scholarly journals Greater Loss of White Matter Integrity in Postural Instability and Gait Difficulty Subtype of Parkinson's Disease

2014 ◽  
Vol 41 (6) ◽  
pp. 763-768 ◽  
Author(s):  
Quanquan Gu ◽  
Peiyu Huang ◽  
Min Xuan ◽  
Xiaojun Xu ◽  
Dan Li ◽  
...  
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Critical Role ◽  
Postural Instability ◽  
White Matter Integrity ◽  
Radial Diffusivity ◽  
Superior Longitudinal Fasciculus ◽  
Axial Diffusivity ◽  
White Matter Abnormalities

ABSTRACTBackground: Patients with the postural instability and gait difficulty (PIGD) subtype of Parkinson disease (PD) are at a higher risk of dysfunction and are less responsive to dopamine replacement therapy. The PIGD subtype was found to largely associate with white matter lesions, but details of the diffusion changes within these lesions have not been fully investigated. Voxel-based analysis for diffusion tensor imaging data is one of the preferred measures to compare diffusion changes in each voxel in any part of the brain. Methods: PD patients with the PIGD (n=12) and non-PIGD subtypes (n=12) were recruited to compare diffusion differences in fractional anisotropy, axial diffusivity, and radial diffusivity with voxel-based analysis. Results: Significantly reduced fractional anisotropy in bilateral superior longitudinal fasciculus, bilateral anterior corona radiata, and the left genu of the corpus callosum were shown in the PIGD subtype compared with the non-PIGD subtype. Increased radial diffusivity in the left superior longitudinal fasciculus was found in the PIGD subtype with no statistical differences in axial diffusivity found. Conclusions: Our study confirms previous findings that white matter abnormalities were greater in the PIGD subtype than in the non-PIGD subtype. Additionally, our findings suggested: (1) compared with the non-PIGD subtype, loss of white matter integrity was greater in the PIGD subtype; (2) bilateral superior longitudinal fasciculus may play a critical role in microstructural white matter abnormalities in the PIGD subtype; and (3) reduced white matter integrity in the PIGD subtype could be mainly attributed to demyelination rather than axonal loss.

scholarly journals Infratentorial pathology in frontotemporal dementia: cerebellar grey and white matter alterations in FTD phenotypes

2021 ◽  
Author(s):  
Mary Clare McKenna ◽  
Rangariroyashe H. Chipika ◽  
Stacey Li Hi Shing ◽  
Foteini Christidi ◽  
Jasmin Lope ◽  
...  
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Cortical Thickness ◽  
Cerebellar Atrophy ◽  
Primary Progressive Aphasia ◽  
Radial Diffusivity ◽  
Axial Diffusivity ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Crus I

AbstractThe contribution of cerebellar pathology to cognitive and behavioural manifestations is increasingly recognised, but the cerebellar profiles of FTD phenotypes are relatively poorly characterised. A prospective, single-centre imaging study has been undertaken with a high-resolution structural and diffusion tensor protocol to systematically evaluate cerebellar grey and white matter alterations in behavioural-variant FTD(bvFTD), non-fluent variant primary progressive aphasia(nfvPPA), semantic-variant primary progressive aphasia(svPPA), C9orf72-positive ALS-FTD(C9 + ALSFTD) and C9orf72-negative ALS-FTD(C9-ALSFTD). Cerebellar cortical thickness and complementary morphometric analyses were carried out to appraise atrophy patterns controlling for demographic variables. White matter integrity was assessed in a study-specific white matter skeleton, evaluating three diffusivity metrics: fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD). Significant cortical thickness reductions were identified in: lobule VII and crus I in bvFTD; lobule VI VII, crus I and II in nfvPPA; and lobule VII, crus I and II in svPPA; lobule IV, VI, VII and Crus I and II in C9 + ALSFTD. Morphometry revealed volume reductions in lobule V in all groups; in addition to lobule VIII in C9 + ALSFTD; lobule VI, VIII and vermis in C9-ALSFTD; lobule V, VII and vermis in bvFTD; and lobule V, VI, VIII and vermis in nfvPPA. Widespread white matter alterations were demonstrated by significant fractional anisotropy, axial diffusivity and radial diffusivity changes in each FTD phenotype that were more focal in those with C9 + ALSFTD and svPPA. Our findings indicate that FTD subtypes are associated with phenotype-specific cerebellar signatures with the selective involvement of specific lobules instead of global cerebellar atrophy.

