scholarly journals Age-Related Differences in White Matter: Understanding Tensor-Based Results Using Fixel-Based Analysis

2021 ◽  
Author(s):  
Shannon Kelley ◽  
John Plass ◽  
Andrew R Bender ◽  
Thad A Polk
Keyword(s):  
White Matter ◽  
Age Differences ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Cerebral White Matter ◽  
Fiber Density ◽  
Cingulum Bundle ◽  
Age Related ◽  
Structural Differences ◽  
Diffusion Tensor Imaging Dti

Abstract Aging is associated with widespread alterations in cerebral white matter (WM). Most prior studies of age differences in WM have used diffusion tensor imaging (DTI), but typical DTI metrics (e.g., fractional anisotropy; FA) can reflect multiple neurobiological features, making interpretation challenging. Here, we used fixel-based analysis (FBA) to investigate age-related WM differences observed using DTI in a sample of 45 older and 25 younger healthy adults. Age-related FA differences were widespread but were strongly associated with differences in multi-fiber complexity (CX), suggesting that they reflected differences in crossing fibers in addition to structural differences in individual fiber segments. FBA also revealed a frontolimbic locus of age-related effects and provided insights into distinct microstructural changes underlying them. Specifically, age differences in fiber density were prominent in fornix, bilateral anterior internal capsule, forceps minor, body of the corpus callosum, and corticospinal tract, while age differences in fiber cross section were largest in cingulum bundle and forceps minor. These results provide novel insights into specific structural differences underlying major WM differences associated with aging.

scholarly journals Age-related differences in white matter: Comparing fixel based and tensor based analyses

2019 ◽  
Author(s):  
Shannon Kelley ◽  
John Plass ◽  
Andrew R. Bender ◽  
Thad A. Polk
Keyword(s):  
White Matter ◽  
Cross Section ◽  
Healthy Aging ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Fiber Density ◽  
Younger Adults ◽  
Diffusion Weighted Images ◽  
Age Related ◽  
Anterior Posterior

AbstractOlder adults tend to perform worse on cognitive, behavioral, motor, and sensory tasks compared to younger adults, and differences in white matter that may be associated with this phenomenon are being actively investigated. Most prior studies of white matter differences between older and younger adults have analyzed diffusion weighted images using diffusion tensor imaging (DTI) analysis. But DTI results can be affected by many different factors (e.g., fiber density, fiber cross-section, crossing fibers) that are difficult to distinguish, making the interpretation of these results challenging. Recently, new fixel-based analysis (FBA) techniques have been developed that address some of these concerns, but these techniques have not yet been applied in the domain of aging. In this study, we used both DTI and FBA to analyze differences in white matter in a large sample of older and younger healthy adults. Both analysis methods identified age differences in forceps minor, fornix, bilateral internal capsule, and bilateral inferior fronto-occipital fasciculi, but the FBA results provided novel insights into the underlying structural differences. Furthermore, DTI analysis identified differences in superior longitudinal fasciculus that are not reflected in fiber density or cross-section and may instead be due to differences in crossing fiber geometry. Finally, the FBA results identified clearer differences in limbic white matter than did the DTI analysis. It also provided stronger evidence of an anterior-posterior asymmetry and segment-specific variations in white matter differences between older and younger adults. These results demonstrate the power of fixel-based analysis and provide novel insights into some of the major white matter differences associated with healthy aging.

White matter microstructural abnormalities in families multiply affected with bipolar I disorder: a diffusion tensor tractography study

2013 ◽  
Vol 44 (10) ◽  
pp. 2139-2150 ◽  
Author(s):  
L. Emsell ◽  
C. Chaddock ◽  
N. Forde ◽  
W. Van Hecke ◽  
G. J. Barker ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Type I ◽  
Genetic Liability ◽  
Inferior Longitudinal Fasciculus ◽  
Participant Group ◽  
Dti Tractography ◽  
Magnetic Resonance Imaging Mri ◽  
Diffusion Tensor Imaging Dti

