Gray Matter Changes in Parkinson’s and Alzheimer’s Disease and Relation to Cognition

Abstract Purpose of Review We summarize structural (s)MRI findings of gray matter (GM) atrophy related to cognitive impairment in Alzheimer’s disease (AD) and Parkinson’s disease (PD) in light of new analytical approaches and recent longitudinal studies results. Recent Findings The hippocampus-to-cortex ratio seems to be the best sMRI biomarker to discriminate between various AD subtypes, following the spatial distribution of tau pathology, and predict rate of cognitive decline. PD is clinically far more variable than AD, with heterogeneous underlying brain pathology. Novel multivariate approaches have been used to describe patterns of early subcortical and cortical changes that relate to more malignant courses of PD. Summary New emerging analytical approaches that combine structural MRI data with clinical and other biomarker outcomes hold promise for detecting specific GM changes in the early stages of PD and preclinical AD that may predict mild cognitive impairment and dementia conversion.

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TAU PATHOLOGY AND GRAY MATTER ATROPHY CONTRIBUTE TO COGNITIVE IMPAIRMENT IN ALZHEIMER’S DISEASE

Alzheimer s & Dementia ◽

10.1016/j.jalz.2017.07.316 ◽

2017 ◽

Vol 13 (7) ◽

pp. P902-P904

Author(s):

Alexandre Bejanin ◽

Daniel R. Schonhaut ◽

Renaud La Joie ◽

Joel H. Kramer ◽

Suzanne L. Baker ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Gray Matter ◽

Tau Pathology ◽

Gray Matter Atrophy

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[IC-P-176]: TAU PATHOLOGY AND GRAY MATTER ATROPHY CONTRIBUTE TO COGNITIVE IMPAIRMENT IN ALZHEIMER's DISEASE

Alzheimer s & Dementia ◽

10.1016/j.jalz.2017.06.2551 ◽

2017 ◽

Vol 13 (7S_Part_2) ◽

pp. P131-P131

Author(s):

Alexandre Bejanin ◽

Daniel R. Schonhaut ◽

Renaud La Joie ◽

Joel H. Kramer ◽

Suzanne L. Baker ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Gray Matter ◽

Tau Pathology ◽

Gray Matter Atrophy

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Anosognosia in Amnestic Mild Cognitive Impairment Is Related to Diminished Hippocampal Volume Comparable to Alzheimer’s Disease Dementia: Preliminary MRI Findings

Frontiers in Aging Neuroscience ◽

10.3389/fnagi.2021.739422 ◽

2021 ◽

Vol 13 ◽

Author(s):

Juan Francisco Flores-Vázquez ◽

Gabriel Ramírez-García ◽

Oscar René Marrufo-Meléndez ◽

Ruth Alcalá-Lozano ◽

Morten Peter Lietz ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Gray Matter ◽

Mean Diffusivity ◽

Amnestic Mild Cognitive Impairment ◽

Matter Density ◽

Mri Findings ◽

Gray Matter Density

Although the presence of anosognosia in amnestic mild cognitive impairment (aMCI) may be predictive of conversion to Alzheimer’s disease (AD), little is known about its neural correlates in AD and aMCI. Four different groups were compared using volumetric and diffusion magnetic resonance imaging metrics in regions of interest (hippocampus and cingulum cortex gray matter, cingulum bundle white matter): aMCI subjects with anosognosia (n = 6), aMCI subjects without anosognosia (n = 12), AD subjects with anosognosia (n = 6), and AD subjects without anosognosia (n = 9). aMCI subjects with anosognosia displayed a significantly lower gray matter density (GMD) in the bilateral hippocampus than aMCI subjects without anosognosia, which was accounted for by bilateral hippocampal differences. Furthermore, we identified that the mean hippocampal gray matter density of aMCI subjects with anosognosia was not statistically different than that of AD subjects. The groups of aMCI and AD subjects with anosognosia also displayed a lower GMD in the bilateral cingulum cortex compared to subjects without anosognosia, but these differences were not statistically significant. No statistically significant differences were found in the fractional anisotropy or mean diffusivity of the hippocampus or cingulum between subjects with and without anosognosia in aMCI or AD groups. While these findings are derived from a small population of subjects and are in need of replication, they suggest that anosognosia in aMCI might be a useful clinical marker to suspect brain changes associated with AD neuropathology.

