DT MRI microstructural cortical lesion damage does not explain cognitive impairment in MS

2017 ◽  
Vol 23 (14) ◽  
pp. 1918-1928 ◽  
Author(s):  
Paolo Preziosa ◽  
Elisabetta Pagani ◽  
Maria E Morelli ◽  
Massimiliano Copetti ◽  
Vittorio Martinelli ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
White Matter ◽  
Diffusion Tensor ◽  
Gray Matter Volume ◽  
Three Dimensional ◽  
Mean Diffusivity ◽  
Cortical Lesion ◽  
Lesion Volume ◽  
Normal Appearing White Matter ◽  
Tissue Abnormalities

Objective: We combined double inversion recovery (DIR) and diffusion tensor (DT) magnetic resonance imaging (MRI) to quantify the severity of cortical lesion (CL) microstructural tissue abnormalities in a large cohort of relapse-onset multiple sclerosis (MS) patients and its contribution to cognitive dysfunction. Methods: DIR, DT, dual-echo, and three-dimensional (3D) T1-weighted scans were acquired from 149 MS patients and 40 controls. Cognitively impaired (CI) patients had ⩾2 abnormal neuropsychological tests. Diffusivity values in CLs, cortex, white matter (WM) lesions, and normal-appearing (NA) WM were assessed. Predictors of cognitive impairment were identified using a random forest analysis. Results: Compared to controls, MS patients had lower normalized brain volume (NBV), gray matter volume (GMV), WM volume, lower fractional anisotropy (FA), and higher mean diffusivity in cortex and normal-appearing white matter (NAWM). A total of 44 (29.5%) patients were CI. Compared to cognitively preserved (CP), CI patients had higher T2 WM lesion volume (LV), lower NBV and GMV, and more severe diffusivity abnormalities in WM lesions, cortex, and NAWM. CL measures did not differ between CI and CP patients. Cortex FA, age, disease duration, T2 WM LV, and GMV best predicted MS-related cognitive impairment (C-statistic = 0.88). Conclusion: “Diffuse” GM and NAWM damage and WM lesions, rather than intrinsic CL damage, contribute to cognitive impairment in MS.

scholarly journals White matter abnormalities in the corpus callosum with cognitive impairment in Parkinson disease

Neurology ◽  
2018 ◽  
Vol 91 (24) ◽  
pp. e2244-e2255 ◽  
Author(s):  
Ian O. Bledsoe ◽  
Glenn T. Stebbins ◽  
Doug Merkitch ◽  
Jennifer G. Goldman
Keyword(s):  
Cognitive Impairment ◽  
White Matter ◽  
Corpus Callosum ◽  
Parkinson Disease ◽  
Information Transfer ◽  
Diffusion Tensor ◽  
Anterior Segment ◽  
Mean Diffusivity ◽  
Cognitive Domain ◽  
White Matter Abnormalities

ObjectiveTo evaluate microstructural characteristics of the corpus callosum using diffusion tensor imaging (DTI) and their relationships to cognitive impairment in Parkinson disease (PD).MethodsSeventy-five participants with PD and 24 healthy control (HC) participants underwent structural MRI brain scans including DTI sequences and clinical and neuropsychological evaluations. Using Movement Disorder Society criteria, PD participants were classified as having normal cognition (PD-NC, n = 23), mild cognitive impairment (PD-MCI, n = 35), or dementia (PDD, n = 17). Cognitive domain (attention/working memory, executive function, language, memory, visuospatial function) z scores were calculated. DTI scalar values, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), were established for 5 callosal segments on a midsagittal plane, single slice using a topographically derived parcellation method. Scalar values were compared among participant groups. Regression analyses were performed on cognitive domain z scores and DTI metrics.ResultsParticipants with PD showed increased AD values in the anterior 3 callosal segments compared to healthy controls. Participants with PDD had significantly increased AD, MD, and RD in the anterior 2 segments compared to participants with PD-NC and most anterior segment compared to participants with PD-MCI. FA values did not differ significantly between participants with PD and participants with HC or among PD cognitive groups. The strongest associations for the DTI metrics and cognitive performance occurred in the most anterior and most posterior callosal segments, and also reflected fronto-striatal and posterior cortical type cognitive deficits, respectively.ConclusionsMicrostructural white matter abnormalities of the corpus callosum, as measured by DTI, may contribute to PD cognitive impairment by disrupting information transfer across interhemispheric and callosal–cortical projections.

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.

