Disrupted white matter integrity is associated with cognitive deficits in patients with amnestic mild cognitive impairment: An atlas-based study

Objective: This study investigated white matter integrity in patients with amnestic mild cognitive impairment by diffusion tensor imaging. Methods: A total of 83 patients with amnestic mild cognitive impairment and 85 elderly healthy controls underwent neuropsychological testing and a diffusion tensor imaging scan. Whole-brain white matter data were parcellated into 50 regions based on the anatomical ICBM-DTI-81 atlas, and regional diffusion metrics consisting of fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity were calculated for each region. Diffusion tensor imaging indices were compared between groups, and it was determined that between-group differences were significantly correlated with neurocognitive performance. Results: Relative to the healthy controls group, the amnestic mild cognitive impairment group exhibited poorer cognitive performance in all neuropsychological tests except the complex figure test ( p = 0.083) and showed decreased mean fractional anisotropy in the fornix, increased mean diffusivity in the fornix and bilateral uncinate fasciculus, elevated axial diffusivity in the fornix and genu of corpus callosum, and elevated radial diffusivity in the fornix and bilateral uncinate fasciculus ( p < 0.05). Behaviorally, integrity of the bilateral uncinate fasciculus was correlated positively with episodic memory function, while left uncinate fasciculus integrity was positively associated with language function in the amnestic mild cognitive impairment group ( p < 0.05). Conclusion: White matter abnormalities in neural pathways associated with memory were correlated with neurocognitive deficiencies in amnestic mild cognitive impairment. Given that amnestic mild cognitive impairment is putatively a prodromal syndrome for Alzheimer’s disease, this study furthers our understanding of the white matter changes associated with Alzheimer’s disease pathogenesis in the predementia stage.

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Changes in Parahippocampal White Matter Integrity in Amnestic Mild Cognitive Impairment: A Diffusion Tensor Imaging Study

Behavioural Neurology ◽

10.1155/2009/408037 ◽

2009 ◽

Vol 21 (1-2) ◽

pp. 51-61 ◽

Cited By ~ 37

Author(s):

E. J. Rogalski ◽

C. M. Murphy ◽

L. deToledo-Morrell ◽

R. C. Shah ◽

M. E. Moseley ◽

...

Keyword(s):

Cognitive Impairment ◽

Diffusion Tensor Imaging ◽

Mild Cognitive Impairment ◽

White Matter ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Amnestic Mild Cognitive Impairment ◽

Perforant Path ◽

Tissue Loss

In the present study, changes in the parahippocampal white matter (PWM), in the region that includes the perforant path, were investigated, in vivo, in 14 individuals with amnestic mild cognitive impairment (aMCI) compared to 14 elderly controls with no cognitive impairment (NCI). For this purpose, (1) volumetry; (2) diffusion tensor imaging (DTI) derived measures of mean diffusivity (MD) and fractional anisotropy (FA); and (3) tractography were used. In addition, regression models were utilized to examine the association of PWM measurements with memory decline. The results from this study confirm previous findings in our laboratory and others, showing that compared to controls, individuals with aMCI have PWM volume loss. In addition to volume reduction, participants with aMCI demonstrated a significant increase in MD, but no difference in FA, both in the PWM region and in fibers modeled to pass through the PWM region. Further, the DTI metric of MD was associated with declarative memory performance, suggesting it may be a sensitive marker for memory dysfunction. These results indicate that there is general tissue loss and degradation (decreased volume; increased MD) in individuals with aMCI compared to older people with normal cognitive function. However, the microstructural organization of remaining fibers, as determined by measures of anisotropic diffusion, is not significantly different from that of controls.

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White Matter Changes in Patients with Amnestic Mild Cognitive Impairment Detected by Diffusion Tensor Imaging

PLoS ONE ◽

10.1371/journal.pone.0059440 ◽

2013 ◽

Vol 8 (3) ◽

pp. e59440 ◽

Cited By ~ 20

Author(s):

Jianghong Liu ◽

Changhao Yin ◽

Shugao Xia ◽

Longfei Jia ◽

Yanqin Guo ◽

...

Keyword(s):

Cognitive Impairment ◽

Diffusion Tensor Imaging ◽

Mild Cognitive Impairment ◽

White Matter ◽

Diffusion Tensor ◽

Amnestic Mild Cognitive Impairment ◽

White Matter Changes

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Diffusion tensor imaging measures of normal appearing white matter in patients who are aging, or have amnestic mild cognitive impairment, or Alzheimer’s disease

Journal of Clinical Neuroscience ◽

10.1016/j.jocn.2012.09.025 ◽

2013 ◽

Vol 20 (8) ◽

pp. 1089-1094 ◽

Cited By ~ 14

Author(s):

Jian-Hua Wang ◽

Pei-Yuan Lv ◽

He-Bo Wang ◽

Zhi-Li Li ◽

Na Li ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Diffusion Tensor Imaging ◽

Mild Cognitive Impairment ◽

White Matter ◽

Diffusion Tensor ◽

Amnestic Mild Cognitive Impairment ◽

Normal Appearing White Matter

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Olfactory Function and Diffusion Tensor Imaging as Markers of Mild Cognitive Impairment in Early Stages of Parkinson's Disease

Clinical EEG and Neuroscience ◽

10.1177/15500594211058263 ◽

2021 ◽

pp. 155005942110582

Author(s):

Sophie A. Stewart ◽

Laura Pimer ◽

John D. Fisk ◽

Benjamin Rusak ◽

Ron A. Leslie ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Cognitive Impairment ◽

Diffusion Tensor Imaging ◽

Mild Cognitive Impairment ◽

White Matter ◽

Neurodegenerative Disorder ◽

Diffusion Tensor ◽

Early Stage ◽

White Matter Integrity

Parkinson's disease (PD) is a neurodegenerative disorder that is typified by motor signs and symptoms but can also lead to significant cognitive impairment and dementia Parkinson's Disease Dementia (PDD). While dementia is considered a nonmotor feature of PD that typically occurs later, individuals with PD may experience mild cognitive impairment (PD-MCI) earlier in the disease course. Olfactory deficit (OD) is considered another nonmotor symptom of PD and often presents even before the motor signs and diagnosis of PD. We examined potential links among cognitive impairment, olfactory functioning, and white matter integrity of olfactory brain regions in persons with early-stage PD. Cognitive tests were used to established groups with PD-MCI and with normal cognition (PD-NC). Olfactory functioning was examined using the University of Pennsylvania Smell Identification Test (UPSIT) while the white matter integrity of the anterior olfactory structures (AOS) was examined using magnetic resonance imaging (MRI) diffusion tensor imaging (DTI) analysis. Those with PD-MCI demonstrated poorer olfactory functioning and abnormalities based on all DTI parameters in the AOS, relative to PD-NC individuals. OD and microstructural changes in the AOS of individuals with PD may serve as additional biological markers of PD-MCI.

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