scholarly journals Abnormal Temporal Lobe Response in Alzheimer's Disease during Cognitive Processing as Measured by 11C-2-Deoxy-D-Glucose and PET

1987 ◽  
Vol 7 (2) ◽  
pp. 248-251 ◽  
Author(s):  
J. D. Miller ◽  
M. J. de Leon ◽  
S. H. Ferris ◽  
A. Kluger ◽  
A. E. George ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Processing ◽  
Temporal Lobe ◽  
Verbal Memory ◽  
Right Hemisphere ◽  
Memory Performance ◽  
Memory Task ◽  
Metabolic Rates ◽  
Positron Emission

Elderly controls and probable Alzheimer's disease patients underwent serial positron emission tomography (PET) studies during a baseline condition and while performing a verbal memory task. for the temporal lobes, all 7 Alzheimer patients demonstrated a relative shift in glucose metabolic rates to the right hemisphere during the memory condition relative to baseline, and 5 of 7 controls showed a shift to the left hemisphere. Baseline absolute regional metabolic rates replicate previous findings and were somewhat less useful than the memory challenge in differentiating patients from controls. These results indicate that a temporal lobe abnormality in Alzheimer's disease is related to memory performance.

scholarly journals Anhedonia in Semantic Dementia—Exploring Right Hemispheric Contributions to the Loss of Pleasure

2021 ◽  
Vol 11 (8) ◽  
pp. 998
Author(s):  
Siobhán R. Shaw ◽  
Hashim El-Omar ◽  
Siddharth Ramanan ◽  
Olivier Piguet ◽  
Rebekah M. Ahmed ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Temporal Lobe ◽  
Rating Scale ◽  
Right Hemisphere ◽  
Semantic Knowledge ◽  
Semantic Dementia ◽  
Anterior Cingulate ◽  
Functional Impairments ◽  
Lobe Atrophy

Semantic dementia (SD) is a younger-onset neurodegenerative disease characterised by progressive deterioration of the semantic knowledge base in the context of predominantly left-lateralised anterior temporal lobe (ATL) atrophy. Mounting evidence indicates the emergence of florid socioemotional changes in SD as atrophy encroaches into right temporal regions. How lateralisation of temporal lobe pathology impacts the hedonic experience in SD remains largely unknown yet has important implications for understanding socioemotional and functional impairments in this syndrome. Here, we explored how lateralisation of temporal lobe atrophy impacts anhedonia severity on the Snaith–Hamilton Pleasure Scale in 28 SD patients presenting with variable right- (SD-R) and left-predominant (SD-L) profiles of temporal lobe atrophy compared to that of 30 participants with Alzheimer’s disease and 30 healthy older Control participants. Relative to Controls, SD-R but not SD-L or Alzheimer’s patients showed clinically significant anhedonia, representing a clear departure from premorbid levels. Overall, anhedonia was more strongly associated with functional impairment on the Frontotemporal Dementia Functional Rating Scale and motivational changes on the Cambridge Behavioural Inventory in SD than in Alzheimer’s disease patients. Voxel-based morphometry analyses revealed that anhedonia severity correlated with reduced grey matter intensity in a restricted set of regions centred on right orbitofrontal and temporopolar cortices, bilateral posterior temporal cortices, as well as the anterior cingulate gyrus and parahippocampal gyrus, bilaterally. Finally, regression and mediation analysis indicated a unique role for right temporal lobe structures in modulating anhedonia in SD. Our findings suggest that degeneration of predominantly right-hemisphere structures deleteriously impacts the capacity to experience pleasure in SD. These findings offer important insights into hemispheric lateralisation of motivational disturbances in dementia and suggest that anhedonia may emerge at different timescales in the SD disease trajectory depending on the integrity of the right hemisphere.

Subjective Cognitive Decline and its Relation to Verbal Memory and Sex in Cognitively Unimpaired Individuals from a Colombian Cohort with Autosomal-Dominant Alzheimer’s Disease

2021 ◽  
pp. 1-9
Author(s):  
Jairo E. Martinez ◽  
Enmanuelle Pardilla-Delgado ◽  
Edmarie Guzmán-Vélez ◽  
Clara Vila-Castelar ◽  
Rebecca Amariglio ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Sex Differences ◽  
Cognitive Decline ◽  
Verbal Memory ◽  
Autosomal Dominant ◽  
Memory Performance ◽  
Subjective Cognitive Decline ◽  
Mutation Carriers ◽  
Study Partner

