A preliminary study of functional abnormalities in aMCI subjects during different episodic memory tasks

Mu, Jin; Pelak, Victoria S.; Curran, Tim; Nandy, Rajesh; Cordes, Dietmar

doi:10.1016/j.mri.2011.12.014

Cited by 21 publications

(23 citation statements)

References 54 publications

(88 reference statements)

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“…Browndyke et al (2013), however, included four of them except one (Clément and Belleville, 2010). With respect to the lower activation foci in aMCI in the MTL structure, six studies (Trivedi et al, 2008; Mandzia et al, 2009; Hampstead et al, 2011; Hanseeuw et al, 2011; Jin et al, 2012; van der Meulen et al, 2012) were analyzed in the present study providing nine foci. Browndyke et al (2013), however, included only three studies (Johnson et al, 2006, 2008; Trivedi et al, 2008) with five foci.…”

Section: Discussionmentioning

confidence: 98%

“…Considering the dysfunctional inhibition of distracting information in AD (Baddeley et al, 2001; Amieva et al, 2004), individuals with aMCI may need more effort to regulate this form of attentional control. Alternatively, as suggested by Jin et al, the elevated activation in precentral gyrus and superior motor area in individuals with aMCI may be caused by the active control state which is not memory relevant (Jin et al, 2012). However, considering the memory task procedures used in the included studies of current meta-analysis, participants performed almost the equal active control effort in both memory processing and baseline task.…”

Section: Discussionmentioning

confidence: 99%

“…Regarding the pattern of activity in neocortical areas, there is an absence of consensus in the literature of individuals with aMCI. In some studies, MTL dysfunction went with concomitant increases in PFC activity, parietal or other sites in both encoding (Heun et al, 2007; Clément and Belleville, 2012) and retrieval (Jin et al, 2012). This leads to the possibility that such changes may represent compensatory increases as a result of the MTL dysfunction.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mild Cognitive Impairment Is Not “Mild” at All in Altered Activation of Episodic Memory Brain Networks: Evidence from ALE Meta-Analysis

Wang

et al. 2016

Front. Aging Neurosci.

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The present study conducted a quantitative meta-analysis aiming at assessing consensus across the functional neuroimaging studies of episodic memory in individuals with amnestic mild cognitive impairment (aMCI) and elucidating consistent activation patterns. An activation likelihood estimation (ALE) was conducted on the functional neuroimaging studies of episodic encoding and retrieval in aMCI individuals published up to March 31, 2015. Analyses covered 24 studies, which yielded 770 distinct foci. Compared to healthy controls, aMCI individuals showed statistically significant consistent activation differences in a widespread episodic memory network, not only in the bilateral medial temporal lobe and prefrontal cortex, but also in the angular gyrus, precunes, posterior cingulate cortex, and even certain more basic structures. The present ALE meta-analysis revealed that the abnormal patterns of widespread episodic memory network indicated that individuals with aMCI may not be completely “mild” in nature.

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Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Mild Cognitive Impairment Is Not “Mild” at All in Altered Activation of Episodic Memory Brain Networks: Evidence from ALE Meta-Analysis

Wang

et al. 2016

Front. Aging Neurosci.

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“… Giovanello, et al 2012 [63] 12 aMCI, 12 CNC Word pair association Whole brain Reduced R inferior and superior frontal gyri, increased anterior cingulate and inferior frontal gyrus activation. Jin, et al 2012 [64] 8 aMCI, 8 CNC Scene encoding, face-occupation and object-location association Whole brain, ROI (MTL) Reduced MTL; increased medial PFC, L precentral and superior motor area activation during scene encoding. Increased L angular gyrus, R cuneus/precuneus activation during face-occupation task.…”

Section: Functional Mrimentioning

confidence: 99%

Current understanding of magnetic resonance imaging biomarkers and memory in Alzheimer's disease