scholarly journals Quantitative diffusion tensor imaging analysis does not distinguish pediatric canines with mucopolysaccharidosis I from control canines

2017 ◽  
Vol 30 (5) ◽  
pp. 454-460
Author(s):  
Dana M Middleton ◽  
Jonathan Y Li ◽  
Steven D Chen ◽  
Leonard E White ◽  
Patricia I Dickson ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Imaging System ◽  
Diffusion Tensor ◽  
Brain Regions ◽  
Magnetic Resonance Imaging System ◽  
Radial Diffusivity ◽  
Mucopolysaccharidosis I ◽  
Diffusivity Measurements

Purpose We compared fractional anisotropy and radial diffusivity measurements between pediatric canines affected with mucopolysaccharidosis I and pediatric control canines. We hypothesized that lower fractional anisotropy and higher radial diffusivity values, consistent with dysmyelination, would be present in the mucopolysaccharidosis I cohort. Methods Six canine brains, three affected with mucopolysaccharidosis I and three unaffected, were euthanized at 7 weeks and imaged using a 7T small-animal magnetic resonance imaging system. Average fractional anisotropy and radial diffusivity values were calculated for four white-matter regions based on 100 regions of interest per region per specimen. A 95% confidence interval was calculated for each mean value. Results No difference was seen in fractional anisotropy or radial diffusivity values between mucopolysaccharidosis affected and unaffected brains in any region. In particular, the 95% confidence intervals for mucopolysaccharidosis affected and unaffected canines frequently overlapped for both fractional anisotropy and radial diffusivity measurements. In addition, in some brain regions a large range of fractional anisotropy and radial diffusivity values were seen within the same cohort. Conclusion The fractional anisotropy and radial diffusivity values of white matter did not differ between pediatric mucopolysaccharidosis affected canines and pediatric control canines. Possible explanations include: (a) a lack of white matter tissue differences between mucopolysaccharidosis affected and unaffected brains at early disease stages; (b) diffusion tensor imaging does not detect any existing differences; (c) inflammatory processes such as astrogliosis produce changes that offset the decreased fractional anisotropy values and increased radial diffusivity values that are expected in dysmyelination; and (d) our sample size was insufficient to detect differences. Further studies correlating diffusion tensor imaging findings to histology are warranted.

scholarly journals A Correlational Study between Microstructural White Matter Properties and Macrostructural Gray Matter Volume Across Normal Ageing: Conjoint DTI and VBM Analysis

2018 ◽  
Vol 11 ◽  
pp. 1178623X1879992 ◽  
Author(s):  
Vikas Pareek ◽  
VP Subramanyam Rallabandi ◽  
Prasun K Roy
Keyword(s):  
White Matter ◽  
Life Span ◽  
Fractional Anisotropy ◽  
Gray Matter ◽  
Healthy Aging ◽  
Gray Matter Volume ◽  
Mean Diffusivity ◽  
Radial Diffusivity ◽  
Axial Diffusivity ◽  
Matter Volume

We investigate the relationship between Gray matter’s volume vis-a-vis White matter’s integrity indices, such Axial diffusivity, Radial diffusivity, Mean diffusivity, and Fractional anisotropy, in individuals undergoing healthy aging. We investigated MRI scans of 177 adults across 20 to 85 years. We used Voxel-based morphometry, and FDT-FSL analysis for estimation of Gray matter volume and White matter’s diffusion indices respectively. Across the life span, we observed an inter-relationship between the Gray matter and White matter, namely that both Axial diffusivity and Mean Diffusivity show strong correlation with Gray matter volume, along the aging process. Furthermore, across all ages the Fractional anisotropy and Mean diffusivity are found to be significantly reduced in females when compared to males, but there are no significant gender differences in Axial Diffusivity and Radial diffusivity. We conclude that for both genders across all ages, the Gray matter’s Volume is strongly correlated with White matter’s Axial Diffusivity and Mean Diffusivity, while being weakly correlated with Fractional Anisotropy. Our study clarifies the multi-scale relationship in brain tissue, by elucidating how the White matter’s micro-structural parameters influences the Gray matter’s macro-structural characteristics, during healthy aging across the life-span.