Abstract Objective: Subjective Cognitive Decline (SCD) may be an early indicator of risk for Alzheimer’s disease (AD). Findings regarding sex differences in SCD are inconsistent. Studying sex differences in SCD within cognitively unimpaired individuals with autosomal-dominant AD (ADAD), who will develop dementia, may inform sex-related SCD variations in preclinical AD. We examined sex differences in SCD within cognitively unimpaired mutation carriers from the world’s largest ADAD kindred and sex differences in the relationship between SCD and memory performance. Methods: We included 310 cognitively unimpaired Presenilin-1 (PSEN-1) E280A mutation carriers (51% females) and 1998 noncarrier family members (56% females) in the study. Subjects and their study partners completed SCD questionnaires and the CERAD word list delayed recall test. ANCOVAs were conducted to examine group differences in SCD, sex, and memory performance. In carriers, partial correlations were used to examine associations between SCD and memory performance covarying for education. Results: Females in both groups had greater self-reported and study partner-reported SCD than males (all p < 0.001). In female mutation carriers, greater self-reported (p = 0.02) and study partner-reported SCD (p < 0.001) were associated with worse verbal memory. In male mutation carriers, greater self-reported (p = 0.03), but not study partner-reported SCD (p = 0.11) was associated with worse verbal memory. Conclusions: Study partner-reported SCD may be a stronger indicator of memory decline in females versus males in individuals at risk for developing dementia. Future studies with independent samples and preclinical trials should consider sex differences when recruiting based on SCD criteria.

scholarly journals Emotional Working Memory and Alzheimer’s Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Nicola Mammarella ◽  
Beth Fairfield
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Working Memory ◽  
Memory Performance ◽  
Memory Task ◽  
Emotional Information ◽  
Healthy Older Adults ◽  
Affective Stimuli ◽  
Age Related ◽  
Dementia Of Alzheimer’S Type

A number of recent studies have reported that working memory does not seem to show typical age-related deficits in healthy older adults when emotional information is involved. Differently, studies about the short-term ability to encode and actively manipulate emotional information in dementia of Alzheimer’s type are few and have yielded mixed results. Here, we review behavioural and neuroimaging evidence that points to a complex interaction between emotion modulation and working memory in Alzheimer’s. In fact, depending on the function involved, patients may or may not show an emotional benefit in their working memory performance. In addition, this benefit is not always clearly biased (e.g., towards negative or positive information). We interpret this complex pattern of results as a consequence of the interaction between multiple factors including the severity of Alzheimer’s disease, the nature of affective stimuli, and type of working memory task.

scholarly journals Lateralized memory circuit dropout in Alzheimer’s disease patients

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Ashley Tyrer ◽  
Jessica R Gilbert ◽  
Sarah Adams ◽  
Alexandra B Stiles ◽  
Azziza O Bankole ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Left Hemisphere ◽  
Explicit Memory ◽  
Empirical Bayes ◽  
Right Hemisphere ◽  
Memory Task ◽  
Recognition Task ◽  
Network Activity ◽  
Memory Circuit

Abstract Altered connectivity within neuronal networks is often observed in Alzheimer’s disease. However, delineating pro-cognitive compensatory changes from pathological network decline relies on characterizing network and task effects together. In this study, we interrogated the dynamics of occipito-temporo-frontal brain networks responsible for implicit and explicit memory processes using high-density EEG and dynamic causal modelling. We examined source-localized network activity from patients with Alzheimer’s disease (n = 21) and healthy controls (n = 21), while they performed both visual recognition (explicit memory) and implicit priming tasks. Parametric empirical Bayes analyses identified significant reductions in temporo-frontal connectivity and in subcortical visual input in patients, specifically in the left hemisphere during the recognition task. There was also slowing in frontal left hemisphere signal transmission during the implicit priming task, with significantly more distinct dropout in connectivity during the recognition task, suggesting that these network drop-out effects are affected by task difficulty. Furthermore, during the implicit memory task, increased right frontal activity was correlated with improved task performance in patients only, suggesting that right-hemisphere compensatory mechanisms may be employed to mitigate left-lateralized network dropout in Alzheimer’s disease. Taken together, these findings suggest that Alzheimer’s disease is associated with lateralized memory circuit dropout and potential compensation from the right hemisphere, at least for simpler memory tasks.

scholarly journals Hippocampal volume and retention in Alzheimer's disease

2004 ◽  
Vol 10 (4) ◽  
pp. 639-643 ◽  
Author(s):  
JOEL H. KRAMER ◽  
NORBERT SCHUFF ◽  
BRUCE R. REED ◽  
DAN MUNGAS ◽  
AN-TAO DU ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Free Recall ◽  
Verbal Memory ◽  
Memory Task ◽  
Structural Mri ◽  
Hippocampal Volume ◽  
Immediate Recall ◽  
Cortical Gray Matter

