scholarly journals Brain Resources: How Semantic Cueing Works in Mild Cognitive Impairment due to Alzheimer’s Disease (MCI-AD)

Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 108
Author(s):  
Andrea Brugnolo ◽  
Nicola Girtler ◽  
Elisa Doglione ◽  
Beatrice Orso ◽  
Federico Massa ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Left Hemisphere ◽  
Brain Metabolism ◽  
Mmse Score ◽  
Structural Connectivity ◽  
Anterior Cingulate ◽  
Study Results

Semantic cues in the Free and Cued Selective Reminding Test (FCRST) play a key role in the neuropsychological diagnosis of Amnesic Mild Cognitive Impairment due to Alzheimer’s Disease (MCI-AD); however, the neural bases of their impact of recall abilities are only partially understood. Here, we thus decided to investigate the relationships between brain metabolism and the FCSRT Index of Sensitivity of Cueing (ISC) in patients with MCI-AD and in healthy controls (HC). Materials: Thirty MCI-AD patients (age: 74.7 ± 5.7 years; education: 9.6 ± 4.6 years, MMSE score: 24.8 ± 3.3, 23 females) and seventeen HC (age: 66.5 ± 11.1 years; education: 11.53 ± 4.2 years, MMSE score: 28.4 ± 1.14, 10 females) who underwent neuropsychological evaluation and brain F-18 fluorodeoxyglucose Positron Emission Tomography (FDG-PET) were included in the study. Results: ISC was able to differentiate HC from MCI-AD subjects as shown by a ROC analysis (AUC of 0.978, effect size Hedges’s g = 2.89). MCI-AD subjects showed significant hypometabolism in posterior cortices, including bilateral inferior Parietal Lobule and Precuneus and Middle Temporal gyrus in the left hemisphere (VOI-1) compared to HC. ISC was positively correlated with brain metabolism in a single cluster (VOI-2) spanning the left prefrontal cortex (superior frontal gyrus) and anterior cingulate cortex (ACC) in the patient group (R2 = 0.526, p < 0.001), but not in HC. Mean uptake values of VOI-2 did not differ between HC and MCI-AD. The structural connectivity analysis showed that VOI-2 is connected with the temporal pole, the cingulate gyrus and the posterior temporal cortices in the left hemisphere. Conclusion: In MCI-AD, the relative preservation of frontal cortex metabolic levels and their correlation with the ISC suggest that the left frontal cortices play a significant role in maintaining a relatively good memory performance despite the presence of posterior hypometabolism in MCI-AD.

Reduced Thickness of the Anterior Cingulate Cortex as a Predictor of Amnestic-Mild Cognitive Impairment Conversion to Alzheimer’s Disease with Psychosis

2021 ◽  
pp. 1-9
Author(s):  
Hee-Jeong Jeong ◽  
Young-Min Lee ◽  
Je-Min Park ◽  
Byung-Dae Lee ◽  
Eunsoo Moon ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cortical Thickness ◽  
Cingulate Cortex ◽  
Amnestic Mild Cognitive Impairment ◽  
Anterior Cingulate ◽  
Prospective Longitudinal Study ◽  
Prospective Longitudinal

Background: A long-term follow-up study in patients with amnestic mild cognitive impairment (aMCI) is needed to elucidate the association between regional brain volume and psychopathological mechanisms of Alzheimer’s disease with psychosis (AD + P). Objective: The purpose of this study was to investigate the effect of the thickness of the angular cingulate cortex (ACC) on the risk of AD + P conversion in patients with aMCI. Methods: This was a hospital-based prospective longitudinal study including 174 patients with aMCI. The main outcome measure was time-to-progression from aMCI to AD + P. Subregions of the ACC (rostral ACC, rACC; caudal ACC, cACC) and hippocampus (HC) were measured as regions of interest with magnetic resonance imaging and the Freesurfer analysis at baseline. Survival analysis with time to incident AD + P as an event variable was calculated with Cox proportional hazards models using the subregions of the ACC and HC as a continuous variable. Results: Cox proportional hazard analyses showed that the risk of AD + P was associated with sub-regional ACC thickness but not HC volume: reduced cortical thickness of the left cACC (HR [95%CI], 0.224 [0.087–0.575], p = 0.002), right cACC (HR [95%CI], 0.318 [0.132–0.768], p = 0.011). This association of the cACC with the risk of AD also remained significant when adjusted for HC volume. Conclusion: We found that reduced cortical thickness of the cACC is a predictor of aMCI conversion to AD + P, independent of HC, suggesting that the ACC plays a vital role in the underlying pathogenesis of AD + P.

scholarly journals Altered Volume and Structural Connectivity of the Hippocampus in Alzheimer’s Disease and Amnestic Mild Cognitive Impairment

2021 ◽  
Vol 13 ◽  
Author(s):  
Feng Feng ◽  
Weijie Huang ◽  
Qingqing Meng ◽  
Weijun Hao ◽  
Hongxiang Yao ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Hippocampal Volume ◽  
Brain Regions ◽  
Amnestic Mild Cognitive Impairment ◽  
Hippocampal Atrophy