scholarly journals White matter differences between essential tremor and Parkinson disease

Neurology ◽  
2018 ◽  
Vol 92 (1) ◽  
pp. e30-e39 ◽  
Author(s):  
Meher R. Juttukonda ◽  
Giulia Franco ◽  
Dario J. Englot ◽  
Ya-Chen Lin ◽  
Kalen J. Petersen ◽  
...  
Keyword(s):  
White Matter ◽  
Parkinson Disease ◽  
Essential Tremor ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Superior Cerebellar Peduncle ◽  
Radial Diffusivity ◽  
Cerebellar Peduncles ◽  
Cerebellar Peduncle

ObjectiveTo assess white matter integrity in patients with essential tremor (ET) and Parkinson disease (PD) with moderate to severe motor impairment.MethodsSedated participants with ET (n = 57) or PD (n = 99) underwent diffusion tensor imaging (DTI) and fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity values were computed. White matter tracts were defined using 3 well-described atlases. To determine candidate white matter regions that differ between ET and PD groups, a bootstrapping analysis was applied using the least absolute shrinkage and selection operator. Linear regression was applied to assess magnitude and direction of differences in DTI metrics between ET and PD populations in the candidate regions.ResultsFractional anisotropy values that differentiate ET from PD localize primarily to thalamic and visual-related pathways, while diffusivity differences localized to the cerebellar peduncles. Patients with ET exhibited lower fractional anisotropy values than patients with PD in the lateral geniculate body (p < 0.01), sagittal stratum (p = 0.01), forceps major (p = 0.02), pontine crossing tract (p = 0.03), and retrolenticular internal capsule (p = 0.04). Patients with ET exhibited greater radial diffusivity values than patients with PD in the superior cerebellar peduncle (p < 0.01), middle cerebellar peduncle (p = 0.05), and inferior cerebellar peduncle (p = 0.05).ConclusionsRegionally, distinctive white matter microstructural values in patients with ET localize to the cerebellar peduncles and thalamo-cortical visual pathways. These findings complement recent functional imaging studies in ET but also extend our understanding of putative physiologic features that account for distinctions between ET and PD.

scholarly journals Discrimination of epileptogenic lesions and perilesional white matter using diffusion tensor magnetic resonance imaging

2018 ◽  
Vol 32 (1) ◽  
pp. 10-16
Author(s):  
Alexander Rau ◽  
Elias Kellner ◽  
Niels A Foit ◽  
Niklas Lützen ◽  
Dieter H Heiland ◽  
...  
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Diffusion Tensor ◽  
Focal Cortical Dysplasia ◽  
Mean Diffusivity ◽  
Area Under The Curve ◽  
P Value ◽  
Radial Diffusivity ◽  
Normal Appearing White Matter ◽  
Diffusion Parameters

The aim of this study was to evaluate whether ganglioglioma (GGL), dysembryoplastic neuroepithelial tumour (DNET) and FCD (focal cortical dysplasia) are distinguishable through diffusion tensor imaging. Additionally, it was investigated whether the diffusion measures differed in the perilesional (pNAWM) and in the contralateral normal appearing white matter (cNAWM). Six GGLs, eight DNETs and seven FCDs were included in this study. Quantitative diffusion measures, that is, axial, radial and mean diffusivity and fractional anisotropy, were determined in the lesion identified on isotropic T2 or FLAIR-weighted images and in pNAWM and cNAWM, respectively. DNET differed from FCD in mean diffusivity, and GGL from FCD in radial diffusivity. Both types of glioneuronal tumours were different from pNAWM in fractional anisotropy and radial diffusivity. For identifying the tumour edges, threshold values for tumour-free tissue were investigated with receiver operating characteristic analyses: tumour could be separated from pNAWM at a threshold ≤ 0.32 (fractional anisotropy) or ≥ 0.56 (radial diffusivity) *10–3 mm2/s (area under the curve 0.995 and 0.990 respectively). While diffusion parameters of FCDs differed from cNAWM (radial diffusivity (*10–3 mm/s2): 0.74 ± 0.19 vs. 0.43 ± 0.05; corrected p-value < 0.001), the pNAWM could not be differentiated from the FCD.

scholarly journals White matter injury induced by diabetes in acute stroke is clinically relevant: A preliminary study