Bayram

Caldwell

Banks

2018

A&D Transl Res & Clin Interv

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Alzheimer's disease (AD) is caused by a cascade of changes to brain integrity. Neuroimaging biomarkers are important in diagnosis and monitoring the effects of interventions. As memory impairments are among the first symptoms of AD, the relationship between imaging findings and memory deficits is important in biomarker research. The most established magnetic resonance imaging (MRI) finding is hippocampal atrophy, which is related to memory decline and currently used as a diagnostic criterion for AD. While the medial temporal lobes are impacted early by the spread of neurofibrillary tangles, other networks and regional changes can be found quite early in the progression. Atrophy in several frontal and parietal regions, cortical thinning, and white matter alterations correlate with memory deficits in early AD. Changes in activation and connectivity have been detected by functional MRI (fMRI). Task-based fMRI studies have revealed medial temporal lobe hypoactivation, parietal hyperactivation, and frontal hyperactivation in AD during memory tasks, and activation patterns of these regions are also altered in preclinical and prodromal AD. Resting state fMRI has revealed alterations in default mode network activity related to memory in early AD. These studies are limited in part due to the historic inclusion of patients who had suspected AD but likely did not have the disorder. Modern biomarkers allow for more diagnostic certainty, allowing better understanding of neuroimaging markers in true AD, even in the preclinical stage. Larger patient cohorts, comparison of candidate imaging biomarkers to more established biomarkers, and inclusion of more detailed neuropsychological batteries to assess multiple aspects of memory are needed to better understand the memory deficit in AD and help develop new biomarkers. This article reviews MRI findings related to episodic memory impairments in AD and introduces a new study with multimodal imaging and comprehensive neuropsychiatric evaluation to overcome current limitations.

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“…Frontal lobe atrophic changes and hyperactivation had been reported in patients with MCI and AD [60][61][62][63][64][65][66][67][68]. However, frontal cortex hypoactivation was reported in MCI patients with prominent cognitive decline [65, 69- 71].…”

Section: Discussionmentioning

confidence: 99%

Value of magnetic resonance spectroscopy in geriatric patients with cognitive impairment

Kotb

Kamal

Aldossary

et al. 2020

Egypt J Neurol Psychiatry Neurosurg

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Background: Mild cognitive impairment is a transitional stage prior to dementia, and it is reported in depressed patients. Early diagnosis could predict the reversible etiologies and prevent further deterioration. Proton magnetic resonance spectroscopy has been used for early diagnosis and differential diagnosis of cognitive impairment. Objective: We aimed to study the difference of hippocampal and frontal white matter metabolites between patients with Alzheimer's disease, mild cognitive impairment, and cognitive impairment associated with depression, and if those metabolites can differentiate between them. Subjects and methods: Geriatric patients with cognitive impairment were recruited from neurology and psychiatry clinics. All subjects underwent comprehensive medical evaluations, neuropsychological testing, laboratory tests as well as brain MRI and 1 H-MRS studies. Results: The present study included 85 subjects. Patients with MCI and AD had lower hippocampal NAA and NAA/ Cr ratio than patients with depression and normal controls, while, frontal NAA and NAA/Cr ratio were lower in all patient's subgroups compared to normal control. Conclusion: Hippocampal NAA and NAA/Cr ratio might help to differentiate between MCI and cognitive impairment associated with depression.

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A preliminary study of functional abnormalities in aMCI subjects during different episodic memory tasks

Cited by 21 publications

References 54 publications

Mild Cognitive Impairment Is Not “Mild” at All in Altered Activation of Episodic Memory Brain Networks: Evidence from ALE Meta-Analysis

Mild Cognitive Impairment Is Not “Mild” at All in Altered Activation of Episodic Memory Brain Networks: Evidence from ALE Meta-Analysis

Current understanding of magnetic resonance imaging biomarkers and memory in Alzheimer's disease

Value of magnetic resonance spectroscopy in geriatric patients with cognitive impairment

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