Background: Hippocampal atrophy is a characteristic of Alzheimer’s disease (AD). However, alterations in structural connectivity (number of connecting fibers) between the hippocampus and whole brain regions due to hippocampal atrophy remain largely unknown in AD and its prodromal stage, amnestic mild cognitive impairment (aMCI).Methods: We collected high-resolution structural MRI (sMRI) and diffusion tensor imaging (DTI) data from 36 AD patients, 30 aMCI patients, and 41 normal control (NC) subjects. First, the volume and structural connectivity of the bilateral hippocampi were compared among the three groups. Second, correlations between volume and structural connectivity in the ipsilateral hippocampus were further analyzed. Finally, classification ability by hippocampal volume, its structural connectivity, and their combination were evaluated.Results: Although the volume and structural connectivity of the bilateral hippocampi were decreased in patients with AD and aMCI, only hippocampal volume correlated with neuropsychological test scores. However, positive correlations between hippocampal volume and ipsilateral structural connectivity were displayed in patients with AD and aMCI. Furthermore, classification accuracy (ACC) was higher in AD vs. aMCI and aMCI vs. NC by the combination of hippocampal volume and structural connectivity than by a single parameter. The highest values of the area under the receiver operating characteristic (ROC) curve (AUC) in every two groups were all obtained by combining hippocampal volume and structural connectivity.Conclusions: Our results showed that the combination of hippocampal volume and structural connectivity (number of connecting fibers) is a new perspective for the discrimination of AD and aMCI.

scholarly journals Energy intake and expenditure in patients with Alzheimer’s disease and mild cognitive impairment: the NUDAD project

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Astrid S. Doorduijn ◽  
Marian A. E. de van der Schueren ◽  
Ondine van de Rest ◽  
Francisca A. de Leeuw ◽  
Heleen M. A. Hendriksen ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Energy Expenditure ◽  
Dietary Intake ◽  
Energy Intake ◽  
Mmse Score ◽  
Fat Free Mass ◽  
Dietary Advice

Abstract Background Malnutrition is common in patients with Alzheimer’s disease (AD) dementia and mild cognitive impairment (MCI) and is associated with institutionalization and increased mortality. Malnutrition is the result of a negative energy balance, which could be due to reduced dietary intake and/or higher energy expenditure. To study underlying mechanisms for malnutrition, we investigated dietary intake and resting energy expenditure (REE) of patients with AD dementia, MCI, and controls. In addition, we studied associations of global cognition (Mini-Mental State Examination (MMSE)) and AD biomarkers with dietary intake and REE. Methods We included 219 participants from the NUDAD project, 71 patients with AD dementia (age 68 ± 8 years, 58% female, MMSE 24 ± 3), 52 with MCI (67 ± 8 years, 42% female, MMSE 26 ± 2), and 96 controls (62 ± 7 years, 52% female, MMSE 28 ± 2). We used a 238-item food frequency questionnaire to assess dietary intake (energy, protein, carbohydrate, and fat). In a subgroup of 92 participants (30 patients with AD dementia, 22 with MCI, and 40 controls) we measured REE with indirect calorimetry. Between-group differences in dietary intake and REE were tested with ANOVAs. In the total sample, linear regression analyses were used to explore potential associations of MMSE score and AD biomarkers with dietary intake and REE. All analyses were adjusted for age, sex, education, and body mass index or fat-free mass. Results Patients with AD dementia and MCI did not differ from controls in total energy intake (1991 ± 71 and 2172 ± 80 vs 2022 ± 61 kcal/day, p > 0.05) nor in protein, carbohydrate, or fat intake. Patients with AD dementia and MCI had a higher REE than controls (1704 ± 41 and 1754 ± 47 vs 1569 ± 34 kcal/day, p < 0.05). We did not find any association of MMSE score or AD biomarkers with dietary intake or REE. Conclusions We found a higher REE, despite similar energy intake in patients with AD and MCI compared to controls. These findings suggest that elevated metabolism rather than reduced energy intake explains malnutrition in AD. These results could be useful to optimize dietary advice for patients with AD dementia and MCI.

scholarly journals Diagnostic power of resting-state fMRI for detection of network connectivity in Alzheimer's disease and Mild Cognitive Impairment: A systematic review

2020 ◽  
Author(s):  
BUHARI IBRAHIM ◽  
Nisha Syed Nasser ◽  
NORMALA IBRAHIM ◽  
Mazlyfarina Mohamed ◽  
Hasyma Abu Hassan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Resting State ◽  
Cingulate Cortex ◽  
Resting State Fmri ◽  
Anterior Cingulate ◽  
Healthy Controls ◽  
Diagnostic Power

Resting state fMRI (rs-fMRI) detects functional connectivity (FC) abnormalities that occur in the brains of patients with Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). FC of the default mode network (DMN), which is involved in memory consolidation, is commonly impaired in AD and MCI. We aimed to determine the diagnostic power of rs-fMRI to identify FC abnormalities in the DMN, which help to distinguish patients with AD or MCI from healthy controls (HCs). We searched articles in PubMed and Scopus databases using the search terms such as AD, MCI, resting-state fMRI, sensitivity and specificity through to 27th March 2020 and removed duplicate papers. We screened 390 published articles, and shortlisted 12 articles for the final analysis. The range of sensitivity of DMN FC at the posterior cingulate cortex (PCC) for diagnosing AD was between 65.7% - 100% and specificity ranged from 66 - 95%. Reduced DMN FC between the PCC and anterior cingulate cortex (ACC) in the frontal lobes was observed in MCI patients. AD patients had impaired FC in most regions of the DMN; particularly the PCC in early AD. This indicates that DMN's rs-fMRI FC can offer moderate to high diagnostic power to distinguish AD and MCI patients. fMRI detected abnormal DMN FC, particularly in the PCC that helps to differentiate AD and MCI patients from healthy controls (HCs). Combining multivariate method of analysis with other MRI parameters such as structural changes improve the diagnostic power of rs-fMRI in distinguishing patients with AD or MCI from HCs.

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