P4-141: Performance of the different proposed criteria for the diagnosis of mild cognitive impairment and Alzheimer's disease: Data from the Australian Imaging, Biomarkers and Lifestyle study of aging

2013 ◽  
Vol 9 ◽  
pp. P755-P756 ◽  
Author(s):  
Yi-Hsuan Chen ◽  
Cassandra Szoeke ◽  
Michael Woodward
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Imaging Biomarkers

scholarly journals Disruption of gray matter microstructure in Alzheimer’s disease continuum using fiber orientation

2020 ◽  
Author(s):  
Peter Lee ◽  
Hang-Rai Kim ◽  
Yong Jeong
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Early Diagnosis ◽  
Gray Matter ◽  
Fiber Orientation ◽  
Imaging Biomarkers ◽  
Normal Vector ◽  
Higher Sensitivity

Abstract There have been several MR imaging biomarkers of Alzheimer’s disease (AD) for early diagnosis. Cortical mean diffusivity (MD) is one of them for the study of the cortical microstructural change in AD. However, several factors may overshadow the feasibility of MD as AD biomarker. Thus, current study investigated feasible gray matter microstructure biomarker with higher sensitivity for early AD detection. With the aim of facilitating the early detection of AD, the Alzheimer’s Disease Neuroimaging Initiative (ADNI) proposed two stages based on the memory performance: early mild cognitive impairment (EMCI) and late mild cognitive impairment (LMCI). We propose single shell DTI measure, ‘ radiality ’, for early AD biomarker. It is a dot product between cortical surface normal vector and primary diffusion direction, which presumably reflects the fiber orientation within the cortical column. Here, we gathered images from ADNI phase 2 & 3; 78 cognitive normal, 51 EMCI, 34 LMCI, and 39 AD patients. Then, we evaluated cortical thickness (CTh), MD, amount of amyloid and tau accumulations using PET, which are conventional AD biomarkers. Radiality was projected on gray matter surface to compare and validate the changes along other neuroimage biomarkers. Results showed decreased radiality primarily in entorhinal, insula, frontal and temporal cortex as disease progress onward. Especially, radiality could delineate the difference between cognitive normal and EMCI group while other biomarkers could not. We looked into the relationship between the radiality and other biomarkers to validate its pathological evidence in AD. Overall, radiality showed high association with conventional biomarkers. Additional ROI analysis exhibit dynamics of AD related changes as stages onward. In conclusion, radiality in cortical gray matter showed AD specific changes and relevance with other conventional AD biomarkers with higher sensitivity. Besides, it could show group differences in early AD changes from EMCI which show advantage for early diagnosis than using conventional biomarkers. We provide the evidence of structure changes with cognitive impairment and suggest radiality as a sensitive biomarker for early diagnose and progress monitor AD.

Cognitive Enhancement at the Mild Cognitive Impairment Stage of Alzheimer’s Disease

2017 ◽  
Author(s):  
Zara Melikyan ◽  
Heather Romero ◽  
Kathleen A. Welsh-Bohmer
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Brain Aging ◽  
Therapeutic Interventions ◽  
Imaging Biomarkers ◽  
Challenges And Opportunities ◽  
Future Challenges ◽  
Neuronal Systems

Alzheimer’s disease (AD) is the most common cause of dementia in aging. Currently, therapeutic interventions are being initiated earlier in the disease course. The rationale of this strategy is to take advantage of the still healthy neuronal systems to optimize function, slow cognitive decline, and facilitate adaptive compensation in deficient brain networks. This chapter provides an overview and critique of the evidence supporting the enhancement of cognitive function at the early symptomatic stage of AD, so-called mild cognitive impairment due to AD (MCI-AD). It reviews the clinical diagnosis of MCI-AD, underscoring the differences between this condition and healthy brain aging and highlighting the importance of fluid and imaging biomarkers in ensuring reliable diagnosis and providing targets for therapeutic modification. Next, it discusses techniques to enhance cognition in MCI, with an emphasis on nonpharmacological interventional approaches. It concludes with a discussion of future challenges and opportunities in the treatment of MCI-AD.

