Clinical, Neuropsychological, and Neuroimaging Characteristics of Amyloid-positive vs. Amyloid-negative Patients with Clinically Diagnosed Alzheimer’s Disease and Amnestic Mild Cognitive Impairment

2021 ◽  
Vol 18 ◽  
Author(s):  
Yue Wang ◽  
Fanghua Lou ◽  
Yonggang Li ◽  
Fang Liu ◽  
Ying Wang ◽  
...  

Background: A significant proportion of patients with clinically diagnosed Alzheimer’s disease (AD) and an even higher proportion of patients with amnestic mild cognitive impairment (aMCI) do not show evidence of amyloid deposition on positron emission tomography (PET) with amyloid-binding tracers such as 11C-labeled Pittsburgh Compound B (PiB). Objective: This study aimed to identify clinical, neuropsychological and neuroimaging factors that might suggest amyloid neuropathology in patients with clinically suspected AD or aMCI. Methods: Forty patients with mild to moderate AD and 23 patients with aMCI who were clinically diagnosed in our memory clinic and had PiB PET scans were included. Clinical, neuropsychologi- cal, and imaging characteristics, such as medial temporal lobe atrophy (MTA) and white matter hy- perintensities (WMH) on MRI and metabolic pattern on 18F-labeled fluorodeoxyglucose (FDG) PET, were compared between patients with PiB positive and negative PET results for AD, aMCI, and all subjects combined, respectively. Results: Compared with PiB positive patients, PiB negative patients had a higher prevalence of hy- pertension history, better performance on the Mini-Mental State Examination, the Rey Auditory Verbal Learning Test, and the Judgement of Line Orientation, lower score of MTA, and were less likely to have temporoparietal-predominant hypometabolism on FDG PET. Affective symptoms were less common in PiB negative patients diagnosed with AD, and the Animal Fluency Test score was higher in PiB negative patients diagnosed with aMCI. Conclusion: : In patients with clinically diagnosed AD or aMCI, absence of a history of hyperten- sion, deficits in verbal learning and memory, visuospatial function, semantic verbal fluency, pres- ence of affective symptoms, MTA on MRI, and temporoparietal hypometabolism on FDG PET suggested amyloid deposition in the brain.

2007 ◽  
Vol 65 (3a) ◽  
pp. 619-622 ◽  
Author(s):  
Marcio L.F. Balthazar ◽  
José E. Martinelli ◽  
Fernando Cendes ◽  
Benito P. Damasceno

OBJECTIVE: To study lexical semantic memory in patients with amnestic mild cognitive impairment (aMCI), mild Alzheimer's disease (AD) and normal controls. METHOD: Fifteen mild AD, 15 aMCI, and 15 normal control subjects were included. Diagnosis of AD was based on DSM-IV and NINCDS-ADRDA criteria, and that of aMCI, on the criteria of the International Working Group on Mild Cognitive Impairment, using CDR 0.5 for aMCI and CDR 1 for mild AD. All subjects underwent semantic memory tests (Boston Naming-BNT, CAMCOG Similarities item), Rey Auditory Verbal Learning Test (RAVLT), Mini-Mental Status Examination (MMSE), neuropsychological tests (counterproofs), and Cornell Scale for Depression in Dementia. Data analysis used Mann-Whitney test for intergroup comparisons and Pearson's coefficient for correlations between memory tests and counterproofs (statistical significance level was p<0.05). RESULTS: aMCI patients were similar to controls on BNT and Similarities, but worse on MMSE and RAVLT. Mild AD patients scored significantly worse than aMCI and controls on all tests. CONCLUSION: aMCI impairs episodic memory but tends to spare lexical semantic system, which can be affected in the early phase of AD.


2004 ◽  
Vol 25 ◽  
pp. S280
Author(s):  
Kejal Kantarci ◽  
Bradley J. Kemp ◽  
Val J. Lowe ◽  
Ronald C. Petersen ◽  
Bradley F. Boeve ◽  
...  

2022 ◽  
Author(s):  
Aleksandra Wabik ◽  
Elżbieta Trypka ◽  
Joanna Bladowska ◽  
Mikołaj Statkiewicz ◽  
Marek Sąsiadek ◽  
...  

