Browse
Submit Data
Databases
API
Help

Dataset Information

9 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Screening for predementia AD: time-dependent operating characteristics of episodic memory tests.

ABSTRACT:

Objective

Data from the Einstein Aging Study (EAS) were used to prospectively evaluate the free recall score from the free and cued selective reminding test (FCSRT-FR) and logical memory I immediate recall (LM-IR) subtest of the Wechsler memory scale-revised for prediction of incident Alzheimer disease (AD) dementia among individuals from a community-based cohort with memory complaints.

Methods

Analyses included 854 participants, age ≥70 years, who initially had no dementia, and had memory complaints. Clinic evaluations were completed annually and AD dementia was diagnosed using standard criteria (n = 86 cases; average follow-up 4.1 years). Time-dependent receiver operating characteristic analysis was used to evaluate the prognostic ability of FCSRT-FR and LM-IR for incident AD over various durations of follow-up.

Results

For identifying those with memory complaints who will develop incident AD dementia over 2-4 years, the FCSRT-FR had better operating characteristics than LM-IR. APOE ε4 status, age, and education did not affect cut points; however, positive predictive values were higher among APOE ε4-positive individuals.

Conclusions

For follow-up intervals of 2-4 years, the FCSRT-FR is more predictive than the LM-IR for identifying individuals with memory complaints who will develop incident AD. APOE ε4 status improves positive predictive value, but does not affect the choice of optimal cuts.

SUBMITTER: Derby CA

PROVIDER: S-EPMC3656458 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Association of common KIBRA variants with episodic memory and AD risk.

Project description:KIBRA single nucleotide polymorphism (SNP) rs17070145 was identified in a genome-wide association study (GWAS) of memory performance, with some but not all follow-up studies confirming association of its T allele with enhanced memory. This allele was associated with reduced Alzheimer's disease (AD) risk in 1 study, which also found overexpression of KIBRA in memory-related brain regions of AD. We genotyped rs17070145 and 14 additional SNPs in 2571 late onset Alzheimer's disease (LOAD) patients vs. 2842 controls, including African-Americans. We found significantly reduced risk for rs17070145 T allele in the older African-American subjects (p = 0.007) and a suggestive effect in the older Caucasian series. Meta-analysis of this allele in > 8000 subjects from our and published series showed a suggestive protective effect (p = 0.07). Analysis of episodic memory in control subjects did not identify associations with rs17070145, though other SNPs showed significant associations in 1 series. KIBRA showed evidence of overexpression in the AD temporal cortex (p = 0.06) but not cerebellum. These results suggest a modest role for KIBRA as a cognition and AD risk gene, and also highlight the multifactorial complexity of its genetic associations.

| S-EPMC3065956 | biostudies-literature

Sleep-dependent facilitation of episodic memory details.

Project description:While a role for sleep in declarative memory processing is established, the qualitative nature of this consolidation benefit, and the physiological mechanisms mediating it, remain debated. Here, we investigate the impact of sleep physiology on characteristics of episodic memory using an item- (memory elements) and context- (contextual details associated with those elements) learning paradigm; the latter being especially dependent on the hippocampus. Following back-to-back encoding of two word lists, each associated with a different context, participants were assigned to either a Nap-group, who obtained a 120-min nap, or a No Nap-group. Six hours post-encoding, participants performed a recognition test involving item-memory and context-memory judgments. In contrast to item-memory, which demonstrated no between-group differences, a significant benefit in context-memory developed in the Nap-group, the extent of which correlated both with the amount of stage-2 NREM sleep and frontal fast sleep-spindles. Furthermore, a difference was observed on the basis of word-list order, with the sleep benefit and associated physiological correlations being selective for the second word-list, learned last (most proximal to sleep). These findings suggest that sleep may preferentially benefit contextual (hippocampal-dependent) aspects of memory, supported by sleep-spindle oscillations, and that the temporal order of initial learning differentially determines subsequent offline consolidation.

| S-EPMC3219667 | biostudies-literature

Effects of Antiepileptic Drug Tapering on Episodic Memory as Measured by Virtual Reality Tests.

