Mapping the brain pathways of declarative verbal memory: Evidence from white matter lesions in the living human brain

NeuroImage ◽  
2008 ◽  
Vol 42 (3) ◽  
pp. 1237-1243 ◽  
Author(s):  
Jorge Sepulcre ◽  
Joseph C. Masdeu ◽  
Jaume Sastre-Garriga ◽  
Joaquín Goñi ◽  
Nieves Vélez-de-Mendizábal ◽  
...  
Keyword(s):  
White Matter ◽  
Human Brain ◽  
Verbal Memory ◽  
White Matter Lesions ◽  
Brain Pathways ◽  
The Brain

Microstructural Hyperelastic Characterization of Brain White Matter in Tension

2019 ◽  
Author(s):  
Mohammadreza Ramzanpour ◽  
Mohammad Hosseini-Farid ◽  
Mariusz Ziejewski ◽  
Ghodrat Karami
Keyword(s):  
Finite Element ◽  
White Matter ◽  
Human Brain ◽  
Volume Fraction ◽  
Fibrous Composite ◽  
Diffuse Axonal Injury ◽  
Stiffness Ratio ◽  
Fibrous Composite Material ◽  
Brain White Matter ◽  
The Brain

Abstract Axons as microstructural constituent elements of brain white matter are highly oriented in extracellular matrix (ECM) in one direction. Therefore, it is possible to model the human brain white matter as a unidirectional fibrous composite material. A micromechanical finite element model of the brain white matter is developed to indirectly measure the brain white matter constituents’ properties including axon and ECM under tensile loading. Experimental tension test on corona radiata conducted by Budday et al. 2017 [1] is used in this study and one-term Ogden hyperelastic constitutive model is applied to characterize its behavior. By the application of genetic algorithm (GA) as a black box optimization method, the Ogden hyperelastic parameters of axon and ECM minimizing the error between numerical finite element simulation and experimental results are measured. Inverse analysis is conducted on the resultant optimized parameters shows high correlation of coefficient (>99%) between the numerical and experimental data which verifies the accuracy of the optimization procedure. The volume fraction of axons in porcine brain white matter is taken to be 52.7% and the stiffness ratio of axon to ECM is perceived to be 3.0. As these values are not accurately known for human brain white matter, we study the material properties of axon and ECM for different stiffness ratio and axon volume fraction values. The results of this study helps to better understand the micromechanical structure of the brain and micro-level injuries such as diffuse axonal injury.

scholarly journals Relationship Between Type 2 Diabetes and White Matter Hyperintensity: A Systematic Review

2020 ◽  
Vol 11 ◽  
Author(s):  
Dan-Qiong Wang ◽  
Lei Wang ◽  
Miao-Miao Wei ◽  
Xiao-Shuang Xia ◽  
Xiao-Lin Tian ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
White Matter ◽  
Structural Changes ◽  
White Matter Lesions ◽  
Poor Performance ◽  
White Matter Hyperintensity ◽  
Diabetic Microangiopathy ◽  
The Relationship ◽  
The Brain

White matter (WM) disease is recognized as an important cause of cognitive decline and dementia. White matter lesions (WMLs) appear as white matter hyperintensities (WMH) on T2-weighted magnetic resonance imaging (MRI) scans of the brain. Previous studies have shown that type 2 diabetes (T2DM) is associated with WMH. In this review, we reviewed the literature on the relationship between T2DM and WMH in PubMed and Cochrane over the past five years and explored the possible links among the presence of T2DM, the course or complications of diabetes, and WMH. We found that: (1) Both from a macro- and micro-scopic point of view, most studies support the relationship of a larger WMH and a decrease in the integrity of WMH in T2DM; (2) From the relationship between brain structural changes and cognition in T2DM, the poor performance in memory, attention, and executive function tests associated with abnormal brain structure is consistent; (3) Diabetic microangiopathy or peripheral neuropathy may be associated with WMH, suggesting that the brain may be a target organ for T2DM microangiopathy; (4) Laboratory markers such as insulin resistance and fasting insulin levels were significantly associated with WMH. High HbA1c and high glucose variability were associated with WMH but not glycemic control.