BackgroundWhite matter (WM) abnormalities are proposed as potential endophenotypic markers of bipolar disorder (BD). In a diffusion tensor imaging (DTI) voxel-based analysis (VBA) study of families multiply affected with BD, we previously reported that widespread abnormalities of fractional anisotropy (FA) are associated with both BD and genetic liability for illness. In the present study, we further investigated the endophenotypic potential of WM abnormalities by applying DTI tractography to specifically investigate tracts implicated in the pathophysiology of BD.MethodDiffusion magnetic resonance imaging (MRI) data were acquired from 19 patients with BD type I from multiply affected families, 21 of their unaffected first-degree relatives and 18 healthy volunteers. DTI tractography was used to identify the cingulum, uncinate fasciculus (UF), arcuate portion of the superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF), corpus callosum, and the anterior limb of the internal capsule (ALIC). Regression analyses were conducted to investigate the effect of participant group and genetic liability on FA and radial diffusivity (RD) in each tract.ResultsWe detected a significant effect of group on both FA and RD in the cingulum, SLF, callosal splenium and ILF driven by reduced FA and increased RD in patients compared to controls and relatives. Increasing genetic liability was associated with decreased FA and increased RD in the UF, and decreased FA in the SLF, among patients.ConclusionsWM microstructural abnormalities in limbic, temporal and callosal pathways represent microstructural abnormalities associated with BD whereas alterations in the SLF and UF may represent potential markers of endophenotypic risk.

White Matter-Governed Superior Frontal Sulcus Surgical Paradigm: A Radioanatomic Microsurgical Study—Part I

2020 ◽  
Vol 19 (4) ◽  
pp. E343-E356 ◽  
Author(s):  
Alejandro Monroy-Sosa ◽  
Srikant S Chakravarthi ◽  
Melanie B Fukui ◽  
Bhavani Kura ◽  
Jonathan E Jennings ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Entry Point ◽  
Coronal Suture ◽  
Corona Radiata ◽  
Cingulum Bundle ◽  
Sagittal Sinus ◽  
Precentral Sulcus ◽  
Superior Frontal Sulcus

Abstract BACKGROUND Frontal subcortical and intraventricular pathologies are traditionally accessed via transcortical or interhemispheric-transcallosal corridors. OBJECTIVE To describe the microsurgical subcortical anatomy of the superior frontal sulcus (SFS) corridor. METHODS Cadaveric dissections were undertaken and correlated with magnetic resonance imaging/diffusion-tensor imaging-Tractography. Surgical cases demonstrated clinical applicability. RESULTS SFS was divided into the following divisions: proximal, precentral sulcus to coronal suture; middle, 3-cm anterior to coronal suture; and distal, middle division to the orbital crest. Anatomy was organized as layered circumferential rings projecting radially towards the ventricles: (1) outer ring: at the level of the SFS, the following lengths were measured: (A) precentral sulcus to coronal suture = 2.29 cm, (B) frontal bone projection of superior sagittal sinus (SSS) to SFS = 2.37 cm, (C) superior temporal line to SFS = 3.0 cm, and (D) orbital crest to distal part of SFS = 2.32 cm; and (2) inner ring: (a) medial to SFS, U-fibers, frontal aslant tract (FAT), superior longitudinal fasciculus I (SLF-I), and cingulum bundle, (b) lateral to SFS, U-fibers, (SLF-II), claustrocortical fibers (CCF), and inferior fronto-occipital fasciculus, and (c) intervening fibers, FAT, corona radiata, and CCF. The preferred SFS parafascicular entry point (SFSP-EP) also referred to as the Kassam-Monroy entry point (KM-EP) bisects the distance between the midpupillary line and the SSS and has the following coordinates: x = 2.3 cm (lateral to SSS), y ≥ 3.5 cm (anterior to CS), and z = parallel corona radiata and anterior limb of the internal capsule. CONCLUSION SFS corridor can be divided into lateral, medial, and intervening white matter tract segments. Based on morphometric assessment, the optimal SFSP-EP is y ≥ 3.5 cm, x = 2.3 cm, and z = parallel to corona radiata and anterior limb of the internal capsule.

Diffusion tensor imaging of adult age differences in cerebral white matter: relation to response time

NeuroImage ◽  
2004 ◽  
Vol 21 (3) ◽  
pp. 1174-1181 ◽  
Author(s):  
David J. Madden ◽  
Wythe L. Whiting ◽  
Scott A. Huettel ◽  
Leonard E. White ◽  
James R. MacFall ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Response Time ◽  
Age Differences ◽  
Diffusion Tensor ◽  
Cerebral White Matter ◽  
Adult Age ◽  
Adult Age Differences

scholarly journals Evaluation of Cerebral White Matter in Prelingually Deaf Children Using Diffusion Tensor Imaging

