scholarly journals Characterizing white matter alterations subject to clinical laterality in drug‐naïve de novo Parkinson's disease

2021 ◽  
Author(s):  
Yiming Xiao ◽  
Terry M. Peters ◽  
Ali R. Khan
2021 ◽  
Author(s):  
Yiming Xiao ◽  
Terry M. Peters ◽  
Ali R. Khan

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.


2018 ◽  
Vol 9 ◽  
Author(s):  
Mahtab Mojtahed Zadeh ◽  
Amir Ashraf-Ganjouei ◽  
Farzaneh Ghazi Sherbaf ◽  
Maryam Haghshomar ◽  
Mohammad Hadi Aarabi

2016 ◽  
Vol 123 (6) ◽  
pp. 601-610 ◽  
Author(s):  
Sarah Geffe ◽  
Katharina A. Schindlbeck ◽  
Arne Mehl ◽  
Johann Jende ◽  
Fabian Klostermann ◽  
...  

Author(s):  
Seung-Hyun Kim ◽  
Ji-Hye Park ◽  
Yu Hwan Kim ◽  
Seong-Beom Koh

Background:Motor deficits associated with Parkinson's disease (PD) have been well described, yet little attention has been paid to non-motor symptoms, especially cortical visual dysfunction. We investigated stereopsis, as well as the relationship between stereopsis and other cognitive function, in a sample of PD patients.Methods:We used Titmus stereotest plates for assessing stereopsis. Fifty-nine subjects (29 PD patients and 30 normal controls) were included in this study. The included patients underwent a neurological examination, clinical rating scale and neuropsychological tests.Results:Drug naïve PD patients showed decreased stereopsis on the Titmus fly stereopsis test (Pearson χ2=23.80, p<0.001) compared to PD patients with normal stereopsis. The Hoehn-Yahr stages and Unified Parkinson's Disease Rating Scale motor scores were significantly higher in patients with PD with abnormal stereopsis than in patients with PD with normal stereopsis (p=0.026; p=0.046). The frequency of abnormal visual perception/constructive function was greater in patients with PD with abnormal stereopsis compared to patients with PD with normal stereopsis (Pearson χ2=5.11, p=0.024).Conclusion:These findings suggest that stereopsis deficits and visual perception/constructive dysfunction are common in de novo PD patients.


2017 ◽  
Author(s):  
Mahsa Dadar ◽  
Yashar Zeighami ◽  
Yvonne Yau ◽  
Seyed-Mohammad Fereshtehnejad ◽  
Josefina Maranzano ◽  
...  

AbstractObjectiveWhite Matter Hyperintensities (WMHs) are associated with cognitive decline in normative aging and Alzheimer’s disease. However, the pathogenesis of cognitive decline in Parkinson’s disease (PD) is not directly related to vascular causes, and therefore the role of WMHs in PD remains unclear. If WMH has a higher impact on cognitive decline in PD, vascular pathology should be assessed and treated with a higher priority in this population. Here we investigate whether WMH leads to increased cognitive decline in PD, and if these effects relate to cortical thinningMethodsTo investigate the role of WMHs in PD, it is essential to study recently-diagnosed/non-treated patients.De novoPD patients and age-matched controls (NPD=365,NControl=174) with FLAIR/T2-weighted scans at baseline were selected from Parkinson’s Progression Markers Initiative (PPMI). WMHs and cortical thickness were measured to analyse the relationship between baseline WMHs and future cognitive decline (follow-up:4.09±1.14 years) and cortical thinning (follow-up:1.05±0.10 years).ResultsHigh WMH load (WMHL) at baseline in PD was associated with increased cognitive decline, significantly more than i) PDs with low WMHL and ii) controls with high WMHL. Furthermore, PD patients with higher baseline WMHL showed more cortical thinning in right frontal lobe than subjects with low WMHL. Cortical thinning of this region also predicted decline in performance on a cognitive test.InterpretationPresence of WMHs inde novoPD patients predicts greater future cognitive decline and cortical thinning than in normal aging. Recognizing WMHs as a potential predictor of cognitive deficit in PD provides an opportunity for timely interventions.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5539 ◽  
Author(s):  
Amir Ashraf-Ganjouei ◽  
Alireza Majd ◽  
Ali Javinani ◽  
Mohammad Hadi Aarabi

Background Autonomic dysfunction (AD) is one of the non-motor features of Parkinson’s disease (PD). Some symptoms tend to occur in the early stages of PD. AD also has a great impact on patient’s quality of life. In this study, we aimed to discover the association between AD (Scales for Outcomes in Parkinson’s disease-Autonomic, SCOPA-AUT) and microstructural changes in white matter tracts in drug-naïve early PD patients to elucidate the central effects of autonomic nervous system impairments. Method In total, this study included 85 subjects with PD recruited from the Parkinson’s Progression Markers Initiative (PPMI) database. Among the 85 PD patients, 38 were in Hoehn & Yahr stage 1 (HY1PD) and 47 were in stage 2 (HY2PD). Diffusion magnetic resonance imaging (DMRI) data were reconstructed in the MNI space using q-space diffeomorphic reconstruction to obtain the spin distribution function. The spin distribution function (SDF) values were used in DMRI connectometry analysis. We investigated through diffusion MRI connectometry the structural correlates of white matter tracts with SCOPA-AUT subscores and total score. Results Connectometry analysis also revealed positive association with white matter density in bilateral corticospinal tract in HY1PD patients and negative association in genu of corpus callosum (CC) and, bilateral cingulum in both groups. In addition, there were associations between gastrointestinal, sexual, thermoregulatory and urinary items and structural brain connectivity in PD. Conclusion Our study reveals positive correlation, suggesting neural compensations in early PD. Cingulum and CC tracts have well-known roles in PD pathology, compatible with our findings that bring new insights to specific areas of AD and its role in central nervous system (CNS) neurodegeneration, paving the way for using prodromal makers in the diagnosis and treatment of PD.


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