scholarly journals Neurofeedback fMRI in the motor system elicits bi-directional changes in activity and white-matter structure in the healthy adult human brain

2020 ◽  
Author(s):  
Cassandra Sampaio-Baptista ◽  
Heather F. Neyedli ◽  
Zeena-Britt Sanders ◽  
Kata Diosi ◽  
David Havard ◽  
...  
Keyword(s):  
White Matter ◽  
Motor Cortex ◽  
Diffusion Tensor ◽  
Brain Activity ◽  
Activity Patterns ◽  
Hand Movement ◽  
Proof Of Concept ◽  
White Matter Microstructure ◽  
Regulation Of Activity ◽  
Diffusion Tensor Imaging Dti

Neurofeedback can be used to alter brain activity and is therefore an attractive tool for neuromodulation in clinical contexts. Different contexts might call for different patterns of activity modulation. For example, following stroke, alternative therapeutic strategies could involve up or down-regulation of activity in the ipsilateral motor cortex. However, effects of such strategies on activity and brain structure are unknown. In a proof of concept study in healthy individuals, we showed that fMRI neurofeedback can be used to drive activity up or down in ipsilateral motor cortex during hand movement. Given evidence for activitydependent white matter plasticity, we also tested effects of activity modulation on white matter microstructure using diffusion tensor imaging (DTI). We show rapid opposing changes in corpus callosum microstructure that depend on the direction of activity modulation. Bidirectional modulation of ipsilateral motor cortex activity is therefore possible, and results not only in online changes in activity patterns, but also in changes in microstructure detectable 24 hours later.

scholarly journals White matter microstructure characterisation in temporal lobe epilepsy

2021 ◽  
Author(s):  
Nicolò Rolandi ◽  
Fulvia Palesi ◽  
Francesco Padelli ◽  
Isabella Giachetti ◽  
Domenico Aquino ◽  
...  
Keyword(s):  
White Matter ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Diffusion Tensor ◽  
Focal Epilepsy ◽  
Spatial Statistical Analysis ◽  
White Matter Microstructure ◽  
Left And Right ◽  
Diffusion Kurtosis ◽  
Diffusion Tensor Imaging Dti

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy. Parameters of microstructural abnormalities derived from diffusion tensor imaging(DTI) have been reported to be helpful in differentiating between Left and Right TLE (L-TLE and R-TLE) but few of them compared L-TLE and R-TLE with a voxelwise approach. In this study, a whole brain tract based spatial statistical analysis was performed on DTI, diffusion kurtosis and NODDI derived parameters of 88 subjects to identify specific white matter patterns of alteration in patient affected by L-TLE and R-TLE with respect to healthy controls. Our findings demonstrated the presence of specific patterns of white matter alterations, with L-TLE more widely affected both in cerebral and cerebellar regions. This result supports the need to consider patients separately, according to the side of their pathology.

Association Study Between White Matter Microstructure and Intelligence Decline in Schizophrenia

2021 ◽  
pp. 155005942110633
Author(s):  
Junya Matsumoto ◽  
Kenichiro Miura ◽  
Masaki Fukunaga ◽  
Kiyotaka Nemoto ◽  
Daisuke Koshiyama ◽  
...  
Keyword(s):  
White Matter ◽  
Functional Connectivity ◽  
Gray Matter ◽  
Diffusion Tensor ◽  
Region Of Interest ◽  
Healthy Controls ◽  
Resonance Imaging ◽  
White Matter Microstructure ◽  
Magnetic Resonance Imaging Mri ◽  
Diffusion Tensor Imaging Dti

Patients with schizophrenia can exhibit intelligence decline, which is an important element of cognitive impairment. Previous magnetic resonance imaging (MRI) studies have demonstrated that patients with schizophrenia have altered gray matter structures and functional connectivity associated with intelligence decline defined by a difference between premorbid and current intelligence quotients (IQs). However, it has remained unclear whether white matter microstructures are related to intelligence decline. In the present study, the indices of diffusion tensor imaging (DTI) obtained from 138 patients with schizophrenia and 554 healthy controls were analyzed. The patients were classified into three subgroups based on intelligence decline: deteriorated (94 patients), preserved (42 patients), and compromised IQ (2 patients) groups. Given that the DTI of each subject was acquired using either one of two different MRI scanners, we analyzed DTI indices separately for each scanner group. In the comparison between the deteriorated IQ group and the healthy controls, differences in some DTI indices were noted in three regions of interest irrespective of the MRI scanners, whereas differences in only one region of interest were noted between the preserved IQ group and the healthy controls. However, the comparisons between the deteriorated and preserved IQ groups did not show any reproducible differences. Together with the previous findings, it is thought that gray matter structures and functional connectivity are more promising as markers of intelligence decline in schizophrenia than white matter microstructures.

