scholarly journals Decline in verbal memory during preclinical Alzheimer's disease: Examination of the effect of APOE genotype

2002 ◽  
Vol 8 (7) ◽  
pp. 943-955 ◽  
Author(s):  
KELLY L. LANGE ◽  
MARK W. BONDI ◽  
DAVID P. SALMON ◽  
DOUGLAS GALASKO ◽  
DEAN C. DELIS ◽  
...  

A subtle decline in episodic memory often occurs prior to the emergence of the full dementia syndrome in nondemented older adults who develop Alzheimer's disease (AD). The APOE-ε4 genotype may engender a more virulent form of AD that hastens this decline. To examine this possibility, we compared the rate of decline in episodic memory during the preclinical phase of AD in individuals with or without at least one APOE ε4 allele. Nondemented normal control (NC; n = 84) participants, nondemented older adults who subsequently developed dementia within 1 or 2 years (i.e., preclinical AD; n = 20), and patients with mild AD (n = 53) were examined with 2 commonly employed tests of episodic memory, the Logical Memory subtest of the Wechsler Memory Scale–Revised and the California Verbal Learning Test. Results revealed a precipitous decline in verbal memory abilities 1 to 2 years prior to the onset of the dementia syndrome, but there was little effect of APOE genotype on the rate of this memory decline. The presence of an APOE-ε4 allele, however, did have a differential effect on the sensitivity of the 2 types of memory tests for tracking progression and made an independent contribution to the prediction of conversion to AD. (JINS, 2002, 8, 943–955.)

2018 ◽  
Vol 15 (10) ◽  
pp. 938-950 ◽  
Author(s):  
Martina Zverova ◽  
Eva Kitzlerova ◽  
Zdenek Fisar ◽  
Roman Jirak ◽  
Jana Hroudova ◽  
...  

Background: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with a complex pathogenesis and a common occurrence of comorbid diseases such as depression. It is accepted that the presence of the ε4 allele of the gene that encodes apolipoprotein E (APOE) is the strongest genetic risk factor for the development of sporadic AD. Melatonin, cortisol, homocysteine, and prolactin are presumed to be risk factors or biomarkers for stress- and age-related disorders. Objective: The interplay between the APOE genotype and plasma biomarkers was examined in patients with AD presenting with or without depression to contribute to understanding the interdependence of various molecular mechanisms in the pathophysiology of AD. Method: The APOE genotype and morning plasma melatonin, cortisol, homocysteine, and prolactin concentrations were measured in 85 patients with AD and 44 elderly controls. Results: A significant association between AD and the allele (ε4) or genotype (ε3/ε4 or ε4/ε4) frequencies of APOE was confirmed. Plasma homocysteine and cortisol levels were significantly increased in patients with AD compared to those in controls, independent of the presence of comorbid depressive symptoms or the severity of dementia. Significantly lower plasma melatonin concentration was found in patients with AD but not in controls, who were noncarriers of the APOE ε4 allele, regardless of the presence of depression or the severity of dementia in AD. Conclusion: Our findings indicate the existence of a little-known specific APOE-mediated mechanism that increases the plasma melatonin level in a subgroup of patients with AD who are carriers of the APOE ε4 allele.


2020 ◽  
Vol 17 (7) ◽  
pp. 667-679
Author(s):  
Matteo De Marco ◽  
Riccardo Manca ◽  
Janine Kirby ◽  
Guillaume M. Hautbergue ◽  
Daniel J. Blackburn ◽  
...  

Background: Research indicates that polygenic indices of risk of Alzheimer’s disease are linked to clinical profiles. Objective: Given the “genetic centrality” of the APOE gene, we tested whether this held true for both APOE-ε4 carriers and non-carriers. Methods: A polygenic hazard score (PHS) was extracted from 784 non-demented participants recruited in the Alzheimer’s Disease Neuroimaging Initiative and stratified by APOE ε4 status. Datasets were split into sub-cohorts defined by clinical (unimpaired/MCI) and amyloid status (Aβ+/Aβ-). Linear models were devised in each sub-cohort and for each APOE-ε4 status to test the association between PHS and memory, executive functioning and grey-matter volumetric maps. Results: PHS predicted memory and executive functioning in ε4ε3 MCI patients, memory in ε3ε3 MCI patients, and memory in ε4ε3 Aβ+ participants. PHS also predicted volume in sensorimotor regions in ε3ε3 Aβ+ participants. Conclusion: The link between polygenic hazard and neurocognitive variables varies depending on APOE-ε4 allele status. This suggests that clinical phenotypes might be influenced by complex genetic interactions.


