The Impact of Amyloid-β or Tau on Cognitive Change in the Presence of Severe Cerebrovascular Disease

2020 ◽  
Vol 78 (2) ◽  
pp. 573-585
Author(s):  
Hyemin Jang ◽  
Hee Jin Kim ◽  
Yeong Sim Choe ◽  
Soo-Jong Kim ◽  
Seongbeom Park ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Cognitive Decline ◽  
Interaction Effect ◽  
Significant Interaction ◽  
Amyloid Β ◽  
Cognitive Change ◽  
Significant Interaction Effect ◽  
The Impact

Background: As Alzheimer’s disease (AD) and cerebral small vessel disease (CSVD) commonly coexist, the interaction between two has been of the considerable interest. Objective: We determined whether the association of Aβ and tau with cognitive decline differs by the presence of significant CSVD. Methods: We included 60 subcortical vascular cognitive impairment (SVCI) from Samsung Medical Center and 82 Alzheimer’s disease-related cognitive impairment (ADCI) from ADNI, who underwent Aβ (florbetaben or florbetapir) and tau (flortaucipir, FTP) PET imaging. They were retrospectively assessed for 5.0±3.9 and 5.6±1.9 years with Clinical Dementia Rating-sum of boxes (CDR-SB)/Mini-Mental State Examination (MMSE). Mixed effects models were used to investigate the interaction between Aβ/tau and group on CDR-SB/MMSE changes. Results: The frequency of Aβ positivity (45% versus 54.9%, p = 0.556) and mean global FTP SUVR (1.17±0.21 versus 1.16±0.17, p = 0.702) were not different between the two groups. We found a significant interaction effect of Aβ positivity and SVCI group on CDR-SB increase/MMSE decrease (p = 0.013/p < 0.001), and a significant interaction effect of global FTP uptake and SVCI group on CDR-SB increase/MMSE decrease (p < 0.001 and p = 0.030). Finally, the interaction effects of regional tau and group were prominent in the Braak III/IV (p = 0.001) and V/VI (p = 0.003) not in Braak I/II region (p = 0.398). Conclusion: The association between Aβ/tau and cognitive decline is stronger in SVCI than in ADCI. Therefore, our findings suggested that Aβ positivity or tau burden (particularly in the Braak III/IV or V/VI regions) and CSVD might synergistically affect cognitive decline.

scholarly journals Plasma Glutathione Levels Decreased with Cognitive Decline among People with Mild Cognitive Impairment (MCI): A Two-Year Prospective Study

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1839
Author(s):  
Chieh-Hsin Lin ◽  
Hsien-Yuan Lane
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Function ◽  
Prospective Study ◽  
Cognitive Decline ◽  
Cognitive Change ◽  
Disease Assessment ◽  
Healthy Individuals

Glutathione (GSH) is a major endogenous antioxidant. Several studies have shown GSH redox imbalance and altered GSH levels in Alzheimer’s disease (AD) patients. Early detection is crucial for the outcome of AD. However, whether GSH can serve as a biomarker during the very early-phase of AD, such as mild cognitive impairment (MCI), remains unknown. The current prospective study aimed to examine the longitudinal change in plasma GSH concentration and its influence on cognitive decline in MCI. Overall, 49 patients with MCI and 16 healthy individuals were recruited. Plasma GSH levels and cognitive function, measured by the Mini-Mental Status Examination (MMSE) and Alzheimer’s disease assessment scale-cognitive subscale (ADAS-cog), were monitored every 6 months. We employed multiple regressions to examine the role of GSH level in cognitive decline in the 2 years period. The MCI patients showed significant decline in plasma GSH levels and cognitive function from baseline to endpoint (month 24). In comparison, the healthy individuals’ GSH concentration and cognitive function did not change significantly. Further, both GSH level at baseline and GSH level change from baseline to endpoint significantly influenced cognitive decline among the MCI patients. To our knowledge, this is the first study to demonstrate that both plasma GSH levels and cognitive function declined 2 years later among the MCI patients in a prospective manner. If replicated by future studies, blood GSH concentration may be regarded as a biomarker for monitoring cognitive change in MCI.

scholarly journals Involvement of Cholinergic, Adrenergic, and Glutamatergic Network Modulation with Cognitive Dysfunction in Alzheimer’s Disease

