Boosting Familiarity-Based Memory Decisions in Alzheimer’s Disease: The Importance of Metacognition

Author(s):  
Marie Geurten ◽  
Eric Salmon ◽  
Sylvie Willems ◽  
Christine Bastin

Abstract Objective: Recent studies in Alzheimer’s disease (AD) have suggested that AD patients are not always able to rely on their feeling of familiarity to improve their memory decisions to the same extent as healthy participants. This underuse of familiarity in AD could result from a learned reinterpretation of fluency as a poor cue for memory that would prevent them to attribute a feeling of fluency to a previous encounter. The primary goal of this study was to determine whether AD patients could relearn the association between processing fluency and past exposure after being repeatedly exposed to situations where using this association improves the accuracy of their memory decisions. Method: Thirty-nine patients with probable AD were recruited and asked to complete several recognition tests. During these tests, participants were put either in a condition where the positive contingency between fluent processing and previous encounters with an item was systematically confirmed (intervention condition) or in a condition where there was no correlation between fluency and prior exposure (control condition). The efficacy of the intervention was evaluated at three time points (baseline, posttest, and 3-month follow-up). Results: Our results indicated that all AD patients do not benefit to the same extent from the training. Two variables appeared to influence the likelihood that participants increase and maintain their reliance on the fluency cues after the intervention: the ability to detect the fluency manipulation and the preservation of implicit metacognitive skills. Conclusion: These findings indicate the importance of metacognition for inferential attribution processes in memory.

Author(s):  
Nuwan Madusanka ◽  
Heung-Kook Choi ◽  
Jae-Hong So ◽  
Boo-Kyeong Choi ◽  
Hyeon Gyun Park

Background: In this study, we investigated the effect of hippocampal subfield atrophy on the development of Alzheimer’s disease (AD) by analyzing baseline magnetic resonance images (MRI) and images collected over a one-year follow-up period. Previous studies have suggested that morphological changes to the hippocampus are involved in both normal ageing and the development of AD. The volume of the hippocampus is an authentic imaging biomarker for AD. However, the diverse relationship of anatomical and complex functional connectivity between different subfields implies that neurodegenerative disease could lead to differences between the atrophy rates of subfields. Therefore, morphometric measurements at subfield-level could provide stronger biomarkers. Methods: Hippocampal subfield atrophies are measured using MRI scans, taken at multiple time points, and shape-based normalization to a Montreal neurological institute (MNI) ICBM 152 nonlinear atlas. Ninety subjects were selected from the Alzheimer’s Disease Neuroimaging Initiative (ADNI), and divided equally into Healthy Controls (HC), AD, and mild cognitive impairment (MCI) groups. These subjects underwent serial MRI studies at three time-points: baseline, 6 months and 12 months. Results: We analyzed the subfield-level hippocampal morphometric effects of normal ageing and AD based on radial distance mapping and volume measurements. We identified a general trend and observed the largest hippocampal subfield atrophies in the AD group. Atrophy of the bilateral CA1, CA2- CA4 and subiculum subfields was higher in the case of AD than in MCI and HC. We observed the highest rate of reduction in the total volume of the hippocampus, especially in the CA1 and subiculum regions, in the case of MCI. Conclusion: Our findings show that hippocampal subfield atrophy varies among the three study groups.


GeroPsych ◽  
2012 ◽  
Vol 25 (4) ◽  
pp. 235-245 ◽  
Author(s):  
Katja Franke ◽  
Christian Gaser

We recently proposed a novel method that aggregates the multidimensional aging pattern across the brain to a single value. This method proved to provide stable and reliable estimates of brain aging – even across different scanners. While investigating longitudinal changes in BrainAGE in about 400 elderly subjects, we discovered that patients with Alzheimer’s disease and subjects who had converted to AD within 3 years showed accelerated brain atrophy by +6 years at baseline. An additional increase in BrainAGE accumulated to a score of about +9 years during follow-up. Accelerated brain aging was related to prospective cognitive decline and disease severity. In conclusion, the BrainAGE framework indicates discrepancies in brain aging and could thus serve as an indicator for cognitive functioning in the future.