Aggregation of Abnormal Memory Scores and Risk of Incident Alzheimer’s Disease Dementia: A Measure of Objective Memory Impairment in Amnestic Mild Cognitive Impairment

2020 ◽  
pp. 1-12
Author(s):  
Nicholas I. Bradfield ◽  
Kathryn A. Ellis ◽  
Greg Savage ◽  
Paul Maruff ◽  
Samantha Burnham ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Sex Education ◽  
Memory Impairment ◽  
Characteristic Curve ◽  
Imaging Biomarkers ◽  
Subjective Memory ◽  
Prognostic Stratification

Abstract Objectives: The criteria for objective memory impairment in mild cognitive impairment (MCI) are vaguely defined. Aggregating the number of abnormal memory scores (NAMS) is one way to operationalise memory impairment, which we hypothesised would predict progression to Alzheimer’s disease (AD) dementia. Methods: As part of the Australian Imaging, Biomarkers and Lifestyle Flagship Study of Ageing, 896 older adults who did not have dementia were administered a psychometric battery including three neuropsychological tests of memory, yielding 10 indices of memory. We calculated the number of memory scores corresponding to z ≤ −1.5 (i.e., NAMS) for each participant. Incident diagnosis of AD dementia was established by consensus of an expert panel after 3 years. Results: Of the 722 (80.6%) participants who were followed up, 54 (7.5%) developed AD dementia. There was a strong correlation between NAMS and probability of developing AD dementia (r = .91, p = .0003). Each abnormal memory score conferred an additional 9.8% risk of progressing to AD dementia. The area under the receiver operating characteristic curve for NAMS was 0.87 [95% confidence interval (CI) .81–.93, p < .01]. The odds ratio for NAMS was 1.67 (95% CI 1.40–2.01, p < .01) after correcting for age, sex, education, estimated intelligence quotient, subjective memory complaint, Mini-Mental State Exam (MMSE) score and apolipoprotein E ϵ4 status. Conclusions: Aggregation of abnormal memory scores may be a useful way of operationalising objective memory impairment, predicting incident AD dementia and providing prognostic stratification for individuals with MCI.

scholarly journals Detection of gray matter microstructural changes in Alzheimer’s disease continuum using fiber orientation

2020 ◽  
Author(s):  
Peter Lee ◽  
Hang-Rai Kim ◽  
Yong Jeong
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Gray Matter ◽  
Fiber Orientation ◽  
Diffusion Tensor ◽  
Imaging Biomarkers ◽  
Normal Vector ◽  
Higher Sensitivity

Abstract Background: This study aims to investigate feasible gray matter microstructural biomarker with higher sensitivity for early Alzheimer’s disease (AD) detection. We propose diffusion tensor imaging (DTI) measure, ‘radiality’, for early AD biomarker. It is a dot product between cortical surface normal vector and primary diffusion direction, which reflects the fiber orientation within the cortical column. Methods: We gathered neuroimages from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database: 78 cognitive normal, 50 early mild cognitive impairment (EMCI), 34 late mild cognitive impairment (LMCI), and 39 AD patients. Then, we evaluated cortical thickness (CTh), mean diffusivity (MD), amount of amyloid and tau accumulations using positron emission tomography (PET), which are conventional AD magnetic resonance (MR) imaging biomarkers. Radiality was projected on gray matter surface to compare and validate the changes along stages with other neuroimage biomarkers. Results: Results showed decreased radiality primarily in entorhinal, insula, frontal and temporal cortex as disease progresses onward. Especially, radiality could delineate the difference between cognitive normal and EMCI group while other biomarkers could not. We looked into the relationship between the radiality and other biomarkers to validate its pathological evidence in AD. Overall, radiality showed high association with conventional biomarkers. Additional ROI analysis exhibits dynamics of AD related changes as stages onward. Conclusion: Radiality in cortical gray matter showed AD specific changes and relevance with other conventional AD biomarkers with higher sensitivity. Besides, it could show group differences in early AD changes from EMCI which show advantage for early diagnosis than using conventional biomarkers. We provide the evidence of structure changes with cognitive impairment and suggest radiality as a sensitive biomarker for early AD.

scholarly journals Disruption of gray matter microstructure in Alzheimer’s disease continuum using fiber orientation

