scholarly journals Manual Correction of Voxel Misclassifications in Mesiotemporal Structures Does Not Alter Brain–Behavioral Results in an Episodic Memory Task

2021 ◽  
Vol 10 (21) ◽  
pp. 4869
Author(s):  
Francina Hartmann ◽  
Julia Reinhardt ◽  
Christoph Stippich ◽  
Sabine Krumm
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Episodic Memory ◽  
Grey Matter ◽  
Memory Performance ◽  
Neuropsychological Testing ◽  
Memory Task ◽  
Disease Spectrum ◽  
Imaging Results ◽  
Manual Correction

Voxel-based morphometry (VBM) is an established method for assessing grey matter volumes across the brain. The quality of magnetic resonance imaging (MRI) and the chosen data preprocessing steps can affect the outcome of VBM analyses. We recognized a lack of publicly available and commonly used protocols, which indicates that standardized and optimized preprocessing protocols are needed. This paper focuses on the time- and resource-consuming manual correction of misclassifications of grey matter voxels in cortical structures important in Alzheimer’s dementia. A total of 126 individuals, including 63 patients with very early Alzheimer’s disease and 63 cognitively normal participants, received thorough neuropsychological testing and 3-Tesla MRI. Automated preprocessing of T1 MPRAGE images was performed, and misclassifications of grey matter voxels were manually identified and corrected. In a second run, the manual correction step was skipped. Multiple regression analyses using DARTEL in SPM8 were then conducted with the manually corrected and uncorrected sample, respectively. Manual correction of voxel misclassifications did not have a major impact on the correlation between episodic memory performance and structural brain imaging results. We conclude that, although performing all preprocessing steps remains the gold standard, skipping manual correction of voxel misclassifications is permitted when investigating populations on the Alzheimer’s disease spectrum.

Impact of Comorbid Depression on Serial Position Effects in Alzheimer’s Disease

GeroPsych ◽  
2014 ◽  
Vol 27 (4) ◽  
pp. 161-169 ◽  
Author(s):  
Nienke A. Hofrichter ◽  
Sandra Dick ◽  
Thomas G. Riemer ◽  
Carsten Schleussner ◽  
Monique Goerke ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Serial Position ◽  
Episodic Memory ◽  
Memory Performance ◽  
Memory Function ◽  
Word List ◽  
Position Effects ◽  
Serial Position Effects ◽  
List Memory

Hippocampal dysfunction and deficits in episodic memory have been reported for both Alzheimer’s disease (AD) and major depressive disorder (MDD). Primacy performance has been associated with hippocampus-dependent episodic memory, while recency may reflect working memory performance. In this study, serial position profiles were examined in a total of 73 patients with MDD, AD, both AD and MDD, and healthy controls (HC) by means of CERAD-NP word list memory. Primacy performance was most impaired in AD with comorbid MDD, followed by AD, MDD, and HC. Recency performance, on the other hand, was comparable across groups. These findings indicate that primacy in AD is impaired in the presence of comorbid MDD, suggesting additive performance decrements in this specific episodic memory function.

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 Association of neuroinflammation with episodic memory: a [11C]PBR28 PET study in cognitively discordant twin pairs

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Noora Lindgren ◽  
Jouni Tuisku ◽  
Eero Vuoksimaa ◽  
Semi Helin ◽  
Mira Karrasch ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Episodic Memory ◽  
Memory Performance ◽  
Disease Process ◽  
Standardized Uptake Value ◽  
Weighted Average ◽  
Translocator Protein ◽  
Interindividual Variation ◽  
Protein Genotype

Abstract Alzheimer’s disease is associated with chronic response of innate immune system, referred as neuroinflammation. PET radioligands binding to the 18 kDa translocator protein are potential biomarkers of neuroinflammation. Translocator protein PET studies in mild cognitive impairment and Alzheimer’s disease have indicated controversial results, possibly reflecting interindividual variation and heterogeneity of study populations. We controlled for genetic and environmental effects by studying twin pairs discordant for episodic memory performance. Episodic memory impairment is a well-known cognitive hallmark of early Alzheimer’s disease process. Eleven same-sex twin pairs (four monozygotic pairs, six female pairs, age 72–77 years) underwent [11C]N-acetyl-N-(2-methoxybenzyl)-2-phenoxy-5-pyridinamine ([11C]PBR28) PET imaging, structural magnetic resonance imaging and neuropsychological testing in 2014–17. Main PET outcome was the volume-weighted average standardized uptake value of cortical regions vulnerable to Alzheimer’s disease pathology. Ten pairs were discordant for episodic memory performance. In the eight pairs with identical translocator protein genotype, twins with poorer episodic memory had ∼20% higher cortical [11C]PBR28 binding compared with their better-performing co-twins (mean intra-pair difference 0.21 standardized uptake value, 95% confidence interval 0.05–0.37, P = 0.017). The result remained the same when including all discordant pairs and controlling for translocator protein genotype. Increased translocator protein PET signal suggests that increased microglial activation is associated with poorer episodic memory performance. Twins with worse episodic memory performance compared with their co-twins had on average 20% higher uptake of the neuroinflammatory marker translocator protein PET tracer 11[11C]PBR28. The findings support a negative association between neuroinflammation and episodic memory and the use of translocator protein positron emission tomography as a useful indicator of Alzheimer’s disease process.

scholarly journals VAMP2 is a cerebrospinal fluid marker of selective hippocampal synapse loss and episodic memory performance in Alzheimer’s disease