scholarly journals Recent advances in diffusion neuroimaging: applications in the developing preterm brain

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1326 ◽  
Author(s):  
Diliana Pecheva ◽  
Christopher Kelly ◽  
Jessica Kimpton ◽  
Alexandra Bonthrone ◽  
Dafnis Batalle ◽  
...  
Keyword(s):  
White Matter ◽  
Neonatal Period ◽  
Diffusion Tensor ◽  
Neurodevelopmental Outcome ◽  
Mean Diffusivity ◽  
Spherical Deconvolution ◽  
White Matter Microstructure ◽  
Recent Developments ◽  
White Matter Development ◽  
Diffusion Tensor Imaging Dti

Measures obtained from diffusion-weighted imaging provide objective indices of white matter development and injury in the developing preterm brain. To date, diffusion tensor imaging (DTI) has been used widely, highlighting differences in fractional anisotropy (FA) and mean diffusivity (MD) between preterm infants at term and healthy term controls; altered white matter development associated with a number of perinatal risk factors; and correlations between FA values in the white matter in the neonatal period and subsequent neurodevelopmental outcome. Recent developments, including neurite orientation dispersion and density imaging (NODDI) and fixel-based analysis (FBA), enable white matter microstructure to be assessed in detail. Constrained spherical deconvolution (CSD) enables multiple fibre populations in an imaging voxel to be resolved and allows delineation of fibres that traverse regions of fibre-crossings, such as the arcuate fasciculus and cerebellar–cortical pathways. This review summarises DTI findings in the preterm brain and discusses initial findings in this population using CSD, NODDI, and FBA.

scholarly journals Evaluating the performance of 3-tissue constrained spherical deconvolution pipelines for within-tumor tractography

2019 ◽  
Author(s):  
Hannelore Aerts ◽  
Thijs Dhollander ◽  
Daniele Marinazzo
Keyword(s):  
White Matter ◽  
Tumor Tissue ◽  
Diffusion Tensor ◽  
Orientation Distribution ◽  
Constrained Spherical Deconvolution ◽  
Spherical Deconvolution ◽  
Fiber Orientation Distribution ◽  
Tissue Compartments ◽  
Diffusion Tensor Imaging Dti ◽  
Single Shell

AbstractThe use of diffusion MRI (dMRI) for assisting in the planning of neurosurgery has become increasingly common practice, allowing to non-invasively map white matter pathways via tractography techniques. Limitations of earlier pipelines based on the diffusion tensor imaging (DTI) model have since been revealed and improvements were made possible by constrained spherical deconvolution (CSD) pipelines. CSD allows to resolve a full white matter (WM) fiber orientation distribution (FOD), which can describe so-called “crossing fibers”: complex local geometries of WM tracts, which DTI fails to model. This was found to have a profound impact on tractography results, with substantial implications for presurgical decision making and planning. More recently, CSD itself has been extended to allow for modeling of other tissue compartments in addition to the WM FOD, typically resulting in a 3-tissue CSD model. It seems likely this may improve the capability to resolve WM FODs in the presence of infiltrating tumor tissue. In this work, we evaluated the performance of 3-tissue CSD pipelines, with a focus on within-tumor tractography. We found that a technique named single-shell 3-tissue CSD (SS3T-CSD) successfully allowed tractography within infiltrating gliomas, without increasing existing single-shell dMRI acquisition requirements.

scholarly journals White Matter Changes on Diffusion Tensor Imaging in the FINGER Randomized Controlled Trial

2020 ◽  
Vol 78 (1) ◽  
pp. 75-86
Author(s):  
Ruth Stephen ◽  
Alina Solomon ◽  
Tiia Ngandu ◽  
Esko Levälahti ◽  
Juha O. Rinne ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Controlled Trial ◽  
Intervention Group ◽  
Control Group ◽  
Pathological Changes ◽  
Cognitive Changes ◽  
Randomized Controlled ◽  
White Matter Microstructure ◽  
Multidomain Intervention