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Cognitive Performance and Cerebrospinal Fluid Markers in Preclinical Alzheimer’s Disease: Results from the Gothenburg H70 Birth Cohort Studies

Journal of Alzheimer s Disease ◽

10.3233/jad-200751 ◽

2021 ◽

Vol 79 (1) ◽

pp. 225-235

Author(s):

Maya Arvidsson Rådestig ◽

Johan Skoog ◽

Henrik Zetterberg ◽

Jürgen Kern ◽

Anna Zettergren ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cerebrospinal Fluid ◽

Cohort Studies ◽

Cognitive Performance ◽

Birth Cohort ◽

Population Based ◽

Tau Pathology ◽

Preclinical Alzheimer’S Disease ◽

Preclinical Ad

Background: We have previously shown that older adults with preclinical Alzheimer’s disease (AD) pathology in cerebrospinal fluid (CSF) had slightly worse performance in Mini-Mental State Examination (MMSE) than participants without preclinical AD pathology. Objective: We therefore aimed to compare performance on neurocognitive tests in a population-based sample of 70-year-olds with and without CSF AD pathology. Methods: The sample was derived from the population-based Gothenburg H70 Birth Cohort Studies in Sweden. Participants (n = 316, 70 years old) underwent comprehensive cognitive examinations, and CSF Aβ-42, Aβ-40, T-tau, and P-tau concentrations were measured. Participants were classified according to the ATN system, and according to their Clinical Dementia Rating (CDR) score. Cognitive performance was examined in the CSF amyloid, tau, and neurodegeneration (ATN) categories. Results: Among participants with CDR 0 (n = 259), those with amyloid (A+) and/or tau pathology (T+, N+) showed similar performance on most cognitive tests compared to participants with A-T-N-. Participants with A-T-N+ performed worse in memory (Supra span (p = 0.003), object Delayed (p = 0.042) and Immediate recall (p = 0.033)). Among participants with CDR 0.5 (n = 57), those with amyloid pathology (A+) scored worse in category fluency (p = 0.003). Conclusion: Cognitively normal participants with amyloid and/or tau pathology performed similarly to those without any biomarker evidence of preclinical AD in most cognitive domains, with the exception of slightly poorer memory performance in A-T-N+. Our study suggests that preclinical AD biomarkers are altered before cognitive decline.

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Brain mechanisms underlying neuropsychiatric symptoms in Alzheimer’s disease: a systematic review of symptom-general and –specific lesion patterns

Molecular Neurodegeneration ◽

10.1186/s13024-021-00456-1 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Yaojing Chen ◽

Mingxi Dang ◽

Zhanjun Zhang

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Neuropsychiatric Symptoms ◽

Onset Time ◽

Anterior Cingulate ◽

Neural Basis ◽

Preclinical Ad ◽

Disease Stages ◽

Mild Cognitive Impairment Stage

AbstractNeuropsychiatric symptoms (NPSs) are common in patients with Alzheimer’s disease (AD) and are associated with accelerated cognitive impairment and earlier deaths. This review aims to explore the neural pathogenesis of NPSs in AD and its association with the progression of AD. We first provide a literature overview on the onset times of NPSs. Different NPSs occur in different disease stages of AD, but most symptoms appear in the preclinical AD or mild cognitive impairment stage and develop progressively. Next, we describe symptom-general and -specific patterns of brain lesions. Generally, the anterior cingulate cortex is a commonly damaged region across all symptoms, and the prefrontal cortex, especially the orbitofrontal cortex, is also a critical region associated with most NPSs. In contrast, the anterior cingulate-subcortical circuit is specifically related to apathy in AD, the frontal-limbic circuit is related to depression, and the amygdala circuit is related to anxiety. Finally, we elucidate the associations between the NPSs and AD by combining the onset time with the neural basis of NPSs.