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Kye Hoon Park ◽  
Won-Ho Chung ◽  
Hunki Kwon ◽  
Jong-Min Lee
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Normal Hearing ◽  
Deaf Children ◽  
Cerebral White Matter ◽  
White Matter Tracts ◽  
Age Related ◽  
Significant Difference ◽  
Prelingually Deaf

This study compared white matter development in prelingually deaf and normal-hearing children using a tract-based spatial statistics (TBSS) method. Diffusion tensor imaging (DTI) was performed in 21 prelingually deaf (DEAF group) and 20 normal-hearing (HEAR group) subjects aged from 1.7 to 7.7 years. Using TBSS, we evaluated the regions of significant difference in fractional anisotropy (FA) between the groups. Correlations between FA values and age in each group were also analyzed using voxel-wise correlation analyses on the TBSS skeleton. Lower FA values of the white matter tract of Heschl’s gyrus, the inferior frontooccipital fasciculus, the uncinate fasciculus, the superior longitudinal fasciculus, and the forceps major were evident in the DEAF group compared with those in the HEAR group below 4 years of age, while the difference was not significant in older subjects. We also found that age-related development of the white matter tracts may continue until 8 years of age in deaf children. These results imply that development of the cerebral white matter tracts is delayed in prelingually deaf children.

scholarly journals Disruptions in White Matter Maturation and Mediation of Cognitive Development in Youth on the Psychosis Spectrum

2018 ◽  
Author(s):  
Catherine E. Hegarty ◽  
Dietsje D. Jolles ◽  
Eva Mennigen ◽  
Maria Jalbrzikowski ◽  
Carrie E. Bearden ◽  
...  
Keyword(s):  
White Matter ◽  
Symptom Severity ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Therapeutic Interventions ◽  
Cross Sectional ◽  
Group Interactions ◽  
Mediation Analyses ◽  
Age Related ◽  
The Relationship

AbstractBackground:Psychosis onset typically occurs in adolescence, and subclinical psychotic experiences peak in adolescence as well. Adolescence is also a time of critical neural and cognitive maturation. Using cross-sectional data from the Philadelphia Neurodevelopmental Cohort, we examine whether regional white matter (WM) development is disrupted in psychosis spectrum (PS) youth whether WM maturation mediates the relationship between age and cognition in typically developing (TD) and PS youth. A third group with intermediate symptom severity (limited PS [LPS]) was included in follow-up analyses to determine whether age-related disruptions in WM scaled with symptom severity.Methods:We examined WM microstructure, as assessed via diffusion tensor imaging, in 707 individuals (aged 10–22 years; 499 TD, 171 PS, 37 LPS) by using Tract-Based Spatial Statistics. Multiple regressions were used to evaluate age x group interactions on regional WM indices. Mediation analyses were conducted using a bootstrapping approach.Results:There were age x group interactions on fractional anisotropy (FA) in the superior longitudinal fasciculus (SLF) and retrolenticular internal capsule (RLIC). SLF FA mediated the relationship between age and Complex Cognition in TD, but not PS. Further, inclusion of LPS youth showed that the relationship between age and SLF FA decreased with increasing symptom severityConclusions:Our results show aberrant age-related changes in SLF and RLIC FA in PS youth. SLF development supports emergence of specific higher-order cognitive functions in TD youth, but not in PS. Future mechanistic explanations for these relationships could facilitate development of earlier and refined targets for therapeutic interventions.

scholarly journals Physical activity predicts population-level age-related differences in frontal white matter

2018 ◽  
Author(s):  
Juho M. Strömmer ◽  
Simon W. Davis ◽  
Richard N. Henson ◽  
Lorraine K. Tyler ◽  
Karen L. Campbell ◽  
...  
Keyword(s):  
Physical Activity ◽  
White Matter ◽  
Diffusion Tensor ◽  
Large Population ◽  
Internal Capsule ◽  
Reaction Time Task ◽  
Population Level ◽  
Simple Reaction Time Task ◽  
Positive Effects ◽  
Age Related

AbstractPhysical activity has positive effects on brain health and cognitive function throughout the lifespan. Thus far, few studies have examined the effects of physical activity on white matter (WM) microstructure and psychomotor speed within the same, population-based sample (critical if conclusions are to extend to the wider population). Here, using diffusion tensor imaging and a simple reaction time task within a relatively large population-derived sample (N = 399; 18–87 years) from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN), we demonstrate that physical activity mediates the effect of age on white matter integrity, measured with fractional anisotropy. Higher self-reported daily physical activity was associated with greater preservation of WM in several frontal tracts, including the genu of corpus callosum, uncinate fasciculus, external capsule and anterior limb of the internal capsule. We also show that the age-related slowing is mediated by WM integrity in the genu. Our findings contribute to a growing body of work suggesting that a physically active lifestyle may protect against age-related structural disconnection and slowing.