2018 ◽  
Vol 15 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Winnie Qian ◽  
Corinne E. Fischer ◽  
Tom A. Schweizer ◽  
David G. Munoz

Background: Psychosis is a common phenomenon in Alzheimer's disease (AD). The APOE ε4 allele is the strongest genetic risk factor for the development of AD, but its association with psychosis remains unclear. Objective: We investigated the associations between psychosis, subdivided into delusions and hallucinations, as well as APOE ε4 allele on cognitive and functional outcomes. Secondarily, we investigated the associations between APOE ε4, Lewy bodies, and psychosis. Methods: Data from the National Alzheimer's Coordinating Center (NACC) were used. Nine hundred patients with a confirmed diagnosis of AD based on the NIA-AA Reagan were included in the analysis. Global cognition was assessed using the Mini-Mental State Exam (MMSE) and functional status was assessed using the Functional Activities Questionnaire (FAQ). Psychosis status was determined using the Neuropsychiatric Inventory Questionnaire (NPI-Q). Factorial design was used to assess the effects of psychosis and APOE ε4, as well as their interaction. Results: Psychosis and the presence of APOE ε4 were both associated with lower MMSE scores, while only psychosis was associated with higher FAQ scores. Furthermore, patients with hallucinations had lower MMSE and higher FAQ scores than patients with only delusions. There was a significant interaction effect between psychosis and APOE ε4 on MMSE scores, with APOE ε4 negatively affecting patients with hallucinations-only psychosis. APOE ε4 was positively associated with the presence of Lewy body pathology, and both were found to be more prevalent in psychotic patients, with a stronger association with hallucinations. Conclusion: Psychosis in AD was associated with greater cognitive and functional impairments. Patients with hallucinations-with or without delusions-conferred even greater deficits compared to patients with only delusions. The APOE ε4 allele was associated with worse cognition, especially for patients with hallucination-only psychosis. APOE ε4 may mediate cognitive impairment in the hallucinations phenotype through the development of Lewy bodies. Our findings support that subtypes of psychosis should be evaluated separately.


2003 ◽  
Vol 9 (5) ◽  
pp. 751-759 ◽  
Author(s):  
MICHAEL J. FINTON ◽  
JOHN A. LUCAS ◽  
JULIE D. RIPPETH ◽  
DARYL L. BOHAC ◽  
GLENN E. SMITH ◽  
...  

The relationship between apolipoprotein E (apoE) genotype and cognitive performance was examined in 200 patients with probable Alzheimer's disease (AD). Differences between composite measures of verbal and nonverbal functioning were used to define asymmetric patterns of cognition. Patients who were homozygous for apoE ε4 demonstrated relatively worse nonverbal as compared to verbal cognitive ability. In contrast, participants who were heterozygous for apoE ε4 or who possessed no ε4 allele demonstrated relatively equivalent verbal and nonverbal cognitive abilities. Although age and dementia severity also contributed to these patterns, apoE genotype appears to have a significant unique contribution to cognitive performance in these individuals. The ε4 allele may thus be associated with a specific neurocognitive phenotype among patients with AD, with the overall pattern of cognitive asymmetry dependent upon ε4 dose. (JINS, 2003, 9, 751–759.)


2020 ◽  
Vol 20 ◽  
Author(s):  
Md. Sahab Uddin ◽  
Sharifa Hasana ◽  
Md. Farhad Hossain ◽  
Md. Siddiqul Islam ◽  
Tapan Behl ◽  
...  

: Alzheimer’s disease (AD) is the most common form of dementia in the elderly and this complex disorder is associated with environmental as well as genetic components. Early-onset AD (EOAD) and late-onset AD (LOAD, more common) are major identified types of AD. The genetics of EOAD is extensively understood with three genes variants such as APP, PSEN1, and PSEN2 leading to disease. On the other hand, some common alleles including APOE are effectively associated with LOAD identified but the genetics of LOAD is not clear to date. It has been accounted that about 5% to 10% of EOAD patients can be explained through mutations in the three familiar genes of EOAD. The APOE ε4 allele augmented the severity of EOAD risk in carriers, and APOE ε4 allele was considered as a hallmark of EOAD. A great number of EOAD patients, who are not genetically explained, indicate that it is not possible to identify disease- triggering genes yet. Although several genes have been identified through using the technology of next-generation sequencing in EOAD families including SORL1, TYROBP, and NOTCH3. A number of TYROBP variants were identified through exome sequencing in EOAD patients and these TYROBP variants may increase the pathogenesis of EOAD. The existence of ε4 allele is responsible for increasing the severity of EOAD. However, several ε4 allele carriers live into their 90s that propose the presence of other LOAD genetic as well as environmental risk factors that are not identified yet. It is urgent to find out missing genetics of EOAD and LOAD etiology to discover new potential genetics facets which will assist to understand the pathological mechanism of AD. These investigations should contribute to developing a new therapeutic candidate for alleviating, reversing and preventing AD. This article based on current knowledge represents the overview of the susceptible genes of EOAD, and LOAD. Next, we represent the probable molecular mechanism which might elucidate the genetic etiology of AD and highlight the role of massively parallel sequencing technologies for novel gene discoveries.