2020 ◽  
Vol 16 (S4) ◽  
Author(s):  
Olivia Belbin ◽  
Beatriu Molina ◽  
Raúl Núñez‐Llaves ◽  
Julie Goossens ◽  
Nele Dewit ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cerebrospinal Fluid ◽  
Episodic Memory ◽  
Memory Performance ◽  
Synapse Loss

scholarly journals APOE4 status is related to differences in memory-related brain function in asymptomatic older adults: Baseline analysis of the PREVENT-AD task fMRI dataset

2019 ◽  
Author(s):  
Sheida Rabipour ◽  
Sricharana Rajagopal ◽  
Elsa Yu ◽  
Stamatoula Pasvanis ◽  
John Breitner ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Episodic Memory ◽  
Brain Activity ◽  
Memory Performance ◽  
Group Differences ◽  
Parental History ◽  
History Of ◽  
Spatial Source

AbstractEpisodic memory decline is one of the earliest symptoms of late-onset Alzheimer’s Disease (AD) and older adults with the apolipoprotein E e4 (+APOE4) genetic risk factor for AD may exhibit altered patterns of memory-related brain activity years prior to initial symptom onset. In the current study we report the baseline episodic memory task fMRI results from the PRe-symptomatic EValuation of Experimental or Novel Treatments for Alzheimer’s Disease (PREVENT-AD) study in Montreal, Canada, in which 327 healthy older adults, within 15 years of the parent’s conversion to AD, were scanned. During the task fMRI protocol volunteers were scanned as they encoded and retrieved object-location spatial source associations. The task was designed to discriminate between brain activity related to successful spatial source recollection and failures in spatial source recollection, with memory for only item (object) memory. Multivariate task-related partial least squares (task PLS) was used to test the hypothesis that +APOE4 adults with a family history of AD would exhibit altered patterns of brain activity in the recollection-related memory network, comprised of medial frontal, parietal and medial temporal cortices, compared to APOE4 non-carriers (-APOE4). We also tested for group differences in the correlation between event-related brain activity and memory performance in +APOE4 compared to -APOE4 adults using behavioral-PLS (B-PLS). We found group similarities in memory performance and in task-related brain activity in the recollection network. However, the B-PLS results indicated there were group differences in brain activity-behavior correlations in ventral occipito-temporal, medial temporal, and medial prefrontal cortices during episodic encoding. These findings are consistent with previous literature on the influence of APOE4 on brain activity and provide new perspective on potential gene-based differences in brain-behavior relationships in people with parental history of AD. Future research should further investigate the potential to distinguish risk of AD development based on memory performance and associated patterns of brain activity.

scholarly journals Deficits in Mitochondrial Spare Respiratory Capacity Contribute to the Neuropsychological Changes of Alzheimer’s Disease

2020 ◽  
Vol 10 (2) ◽  
pp. 32 ◽  
Author(s):  
Simon M. Bell ◽  
Matteo De Marco ◽  
Katy Barnes ◽  
Pamela J. Shaw ◽  
Laura Ferraiuolo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Semantic Memory ◽  
Grey Matter ◽  
Neuropsychological Testing ◽  
Structural Mri ◽  
Respiratory Capacity ◽  
Immediate Recall ◽  
Extracellular Lactate ◽  
Neuropsychological Changes

Alzheimer’s disease (AD) is diagnosed using neuropsychological testing, supported by amyloid and tau biomarkers and neuroimaging abnormalities. The cause of neuropsychological changes is not clear since they do not correlate with biomarkers. This study investigated if changes in cellular metabolism in AD correlate with neuropsychological changes. Fibroblasts were taken from 10 AD patients and 10 controls. Metabolic assessment included measuring total cellular ATP, extracellular lactate, mitochondrial membrane potential (MMP), mitochondrial respiration and glycolytic function. All participants were assessed with neuropsychological testing and brain structural MRI. AD patients had significantly lower scores in delayed and immediate recall, semantic memory, phonemic fluency and Mini Mental State Examination (MMSE). AD patients also had significantly smaller left hippocampal, left parietal, right parietal and anterior medial prefrontal cortical grey matter volumes. Fibroblast MMP, mitochondrial spare respiratory capacity (MSRC), glycolytic reserve, and extracellular lactate were found to be lower in AD patients. MSRC/MMP correlated significantly with semantic memory, immediate and delayed episodic recall. Correlations between MSRC and delayed episodic recall remained significant after controlling for age, education and brain reserve. Grey matter volumes did not correlate with MRSC/MMP. AD fibroblast metabolic assessment may represent an emergent disease biomarker of AD.

scholarly journals White matter disruption at the prodromal stage of Alzheimer's disease: Relationships with hippocampal atrophy and episodic memory performance

2015 ◽  
Vol 7 ◽  
pp. 482-492 ◽  
Author(s):  
Florence Rémy ◽  
Nathalie Vayssière ◽  
Laure Saint-Aubert ◽  
Emmanuel Barbeau ◽  
Jérémie Pariente
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
White Matter ◽  
Episodic Memory ◽  
Memory Performance ◽  
Hippocampal Atrophy ◽  
Prodromal Stage

IC-P-122: Association of hippocampus head diffusivity and episodic memory performance in early Alzheimer's disease

2009 ◽  
Vol 5 (4S_Part_2) ◽  
pp. P50-P50
Author(s):  
Andreas Fellgiebel ◽  
Igor Yakushev ◽  
Ingrid Schermuly ◽  
Markus Lorscheider ◽  
Isabel Keller ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Episodic Memory ◽  
Memory Performance ◽  
Early Alzheimer’S Disease
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