2021 ◽  
Vol 22 (5) ◽  
pp. 2283
Author(s):  
Yu-Jung Cheng ◽  
Chieh-Hsin Lin ◽  
Hsien-Yuan Lane
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Cognitive Decline ◽  
Early Stage ◽  
Amyloid Β ◽  
Tau Proteins ◽  
And Oxidative Stress

Alzheimer’s disease (AD), the most common cause of dementia, is a progressive neurodegenerative disease. The number of AD cases has been rapidly growing worldwide. Several the related etiological hypotheses include atypical amyloid β (Aβ) deposition, neurofibrillary tangles of tau proteins inside neurons, disturbed neurotransmission, inflammation, and oxidative stress. During AD progression, aberrations in neurotransmission cause cognitive decline—the main symptom of AD. Here, we review the aberrant neurotransmission systems, including cholinergic, adrenergic, and glutamatergic network, and the interactions among these systems as they pertain to AD. We also discuss the key role of N-methyl-d-aspartate receptor (NMDAR) dysfunction in AD-associated cognitive impairment. Furthermore, we summarize the results of recent studies indicating that increasing glutamatergic neurotransmission through the alteration of NMDARs shows potential for treating cognitive decline in mild cognitive impairment or early stage AD. Future studies on the long-term efficiency of NMDA-enhancing strategies in the treatment of AD are warranted.

scholarly journals p-tau/Aβ42 Ratio Associates with Cognitive Decline in Alzheimer’s disease, Mild Cognitive Impairment, and Cognitively Unimpaired Older Adults

2020 ◽  
Author(s):  
Ruchika Shaurya Prakash ◽  
Michael R. McKenna ◽  
Oyetunde Gbadeyan ◽  
Rebecca Andridge ◽  
Douglas W. Scharre ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Executive Functioning ◽  
Episodic Memory ◽  
Cognitive Decline ◽  
Cognitive Functioning ◽  
The Impact

AbstractINTRODUCTIONThe most well-studied biomarkers in AD are CSF amyloid beta-42 (Aβ42), tau, p-tau, and the ratio p-tau/Aβ42. The ratiometric measure of p-tau/Aβ42 shows the best diagnostic accuracy, and correlates reliably with metrics of cognition in unimpaired participants. However, no study has examined the impact of the CSF p-tau/Aβ42 ratio in predicting cognitive decline in both healthy and AD individuals in one sample. The goal of this study was to examine whether CSF-based p-tau/Aβ42 predicts changes in global cognitive functioning, episodic memory, and executive functioning over a two-year period in cognitively impaired older adults (CU), and in individuals with Mild Cognitive Impairment (MCI) and Alzheimer’s disease (AD).METHODSThis study involves secondary analysis of data from 1215 older adults available in the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Neuropsychological variables, collected at baseline, 6-month, 12-month, and 24-month follow-ups, included the Preclinical Alzheimer’s Cognitive Composite (PACC) to assess global cognitive functioning, ADNI-MEM to assess episodic memory functioning, and ADNI-EF to assess executive functioning. Linear mixed models were constructed to examine the effect of CSF p-tau/Aβ42, diagnostic group, and change over time (baseline, 6-month, 12-month, and 24-month) on cognitive scores.RESULTSCSF p-tau/Aβ42 ratios predicted worsening cognitive impairment, both on global cognition and episodic memory in individuals with MCI and AD, but not in CU older adults and predicted decline in executive functioning for all three diagnostic groups.DISCUSSIONOur study, including CU, MCI, and AD individuals, provides evidence for differential cognitive consequences of accumulated AD pathology based on diagnostic groups.