Background: Early pathological changes in white matter microstructure can be studied using the diffusion tensor imaging (DTI). It is not only important to study these subtle pathological changes leading to cognitive decline, but also to ascertain how an intervention would impact the white matter microstructure and cognition in persons at-risk of dementia. Objectives: To study the impact of a multidomain lifestyle intervention on white matter and cognitive changes during the 2-year Finnish Geriatric Intervention Study to prevent Cognitive Impairment and Disability (FINGER), a randomized controlled trial in at-risk older individuals (age 60–77 years) from the general population. Methods: This exploratory study consisted of a subsample of 60 FINGER participants. Participants were randomized to either a multidomain intervention (diet, exercise, cognitive training, and vascular risk management, n = 34) or control group (general health advice, n = 26). All underwent baseline and 2-year brain DTI. Changes in fractional anisotropy (FA), diffusivity along domain (F1) and non-domain (F2) diffusion orientations, mean diffusivity (MD), axial diffusivity (AxD), radial diffusivity (RD), and their correlations with cognitive changes during the 2-year multidomain intervention were analyzed. Results: FA decreased, and cognition improved more in the intervention group compared to the control group (p < 0.05), with no significant intergroup differences for changes in F1, F2, MD, AxD, or RD. The cognitive changes were significantly positively related to FA change, and negatively related to RD change in the control group, but not in the intervention group. Conclusion: The 2-year multidomain FINGER intervention may modulate white matter microstructural alterations.

scholarly journals Imaging Neurochemistry and Brain Structure Tracks Clinical Decline and Mechanisms of ALS in Patients

2020 ◽  
Vol 11 ◽  
Author(s):  
Ovidiu C. Andronesi ◽  
Katharine Nicholson ◽  
Kourosh Jafari-Khouzani ◽  
Wolfgang Bogner ◽  
Jing Wang ◽  
...  
Keyword(s):  
White Matter ◽  
Motor Cortex ◽  
Corticospinal Tract ◽  
Rating Scale ◽  
Diffusion Tensor ◽  
Structural Parameters ◽  
Imaging Biomarkers ◽  
Imaging Protocol ◽  
Time Motion ◽  
Als Patients

Background: Oxidative stress and protein aggregation are key mechanisms in amyotrophic lateral sclerosis (ALS) disease. Reduced glutathione (GSH) is the most important intracellular antioxidant that protects neurons from reactive oxygen species. We hypothesized that levels of GSH measured by MR spectroscopic imaging (MRSI) in the motor cortex and corticospinal tract are linked to clinical trajectory of ALS patients.Objectives: Investigate the value of GSH imaging to probe clinical decline of ALS patients in combination with other neurochemical and structural parameters.Methods: Twenty-four ALS patients were imaged at 3 T with an advanced MR protocol. Mapping GSH levels in the brain is challenging, and for this purpose, we used an optimized spectral-edited 3D MRSI sequence with real-time motion and field correction to image glutathione and other brain metabolites. In addition, our imaging protocol included (i) an adiabatic T1ρ sequence to image macromolecular fraction of brain parenchyma, (ii) diffusion tensor imaging (DTI) for white matter tractography, and (iii) high-resolution anatomical imaging.Results: We found GSH in motor cortex (r = −0.431, p = 0.04) and corticospinal tract (r = −0.497, p = 0.016) inversely correlated with time between diagnosis and imaging. N-Acetyl-aspartate (NAA) in motor cortex inversely correlated (r = −0.416, p = 0.049), while mean water diffusivity (r = 0.437, p = 0.033) and T1ρ (r = 0.482, p = 0.019) positively correlated with disease progression measured by imputed change in revised ALS Functional Rating Scale. There is more decrease in the motor cortex than in the white matter for GSH compared to NAA, glutamate, and glutamine.Conclusions: Our study suggests that a panel of biochemical and structural imaging biomarkers defines a brain endophenotype, which can be used to time biological events and clinical progression in ALS patients. Such a quantitative brain endophenotype may stratify ALS patients into more homogeneous groups for therapeutic interventions compared to clinical criteria.

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