2020 ◽  
Author(s):  
Peter Lee ◽  
Hang-Rai Kim ◽  
Yong Jeong
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Early Diagnosis ◽  
Gray Matter ◽  
Fiber Orientation ◽  
Imaging Biomarkers ◽  
Normal Vector ◽  
Higher Sensitivity

Abstract There have been several MR imaging biomarkers of Alzheimer’s disease (AD) for early diagnosis. Cortical mean diffusivity (MD) is one of them for the study of the cortical microstructural change in AD. However, the feasibility of MD often remain in doubt as partial volume effects may overestimate the results. This study aims to investigate feasible gray matter microstructural biomarker with higher sensitivity for early AD detection. We propose diffusion tensor imaging (DTI) measure, ‘radiality’, for early AD biomarker. It is a dot product between cortical surface normal vector and primary diffusion direction, which reflects the fiber orientation within the cortical column. Here, we gathered neuroimages from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database; 78 cognitive normal, 50 early mild cognitive impairment (EMCI), 34 late mild cognitive impairment (LMCI), and 39 AD patients. Then, we evaluated cortical thickness (CTh), MD, amount of amyloid and tau accumulations using positron emission tomography (PET), which are conventional AD biomarkers. Radiality was projected on gray matter surface to compare and validate the changes along other neuroimage biomarkers. Results showed decreased radiality primarily in entorhinal, insula, frontal and temporal cortex as disease progress onward. Especially, radiality could delineate the difference between cognitive normal and EMCI group while other biomarkers could not. We looked into the relationship between the radiality and other biomarkers to validate its pathological evidence in AD. Overall, radiality showed high association with conventional biomarkers. Additional ROI analysis exhibits dynamics of AD related changes as stages onward. In conclusion, radiality in cortical gray matter showed AD specific changes and relevance with other conventional AD biomarkers with higher sensitivity. Besides, it could show group differences in early AD changes from EMCI which show advantage for early diagnosis than using conventional biomarkers. We provide the evidence of structure changes with cognitive impairment and suggest radiality as a sensitive biomarker for early AD.

scholarly journals Detection of gray matter microstructural changes in Alzheimer’s disease continuum using fiber orientation

2020 ◽  
Author(s):  
Peter Lee ◽  
Hang-Rai Kim ◽  
Yong Jeong
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Early Diagnosis ◽  
Gray Matter ◽  
Fiber Orientation ◽  
Imaging Biomarkers ◽  
Normal Vector ◽  
Higher Sensitivity

Abstract There have been several magnetic resonance (MR) imaging biomarkers of Alzheimer’s disease (AD) for early diagnosis. Cortical mean diffusivity (MD) is one of them for the study of the cortical microstructural change in AD. However, the feasibility of MD often remains in doubt as partial volume effects may overestimate the results. This study aims to investigate feasible gray matter microstructural biomarker with higher sensitivity for early AD detection. We propose diffusion tensor imaging (DTI) measure, ‘radiality’, for early AD biomarker. It is a dot product between cortical surface normal vector and primary diffusion direction, which reflects the fiber orientation within the cortical column. Here, we gathered neuroimages from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database: 78 cognitive normal, 50 early mild cognitive impairment (EMCI), 34 late mild cognitive impairment (LMCI), and 39 AD patients. Then, we evaluated cortical thickness (CTh), MD, amount of amyloid and tau accumulations using positron emission tomography (PET), which are conventional AD biomarkers. Radiality was projected on gray matter surface to compare and validate the changes along other neuroimage biomarkers. Results showed decreased radiality primarily in entorhinal, insula, frontal and temporal cortex as disease progresses onward. Especially, radiality could delineate the difference between cognitive normal and EMCI group while other biomarkers could not. We looked into the relationship between the radiality and other biomarkers to validate its pathological evidence in AD. Overall, radiality showed high association with conventional biomarkers. Additional ROI analysis exhibits dynamics of AD related changes as stages onward. In conclusion, radiality in cortical gray matter showed AD specific changes and relevance with other conventional AD biomarkers with higher sensitivity. Besides, it could show group differences in early AD changes from EMCI which show advantage for early diagnosis than using conventional biomarkers. We provide the evidence of structure changes with cognitive impairment and suggest radiality as a sensitive biomarker for early AD.

Sign in / Sign up

Export Citation Format

Share Document