Longitudinal Cognitive Decline in Patients With Mild Cognitive Impairment or Dementia Due to Alzheimer’s Disease

2021 ◽  
pp. 1-6
Author(s):  
Y.Y. Lim ◽  
J. Kong ◽  
P. Maruff ◽  
J. Jaeger ◽  
E. Huang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Episodic Memory ◽  
Cognitive Decline ◽  
Cognitive Change ◽  
Rate Of Change ◽  
Imaging Biomarker ◽  
Cognitively Normal

Sensitive cognitive assessments accurately detect and track cognitive decline in Alzheimer’s disease. The Cogstate battery was used to measure cognitive change in cognitively normal participants and in individuals with mild cognitive impairment and mild Alzheimer’s disease enrolled in the Australian Imaging, Biomarker and Lifestyle Rate of Change Substudy. Over 18 months, verbal episodic memory performance declined for mild cognitive impairment and mild Alzeheimer’s disease groups when compared to cognitively normal participants. Frequent assessments of episodic memory may facilitate early detection of cognitive decline due to Alzheimer’s disease.

scholarly journals Genetic effects on longitudinal cognitive decline during the early stages of Alzheimer's disease

2021 ◽  
Author(s):  
Atul Kumar ◽  
Maryam Shoai ◽  
Sebastian Palmqvist ◽  
Erik Stomrud ◽  
John Hardy ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Cognitive Decline ◽  
Genetic Variants ◽  
Cognitive Change ◽  
Mediation Effect ◽  
Polygenic Risk Score ◽  
Preclinical Ad ◽  
Polygenic Scores

Abstract Background: Cognitive decline in early-stage Alzheimer’s disease (AD) may depend on genetic variability.Methods: In the Swedish BioFINDER study, we used polygenic scores (PGS) (for AD, intelligence and educational attainment) to predict longitudinal cognitive change (measured by MMSE) over a mean of 4.2 years. We included 260 b-amyloid (Ab) negative cognitively unimpaired (CU) individuals, 121 Ab-positive CU (preclinical AD), 50 Ab-negative mild cognitive impairment (MCI) patients, and 127 Ab-positive MCI patients (prodromal AD). Results: The polygenic score (PGS) for intelligence (p = 2.9e-02, beta = 0.1) was protective in CU and MCI participants regardless of Ab status, while polygenic risk score for AD (p = 8.2e-03, beta = -0.12) was correlated with rate of cognitive impairment and was partially mediated by Ab-pathology (mediation effect 20 %). There was no influence of education PGS, implying that educational achievement and rate of cognitive impairment are unrelated.Conclusions: Genetic variants associated with intelligence mitigate cognitive decline independent of Ab-pathology, but the effects of genetic variants associated with AD are partly mediated by Ab-pathology.

scholarly journals Pattern Recognition to Objectively Differentiate the Etiology of Cognitive Decline: Analysis of the Impact of Stroke and Alzheimer’s Disease

2020 ◽  
Vol 54 (6) ◽  
pp. 446-453
Author(s):  
Sean A.P. Clouston ◽  
Lauren L. Richmond ◽  
Stacey B. Scott ◽  
Christian C. Luhmann ◽  
Ginny Natale ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Pattern Recognition ◽  
Episodic Memory ◽  
Cognitive Decline ◽  
Multilevel Models ◽  
Cognitive Change ◽  
Normal Aging ◽  
Age Related ◽  
The Impact

<b><i>Background:</i></b> Undetected Alzheimer’s disease (AD) and stroke neuropathology is believed to account for a large proportion of decline in cognitive performance that is attributed to normal aging. This study examined the amount of variance in age-related cognitive change that is accounted for by AD and stroke using a novel pattern recognition protocol. <b><i>Method:</i></b> Secondary analyses of data collected for the Health and Retirement Study (<i>N</i> = 17,579) were used to objectively characterize patterns of cognitive decline associated with AD and stroke. The rate of decline in episodic memory and orientation was the outcome of interest, while algorithms indicative of AD and stroke pathology were the predictors of interest. <b><i>Results:</i></b> The average age of the sample was 67.54 ± 10.45 years at baseline, and they completed, on average, 14.20 ± 3.56 years of follow-up. After adjusting for demographics, AD and stroke accounted for approximately half of age-associated decline in cognition (51.07–55.6% for orientation and episodic memory, respectively) and explained variance attributed to random slopes in longitudinal multilevel models. <b><i>Discussion:</i></b> The results of this study suggested that approximately half of the cognitive decline usually attributed to normal aging are more characteristic of AD and stroke.