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A comparison of resting state EEG and structural MRI for classifying Alzheimer’s disease and mild cognitive impairment

NeuroImage ◽

10.1016/j.neuroimage.2020.116795 ◽

2020 ◽

Vol 215 ◽

pp. 116795 ◽

Cited By ~ 2

Author(s):

F.R. Farina ◽

D.D. Emek-Savaş ◽

L. Rueda-Delgado ◽

R. Boyle ◽

H. Kiiski ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Resting State ◽

Structural Mri

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A comparison of resting state EEG and structural MRI for classifying Alzheimer’s disease and mild cognitive impairment

10.1101/711465 ◽

2019 ◽

Author(s):

FR Farina ◽

DD Emek-Savaş ◽

L Rueda-Delgado ◽

R Boyle ◽

H Kiiski ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Resting State ◽

Healthy Aging ◽

Neurodegenerative Disorder ◽

Low Cost ◽

Structural Mri ◽

Lower Accuracy

AbstractAlzheimer’s disease (AD) is a neurodegenerative disorder characterised by severe cognitive decline and loss of autonomy. AD is the leading cause of dementia. AD is preceded by mild cognitive impairment (MCI). By 2050, 68% of new dementia cases will occur in low- and middle-income countries. In the absence of objective biomarkers, psychological assessments are typically used to diagnose MCI and AD. However, these require specialist training and rely on subjective judgements. The need for low-cost, accessible and objective tools to aid AD and MCI diagnosis is therefore crucial. Electroencephalography (EEG) has potential as one such tool: it is relatively inexpensive (cf. magnetic resonance imaging; MRI) and is portable. In this study, we collected resting state EEG, structural MRI and rich neuropsychological data from older adults (55+ years) with AD, with MCI and from healthy controls (n~60 per group). Our goal was to evaluate the utility of EEG, relative to MRI, for the classification of MCI and AD. We also assessed the performance of combined EEG and behavioural (Mini-Mental State Examination; MMSE) and structural MRI classification models. Resting state EEG classified AD and HC participants with moderate accuracy (AROC=0.76), with lower accuracy when distinguishing MCI from HC participants (AROC=0.67). The addition of EEG data to MMSE scores had no additional value compared to MMSE alone. Structural MRI out-performed EEG (AD vs HC, AD vs MCI: AROCs=1.00; HC vs MCI: AROC=0.73). Resting state EEG does not appear to be a suitable tool for classifying AD. However, EEG classification accuracy was comparable to structural MRI when distinguishing MCI from healthy aging, although neither were sufficiently accurate to have clinical utility. This is the first direct comparison of EEG and MRI as classification tools in AD and MCI participants.

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Progressive Volume Atrophy in Hippocampal Subfields and the Correlation with Cognition in Alzheimer’s Disease and Mild Cognitive Impairment

10.21203/rs.3.rs-304948/v1 ◽

2021 ◽

Author(s):

Guixia Kang ◽

Peiqi Luo ◽

Xin Xu ◽

Ying Han ◽

Xuemei Li ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Reference Value ◽

Structural Mri ◽

Volume Changes ◽

Brain Scans ◽

Left Hippocampus ◽

The Right

Abstract Objective: To assess the progression of volume changes in hippocampus and its subfields of patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI), and to explore the association of the hippocampus and its subfields volumes with cognitive function.Methods: Five groups of participants including 35 normal controls (NC) persons, 30 MCI patients, 30 Mild AD patients, 30 Moderate AD patients and 8 Severe AD patients received structural MRI brain scans. Freesurfer6.0 was used for automatically segmentation of MRI, and the left and right hippocampus were respectively divided into 12 subfields. By statistical analysis, the volumes of hippocampus and its subfields were compared between the five groups, and the correlation of the volumes with Mini-mental State Examination (MMSE) score was analyzed.Result & Conclusion: In the disease, each hippocampal subfield shows an uneven atrophy trajectory; The volumes of the subiculum and presubiculum are significantly different between Mild AD and MCI, which can contribute to the early diagnosis of AD; Parasubiculum is the least sensitive subfield for volume atrophy of AD, while subiculum, presubiculum, CA1, molecular_layer_HP and fimbria show much more significant volume changes. Meanwhile the volumes of these five subfields are positively correlated with MMSE, which may help in stage division of AD; Compared with the right hippocampus, the volume atrophy on the left side is more significantly, and the volumes are more significantly correlated with MMSE, So the left hippocampus and its subfields may provide a higher reference value for the clinical evaluation of AD than the right side.

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