Diffusion Tensor Imaging Surpasses Cerebrospinal Fluid as Predictor of Cognitive Decline and Medial Temporal Lobe Atrophy in Subjective Cognitive Impairment and Mild Cognitive Impairment

Background: Visual rating of medial temporal lobe atrophy (MTA) is an accepted structural neuroimaging marker of Alzheimer’s disease. Corneal confocal microscopy (CCM) is a non-invasive ophthalmic technique that detects neuronal loss in peripheral and central neurodegenerative disorders. Objective: To determine the diagnostic accuracy of CCM for mild cognitive impairment (MCI) and dementia compared to medial temporal lobe atrophy (MTA) rating on MRI. Methods: Subjects aged 60–85 with no cognitive impairment (NCI), MCI, and dementia based on the ICD-10 criteria were recruited. Subjects underwent cognitive screening, CCM, and MTA rating on MRI. Results: 182 subjects with NCI (n = 36), MCI (n = 80), and dementia (n = 66), including AD (n = 19, 28.8%), VaD (n = 13, 19.7%), and mixed AD (n = 34, 51.5%) were studied. CCM showed a progressive reduction in corneal nerve fiber density (CNFD, fibers/mm2) (32.0±7.5 versus 24.5±9.6 and 20.8±9.3, p < 0.0001), branch density (CNBD, branches/mm2) (90.9±46.5 versus 59.3±35.7 and 53.9±38.7, p < 0.0001), and fiber length (CNFL, mm/mm2) (22.9±6.1 versus 17.2±6.5 and 15.8±7.4, p < 0.0001) in subjects with MCI and dementia compared to NCI. The area under the ROC curve (95% CI) for the diagnostic accuracy of CNFD, CNBD, CNFL compared to MTA-right and MTA-left for MCI was 78% (67–90%), 82% (72–92%), 86% (77–95%) versus 53% (36–69%) and 40% (25–55%), respectively, and for dementia it was 85% (76–94%), 84% (75–93%), 85% (76–94%) versus 86% (76–96%) and 82% (72–92%), respectively. Conclusion: The diagnostic accuracy of CCM, a non-invasive ophthalmic biomarker of neurodegeneration, was high and comparable with MTA rating for dementia but was superior to MTA rating for MCI.

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Medial Temporal Lobe Atrophy is Related to Learning Strategy Changes in Amnestic Mild Cognitive Impairment

Journal of the International Neuropsychological Society ◽

10.1017/s1355617719000353 ◽

2019 ◽

Vol 25 (7) ◽

pp. 706-717 ◽

Cited By ~ 3

Author(s):

Liling Zhang ◽

Wen-hao Sun ◽

Mengya Xing ◽

Yue Wang ◽

Yuanyuan Zhang ◽

...

Keyword(s):

Cognitive Impairment ◽

Executive Function ◽

Mild Cognitive Impairment ◽

Medial Temporal Lobe ◽

Learning Strategy ◽

Amnestic Mild Cognitive Impairment ◽

Medial Temporal Lobe Atrophy ◽

Semantic Learning ◽

Semantic Clustering ◽

Lobe Atrophy

AbstractObjective: Deficits in the semantic learning strategy were observed in subjects with amnestic mild cognitive impairment (aMCI) in our previous study. In the present study, we explored the contributions of executive function and brain structure changes to the decline in the semantic learning strategy in aMCI. Methods: A neuropsychological battery was used to test memory and executive function in 96 aMCI subjects and 90 age- and gender-matched healthy controls (HCs). The semantic clustering ratio on the verbal learning test was calculated to evaluate learning strategy. Medial temporal lobe atrophy (MTA) and white matter hyperintensities (WMH) were measured on MRI with the MTA and Fazekas visual rating scales, respectively. Results: Compared to HCs, aMCI subjects had poorer performance in terms of memory, executive function, and the semantic clustering ratio (P < .001). In aMCI subjects, no significant correlation between learning strategy and executive function was observed. aMCI subjects with obvious MTA demonstrated a lower semantic clustering ratio than those without MTA (P < .001). There was no significant difference in the learning strategies between subjects with high-grade WMH and subjects with low-grade WMH. Conclusion: aMCI subjects showed obvious impairment in the semantic learning strategy, which was attributable to MTA but independent of executive dysfunction and subcortical WMH. These findings need to be further validated in large cohorts with biomarkers identified using volumetric brain measurements. (JINS, 2019, 25, 706–717)

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Conversion from cognitive health to mild cognitive impairment and Alzheimer's disease: Prediction by plasma amyloid beta 42, medial temporal lobe atrophy and homocysteine

Neurobiology of Aging ◽

10.1016/j.neurobiolaging.2006.09.002 ◽

2008 ◽

Vol 29 (1) ◽

pp. 1-11 ◽

Cited By ~ 62

Author(s):

Imrich Blasko ◽

Kurt Jellinger ◽

Georg Kemmler ◽

Wolfgang Krampla ◽

Susanne Jungwirth ◽

...

Keyword(s):

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Temporal Lobe ◽

Amyloid Beta ◽

Medial Temporal Lobe ◽

Disease Prediction ◽

Cognitive Health ◽

Medial Temporal Lobe Atrophy ◽

Amyloid Beta 42 ◽

Lobe Atrophy

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Diffusion Tensor Imaging Study of Olfactory Identification Deficit in Patients With Mild Cognitive Impairment

Frontiers in Aging Neuroscience ◽

10.3389/fnagi.2021.765432 ◽

2021 ◽

Vol 13 ◽

Author(s):

Yongjia Shao ◽

Zijian Wang ◽

Bin Ji ◽

Hang Qi ◽

Shangci Hao ◽

...

Keyword(s):

Cognitive Impairment ◽

Diffusion Tensor Imaging ◽

Mild Cognitive Impairment ◽

Cognitive Decline ◽

Entorhinal Cortex ◽

Diffusion Tensor ◽

Brain Regions ◽

Olfactory Function ◽

Imaging Results ◽

Olfactory Ability

Objective: To explore the relationship between white matter changes and olfactory ability among patients with mild cognitive impairment (MCI) and to develop a tool to predict the development of Alzheimer’s disease among patients with MCI.Methods: The Montreal Cognitive Assessment (MoCA) was used for cognitive assessments, and the 70% isopropanol test paper was used to evaluate olfactory function. Tract-based spatial statistics, based on the diffusion tensor imaging technology, were used to obtain relevant parameters, and behavioral and imaging results were compared between patients with MCI (n = 36) and healthy older adults (n = 32).Results: The olfactory ability of MCI patients was lower overall, which was positively correlated with the MoCA score. Fractional anisotropy (FA) changes significantly of all parameters. Lower FA regions were mainly located in the corpus callosum, the orbitofrontal gyrus, and the left occipital lobe. The olfactory score was significantly correlated with the FA value of the orbitofrontal gyrus. Fibrous connections in several brain regions, such as the entorhinal cortex, were stronger in patients with MCI.Conclusion: The olfactory ability of MCI patients in our group was positively correlated with the neuropsychological scale results. Impairment in olfactory function was superior to memory deficits for predicting cognitive decline among cognitively intact participants. The fibrous connections in several brain regions, such as the entorhinal cortex, were higher in patients with MCI, which suggested that there may be a compensatory mechanism in the olfactory pathway in MCI patients. The decline in olfactory function may be a significant and useful indicator of neuropathological changes in MCI patients and an effective marker for the development of cognitive decline and dementia.

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