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

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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Assessment of White Matter Lesions in Parkinson's Disease: Voxel-based Analysis and Tract-based Spatial Statistics Analysis of Parkinson's Disease with Mild Cognitive Impairment

Current Neurovascular Research ◽

10.2174/1567202617666200901181842 ◽

2020 ◽

Vol 17 (4) ◽

pp. 480-486

Author(s):

Wei Pu ◽

Xudong Shen ◽

Mingming Huang ◽

Zhiqian Li ◽

Xianchun Zeng ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

White Matter ◽

Corpus Callosum ◽

Fractional Anisotropy ◽

Spatial Statistics ◽

Diffusion Tensor ◽

Tract Based Spatial Statistics

Objective: Application of diffusion tensor imaging (DTI) to explore the changes of FA value in patients with Parkinson's disease (PD) with mild cognitive impairment. Methods: 27 patients with PD were divided into PD with mild cognitive impairment (PD-MCI) group (n = 7) and PD group (n = 20). The original images were processed using voxel-based analysis (VBA) and tract-based spatial statistics (TBSS). Results: The average age of pd-mci group was longer than that of PD group, and the course of disease was longer than that of PD group. Compared with PD group, the voxel based analysis-fractional anisotropy (VBA-FA) values of PD-MCI group decreased in the following areas: bilateral frontal lobe, bilateral temporal lobe, bilateral parietal lobe, bilateral subthalamic nucleus, corpus callosum, and gyrus cingula. Tract-based spatial statistics-fractional anisotropy (TBSS-FA) values in PD-MCI group decreased in bilateral corticospinal tract, anterior cingulum, posterior cingulum, fornix tract, bilateral superior thalamic radiation, corpus callosum(genu, body and splenium), bilateral uncinate fasciculus, bilateral inferior longitudinal fasciculus, bilateral superior longitudinal fasciculus, bilateral superior fronto-occipital fasciculus, bilateral inferior fronto-occipital fasciculus, and bilateral parietal-occipital tracts. The mean age of onset in the PD-MCI group was greater than that in the PD group, and the disease course was longer than that in the PD group. Conclusion: DTI-based VBA and TBSS post-processing methods can detect abnormalities in multiple brain areas and white matter fiber tracts in PD-MCI patients. Impairment of multiple cerebral cortex and white matter fiber pathways may be an important causes of cognitive dysfunction in PD-MCI.

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Characterizing white matter alterations in drug-naïve de novo Parkinson’s disease with diffusion MRI

10.1101/2021.02.13.431081 ◽

2021 ◽

Author(s):

Yiming Xiao ◽

Terry M. Peters ◽

Ali R. Khan

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

White Matter ◽

De Novo ◽

Neurodegenerative Disorder ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Motor Dysfunction ◽

White Matter Integrity ◽

Drug Naïve

AbstractParkinson’s disease (PD) is a progressive neurodegenerative disorder that is characterized by a range of motor and non-motor symptoms, often with the motor dysfunction initiated unilaterally. Knowledge regarding disease-related alterations in white matter pathways can effectively help improve the understanding of the disease and propose targeted treatment strategies. Microstructural imaging techniques, including diffusion tensor imaging (DTI), allows inspection of white matter integrity to study the pathogenesis of various neurological conditions. Previous voxel-based analyses with DTI measures, such as fractional anisotropy and mean diffusivity have uncovered changes in brain regions that are associated with PD, but the conclusions were inconsistent, partially due to small patient cohorts and the lack of consideration for clinical laterality onset, particularly in early PD. Fixel-based analysis (FBA) is a recent framework that offers tract-specific insights regarding white matter health, but very few FBA studies on PD exist. We present a study that reveals strengthened and weakened white matter integrity that is subject to symptom laterality in a large drug-naïve de novo PD cohort using complementary DTI and FBA measures. The findings suggest that the disease gives rise to both functional degeneration and the creation of compensatory networks in the early stage.

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Diffusion Tensor Imaging Reveals White Matter Changes Associated With Cognitive Status in Patients With Parkinson’s Disease

American Journal of Alzheimer s Disease & Other Dementias® ◽

10.1177/1533317512470207 ◽

2012 ◽

Vol 28 (2) ◽

pp. 154-164 ◽

Cited By ~ 33

Author(s):

Bingmei Deng ◽

Yuhu Zhang ◽

Lijuan Wang ◽

Kairun Peng ◽

Lixin Han ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Cognitive Impairment ◽

Diffusion Tensor Imaging ◽

White Matter ◽

Rating Scale ◽

Diffusion Tensor ◽

Region Of Interest ◽

Cognitive Status ◽

Cerebral White Matter

Objective : Cognitive deficit and white matter alteration relationships in Parkinson’s disease (PD) were investigated. Methods : Comparison of 64 patients with PD (M:F, 34:30; 64.4 ± 10.4 years) classified as cognitively normal (PD-CogNL, n = 24), mild cognitive impairment (PD-MCI, n = 30), and dementia (PD-D, n = 10) with 21 healthy participants (M:F, 10:11; 60.1 ± 13.6 years) was conducted using white matter fractional anisotropy (FA), region-of-interest analysis, and diffusion tensor imaging. Results : The PD-D and PD-MCI exhibited higher Unified Parkinson’s Disease Rating Scale motor scores ( P < .001; P < .01) and Hoehn-Yahr stages ( P < .001; P < .05) and FA reductions in left frontal/right temporal white matter and bilateral anterior cingulated bundles. Largest FA reductions occurred in PD-D left anterior cingulated bundle and corpus callosum splenium. Disease durations of PD-D = 6.8 ± 6.86, PD-MCI = 5.1 ± 2.9, and PD-CogNL = 4.7 ± 3.4 years, suggesting progressive deterioration. Conclusions : Cerebral white matter deterioration may underlie progressive cognitive impairment in PD.

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