Association between Mid-Regional Proadrenomedullin Levels and Progression of Deep White Matter Lesions in the Brain Accompanying Cognitive Decline

2017 ◽  
Vol 56 (4) ◽  
pp. 1253-1262 ◽  
Author(s):  
Nagato Kuriyama ◽  
Masafumi Ihara ◽  
Toshiki Mizuno ◽  
Etsuko Ozaki ◽  
Daisuke Matsui ◽  
...  
Keyword(s):  
White Matter ◽  
Cognitive Decline ◽  
White Matter Lesions ◽  
Deep White Matter ◽  
The Brain

scholarly journals Oxidative Glial Cell Damage Associated with White Matter Lesions in the Aging Human Brain

2014 ◽  
Vol 25 (5) ◽  
pp. 565-574 ◽  
Author(s):  
Sufana Al-Mashhadi ◽  
Julie E. Simpson ◽  
Paul R. Heath ◽  
Mark Dickman ◽  
Gillian Forster ◽  
...  
Keyword(s):  
White Matter ◽  
Human Brain ◽  
Glial Cell ◽  
Cell Damage ◽  
White Matter Lesions

MRI of white matter lesions in the brain stem: Narrowing the differential diagnosis for appropriate therapy

1998 ◽  
Vol 5 (10) ◽  
pp. 737-738
Author(s):  
Toni C. Roth ◽  
Beverly L. Hershey ◽  
Amy L. Kotsenas ◽  
Todd L. Siegal
Keyword(s):  
Differential Diagnosis ◽  
White Matter ◽  
Brain Stem ◽  
White Matter Lesions ◽  
Appropriate Therapy ◽  
The Brain

scholarly journals Distinctive Patterns of Tau Accumulation and White-Matter Degeneration on Domain-Specific Neuropsychiatric Test Scores

2020 ◽  
Vol 3 ◽  
Author(s):  
Zack Hall ◽  
Billy Chien ◽  
Shannon Risacher ◽  
Andrew Saykin ◽  
Yu-Chien Wu ◽  
...  
Keyword(s):  
White Matter ◽  
Verbal Memory ◽  
Test Scores ◽  
Visual Memory ◽  
Visuospatial Ability ◽  
Domain Specific ◽  
Brain Functions ◽  
White Matter Degeneration ◽  
Tau Pet ◽  
The Brain

Background:  Diagnosis of AD is often started via cognitive tests such as the Mini Mental Status Exam (MMSE) or Montreal Cognitive Assessment (MOCA) with the diagnosis being finalized with autopsy. Currently, positron emission tomography (PET) tracers are used to visualize tau and beta amyloid accumulation in the brain. These imaging techniques demonstrate significant correlations with cognitive decline and have been used to aid in the diagnosis of AD. Particularly, tau accumulation has been shown to progress in a distinct pattern and has been linked to white matter degeneration. We hypothesized that tau accumulation and white matter degeneration in different brain regions have unique correlation patterns with domain-specific neuropsychiatric test scores.   Methods:  This study included 87 older adults (57 cognitively normal subjects and 27 mild cognitive impairment) from the Indiana Alzheimer’s Disease Center. All participants underwent tau-PET ([18F] Flortaucipir PET) and diffusion MRI (dMRI) exams. Tau accumulation was quantified with tau-PET SUVR. White-matter structural connectivity (SC), which probes the integrity of white-matter connections of the brain, was quantified by metrices extracted from dMRI using network analysis. Both tau accumulation and SC measurements were quantified in 84 cortical region of interests (ROIs) and were compared to their domain specific neuropsychiatric test scores with linear regression analysis.  Results:  The verbal memory, visual memory, and visuospatial ability all had unique region-specific correlations with white-matter degeneration and tau accumulation. Verbal memory was solely correlated with tau accumulation. Visual memory was related to both tau accumulation and white-matter SC. Finally, visuospatial ability was only correlated with white-matter SC.   Potential Impact:  This data reveals that although there is a tight interplay between tau accumulation and white-matter degeneration, they affect brain functions in different ways. Specifically, grey-matter tau accumulation is associated with overall memory loss and decrease in the white-matter connectivity affects the visual-related information processing.  

Tractography of White Matter Fibers Using Diffusion MRI

2022 ◽  
pp. 98-112
Author(s):  
Strivathsav Ashwin Ramamoorthy
Keyword(s):  
White Matter ◽  
Human Brain ◽  
Diffusion Mri ◽  
Neural Circuits ◽  
Water Molecules ◽  
Neural Connectivity ◽  
Non Invasive ◽  
Diffusion Weighted Images ◽  
Different Types ◽  
The Brain

To understand more about the human brain and how it works, it is vital to understand how the neural circuits connect different regions of the brain. The human brain is filled predominantly with water and the majority of the water molecules undergo diffusion which can be captured with the help of diffusion MRI. Diffusion weighted images enable us to reconstruct the neural circuits in a non-invasive manner, and this procedure is referred to as tractography. Tractography aids neurosurgeons to understand the neural connectivity of the patient. This chapter attempts to explain the procedure of tractography and different types of algorithms.

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