2020 ◽  
Vol 17 ◽  
Author(s):  
Hyung-Ji Kim ◽  
Jae-Hong Lee ◽  
E-nae Cheong ◽  
Sung-Eun Chung ◽  
Sungyang Jo ◽  
...  

Background: Amyloid PET allows for the assessment of amyloid β status in the brain, distinguishing true Alzheimer’s disease from Alzheimer’s disease-mimicking conditions. Around 15–20% of patients with clinically probable Alzheimer’s disease have been found to have no significant Alzheimer’s pathology on amyloid PET. However, a limited number of studies had been conducted this subpopulation in terms of clinical progression. Objective: We investigated the risk factors that could affect the progression to dementia in patients with amyloid-negative amnestic mild cognitive impairment (MCI). Methods: This study was a single-institutional, retrospective cohort study of patients over the age of 50 with amyloidnegative amnestic MCI who visited the memory clinic of Asan Medical Center with a follow-up period of more than 36 months. All participants underwent brain magnetic resonance imaging (MRI), detailed neuropsychological testing, and fluorine-18[F18]-florbetaben amyloid PET. Results: During the follow-up period, 39 of 107 patients progressed to dementia from amnestic MCI. In comparison with the stationary group, the progressed group had a more severe impairment in verbal and visual episodic memory function and hippocampal atrophy, which showed an Alzheimer’s disease-like pattern despite the lack of evidence for significant Alzheimer’s disease pathology. Voxel-based morphometric MRI analysis revealed that the progressed group had a reduced gray matter volume in the bilateral cerebellar cortices, right temporal cortex, and bilateral insular cortices. Conclusion: Considering the lack of evidence of amyloid pathology, clinical progression of these subpopulation may be caused by other neuropathologies such as TDP-43, abnormal tau or alpha synuclein that lead to neurodegeneration independent of amyloid-driven pathway. Further prospective studies incorporating biomarkers of Alzheimer’s diseasemimicking dementia are warranted.


1997 ◽  
Vol 9 (4) ◽  
pp. 381-388 ◽  
Author(s):  
Clive Ballard ◽  
Ian McKeith ◽  
Richard Harrison ◽  
John O'Brien ◽  
Peter Thompson ◽  
...  

Visual hallucinations (VH) are a core feature of dementia with Lewy bodies (DLB), but little is known about their phenomenology. A total of 73 dementia patients (42 DLB, 30 Alzheimer's disease [AD], 1 undiagnosed) in contact with clinical services were assessed with a detailed standardized inventory. DLB was diagnosed according to the criteria of McKeith and colleagues, AD was diagnosed using the NINCDS-ADRDA criteria. Autopsy confirmation has been obtained when possible. VH were defined using the definition of Burns and colleagues. Detailed descriptions of hallucinatory experiences were recorded. Annual follow-up interviews were undertaken. The clinical diagnosis has been confirmed in 18 of the 19 cases that have come to autopsy. A total of 93% of DLB patients and 27% of AD patients experienced VH. DLB patients were significantly more likely to experience multiple VH that persisted over follow-up. They were significantly more likely to hear their VH speak but there were no significant differences in the other phenomenological characteristics including whether the hallucinations moved, the time of day that they were experienced, their size, the degree of insight, and whether they were complete. VH may be more likely to be multiple, to speak, and to be persistent in DLB patients. These characteristics could potentially aid accurate diagnosis.


1997 ◽  
Vol 171 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Sergio E. Starkstein ◽  
Erán Chemerinski ◽  
Liliana Sabe ◽  
Gabriela Kuzis ◽  
Gustavo Petracca ◽  
...  

