength was computed to quantify the overall caudate FC strength. Association analysis between caudate nodal strength and age was carried out in MCI and CN separately using linear mixed effect (LME) model with covariates (education, handedness, sex, Apolipoprotein E4 and intra-subject effect). Analysis of covariance was conducted to investigate sex, amyloid status and their interaction effects on aging with the fMRI data subset having amyloid status available. LME model was applied to women and men separately within MCI group to evaluate aging effects on caudate nodal strength and each region’s connectivity with caudate. We then evaluated the roles of sex and amyloid status in the associations of neuropsychological scores with age or caudate nodal strength. An independent cohort was used to validate the sex-dependent aging effects in MCI. Results The MCI group had significantly stronger age-related increase of caudate nodal strength compared to the CN group. Analyzing women and men separately revealed that the aging effect on caudate nodal strength among MCI participants was significant only for women (left: P=6.23x10−7, right: P=3.37x10−8), but not for men (P>0.3 for bilateral caudate). The aging effects on caudate nodal strength were not significantly mediated by brain amyloid burden. Caudate connectivity with ventral prefrontal cortex substantially contributed to the aging effect on caudate nodal strength in women with MCI. Higher caudate nodal strength is significantly related to worse cognitive performance in women but not in men with MCI. Conclusion Sex modulates the pathological aging effects on caudate nodal strength in MCI regardless of amyloid status. Caudate nodal strength may be a sensitive biomarker of pathological aging in women with MCI.

scholarly journals MULTIMODAL PERSONALIZED CHRONOTHERAPY IMPROVES SLEEP IN ADULTS WITH MILD COGNITIVE IMPAIRMENT: A RANDOMIZED TRIAL

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S367-S367
Author(s):  
Ryan S Falck ◽  
John R Best ◽  
Jennifer C Davis ◽  
Patrick Chan ◽  
Daniel Backhouse ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Sleep Quality ◽  
Sleep Hygiene ◽  
Sleep Fragmentation ◽  
Control Group ◽  
Significant Group ◽  
Increased Risk ◽  
Improve Sleep Quality

Abstract Poor sleep is common among older adults with Mild Cognitive Impairment (MCI) and may contribute to their increased risk for dementia. Chronotherapy is a set of intervention strategies which can improve sleep quality by strengthening the entrainment of the biological clock to the solar light-dark cycle, and includes strategies such as: 1) bright light therapy (BLT); 2) physical activity (PA); and 3) good sleep hygiene. Thus, in this 24-week randomized controlled trial (RCT; NCT02926157), we aimed to examine the efficacy of a multimodal, personalized chronotherapy intervention to improve sleep quality among older adults with MCI. Ninety-six older adults (65+ years) with MCI were randomized to either: 1) a multimodal personalized chronotherapy group (INT); or 2) a waitlist-plus-education control group (CON). Participants allocated to the INT received four once-weekly, general sleep hygiene education classes, followed by 20 weeks of 1) individually-timed BLT; and 2) bi-weekly, individually-tailored PA counselling in conjunction with receiving a consumer-available PA tracker (Fitbit® FlexTM). We found a significant group x time interaction for objectively measured sleep fragmentation (5.01; p&lt; 0.01) and also for Pittsburgh Sleep Quality Index (PSQI) score (p= 0.03), such that the INT: 1) maintained sleep fragmentation while CON worsened at 12 weeks (p&lt; 0.01); and 2) had improved PSQI score compared to CON at both 12 weeks (p&lt; 0.01) and 24 weeks (p= 0.04). Our results provide novel evidence that a multimodal personalized chronotherapy approach may promote both objective and subjective aspects of sleep quality in older adults with MCI.

The effect of group exercises on balance, mobility, and depressive symptoms in older adults with mild cognitive impairment: a randomized controlled trial

2018 ◽  
Vol 33 (3) ◽  
pp. 439-449 ◽  
Author(s):  
Chandra da Silveira Langoni ◽  
Thais de Lima Resende ◽  
Andressa Bombardi Barcellos ◽  
Betina Cecchele ◽  
Juliana Nunes da Rosa ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Depressive Symptoms ◽  
Mild Cognitive Impairment ◽  
Intervention Group ◽  
Depression Scale ◽  
Community Dwelling ◽  
Effect Sizes ◽  
Control Group ◽  
Community Dwelling Older Adults

Objective: To determine the effects of group exercises on balance, mobility, and depressive symptoms in community-dwelling older adults with mild cognitive impairment. Design: Single blinded, randomized, matched pairs clinical trial. Setting: Four primary healthcare units. Subjects: Fifty-two sedentary subjects with mild cognitive impairment were paired (age, sex, body mass index, and Addenbrooke’s Cognitive Examination Revised score), tested, and then randomized into an intervention group ( n = 26) and a control group ( n = 26). Intervention: The intervention group performed strength (ankle weights, elastic bands, and dumbbells) and aerobic exercises (walking) in their communities’ public spaces, twice a week (60 minutes each), during 24 weeks. The control group maintained its usual routine. Main measures: Balance (Berg Balance Scale (BBS)), mobility (Timed Up and Go Test (TUG)), and depressive symptoms (Geriatric Depression Scale-15) were assessed before and after the intervention. Results: Before the intervention, the two groups did not differ statistically. After, the intervention group showed significant improvement ( P < 0.05) in balance (before: 53 ± 3; after: 55.1 ± 1.1 points), mobility (before: 10.7 ± 2.9 seconds; after: 8.3 ± 2 seconds), and depressive symptoms (median punctuation (interquartile range) before: 4 (1.8–6); after: 2.5 (1–4)). The control group presented a significant increase in their depressive symptoms (median before: 3.5 (2–7.3); after: 4 (2–5.3)), while their balance and mobility showed no significant modification. Small effect sizes were observed in the intervention group and control group depressive symptoms, as well as in the control group’s mobility and balance. Large effect sizes were observed the intervention group’s mobility and balance. Conclusion: Group exercises improved balance, mobility, and depressive symptoms in community-dwelling older adults with mild cognitive impairment.

Effects of virtual reality-based spatial cognitive training on hippocampal function of older adults with mild cognitive impairment

2020 ◽  
pp. 1-7
Author(s):  
Jin-Hyuck Park
Keyword(s):  
Older Adults ◽  
Virtual Reality ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Episodic Memory ◽  
Spatial Cognition ◽  
Cognitive Training ◽  
Verbal Learning ◽  
Cognitive Intervention ◽  
Hippocampal Function

ABSTRACT Background: To date, there is a controversy on effects of cognitive intervention to maintain or improve hippocampal function for older adults with mild cognitive impairment (MCI). Objective: The main objective of this study was to exam effects of virtual reality-based spatial cognitive training (VR-SCT) using VR on hippocampal function of older adults with MCI. Method: Fifty-six older adults with MCI were randomly allocated to the experimental group (EG) that received the VR-SCT or the waitlist control group (CG) for a total of 24 sessions. To investigate effects of the VR-SCT on spatial cognition and episodic memory, the Weschsler Adult Intelligence Scale-Revised Block Design Test (WAIS-BDT) and the Seoul Verbal Learning Test (SVLT) were used. Results: During the sessions, the training performances gradually increased (p < .001). After the intervention, the EG showed significant greater improvements in the WAIS-BDT (p < .001, η2 = .667) and recall of the SVLT (p < .05, η2 =.094) compared to the CG but in recognition of the SVLT (p > .05, η2 =.001). Conclusion: These results suggest that the VR-SCT might be clinically beneficial to enhance spatial cognition and episodic memory of older adults with MCI.

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