This study tested the hypothesis that the hippocampus has a relatively specific role in retaining information over delays. Thirty-seven subjects with probable Alzheimer's disease were evaluated with a verbal memory task and structural MRI. Cortical gray matter but not hippocampal volume predicted immediate free recall. In contrast, hippocampal volume was the best predictor of how well information was retained over a delay, even after controlling for levels of immediate recall. Results suggest that the role of the hippocampus is relatively specific to the consolidation of new memories. (JINS, 2004, 10, 639–643.)

scholarly journals Women can bear a bigger burden: ante- and post-mortem evidence for reserve in the face of tau

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Leonardino A Digma ◽  
John R Madsen ◽  
Robert A Rissman ◽  
Diane M Jacobs ◽  
James B Brewer ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Verbal Memory ◽  
Memory Performance ◽  
Verbal Learning ◽  
Amyloid Β ◽  
Auditory Verbal Learning Test ◽  
Logical Memory ◽  
Auditory Verbal Learning ◽  
Learning Test

Abstract In this study, we aimed to assess whether women are able to withstand more tau before exhibiting verbal memory impairment. Using data from 121 amyloid-β-positive Alzheimer’s Disease Neuroimaging Initiative participants, we fit a linear model with Rey Auditory Verbal Learning Test score as the response variable and tau-PET standard uptake value ratio as the predictor and took the residuals as an estimate of verbal memory reserve for each subject. Women demonstrated higher reserve (i.e. residuals), whether the Learning (t = 2.78, P = 0.006) or Delay (t = 2.14, P = 0.03) score from the Rey Auditory Verbal Learning Test was used as a measure of verbal memory ability. To validate these findings, we examined 662 National Alzheimer’s Coordinating Center participants with a C2/C3 score (Consortium to Establish a Registry for Alzheimer’s Disease) at autopsy. We stratified our National Alzheimer’s Coordinating Center sample into Braak 1/2, Braak 3/4 and Braak 5/6 subgroups. Within each subgroup, we compared Logical Memory scores between men and women. Men had worse verbal memory scores within the Braak 1/2 (Logical Memory Immediate: β = −5.960 ± 1.517, P &lt; 0.001, Logical Memory Delay: β = −5.703 ± 1.677, P = 0.002) and Braak 3/4 (Logical Memory Immediate: β = −2.900 ± 0.938, P = 0.002, Logical Memory Delay: β = −2.672 ± 0.955, P = 0.006) subgroups. There were no sex differences in Logical Memory performance within the Braak 5/6 subgroup (Logical Memory Immediate: β = −0.314 ± 0.328, P = 0.34, Logical Memory Delay: β = −0.195 ± 0.287, P = 0.50). Taken together, our results point to a sex-related verbal memory reserve.

scholarly journals Pathological correlates of impaired self-awareness of memory function in Alzheimer’s disease

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Geoffroy Gagliardi ◽  
Madeline Kuppe ◽  
Cristina Lois ◽  
Bernard Hanseeuw ◽  
Patrizia Vannini ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Memory Performance ◽  
Memory Function ◽  
Common Symptom ◽  
Self Awareness ◽  
Delayed Recall ◽  
Clinically Normal ◽  
Positron Emission ◽  
The Impact

Abstract Introduction Impaired self-awareness of memory function, a.k.a. anosognosia, is a common symptom in Alzheimer’s disease (AD); however, its pathological correlates remain unclear. Here, we investigated the impact of amyloid and tau on memory self-awareness. Methods Two hundred thirty-six clinically normal (N) and 102 impaired (I) participants from the ADNI cohort were included. Amyloid (global) and tau burden (in entorhinal and inferior temporal cortices) were assessed using positron emission tomography (PET). Self-awareness of memory was assessed using discrepancy indexes of subjective participant-informant ratings, as well as participant-objective scores of memory performance. Subjective and objective values were derived from the Everyday Cognition memory questionnaire and Logical Memory (delayed recall). Results Lower awareness (both methods) of memory function was associated with higher levels of pathology in the I group as compared to N. There was a significant effect of tauopathy, but not amyloidosis, on individual complaint, such that higher levels of tau associated with lower awareness. Discussion Impaired self-awareness appears progressively in the evolution of the disease related to AD biomarkers. Discordant subjective and objective measures may be important for clinical consideration.

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