BackgroundThe aim was to examine the longitudinal evolution of depression and anosognosia in patients with probable Alzheimer's disease (AD).MethodSixty-two of a consecutive series of 116 AD patients that were examined with a structured psychiatric interview had a follow-up evaluation between one and two years after the initial evaluation.ResultsAt the initial evaluation 19% of the 62 patients had major depression, 34% had dysthymia, and 47% were not depressed. After a mean follow-up of 16 months, 58% of patients with major depression at the initial evaluation were still depressed, whereas only 28% of patients with initial dysthymia and 21% of the non-depressed patients were depressed at follow-up. During the follow-up period, all three groups showed similar declines in cognitive status and activities of daily living. At the initial evaluation, 39% of the patients had anosognosia, and there was a significant increment of anosognosia during the follow-up period.ConclusionsWhile dysthymia in AD is a brief emotional disorder, major depression is a longer-lasting mood change. Anosognosia is another prevalent disorder among AD patients, and increases with the progression of the illness.


2021 ◽  
Vol 80 (2) ◽  
pp. 749-759
Author(s):  
Albert Lladó ◽  
Lutz Froelich ◽  
Rezaul K. Khandker ◽  
Montserrat Roset ◽  
Christopher M. Black ◽  
...  

Background: There exists considerable variation in disease progression rates among patients with Alzheimer’s disease (AD). Objective: The primary objective of this observational study is to assess the progression of AD by characterizing cognitive, functional, and behavioral changes during the follow-up period between 6 and 24 months. Methods: A longitudinal prospective study with community-dwelling patients with an established clinical diagnosis of AD of mild to moderate severity was conducted in Germany, Spain and the UK. A sample of 616 patients from 69 sites was included. Results: Patients had a mean of 1.9 years (SD = 1.9) since AD diagnosis at study inclusion. Cognitive symptoms were reported to have first occurred a mean of 1.1 years (SD = 1.7) prior to AD diagnosis and 1.4 (SD = 1.8) years prior to AD treatment. Patients initially diagnosed with mild and moderate AD spent a median (95%CI) of 3.7 (2.8; 4.4) and 11.1 (6.1, ‘not reached’) years until progression to moderate and severe AD, respectively, according to the Mini-Mental State Examination (MMSE) scores. A mixed model developed for cognitive, functional, and neuropsychiatric scores, obtained from study patients at baseline and during follow-up period, showed progressive deterioration of AD patients over time. Conclusion: The study showed a deterioration of cognitive, functional, and neuropsychiatric functions during the follow-up period. Cognitive deterioration was slightly faster in patients with moderate AD compared to mild AD. The duration of moderate AD can be overestimated due to the use of retrospective data, lack of availability of MMSE scores in clinical charts and exclusion of patients at time of institutionalization.


2021 ◽  
Vol 19 ◽  
Author(s):  
Fatma Sena Dost ◽  
Derya Kaya ◽  
Mehmet Selman Ontan ◽  
Neziha Erken ◽  
Esra Ateş Bulut ◽  
...  

Background: Alzheimer’s Disease (AD) is still a great global challenge and agents with various mechanisms represent a promising therapeutic opportunity. Theracurmin, a very highly absorbable curcumin formulation, was shown to improve memory and attention in non-demented people. Objective: To investigate the effect of Theracurmin on disease course in elderly patients with mild cognitive impairment (MCI) and AD. Methods: This follow-up study was performed retrospectively on 93 patients with MCI or AD. All patients underwent comprehensive geriatric assessment, including Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MOCA), clock-drawing test, activities of daily living (ADL), at baseline and end of the 6th-month. 19 patients with AD and 17 with MCI were treated with Theracurmin 180 mg/day per oral. Results: MMSE, MOCA and instrumental ADL scores decreased in AD patients that were not treated with Theracurmin (p<0.001, p=0.011, and p=0.004, respectively), whereas these scores remained stable in those treated with Theracurmin. This stabilization in the instrumental ADL was also observed in MCI patients treated with Theracurmin. During the follow-up, three of MCI patients who did not receive Theracurmin progressed to AD, whereas only one patient progressed in those who received it. Conclusion: Theracurmin seems to be a therapeutic option for elderly patients with AD and MCI via providing stabilization of the disease course by preventing progressive loss in cognitive functions and ADLs.


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