Associations Between Amyloid and Tau Pathology, and Connectome Alterations, in Alzheimer’s Disease and Mild Cognitive Impairment

2021 ◽  
pp. 1-20
Author(s):  
Josh King-Robson ◽  
Heather Wilson ◽  
Marios Politis ◽  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Rating Scale ◽  
Amyloid Β ◽  
Tau Pathology ◽  
Diffusion Tractography ◽  
The Right ◽  
The Impact

Background: The roles of amyloid-β and tau in the degenerative process of Alzheimer’s disease (AD) remain uncertain. [18F]AV-45 and [18F]AV-1451 PET quantify amyloid-β and tau pathology, respectively, while diffusion tractography enables detection of their microstructural consequences. Objective: Examine the impact of amyloid-β and tau pathology on the structural connectome and cognition, in mild cognitive impairment (MCI) and AD. Methods: Combined [18F]AV-45 and [18F]AV-1451 PET, diffusion tractography, and cognitive assessment in 28 controls, 32 MCI, and 26 AD patients. Results: Hippocampal connectivity was reduced to the thalami, right lateral orbitofrontal, and right amygdala in MCI; alongside the insula, posterior cingulate, right entorhinal, and numerous cortical regions in AD (all p <  0.05). Hippocampal strength inversely correlated with [18F]AV-1451 SUVr in MCI (r = –0.55, p = 0.049) and AD (r = –0.57, p = 0.046), while reductions in hippocampal connectivity to ipsilateral brain regions correlated with increased [18F]AV-45 SUVr in those same regions in MCI (r = –0.33, p = 0.003) and AD (r = –0.31, p = 0.006). Cognitive scores correlated with connectivity of the right temporal pole in MCI (r = –0.60, p = 0.035) and left hippocampus in AD (r = 0.69, p = 0.024). Clinical Dementia Rating Scale scores correlated with [18F]AV-1451 SUVr in multiple areas reflecting Braak stages I-IV, including the right (r = 0.65, p = 0.004) entorhinal cortex in MCI; and Braak stages III-VI, including the right (r = 0.062, p = 0.009) parahippocampal gyrus in AD. Conclusion: Reductions in hippocampal connectivity predominate in the AD connectome, correlating with hippocampal tau in MCI and AD, and with amyloid-β in the target regions of those connections. Cognitive scores correlate with microstructural changes and reflect the accumulation of tau pathology.

Subjective Spatial Navigation Complaints - A Frequent Symptom Reported by Patients with Subjective Cognitive Decline, Mild Cognitive Impairment and Alzheimer's Disease

2018 ◽  
Vol 15 (3) ◽  
pp. 219-228 ◽  
Author(s):  
Jiri Cerman ◽  
Ross Andel ◽  
Jan Laczo ◽  
Martin Vyhnalek ◽  
Zuzana Nedelska ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Spatial Navigation ◽  
Subjective Cognitive Decline ◽  
Great Effort ◽  
Frequent Symptom ◽  
Normal Controls

Background: Great effort has been put into developing simple and feasible tools capable to detect Alzheimer's disease (AD) in its early clinical stage. Spatial navigation impairment occurs very early in AD and is detectable even in the stage of mild cognitive impairment (MCI). Objective: The aim was to describe the frequency of self-reported spatial navigation complaints in patients with subjective cognitive decline (SCD), amnestic and non-amnestic MCI (aMCI, naMCI) and AD dementia and to assess whether a simple questionnaire based on these complaints may be used to detect early AD. Method: In total 184 subjects: patients with aMCI (n=61), naMCI (n=27), SCD (n=63), dementia due to AD (n=20) and normal controls (n=13) were recruited. The subjects underwent neuropsychological examination and were administered a questionnaire addressing spatial navigation complaints. Responses to the 15 items questionnaire were scaled into four categories (no, minor, moderate and major complaints). Results: 55% of patients with aMCI, 64% with naMCI, 68% with SCD and 72% with AD complained about their spatial navigation. 38-61% of these complaints were moderate or major. Only 33% normal controls expressed complaints and none was ranked as moderate or major. The SCD, aMCI and AD dementia patients were more likely to express complaints than normal controls (p's<0.050) after adjusting for age, education, sex, depressive symptoms (OR for SCD=4.00, aMCI=3.90, AD dementia=7.02) or anxiety (OR for SCD=3.59, aMCI=3.64, AD dementia=6.41). Conclusion: Spatial navigation complaints are a frequent symptom not only in AD, but also in SCD and aMCI and can potentially be detected by a simple and inexpensive questionnaire.

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