Deep microbleeds and periventricular white matter disintegrity are independent predictors of attention/executive dysfunction in non-dementia patients with small vessel disease

2016 ◽  
Vol 29 (5) ◽  
pp. 793-803 ◽  
Author(s):  
Wen-wei Cao ◽  
Yao Wang ◽  
Quan Dong ◽  
Xue Chen ◽  
Yan-sheng Li ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
White Matter ◽  
Diffusion Tensor ◽  
Small Vessel Disease ◽  
Early Stage ◽  
Mean Diffusivity ◽  
Executive Dysfunction ◽  
Small Vessel ◽  
Periventricular White Matter ◽  
Vessel Disease

ABSTRACTBackground:Cerebral small vessel disease (SVD) is the common cause of cognitive decline in the old population. MRI can be used to clarify its mechanisms. However, the surrogate markers of MRI for early cognitive impairment in SVD remain uncertain to date. We investigated the cognitive impacts of cerebral microbleeds (CMBs), diffusion tensor imaging (DTI), and brain volumetric measurements in a cohort of post-stroke non-dementia SVD patients.Methods:Fifty five non-dementia SVD patients were consecutively recruited and categorized into two groups as no cognitive impairment (NCI) (n = 23) or vascular mild cognitive impairment (VaMCI) (n = 32). Detailed neuropsychological assessment and multimodal MRI were completed.Results:The two groups differed significantly on Z scores of all cognitive domains (all p < 0.01) except for the language. There were more patients with hypertension (p = 0.038) or depression (p = 0.019) in the VaMCI than those in the NCI group. Multiple regression analysis of cognition showed periventricular mean diffusivity (MD) (β = −0.457, p < 0.01) and deep CMBs numbers (β = −0.352, p < 0.01) as the predictors of attention/executive function, which explained 45.2% of the total variance. Periventricular MD was the independent predictor for either memory (β = −0.314, p < 0.05) or visuo-spatial function (β = −0.375, p < 0.01); however, only small proportion of variance could be accounted for (9.8% and 12.4%, respectively). Language was not found to be correlated with any of the MRI parameters. No correlation was found between brain atrophic indices and any of the cognitive measures.Conclusion:Arteriosclerotic CMBs and periventricular white matter disintegrity seem to be independent MRI surrogated markers in the early stage of cognitive impairment in SVD.

scholarly journals Spatial Gradient of Microstructural Changes in Normal-Appearing White Matter in Tracts Affected by White Matter Hyperintensities in Older Age

2018 ◽  
Author(s):  
Susana Muñoz Maniega ◽  
Rozanna Meijboom ◽  
Francesca M. Chappell ◽  
Maria C. Valdés Hernández ◽  
John M. Starr ◽  
...  
Keyword(s):  
White Matter ◽  
White Matter Hyperintensities ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Pathological Process ◽  
Spatial Gradient ◽  
Microstructural Changes ◽  
Normal Appearing White Matter ◽  
Brain White Matter ◽  
Lothian Birth Cohort

AbstractBrain white matter hyperintensities (WMH), common in older adults, may contribute to cortical disconnection and cognitive dysfunction. The presence of WMH within white matter (WM) tracts indicates underlying microstructural WM changes that may also affect the normal-appearing WM (NAWM) of a tract. We performed an exploratory study using diffusion magnetic resonance imaging of 52 healthy participants from the Lothian Birth Cohort 1936 (age 72.2 ± 0.7 years) selected to include a range of WMH burden, to quantify microstructural changes of tracts intersecting WMH. We reconstructed tracts using automated tractography and identified intersections with WMH. Tissue volumes and water diffusion tensor parameters (mean diffusivity (MD) and fractional anisotropy (FA)) were established for tract-WMH and tract-NAWM. MD and FA were also measured for tract-NAWM at 2 mm incremental distances from the tract-WMH edge, and from the edge of nearby, non-intersecting, WMH. We observed microstructural changes in tract-WMH suggestive of tissue damage. Tract-NAWM also showed a spatial gradient of FA and MD abnormalities, which diminished with distance from the tract-WMH. Nearby WMH lesions, not directly crossed by the tract, also affected tract microstructure with a similar pattern. Additionally, both FA and MD changes in tract-NAWM were predicted by FA and MD changes respectively in tract-WMH. FA was also predicted by tract-WMH overlap volume, whereas MD was better predicted by whole-brain WMH load. These results suggest that tract-NAWM microstructure is affected by the pathological process underlying WMH, when WMH are either within or near to the tract. The changes in NAWM tract tissue may indicate future lesion progression and may play an important role in cognitive ageing.

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

2016 ◽  
Vol 4 ◽  
pp. 205031211664881 ◽  
Author(s):  
Duan Liu ◽  
Zan Wang ◽  
Hao Shu ◽  
Zhijun Zhang
Keyword(s):  
Cognitive Impairment ◽  
Diffusion Tensor Imaging ◽  
Mild Cognitive Impairment ◽  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Amnestic Mild Cognitive Impairment ◽  
Uncinate Fasciculus ◽  
Radial Diffusivity ◽  
Mild Cognitive Impairment Group

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.

scholarly journals White matter and neurocognitive changes in adults with chronic traumatic brain injury

2009 ◽  
Vol 15 (1) ◽  
pp. 130-136 ◽  
Author(s):  
MARY R.T. KENNEDY ◽  
JEFFREY R. WOZNIAK ◽  
RYAN L. MUETZEL ◽  
BRYON A. MUELLER ◽  
HSIN-HUEI CHIOU ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Cognitive Impairment ◽  
Brain Injury ◽  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Analysis Of Covariance ◽  
Severely Injured ◽  
Motor Speed ◽  
Time Since Injury