Project description:Antiepileptic drugs impair episodic memory in patients with epilepsy, but this effect has so far only been examined with tests that do not provide first-person experience-an aspect that is crucial for episodic memory. Virtual reality techniques facilitate the development of ecologically valid tests. In the present study, we measure the effect of antiepileptic drug changes in a within-subject design using a virtual reality test in order to provide direct evidence for effects of antiepileptic drugs on episodic memory. Among 106 recruited patients, 97 participated in a virtual reality test up to six times during a 4-day hospitalization, and 78 patients underwent changes in drug load during this period. There were six parallel versions of a virtual town test, with immediate recall and delayed recall after about 12 h. The test requires recall of elements, details, sequence of experience, and egocentric and allocentric spatial memory. We determined drug load by defined daily dose, and compared test performance at lowest antiepileptic drug load to highest antiepileptic drug load. Across the six towns, performance was lower in delayed compared to immediate recall. There was an overall effect of medication when comparing patients taking vs. not taking antiepileptic drugs and/or psychoactive drugs (p = 0.005). Furthermore, there was a within-subject effect of antiepileptic drug load (p = 0.01), indicating lower test performance at higher drug load. There was no effect of gender, daytime, circadian type, depression, seizures, lesions, and epilepsy. For patients with temporal lobe epilepsy, there was no effect of lateralization. The present study provides direct evidence for episodic memory impairment due to antiepileptic drugs, suggesting that a small change in drug load can matter. This study can serve as a proof of principle for the methodology, but a larger sample is needed to examine the differential effects of individual antiepileptic drugs.

| S-EPMC7045343 | biostudies-literature

Censoring-robust time-dependent receiver operating characteristic curve estimators.

Project description:Time-dependent receiver operating characteristic curves are often used to evaluate the classification performance of continuous measures when considering time-to-event data. When one is interested in evaluating the predictive performance of multiple covariates, it is common to use the Cox proportional hazards model to obtain risk scores; however, previous work has shown that when the model is mis-specified, the estimand corresponding to the partial likelihood estimator depends on the censoring distribution. In this manuscript, we show that when the risk score model is mis-specified, the AUC will also depend on the censoring distribution, leading to either over- or under-estimation of the risk score's predictive performance. We propose the use of censoring-robust estimators to remove the dependence on the censoring distribution and provide empirical results supporting the use of censoring-robust risk scores.

| S-EPMC8671363 | biostudies-literature

Temporal unfolding of declining episodic memory on the Free and Cued Selective Reminding Test in the predementia phase of Alzheimer's disease: Implications for clinical trials.

Project description:Introduction:Free and Cued Selective Reminding Test (FCSRT) performance identifies patients with preclinical disease at elevated risk for developing Alzheimer's dementia, predicting diagnosis better than other memory tests. Methods:Based on literature mapping FCSRT performance to clinical outcomes and biological markers, and on longitudinal preclinical data from the Baltimore Longitudinal Study of Aging, we developed the Stages of Objective Memory Impairment (SOMI) model. Five sequential stages of episodic memory decline are defined by Free Recall (FR) and Total Recall (TR) score ranges and years prior to dementia diagnosis. We sought to replicate the SOMI model using longitudinal assessments of 142 Einstein Aging Study participants who developed AD over 10 years. Results:Time to diagnosis was at least seven years if FR was intact, at least four years if TR was intact, and two years if TR was impaired, consistent with SOMI model predictions. The SOMI identified incipient dementia with excellent sensitivity and specificity. Discussion:The SOMI model provides an efficient approach for clinical trial cognitive screening in advance of more costly biomarker studies and ultimately in clinical practice, and provides a vocabulary for understanding AD biomarker patterns and for re-analysis of existing clinical trial data.

| S-EPMC5852329 | biostudies-literature

Time cells in the human hippocampus and entorhinal cortex support episodic memory.

Project description:The organization of temporal information is critical for the encoding and retrieval of episodic memories. In the rodent hippocampus and entorhinal cortex, evidence accumulated over the last decade suggests that populations of "time cells" in the hippocampus encode temporal information. We identify time cells in humans using intracranial microelectrode recordings obtained from 27 human epilepsy patients who performed an episodic memory task. We show that time cell activity predicts the temporal organization of retrieved memory items. We also uncover evidence of ramping cell activity in humans, which represents a complementary type of temporal information. These findings establish a cellular mechanism for the representation of temporal information in the human brain needed to form episodic memories.

| S-EPMC7668099 | biostudies-literature

Negative Aging Stereotypes Impair Performance on Brief Cognitive Tests Used to Screen for Predementia.