2013 ◽  
Vol 10 (10) ◽  
pp. 1107-1117 ◽  
Author(s):  
Jennifer Lalanne ◽  
Johanna Rozenberg ◽  
Pauline Grolleau ◽  
Pascale Piolino

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Jiangyi Xia ◽  
Ali Mazaheri ◽  
Katrien Segaert ◽  
David P Salmon ◽  
Danielle Harvey ◽  
...  

Abstract Reliable biomarkers of memory decline are critical for the early detection of Alzheimer’s disease. Previous work has found three EEG measures, namely the event-related brain potential P600, suppression of oscillatory activity in the alpha frequency range (∼10 Hz) and cross-frequency coupling between low theta/high delta and alpha/beta activity, each of which correlates strongly with verbal learning and memory abilities in healthy elderly and patients with mild cognitive impairment or prodromal Alzheimer’s disease. In the present study, we address the question of whether event-related or oscillatory measures, or a combination thereof, best predict the decline of verbal memory in mild cognitive impairment and Alzheimer’s disease. Single-trial correlation analyses show that despite a similarity in their time courses and sensitivities to word repetition, the P600 and the alpha suppression components are minimally correlated with each other on a trial-by-trial basis (generally |rs| < 0.10). This suggests that they are unlikely to stem from the same neural mechanism. Furthermore, event-related brain potentials constructed from bandpass filtered (delta, theta, alpha, beta or gamma bands) single-trial data indicate that only delta band activity (1–4 Hz) is strongly correlated (r = 0.94, P < 0.001) with the canonical P600 repetition effect; event-related potentials in higher frequency bands are not. Importantly, stepwise multiple regression analyses reveal that the three event-related brain potential/oscillatory measures are complementary in predicting California Verbal Learning Test scores (overall R2’s in 0.45–0.63 range). The present study highlights the importance of combining EEG event-related potential and oscillatory measures to better characterize the multiple mechanisms of memory failure in individuals with mild cognitive impairment or prodromal Alzheimer’s disease.


2021 ◽  
pp. 0271678X2110563
Author(s):  
W Hudson Robb ◽  
Omair A Khan ◽  
Humza A Ahmed ◽  
Judy Li ◽  
Elizabeth E Moore ◽  
...  

Oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) are markers of cerebral oxygen homeostasis and metabolism that may offer insights into abnormal changes in brain aging. The present study cross-sectionally related OEF and CMRO2 to cognitive performance and structural neuroimaging variables among older adults (n = 246, 74 ± 7 years, 37% female) and tested whether apolipoprotein E ( APOE)-ε4 status modified these associations. Main effects of OEF and CMRO2 were null (p-values >0.06), and OEF interactions with APOE-ε4 status on cognitive and structural imaging outcomes were null (p-values >0.06). However, CMRO2 interacted with APOE-ε4 status on language (p = 0.002), executive function (p = 0.03), visuospatial (p = 0.005), and episodic memory performances (p = 0.03), and on hippocampal (p = 0.006) and inferior lateral ventricle volumes (p = 0.02). In stratified analyses, lower oxygen metabolism related to worse language (p = 0.02) and episodic memory performance (p = 0.03) among APOE-ε4 carriers only. Associations between CMRO2 and cognitive performance were primarily driven by APOE-ε4 carriers with existing cognitive impairment. Congruence across language and episodic memory results as well as hippocampal and inferior lateral ventricle volume findings suggest that APOE-ε4 may interact with cerebral oxygen metabolism in the pathogenesis of Alzheimer’s disease and related neurodegeneration.


2008 ◽  
Vol 66 (2b) ◽  
pp. 298-302 ◽  
Author(s):  
Anália Nusya Garcia ◽  
Helker Albuquerque da Silva ◽  
Renan Carlos Silva ◽  
Eliane Maria Medeiros Leal ◽  
Lorena Rodrigues ◽  
...  

BACKGROUND: Polymorphism of the gene for apolipoprotein E (APOE) is an important risk factor for the development of Alzheimer's disease. The ε4 allele of the APOE gene has been linked with a number of neuropsychiatric illnesses, and also with stress and depression among geriatric populations. OBJECTIVE: To identify APOE-ε4 polymorphism and correlate this with cognitive deficit among the elderly population of the island of Fernando de Noronha. METHOD: Neuropsychiatric tests (mini-mental state examination, verbal fluency test and clock drawing test) were applied to 52 elderly people without Alzheimer's disease. DNA was isolated from peripheral blood and genotyping of APOE was done by the PCR-RFLP method. RESULTS: 87% of the elderly population (mean age 69.6±7.0) had cognitive deficit. CONCLUSION: The observed frequency of the ε4 allele was 10%, but the correlation between the presence of ε4 and cognitive deficit in this population was not statistically significant.


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