scholarly journals Left frontal cortex connectivity underlies cognitive reserve in prodromal Alzheimer disease

Neurology ◽  
2017 ◽  
Vol 88 (11) ◽  
pp. 1054-1061 ◽  
Author(s):  
Nicolai Franzmeier ◽  
Marco Duering ◽  
Michael Weiner ◽  
Martin Dichgans ◽  
Michael Ewers ◽  
...  
Keyword(s):  
Alzheimer Disease ◽  
Linear Regression ◽  
Episodic Memory ◽  
Frontal Cortex ◽  
Fdg Pet ◽  
Cognitive Reserve ◽  
Early Stage ◽  
Memory Performance ◽  
Amyloid Pet ◽  
Regression Analyses

Objective:To test whether higher global functional connectivity of the left frontal cortex (LFC) in Alzheimer disease (AD) is associated with more years of education (a proxy of cognitive reserve [CR]) and mitigates the association between AD-related fluorodeoxyglucose (FDG)-PET hypometabolism and episodic memory.Methods:Forty-four amyloid-PET–positive patients with amnestic mild cognitive impairment (MCI-Aβ+) and 24 amyloid-PET–negative healthy controls (HC) were included. Voxel-based linear regression analyses were used to test the association between years of education and FDG-PET in MCI-Aβ+, controlled for episodic memory performance. Global LFC (gLFC) connectivity was computed through seed-based resting-state fMRI correlations between the LFC (seed) and each voxel in the gray matter. In linear regression analyses, education as a predictor of gLFC connectivity and the interaction of gLFC connectivity × FDG-PET hypometabolism on episodic memory were tested.Results:FDG-PET metabolism in the precuneus was reduced in MCI-Aβ+ compared to HC (p = 0.028), with stronger reductions observed in MCI-Aβ+ with more years of education (p = 0.006). In MCI-Aβ+, higher gLFC connectivity was associated with more years of education (p = 0.021). At higher levels of gLFC connectivity, the association between precuneus FDG-PET hypometabolism and lower memory performance was attenuated (p = 0.027).Conclusions:Higher gLFC connectivity is a functional substrate of CR that helps to maintain episodic memory relatively well in the face of emerging FDG-PET hypometabolism in early-stage AD.

Hemisphere-specific Episodic Memory Networks in the Human Brain: A Correlation Study between Intracarotid Amobarbital Test and [18F]FDG-PET

2009 ◽  
Vol 21 (3) ◽  
pp. 605-622 ◽  
Author(s):  
Nozomi Akanuma ◽  
Laurence J. Reed ◽  
Paul K. Marsden ◽  
Jozeph Jarosz ◽  
Naoto Adachi ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Frontal Cortex ◽  
Fdg Pet ◽  
Cerebral Metabolism ◽  
Memory Performance ◽  
Anterior Cingulate ◽  
Precentral Gyrus ◽  
Fdg Uptake ◽  
The Right ◽  
Intracarotid Amobarbital Test

The purpose of the present study was to explore the brain regions involved in human episodic memory by correlating unilateral memory performance estimated by the intracarotid amobarbital test (IAT) and interictal cerebral metabolism measured by [18F]fluorodeoxyglucose positron emission tomography ([18F]FDG-PET). Using this method, regional alterations of cerebral metabolism associated with epilepsy pathophysiology are used to predict hemisphere-specific episodic memory function, hence, investigate the differential distribution of memory in each hemisphere. Sixty-two patients with unilateral temporal lobe epilepsy (35 left and 27 right) were studied using [18F]FDG-PET with complementary voxel-based statistical parametric mapping (SPM) and region-of-interest (ROI) methods of analysis. Positive regression was analyzed in SPM with a series of different thresholds (p = .001, .01 or .05) with a correction to 100 voxels. IAT memory performance in which left hemisphere was tested by right-sided injection of amobarbital correlated with [18F]FDG uptake in left lateral and medial temporal regions, and in the left ventrolateral frontal cortex. Right IAT memory performance correlated with [18F]FDG uptake in the right inferior parietal lobule, right dorsolateral frontal cortex, right precentral gyrus, and caudal portion of the right anterior cingulate cortex. ROI analysis corroborated these results. Analyses carried out separately in patients with left (n = 50) and nonleft (n = 12) dominance for language showed that in the nonleft dominant group, right IAT scores correlated with right fronto-temporal regions, whereas left total memory scores correlated with left lateral and medial temporal regions. The findings indicate that (i) episodic memory is subserved by more widespread cortical regions beyond the core mesiotemporal lobe memory structures; (ii) there are different networks functional in the two hemispheres; and (iii) areas involved in memory may be different between patients with left and nonleft dominance for language, particularly in the right hemisphere.