Project description:ObjectivesThere is today ample evidence that negative aging stereotypes impair healthy older adults' performance on cognitive tasks. Here, we tested whether these stereotypes also decrease performance during the screening for predementia on short cognitive tests widely used in primary care.MethodAn experiment was conducted on 80 healthy older adults taking the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) under Threat or Reduced-threat condition.ResultsStereotype threat significantly impaired older adults' performance on both tests, resulting in 40% of older adults meeting the screening criteria for predementia, compared with 10% in Reduced-threat condition (MMSE and MoCA averaged).DiscussionOur research highlights the influence of aging stereotypes on short cognitive tests used to screen for predementia. It is of critical importance that physicians provide a threat-free testing environment. Further research should clarify whether this socially induced bias may also operate in secondary care by generating false positives.

| S-EPMC5926988 | biostudies-literature

Sex-dependent differences in connectivity patterns are related to episodic memory recall.

Project description:Previous studies have shown that females typically outperform males on episodic memory tasks. In this study, we investigated if (1) there are differences between males and females in their connectome characteristics, (2) if these connectivity patterns are associated with memory performance, and (3) if these brain connectome characteristics contribute to the differences in episodic memory performance between sexes. In a sample of 655 healthy young subjects (n = 391 females; n = 264 males), we derived brain network characteristics from diffusion-weighted imaging (DWI) data using models of crossing fibers within each voxel of the brain and probabilistic tractography (graph strength, shortest path length, global efficiency, and weighted transitivity). Group differences were analysed with linear models and mediation analyses were used to explore how connectivity patterns might relate to sex-dependent differences in memory performance. Our results show significant sex-dependent differences in weighted transitivity (d = 0.42), with males showing higher values. Further, we observed a negative association between weighted transitivity and memory performance (r = -0.12). Finally, these distinct connectome characteristics partially mediated the observed differences in memory performance (effect size of the indirect effect r = 0.02). Our findings indicate a higher interconnectedness in females compared to males. Additionally, we demonstrate that the sex-dependent differences in episodic memory performance can be partially explained by the differences in this connectome measure. These results further underscore the importance of sex-dependent differences in brain connectivity and their impact on cognitive function.

| S-EPMC10619411 | biostudies-literature

Delay-dependent contributions of medial temporal lobe regions to episodic memory retrieval.

Project description:The medial temporal lobes play an important role in episodic memory, but over time, hippocampal contributions to retrieval may be diminished. However, it is unclear whether such changes are related to the ability to retrieve contextual information, and whether they are common across all medial temporal regions. Here, we used functional neuroimaging to compare neural responses during immediate and delayed recognition. Results showed that recollection-related activity in the posterior hippocampus declined after a 1-day delay. In contrast, activity was relatively stable in the anterior hippocampus and in neocortical areas. Multi-voxel pattern similarity analyses also revealed that anterior hippocampal patterns contained information about context during item recognition, and after a delay, context coding in this region was related to successful retention of context information. Together, these findings suggest that the anterior and posterior hippocampus have different contributions to memory over time and that neurobiological models of memory must account for these differences.

| S-EPMC4337612 | biostudies-literature

Human intracranial high-frequency activity maps episodic memory formation in space and time.

Project description:Noninvasive neuroimaging studies have revealed a network of brain regions that activate during human memory encoding; however, the relative timing of such activations remains unknown. Here we used intracranially recorded high-frequency activity (HFA) to first identify regions that activate during successful encoding. Then, we leveraged the high-temporal precision of HFA to investigate the timing of such activations. We found that memory encoding invokes two spatiotemporally distinct activations: early increases in HFA that involve the ventral visual pathway as well as the medial temporal lobe and late increases in HFA that involve the left inferior frontal gyrus, left posterior parietal cortex, and left ventrolateral temporal cortex. We speculate that these activations reflect higher-order visual processing and top-down modulation of attention/semantic information, respectively.

| S-EPMC4289670 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data