2016 ◽  
Vol 14 (1) ◽  
pp. 40-46 ◽  
Author(s):  
Xinfeng Yu ◽  
Ruirui Song ◽  
Yerfan Jiaerken ◽  
Lixia Yuan ◽  
Peiyu Huang ◽  
...  
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
White Matter Injury ◽  
Neurological Deficits ◽  
Diabetic Patients ◽  
Stroke Severity ◽  
Superior Longitudinal Fasciculus ◽  
Poor Outcome

The importance of white matter injury induced by diabetes in stroke severity and prognosis is largely unknown. We aimed to investigate the relationship between diabetes-related white matter injury beyond stroke lesions with acute neurological deficits and clinical outcome after stroke. In total, 36 stroke patients within 3–7 days after onset were enrolled. Neurological deficits on admission were assessed by National Institute of Health Stroke Score, and poor outcome at 3 months was defined as modified Rankin score >2. White matter tracts were compared between patients with diabetic and non-diabetic stroke using fractional anisotropy from diffusion tensor imaging. Regional white matter abnormality with decreased fractional anisotropy was observed in diabetic patients ( n = 18) when compared to non-diabetic patients ( n = 18). Decreased fractional anisotropy in ipsilesional distal corticospinal tract was independently associated with higher National Institute of Health Stroke Score motor component score ( β = −0.444, p = 0.005), and decreased fractional anisotropy in contralesional superior longitudinal fasciculus I was independently related to poor outcome (odds ratio, 0.900; p = 0.033). Our findings suggested that only white matter injury induced by diabetes in specific tracts like corticospinal tract and superior longitudinal fasciculus beyond stroke lesions has clinically relevant, providing insight into the mechanism of stroke recovery under the diabetic condition.

scholarly journals Prenatal depression exposure alters white matter integrity and neurodevelopment in early childhood

2022 ◽  
Author(s):  
Annerine Roos ◽  
Catherine J. Wedderburn ◽  
Jean-Paul Fouche ◽  
Shantanu H Joshi ◽  
Katherine L Narr ◽  
...  
Keyword(s):  
White Matter ◽  
Prenatal Exposure ◽  
Diffusion Tensor ◽  
Depression Scale ◽  
Prenatal Depression ◽  
White Matter Integrity ◽  
Health Study ◽  
Radial Diffusivity ◽  
Diffusion Weighted Images ◽  
Microstructural Integrity

AbstractPrenatal exposure to maternal depression increases the risk for onset of emotional and behavioral disorders in children. We investigated the effects of exposure to prenatal depression on white matter microstructural integrity at birth and at 2-3 years, and associated neurodevelopment. Diffusion-weighted images were acquired for children of the Drakenstein Child Health Study at 2-4 weeks postpartum (n=70, 47% boys) and at 2-3 years of age (n=60, 58% boys). Tract-Based Spatial Statistics was used to compare, using an ROI based approach, diffusion tensor metrics across groups defined by presence (>19 on Beck’s Depression Inventory and/or >12 on the Edinburgh Postnatal Depression Scale) or absence (below depression thresholds) of depression, and associations with neurodevelopmental measures at age 2-3 years were determined. We did not detect group differences in white matter integrity at neonatal age, but at 2-3 years, children in the exposed group demonstrated higher fractional anisotropy, and lower mean and radial diffusivity in association tracts compared to controls. This was notable in the sagittal stratum (radial diffusivity: p<0.01). Altered white matter integrity metrics were also observed in projection tracts, including the corona radiata, which associated with cognitive and motor outcomes in exposed 2-3-year-olds (p<0.05). Our findings of widespread white matter alterations in 2-3-year-old children with prenatal exposure to depression are consistent with previous findings, as well as with neuroimaging findings in adults with major depression. Further, we identified novel associations of altered white matter integrity with cognitive development in depression-exposed children, suggesting that these neuroimaging findings may have early functional impact.

