scholarly journals Prospective predictors of decline v. stability in mild cognitive impairment with Lewy bodies or Alzheimer's disease

2020 ◽  
pp. 1-9
Author(s):  
Calum A. Hamilton ◽  
Fiona E. Matthews ◽  
Paul C. Donaghy ◽  
John-Paul Taylor ◽  
John T. O'Brien ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Latent Class ◽  
Lewy Bodies ◽  
Cognitive Status ◽  
Rapid Decline ◽  
Visual Hallucinations ◽  
Full Cohort

Abstract Background Mild cognitive impairment (MCI) may gradually worsen to dementia, but often remains stable for extended periods of time. Little is known about the predictors of decline to help explain this variation. We aimed to explore whether this heterogeneous course of MCI may be predicted by the presence of Lewy body (LB) symptoms in a prospectively-recruited longitudinal cohort of MCI with Lewy bodies (MCI-LB) and Alzheimer's disease (MCI-AD). Methods A prospective cohort (n = 76) aged ⩾60 years underwent detailed assessment after recent MCI diagnosis, and were followed up annually with repeated neuropsychological testing and clinical review of cognitive status and LB symptoms. Latent class mixture modelling identified data-driven sub-groups with distinct trajectories of global cognitive function. Results Three distinct trajectories were identified in the full cohort: slow/stable progression (46%), intermediate progressive decline (41%) and a small group with a much faster decline (13%). The presence of LB symptomology, and visual hallucinations in particular, predicted decline v. a stable cognitive trajectory. With time zeroed on study end (death, dementia or withdrawal) where available (n = 39), the same subgroups were identified. Adjustment for baseline functioning obscured the presence of any latent classes, suggesting that baseline function is an important parameter in prospective decline. Conclusions These results highlight some potential signals for impending decline in MCI; poorer baseline function and the presence of probable LB symptoms – particularly visual hallucinations. Identifying people with a rapid decline is important but our findings are preliminary given the modest cohort size.

scholarly journals Neuropsychological Impairments and Their Cognitive Architecture in Mild Cognitive Impairment (MCI) with Lewy Bodies and MCI-Alzheimer’s Disease

2021 ◽  
pp. 1-11
Author(s):  
Joanna Ciafone ◽  
Alan Thomas ◽  
Rory Durcan ◽  
Paul C Donaghy ◽  
Calum A Hamilton ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Executive Function ◽  
Mild Cognitive Impairment ◽  
Processing Speed ◽  
Lewy Bodies ◽  
Trail Making Test ◽  
Neuropsychological Profile ◽  
Trail Making

Abstract Objective: The present study aimed to clarify the neuropsychological profile of the emergent diagnostic category of Mild Cognitive Impairment with Lewy bodies (MCI-LB) and determine whether domain-specific impairments such as in memory were related to deficits in domain-general cognitive processes (executive function or processing speed). Method: Patients (n = 83) and healthy age- and sex-matched controls (n = 34) underwent clinical and imaging assessments. Probable MCI-LB (n = 44) and MCI-Alzheimer’s disease (AD) (n = 39) were diagnosed following National Institute on Aging-Alzheimer’s Association (NIA-AA) and dementia with Lewy bodies (DLB) consortium criteria. Neuropsychological measures included cognitive and psychomotor speed, executive function, working memory, and verbal and visuospatial recall. Results: MCI-LB scored significantly lower than MCI-AD on processing speed [Trail Making Test B: p = .03, g = .45; Digit Symbol Substitution Test (DSST): p = .04, g = .47; DSST Error Check: p < .001, g = .68] and executive function [Trail Making Test Ratio (A/B): p = .04, g = .52] tasks. MCI-AD performed worse than MCI-LB on memory tasks, specifically visuospatial (Modified Taylor Complex Figure: p = .01, g = .46) and verbal (Rey Auditory Verbal Learning Test: p = .04, g = .42) delayed recall measures. Stepwise discriminant analysis correctly classified the subtype in 65.1% of MCI patients (72.7% specificity, 56.4% sensitivity). Processing speed accounted for more group-associated variance in visuospatial and verbal memory in both MCI subtypes than executive function, while no significant relationships between measures were observed in controls (all ps > .05) Conclusions: MCI-LB was characterized by executive dysfunction and slowed processing speed but did not show the visuospatial dysfunction expected, while MCI-AD displayed an amnestic profile. However, there was considerable neuropsychological profile overlap and processing speed mediated performance in both MCI subtypes.

Blink rate study in patients with Alzheimer's disease, Mild Cognitive Impairment and Subjective Cognitive Decline

2021 ◽  
Vol 19 ◽  
Author(s):  
Fabrizia D’Antonio ◽  
Maria Ilenia De Bartolo ◽  
Gina Ferrazzano ◽  
Micaela Sepe Monti ◽  
Letizia Imbriano ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Cognitive Status ◽  
Subjective Cognitive Decline ◽  
Blink Rate ◽  
Compensatory Mechanisms ◽  
Rate Study