scholarly journals Analysis of Age-Related White Matter Microstructures Based on Diffusion Tensor Imaging

2021 ◽  
Vol 13 ◽  
Author(s):  
Yahui Ouyang ◽  
Dong Cui ◽  
Zilong Yuan ◽  
Zhipeng Liu ◽  
Qing Jiao ◽  
...  
Keyword(s):  
White Matter ◽  
Fiber Length ◽  
Middle Age ◽  
Diffusion Tensor ◽  
Age Groups ◽  
Internal Capsule ◽  
Fiber Tracking ◽  
Posterior Limb ◽  
Corona Radiata ◽  
Age Related

Population aging has become a serious social problem. Accordingly, many researches are focusing on changes in brains of the elderly. In this study, we used multiple parameters to analyze age-related changes in white matter fibers. A sample cohort of 58 individuals was divided into young and middle-age groups and tract-based spatial statistics (TBSS) were used to analyze the differences in fractional anisotropy (FA), mean diffusion (MD), axial diffusion (AD), and radial diffusion (RD) between the two groups. Deterministic fiber tracking was used to investigate the correlation between fiber number and fiber length with age. The TBSS analysis revealed significant differences in FA, MD, AD, and RD in multiple white matter fibers between the two groups. In the middle-age group FA and AD were lower than in young people, whereas the MD and RD values were higher. Deterministic fiber tracking showed that the fiber length of some fibers correlated positively with age. These fibers were observed in the splenium of corpus callosum (SCC), the posterior limb of internal capsule (PLIC), the right posterior corona radiata (PCR_R), the anterior corona radiata (ACR), the left posterior thalamic radiation (include optic radiation; PTR_L), and the left superior longitudinal fasciculus (SLF_L), among others. The results showed that the SCC, PLIC, PCR_R, ACR, PTR_L, and SLF_L significantly differed between young and middle-age people. Therefore, we believe that these fibers could be used as image markers of age-related white matter changes.

scholarly journals Evaluation of White Matter Integrity Utilizing the DELPHI (TMS-EEG) System

2020 ◽  
Vol 14 ◽  
Author(s):  
Ofri Levy-Lamdan ◽  
Noa Zifman ◽  
Efrat Sasson ◽  
Shai Efrati ◽  
Dallas C. Hack ◽  
...  
Keyword(s):  
White Matter ◽  
Evoked Potentials ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Brain Network ◽  
Multidimensional Approach ◽  
Microstructure Changes ◽  
Brain White Matter ◽  
Age Related ◽  
Significant Difference

ObjectiveThe aim of this study was to evaluate brain white matter (WM) fibers connectivity damage in stroke and traumatic brain injury (TBI) subjects by direct electrophysiological imaging (DELPHI) that analyzes transcranial magnetic stimulation (TMS)-evoked potentials (TEPs).MethodsThe study included 123 participants, out of which 53 subjects with WM-related pathologies (39 stroke, 14 TBI) and 70 healthy age-related controls. All subjects underwent DELPHI brain network evaluations of TMS-electroencephalogram (EEG)-evoked potentials and diffusion tensor imaging (DTI) scans for quantification of WM microstructure fractional anisotropy (FA).ResultsDELPHI output measures show a significant difference between the healthy and stroke/TBI groups. A multidimensional approach was able to classify healthy from unhealthy with a balanced accuracy of 0.81 ± 0.02 and area under the curve (AUC) of 0.88 ± 0.01. Moreover, a multivariant regression model of DELPHI output measures achieved prediction of WM microstructure changes measured by FA with the highest correlations observed for fibers proximal to the stimulation area, such as frontal corpus callosum (r = 0.7 ± 0.02), anterior internal capsule (r = 0.7 ± 0.02), and fronto-occipital fasciculus (r = 0.65 ± 0.03).ConclusionThese results indicate that features of TMS-evoked response are correlated to WM microstructure changes observed in pathological conditions, such as stroke and TBI, and that a multidimensional approach combining these features in supervised learning methods serves as a strong indicator for abnormalities and changes in WM integrity.

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