Quality of Life of People With Alzheimer Disease: Comparison Between Dyads Degree of Kinship

2020 ◽  
pp. 089198872091552
Author(s):  
Marcela Moreira Lima Nogueira ◽  
Jose Pedro Simões Neto ◽  
Marcia Cristina Nascimento Dourado
Keyword(s):  
Quality Of Life ◽  
Alzheimer Disease ◽  
Linear Regression ◽  
Multivariate Regression ◽  
Self Report ◽  
Regression Analyses ◽  
Burden Of Care ◽  
Significant Difference ◽  
Better Than

The quality of life (QoL) of people with Alzheimer disease (PwAD) may be influenced by the type of relationship between carer and the PwAD. Dyads of 98 PwAD/carers (N = 49 spouse-carers; N = 49 nonspouses carers) were measured about QoL, cognition, dementia severity, awareness of disease, functionality, depression, anxiety, and burden of care. Univariate and multivariate regression analyses were conducted to identify the factors that influenced the spouse and nonspouse self-report PwAD QoL (PQOL) and to compare carers’ ratings of PwAD QoL (C-PQOL). The total score of QoL for spouse and nonspouse PwAD showed no significant difference ( P = .29). The linear regression demonstrated that higher awareness of disease was significantly related to spouse PQOL ( P = .001). Nonspouse PQOL was negatively related to lower depression ( P = .007). The total score of QoL for spouse and nonspouse C-PQOL showed no significant difference ( P = .14). The linear regression demonstrated that depression of spouse-PwAD ( P < .001) and burden of care ( P = .001) were negatively related to spouse-dyads’ C-PQOL. The nonspouse-dyads C-PQOL was negatively related to depression of nonspouse-PwAD ( P < .001), awareness of disease ( P = .001), and the mood of the carer ( P = .01). Spouse and nonspouse PwAD evaluate PQOL better than carers (C-PQOL). No significant difference was found in the total PQOL and C-PQOL of spouse and nonspouse, but dyads evaluated differently about what is important to assess QoL.

scholarly journals Quantifying Cognitive Reserve in Older Adults by Decomposing Episodic Memory Variance: Replication and Extension

2013 ◽  
Vol 19 (8) ◽  
pp. 854-862 ◽  
Author(s):  
Laura B. Zahodne ◽  
Jennifer J. Manly ◽  
Adam M. Brickman ◽  
Karen L. Siedlecki ◽  
Charles DeCarli ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Reading Ability ◽  
Cognitive Reserve ◽  
Negative Impact ◽  
Memory Performance ◽  
White Matter Hyperintensity ◽  
Residual Variance ◽  
Brain Pathology ◽  
Language Abilities ◽  
Age Related

AbstractThe theory of cognitive reserve attempts to explain why some individuals are more resilient to age-related brain pathology. Efforts to explore reserve have been hindered by measurement difficulties. Reed et al. (2010) proposed quantifying reserve as residual variance in episodic memory performance that remains after accounting for demographic factors and brain pathology (whole brain, hippocampal, and white matter hyperintensity volumes). This residual variance represents the discrepancy between an individual's predicted and actual memory performance. The goals of the present study were to extend these methods to a larger, community-based sample and to investigate whether the residual reserve variable is explained by age, predicts longitudinal changes in language, and predicts dementia conversion independent of age. Results support this operational measure of reserve. The residual reserve variable was associated with higher reading ability, lower likelihood of meeting criteria for mild cognitive impairment, lower odds of dementia conversion independent of age, and less decline in language abilities over 3 years. Finally, the residual reserve variable moderated the negative impact of memory variance explained by brain pathology on language decline. This method has the potential to facilitate research on the mechanisms of cognitive reserve and the efficacy of interventions designed to impart reserve. (JINS, 2013, 19, 1–9)

scholarly journals Influence of tau PET, amyloid PET, and hippocampal volume on cognition in Alzheimer disease