Abstract 73: Improvement of Arm Function Following Intensive Rehabilitation in Chronic Stroke Correlates With Increase in Fractional Anisotropy in Major White Matter Tracts

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Svetlana Pundik ◽  
Peggy Skelly ◽  
Jessica P McCabe ◽  
Curtis Tatsuoka ◽  
Janis J Daly
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Motor Function ◽  
Upper Limb ◽  
Diffusion Tensor ◽  
Wilcoxon Test ◽  
Motor Deficits ◽  
Radial Diffusivity ◽  
White Matter Tracts ◽  
Visual Spatial

Introduction: White matter changes in response to rehabilitation of chronic motor deficits after stroke has not been well understood. Our hypothesis is that there is a relationship between gains in motor function and changes in structure of white matter tracts. Methods: Fugl-Meyer upper limb (FM) score and Diffusion Tensor Imaging (DTI) were collected before and after a 12-week upper limb motor learning therapy. DTI data was processed using the longitudinal Freesurfer Tracula stream where white matter tracts are reconstructed using global probabilistic tractography. The average fractional anisotropy (FA), as well as axial diffusivity (Da) and radial diffusivity (Dr) were computed for 14 major white matter tracts. General linear models were fit where pre-to-post change in FA for a given tract were dependent variables and pre-to-post change in FM was a predictor. The relationship was adjusted for baseline FM score. Spearman correlations were determined between FA, Da and Dr. Wilcoxon test was used for pre-to-post comparisons. Results: We evaluated and treated 21 stroke survivors; they were 1.9±1.2 (mean±std.dev) years post stroke, 55.1±12.9 yrs old and 42% female. FM improved from 23±8.75 to 34.1±10.5 (p<0.001). There was a significant association between gain in motor function and the decrease in FA for the following tracts: ipsilesional inferior longitudinal fasciculus (iplsi-ILF), contralesional ILF (contra-ILF) and transcallosal forceps major tract, controlling for baseline FM scores, (for ipsi-ILF: R2=0.4, p=0.006; for contra-ILF: R2=0.38, p=0.004; for forceps major: R2=0.31,p=0.02). According to the correlation analysis, decrease in FA could be explained by increase in Dr, but not by change in Da. Correlation between FA and Dr for ipsi-ILF was r=.75,p<0.001, for contra-ILF - r=.72,p<0.001 and for forceps major - r=.88, p<0.001. Conclusion: Improvement in function of chronic motor deficits in the upper extremity is related to structural changes in temporal-occipital and transcallosal occipital tracts that connect visual-spatial processing regions. Furthermore, our results suggest that changes in neuronal activity of the identified tracts may be associated with microstructural changes that increase radial diffusivity.

scholarly journals Dynamics of White Matter Plasticity Underlying Working Memory Training: Multimodal Evidence from Diffusion MRI and Relaxometry

2017 ◽  
Vol 29 (9) ◽  
pp. 1509-1520 ◽  
Author(s):  
Claudia Metzler-Baddeley ◽  
Sonya Foley ◽  
Silvia de Santis ◽  
Cyril Charron ◽  
Adam Hampshire ◽  
...  
Keyword(s):  
Working Memory ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Volume Fraction ◽  
Radial Diffusivity ◽  
Superior Longitudinal Fasciculus ◽  
Microstructural Changes ◽  
Water Fraction ◽  
Myelin Water Fraction ◽  
Restricted Volume

Adaptive working memory (WM) training may lead to cognitive benefits that are associated with white matter plasticity in parietofrontal networks, but the underlying mechanisms remain poorly understood. We investigated white matter microstructural changes after adaptive WM training relative to a nonadaptive comparison group. Microstructural changes were studied in the superior longitudinal fasciculus, the main parietofrontal connection, and the cingulum bundle as a comparison pathway. MRI-based metrics were the myelin water fraction and longitudinal relaxation rate R1 from multicomponent relaxometry (captured with the mcDESPOT approach) as proxy metrics of myelin, the restricted volume fraction from the composite hindered and restricted model of diffusion as an estimate of axon morphology, and fractional anisotropy and radial diffusivity from diffusion tensor imaging. PCA was used for dimensionality reduction. Adaptive training was associated with benefits in a “WM capacity” component and increases in a microstructural component (increases in R1, restricted volume fraction, fractional anisotropy, and reduced radial diffusivity) that predominantly loaded on changes in the right dorsolateral superior longitudinal fasciculus and the left parahippocampal cingulum. In contrast, nonadaptive comparison activities were associated with the opposite pattern of reductions in WM capacity and microstructure. No group differences were observed for the myelin water fraction metric suggesting that R1 was a more sensitive “myelin” index. These results demonstrate task complexity and location-specific white matter microstructural changes that are consistent with tissue alterations underlying myelination in response to training.

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