AbstractDiffusion tensor imaging was used to investigate white matter (WM) integrity in adults with traumatic brain injury (TBI) and healthy adults as controls. Adults with TBI had sustained severe vehicular injuries on the average of 7 years earlier. A multivariate analysis of covariance with verbal IQ as the covariate revealed that adults with TBI had lower fractional anisotropy and higher mean diffusivity than controls, specifically in the three regions of interest (ROIs), the centrum semiovale (CS), the superior frontal (SPF), and the inferior frontal (INF). Adults with TBI averaged in the normal range in motor speed and two of three executive functions and were below average in delayed verbal recall and inhibition, whereas controls were above average. Time since injury, but not age, was associated with WM changes in the SPF ROI, whereas age, but not time since injury, was associated with WM changes in the INF ROI, suggesting that the effects of WM on time since injury may interact with age. To understand the utility of WM changes in chronic recovery, larger sample sizes are needed to investigate associations between cognition and WM integrity of severely injured individuals who have substantial cognitive impairment compared to severely injured individuals with little cognitive impairment. (JINS, 2009, 15, 130–136.)

scholarly journals Cortical axonal loss is associated with both gray matter demyelination and white matter tract pathology in progressive multiple sclerosis: Evidence from a combined MRI-histopathology study

2020 ◽  
pp. 135245852091897 ◽  
Author(s):  
Svenja Kiljan ◽  
Paolo Preziosa ◽  
Laura E Jonkman ◽  
Wilma DJ van de Berg ◽  
Jos Twisk ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
White Matter Lesions ◽  
Progressive Multiple Sclerosis ◽  
Axonal Loss ◽  
Normal Appearing White Matter ◽  
Axonal Density ◽  
Neuroaxonal Degeneration

Background: Neuroaxonal degeneration is one of the hallmarks of clinical deterioration in progressive multiple sclerosis (PMS). Objective: To elucidate the association between neuroaxonal degeneration and both local cortical and connected white matter (WM) tract pathology in PMS. Methods: Post-mortem in situ 3T magnetic resonance imaging (MRI) and cortical tissue blocks were collected from 16 PMS donors and 10 controls. Cortical neuroaxonal, myelin, and microglia densities were quantified histopathologically. From diffusion tensor MRI, fractional anisotropy, axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) were quantified in normal-appearing white matter (NAWM) and white matter lesions (WML) of WM tracts connected to dissected cortical regions. Between-group differences and within-group associations were investigated through linear mixed models. Results: The PMS donors displayed significant axonal loss in both demyelinated and normal-appearing (NA) cortices ( p < 0.001 and p = 0.02) compared with controls. In PMS, cortical axonal density was associated with WML MD and AD ( p = 0.003; p = 0.02, respectively), and NAWM MD and AD ( p = 0.04; p = 0.049, respectively). NAWM AD and WML AD explained 12.6% and 22.6%, respectively, of axonal density variance in NA cortex. Additional axonal loss in demyelinated cortex was associated with cortical demyelination severity ( p = 0.002), explaining 34.4% of axonal loss variance. Conclusion: Reduced integrity of connected WM tracts and cortical demyelination both contribute to cortical axonal loss in PMS.

scholarly journals Corpus Callosum and Cingulum Tractography in Parkinson's Disease

2010 ◽  
Vol 37 (5) ◽  
pp. 595-600 ◽  
Author(s):  
Katie Wiltshire ◽  
Luis Concha ◽  
Myrlene Gee ◽  
Thomas Bouchard ◽  
Christian Beaulieu ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cognitive Impairment ◽  
White Matter ◽  
Corpus Callosum ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Method ◽  
Motor Symptoms ◽  
Mri Scans

Background:In Parkinson's disease (PD) cell loss in the substantia nigra is known to result in motor symptoms; however widespread pathological changes occur and may be associated with non-motor symptoms such as cognitive impairment. Diffusion tensor imaging is a quantitative imaging method sensitive to the micro-structure of white matter tracts.Objective:To measure fractional anisotropy (FA) and mean diffusivity (MD) values in the corpus callosum and cingulum pathways, defined by diffusion tensor tractography, in patients with PD, PD with dementia (PDD) and controls and to determine if these measures correlate with Mini-Mental Status Examination (MMSE) scores in parkinsonian patients.Methods:Patients with PD (17 Males [M], 12 Females [F]), mild PDD (5 M, 1F) and controls (8 M, 7F) underwent cognitive testing and MRI scans. The corpus callosum was divided into four regions and the cingulum into two regions bilaterally to define tracts using the program DTIstudio (Johns Hopkins University) using the fiber assignment by continuous tracking algorithm. Volumetric MRI scans were used to measure white and gray matter volumes.Results:Groups did not differ in age or education. There were no overall FA or MD differences between groups in either the corpus callosum or cingulum pathways. In PD subjects the MMSE score correlated with MD within the corpus callosum. These findings were independent of age, sex and total white matter volume.Conclusions:The data suggest that the corpus callosum or its cortical connections are associated with cognitive impairment in PD patients.

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