Neurology ◽  
2018 ◽  
Vol 91 (9) ◽  
pp. e859-e866 ◽  
Author(s):  
Andrew J. Aschenbrenner ◽  
Brian A. Gordon ◽  
Tammie L.S. Benzinger ◽  
John C. Morris ◽  
Jason J. Hassenstab
Keyword(s):  
Alzheimer Disease ◽  
Executive Functioning ◽  
Episodic Memory ◽  
Cognitive Decline ◽  
Hippocampal Volume ◽  
Cognitive Change ◽  
Pet Scan ◽  
Cognitive Domain ◽  
Amyloid Pet ◽  
Tau Pet

ObjectiveTo examine the independent and interactive influences of neuroimaging biomarkers on retrospective cognitive decline.MethodsA total of 152 middle-aged and older adult participants with at least 2 clinical and cognitive assessments, a Clinical Dementia Rating score of 0 or 0.5, and a flortaucipir (18F-AV-1451) tau PET scan, a florbetapir (18F-AV-45) amyloid PET scan, and a structural MRI scan were recruited from the Knight Alzheimer Disease Research Center at Washington University in St. Louis. Cognition was assessed with standard measures reflecting episodic memory, executive functioning, semantic fluency, and processing speed.ResultsResults from retrospective longitudinal analyses showed that each biomarker had a univariate association with the global cognitive composite; however, when each marker was analyzed in a single statistical model, only tau was a significant predictor of global cognitive decline. There was an interaction between tau and amyloid such that tau-related cognitive decline was worse in individuals with high amyloid. There was also an interaction with hippocampal volume indicating that individuals with high levels of all 3 pathologies exhibited the greatest declines in cognition. Additional analyses within each cognitive domain indicated that tau had the largest negative influence on tests of episodic memory and executive functioning.ConclusionsTogether, these results suggest that increasing levels of tau most consistently relate to declines in cognition preceding biomarker collection. These findings support models of Alzheimer disease (AD) staging that suggest that elevated β-amyloid alone may be insufficient to produce cognitive change in individuals at risk for AD and support the use of multiple biomarkers to stage AD progression.

scholarly journals Cognitive reserve associated with FDG-PET in preclinical Alzheimer disease

Neurology ◽  
2013 ◽  
Vol 80 (13) ◽  
pp. 1194-1201 ◽  
Author(s):  
M. Ewers ◽  
P. S. Insel ◽  
Y. Stern ◽  
M. W. Weiner ◽  
Keyword(s):  
Alzheimer Disease ◽  
Fdg Pet ◽  
Cognitive Reserve

Amyloid PET Screening for Enrichment of Early-Stage Alzheimer Disease Clinical Trials

2016 ◽  
Vol 30 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Jeff Sevigny ◽  
Joyce Suhy ◽  
Ping Chiao ◽  
Tianle Chen ◽  
Gregory Klein ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Alzheimer Disease ◽  
Early Stage ◽  
Amyloid Pet

Perfusion SPECT and FDG-PET

2011 ◽  
Vol 23 (S2) ◽  
pp. S25-S31 ◽  
Author(s):  
Karl Herholz
Keyword(s):  
Fdg Pet ◽  
Clinical Symptoms ◽  
Early Stage ◽  
Clinical Stage ◽  
Cortical Atrophy ◽  
Association Cortex ◽  
Amyloid Pet ◽  
Variable Degree ◽  
Multicenter Studies ◽  
Perfusion Spect

ABSTRACTBoth perfusion SPECT and FDG-PET provide images that closely reflect neuronal activity. There is a characteristic regional impairment in Alzheimer's disease (AD) that involves mainly the temporo-parietal association cortices, mesial temporal structures and to a more variable degree also the frontal association cortex. This pattern of functional impairment can provide a biomarker for diagnosis of AD and other neurodegenerative dementias at the clinical stage of mild cognitive impairment, and for monitoring of progression. FDG-PET is quantitatively more accurate and thus better suited to multicenter studies than perfusion SPECT. Regional metabolic and blood flow changes are closely related to clinical symptoms, and most areas involved in these changes will also develop significant cortical atrophy. FDG-PET is complementary to amyloid PET, which targets a molecular marker that does not have a close relation to current symptoms. Current restrictions in the availability and cost of FDG-PET are being reduced, as oncological FDG-PET is being adopted as a standard clinical service in most countries. Limitations in the availability of trained staff should be overcome by training programs set up by professional organizations. Against the background of the development of new criteria for diagnosing AD before the onset of dementia, FDG-PET is expected to play an increasing role in diagnosing patients at an early stage of AD and in clinical trials of drugs aimed at preventing or delaying the onset of dementia.