Background: Blink rate (BR) is considered a marker of dopaminergic activity in humans. BR is increased in patients with Mild Cognitive Impairment (MCI), but no study has yet investigated whether BR changes with the progression of cognitive decline from MCI to Alzheimer’s disease (AD) and whether BR abnormalities are present in subjects with Subjective Cognitive Decline (SCD). Objective: The aim of our study was to assess BR in patients with AD, MCI, and SCD and to correlate BR with demographic and clinical features of cognitive decline. Methods: We enrolled 22 subjects with SCD, 23 with MCI, and 18 with AD and a group of 20 age-matched healthy controls (HCs). Cognitive function was assessed by testing global cognitive status and frontal, attentional, memory, verbal, and visuospatial functions. BR was measured by counting the number of blinks per minute. Results: MCI subjects had an increased BR (p<0.001), whereas AD subjects had a lower BR than HCs (p<0.05). Conversely, SCD subjects had a BR similar to HCs. No significant correlations emerged between neuropsychological scores and BR in SCD, MCI, and AD subjects. Conclusion: Increased BR in MCI likely reflects early compensatory mechanisms occurring before AD, whereas decreased BR in AD suggests dopaminergic system involvement in this condition.

scholarly journals MRS in Mild Cognitive Impairment: Early Differentiation of Dementia with Lewy Bodies and Alzheimer's Disease

2014 ◽  
Vol 25 (2) ◽  
pp. 269-274 ◽  
Author(s):  
Bing Zhang ◽  
Tanis J. Ferman ◽  
Bradley F. Boeve ◽  
Glenn E. Smith ◽  
Mandie Maroney-Smith ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Dementia With Lewy Bodies ◽  
Lewy Bodies ◽  
Early Differentiation

scholarly journals Validity Evidence for the Research Category, “Cognitively Unimpaired – Declining,” as a Risk Marker for Mild Cognitive Impairment and Alzheimer’s Disease

2021 ◽  
Vol 13 ◽  
Author(s):  
Rebecca Langhough Koscik ◽  
Bruce P. Hermann ◽  
Samantha Allison ◽  
Lindsay R. Clark ◽  
Erin M. Jonaitis ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Operational Definition ◽  
Cognitive Status ◽  
Validity Evidence ◽  
Positron Emission ◽  
Clinically Significant

While clinically significant cognitive impairment is the key feature of the symptomatic stages of the Alzheimer’s disease (AD) continuum, subtle cognitive decline is now known to occur years before a clinical diagnosis of mild cognitive impairment (MCI) or dementia due to AD is made. The primary aim of this study was to examine criterion validity evidence for an operational definition of “cognitively unimpaired-declining” (CU-D) in the Wisconsin Registry for Alzheimer’s Prevention (WRAP), a longitudinal cohort study following cognition and risk factors from mid-life and on. Cognitive status was determined for each visit using a consensus review process that incorporated internal norms and published norms; a multi-disciplinary panel reviewed cases first to determine whether MCI or dementia was present, and subsequently whether CU-D was present, The CU-D group differed from CU-stable (CU-S) and MCI on concurrent measures of cognition, demonstrating concurrent validity. Participants who changed from CU-S to CU-D at the next study visit demonstrated greater declines than those who stayed CU-S. In addition, those who were CU-D were more likely to progress to MCI or dementia than those who were CU-S (predictive validity). In a subsample with positron emission tomography (PET) imaging, the CU-D group also differed from the CU-S and MCI/Dementia groups on measures of amyloid and tau burden, indicating that biomarker evidence of AD was elevated in those showing sub-clinical (CU-D) decline. Together, the results corroborate other studies showing that cognitive decline begins long before a dementia diagnosis and indicate that operational criteria can detect subclinical decline that may signal AD or other dementia risk.

Olfactory impairment in mild cognitive impairment with Lewy bodies and Alzheimer’s disease

2021 ◽  
pp. 1-8
Author(s):  
Alan J. Thomas ◽  
Calum A. Hamilton ◽  
Sally Barker ◽  
Rory Durcan ◽  
Sarah Lawley ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Lewy Bodies ◽  
Cutoff Score ◽  
Cross Sectional ◽  
North East ◽  
Olfactory Testing ◽  
Lower Cutoff

ABSTRACT Objectives: Impaired olfaction may be a biomarker for early Lewy body disease, but its value in mild cognitive impairment with Lewy bodies (MCI-LB) is unknown. We compared olfaction in MCI-LB with MCI due to Alzheimer’s disease (MCI-AD) and healthy older adults. We hypothesized that olfactory function would be worse in probable MCI-LB than in both MCI-AD and healthy comparison subjects (HC). Design: Cross-sectional study assessing olfaction using Sniffin’ Sticks 16 (SS-16) in MCI-LB, MCI-AD, and HC with longitudinal follow-up. Differences were adjusted for age, and receiver operating characteristic (ROC) curves were used for discriminating MCI-LB from MCI-AD and HC. Setting: Participants were recruited from Memory Services in the North East of England. Participants: Thirty-eight probable MCI-LB, 33 MCI-AD, 19 possible MCI-LB, and 32HC. Measurements: Olfaction was assessed using SS-16 and a questionnaire. Results: Participants with probable MCI-LB had worse olfaction than both MCI-AD (age-adjusted mean difference (B) = 2.05, 95% CI: 0.62–3.49, p = 0.005) and HC (B = 3.96, 95% CI: 2.51–5.40, p < 0.001). The previously identified cutoff score for the SS-16 of ≤ 10 had 84% sensitivity for probable MCI-LB (95% CI: 69–94%), but 30% specificity versus MCI-AD. ROC analysis found a lower cutoff of ≤ 7 was better (63% sensitivity for MCI-LB, with 73% specificity vs MCI-AD and 97% vs HC). Asking about olfactory impairments was not useful in identifying them. Conclusions: MCI-LB had worse olfaction than MCI-AD and normal aging. A lower cutoff score of ≤ 7 is required when using SS-16 in such patients. Olfactory testing may have value in identifying early LB disease in memory services.

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