Abstract Background: The aim of this study was to compare Dynamic Susceptibility Contrast Enhanced MRI (DSC-MRI) and PET with flurodeoxyglucose (FDG-PET) in the diagnosis of Alzheimer’s Disease (AD) and amnestic Mild Cognitive Impairment (aMCI).Methods: Age and sex matched 27 patients with AD, 39 with aMCI and 16 controls underwent brain DSC-MRI followed by FDG-PET. Values of relative Cerebral Blood Volume (rCBV) and rCBV z-scores from frontal, temporal, parietal and PCG cortices were correlated with the rate of glucose metabolism from PET. Sensitivity, specificity and accuracy of DSC-MRI and FDG-PET in the diagnosis of AD and aMCI were assessed and compared.Results: In AD hypoperfusion was found within all examined locations, while in aMCI in both parietal and temporal cortices and left PCG. FDG-PET showed the greatest hypometabolism in parietal, temporal and left PCG regions in both AD and aMCI. FDG-PET was more accurate in distinguishing aMCI from controls than DSC-MRI. In AD and combined group (AD + aMCI ) there were numerous correlations between DSC-MRI and FDG-PET results. Conclusions: In AD the patterns of hypoperfusion and glucose hypometabolism are similar thus DSC-MRI may be a competitive method to FDG-PET. FDG-PET is a more accurate method in the diagnosis of aMCI.


2008 ◽  
Vol 2 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Nathalia Carollina Peruzza Marchiani ◽  
Marcio Luiz Figueredo Balthazar ◽  
Fernando Cendes ◽  
Benito Pereira Damasceno

Abstract To evaluate hippocampal volume in patients with AD and aMCI, and correlate its atrophy with verbal episodic memory performance. Methods: We studied 42 individuals older than 50 years, including 14 with amnestic mild cognitive impairment (aMCI), 14 with mild Alzheimer's disease (AD) and 14 normal controls. All individuals were submitted to the Rey auditory verbal learning test (RAVLT) to evaluate episodic memory. They were also submitted to the forward (FDS) and backward digit span (BDS) subtest of WAIS-R to evaluate working memory and attention, and to the Mini Mental State Examination (MMSE). Hippocampal volumetric measurements were performed according to anatomic guidelines from a standard protocol using high-resolution T1-inversion recovery 3-mm coronal MRI slices. Hippocampal volumes (HV) were corrected for the variation in total intracranial volume. There was no significant difference between the three groups concerning age and education. Results: On RAVLT, there was a continuum between the three groups, with AD recalling less words, controls more, and aMCI subjects showing an intermediate performance on all sub-items. We found an asymmetry between HVs, with smaller mean left HV for all groups. ANOVA and post hoc Tukey's test for comparisons of HV showed a significant difference among groups, with difference between controls and both AD and aMCI, although there was no significant difference between AD and aMCI groups. Conclusions: There was a significant correlation between hippocampal volumes and scores on RAVLT, confirming that medial temporal structures are closely associated with memory performance in normal ageing as well as in aMCI and AD.


2021 ◽  
pp. 1-13
Author(s):  
Weihua Li ◽  
Zhilian Zhao ◽  
Min Liu ◽  
Shaozhen Yan ◽  
Yanhong An ◽  
...  

Background: Alzheimer’s disease (AD) is a progressive neurodegenerative disease characterized by cognitive decline and memory impairment. Amnestic mild cognitive impairment (aMCI) is the intermediate stage between normal cognitive aging and early dementia caused by AD. It can be challenging to differentiate aMCI patients from healthy controls (HC) and mild AD patients. Objective: To validate whether the combination of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) and diffusion tensor imaging (DTI) will improve classification performance compared with that based on a single modality. Methods: A total of thirty patients with AD, sixty patients with aMCI, and fifty healthy controls were included. AD was diagnosed according to the National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer’s Disease and Related Disorders Association (NINCDS-ADRDA) criteria for probable. aMCI diagnosis was based on Petersen’s criteria. The 18F-FDG PET and DTI measures were each used separately or in combination to evaluate sensitivity, specificity, and accuracy for differentiating HC, aMCI, and AD using receiver operating characteristic analysis together with binary logistic regression. The rate of accuracy was based on the area under the curve (AUC). Results: For classifying AD from HC, we achieve an AUC of 0.96 when combining two modalities of biomarkers and 0.93 when using 18F-FDG PET individually. For classifying aMCI from HC, we achieve an AUC of 0.79 and 0.76 using the best individual modality of biomarkers. Conclusion: Our results show that the combination of two modalities improves classification performance, compared with that using any individual modality.


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