The effects of different proxies of cognitive reserve on episodic memory performance: aging study in Iran

2019 ◽  
Vol 32 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Neda Mohammad ◽  
Tara Rezapour ◽  
Reza Kormi-Nouri ◽  
Ehsan Abdekhodaie ◽  
Atieh M. Ghamsari ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Educational Level ◽  
Successful Aging ◽  
Healthy Aging ◽  
Cognitive Reserve ◽  
Memory Performance ◽  
Cross Sectional Study ◽  
Educational Training ◽  
Cross Sectional ◽  
Continuous Type

ABSTRACTObjective:The main aim of the present study is to investigate the association between different measures of cognitive reserve including bilingualism, mental activities, type of education (continuous versus distributed), age, educational level, and episodic memory in a healthy aging sample.Methods:Four hundred and fifteen participants aged between 50 and 83 years participated in this cross-sectional study and were assessed with the Psychology Experimental Building Language Test battery tapping episodic memory. Demographic variables were collected from a questionnaire designed by the research team.Results:Compared to participants with continuous type of education, those with distributed type performed better in tests of episodic memory, while no differences were found between bilingual and monolingual participants. We additionally found that age negatively predicts episodic memory, whereas playing mind teasers and educational level have positive relationships with episodic memory.Conclusions:Our results indicate that higher cognitive reserve, as measured by distributed educational training, higher level of education, and doing regular mental activities, is associated with better performance on episodic memory tasks in older adults. These results were discussed in connection with successful aging and protection against memory decline with aging.

scholarly journals Left frontal connectivity attenuates the adverse effect of entorhinal tau pathology on memory

Neurology ◽  
2019 ◽  
Vol 93 (4) ◽  
pp. e347-e357 ◽  
Author(s):  
Julia Neitzel ◽  
Nicolai Franzmeier ◽  
Anna Rubinski ◽  
Michael Ewers ◽  
Keyword(s):  
Adverse Effect ◽  
Free Recall ◽  
Frontal Cortex ◽  
Resting State ◽  
Early Stage ◽  
Recall Performance ◽  
Resting State Fmri ◽  
Amyloid Pet ◽  
Tau Pathology ◽  
Tau Pet

ObjectiveTo investigate whether higher global left frontal cortex (gLFC) connectivity, a putative neural substrate of cognitive reserve, attenuates the effect of entorhinal tau PET levels on episodic memory in older adults.MethodsCross-sectional 18F-AV-1451 PET (to assess tau pathology), 18F-AV-45 or 18F-BAY94-9172 PET (to assess β-amyloid [Aβ]), and resting-state fMRI were obtained in 125 elderly participants from the Alzheimer's Neuroimaging Initiative, including 82 cognitively normal participants (amyloid PET-positive [Aβ+], n = 27) and 43 patients with amnestic mild cognitive impairment (Aβ+ = 15). Resting-state fMRI gLFC connectivity was computed for each participant as the average functional connectivity between the left frontal cortex (LFC) (seed) and each remaining voxel in the gray matter. As a measure of tau pathology, we assessed the mean tau PET uptake in the entorhinal cortex. In linear mixed-effects regression analysis, we tested the interaction term gLFC connectivity × entorhinal tau PET on delayed free recall performance. In addition, we assessed whether higher connectivity of the whole frontoparietal control network (FPCN), of which the LFC is a major hub, is associated with reserve.ResultsHigher entorhinal tau PET was strongly associated with poorer delayed free recall performance (β/SE = −0.49/0.07, p < 0.001). A significant gLFC connectivity × entorhinal tau PET interaction was found (β/SE = 0.19/0.06, p = 0.003), such that at higher levels of gLFC connectivity, the decrease in memory score per unit of entorhinal tau PET was attenuated. The FPCN connectivity × tau interaction was also significant (β/SE = 0.10/0.04, p = 0.012).ConclusionBoth gLFC and FPCN connectivity are associated with higher resilience against the adverse effect of early-stage entorhinal tau pathology on memory performance.

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