Magnetic resonance imaging in rapid eye movement sleep behavior disorder: Diffusion tensor imaging and voxel-based morphometry

Background: Several authors have used advanced magnetic resonance imaging (MRI) techniques to investigate whether patients with neuromyelitis optica (NMO) have occult damage in normal-appearing brain tissue, similarly to multiple sclerosis (MS). To date, the literature contains no data derived from the combined use of several advanced MRI techniques in the same NMO subjects. Objective: We set out to determine whether occult damage could be detected in the normal-appearing brain tissue of a small group of patients with NMO using a multiparametric MRI approach. Methods: Eight female patients affected by NMO (age range 44–58 years) and seven sex- and age-matched healthy controls were included. The techniques used on a 1.5 T MRI imaging scanner were magnetization transfer imaging, diffusion tensor imaging, tract-based spatial statistics, spectroscopy and voxel-based morphometry in order to analyse normal-appearing white matter and normal-appearing grey matter. Results: Structural and metabolic parameters showed no abnormalities in normal-appearing white matter of patients with NMO. Conversely, tract-based spatial statistics demonstrated a selective alteration of the optic pathways and the lateral geniculate nuclei. Diffusion tensor imaging values in the normal-appearing grey matter were found to be significantly different in the patients with NMO versus the healthy controls. Moreover, voxel-based morphometry analysis demonstrated a significant density and volume reduction of the sensorimotor cortex and the visual cortex. Conclusions: Our data disclosed occult structural damage in the brain of patients with NMO, predominantly involving regions connected with motor and visual systems. This damage seems to be the direct consequence of transsynaptic degeneration triggered by lesions of the optic nerve and spine.

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Magnetic resonance imaging abnormalities as a marker of multiple system atrophy in isolated rapid eye movement sleep behavior disorder

SLEEP ◽

10.1093/sleep/zsaa089 ◽

2020 ◽

Author(s):

Amaia Muñoz-Lopetegi ◽

Joan Berenguer ◽

Alex Iranzo ◽

Monica Serradell ◽

Teresa Pujol ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Multiple System Atrophy ◽

Eye Movement ◽

Likelihood Ratio ◽

Behavior Disorder ◽

Rapid Eye Movement ◽

Resonance Imaging ◽

Sleep Behavior ◽

Mri Changes

Abstract Study Objectives Patients with isolated rapid eye movement (REM) sleep behavior disorder (IRBD) develop Parkinson disease (PD), dementia with Lewy bodies (DLB), or multiple system atrophy (MSA). Magnetic resonance imaging (MRI) is abnormal in MSA showing abnormalities in the putamen, cerebellum, and brainstem. Our objective was to evaluate the usefulness of MRI to detect MRI abnormalities in IRBD and predict development of MSA and not PD and DLB. Methods In IRBD patients that eventually developed PD, DLB, and MSA, we looked for the specific structural MRI abnormalities described in manifest MSA (e.g. hot cross-bun sign, putaminal rim, and cerebellar atrophy). We compared the frequency of these MRI changes among groups of converters (PD, DLB, and MSA) and analyzed their ability to predict development of MSA. The clinical and radiological features of the IRBD patients that eventually converted to MSA are described in detail. Results A total of 61 IRBD patients who underwent MRI phenoconverted to PD (n = 30), DLB (n = 26), and MSA (n = 5) after a median follow-up of 2.4 years from neuroimaging. MRI changes typical of MSA were found in four of the five (80%) patients who converted to MSA and in three of the 56 (5.4%) patients who developed PD or DLB. MRI changes of MSA had sensitivity of 80.0%, specificity of 94.6%, positive likelihood ratio of 14.9 (95% CI 4.6–48.8), and negative likelihood ratio of 0.2 (95% CI 0.04–1.2) to predict MSA. Conclusions In IRBD, conventional brain MRI is helpful to predict conversion to MSA. The specific MRI abnormalities of manifest MSA may be detected in its premotor stage.

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Diffusion Magnetic Resonance Imaging-Based Biomarkers for Neurodegenerative Diseases

International Journal of Molecular Sciences ◽

10.3390/ijms22105216 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5216

Author(s):

Koji Kamagata ◽

Christina Andica ◽

Ayumi Kato ◽

Yuya Saito ◽

Wataru Uchida ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Diffusion Tensor Imaging ◽

Magnetic Resonance ◽

Neurodegenerative Diseases ◽

Diffusion Magnetic Resonance Imaging ◽

New Technologies ◽

Diffusion Tensor ◽

Free Water ◽

Diffusion Kurtosis Imaging ◽

Resonance Imaging

There has been an increasing prevalence of neurodegenerative diseases with the rapid increase in aging societies worldwide. Biomarkers that can be used to detect pathological changes before the development of severe neuronal loss and consequently facilitate early intervention with disease-modifying therapeutic modalities are therefore urgently needed. Diffusion magnetic resonance imaging (MRI) is a promising tool that can be used to infer microstructural characteristics of the brain, such as microstructural integrity and complexity, as well as axonal density, order, and myelination, through the utilization of water molecules that are diffused within the tissue, with displacement at the micron scale. Diffusion tensor imaging is the most commonly used diffusion MRI technique to assess the pathophysiology of neurodegenerative diseases. However, diffusion tensor imaging has several limitations, and new technologies, including neurite orientation dispersion and density imaging, diffusion kurtosis imaging, and free-water imaging, have been recently developed as approaches to overcome these constraints. This review provides an overview of these technologies and their potential as biomarkers for the early diagnosis and disease progression of major neurodegenerative diseases.

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Changes in the corticospinal tract after wearing prosthesis in bilateral transtibial amputation

Prosthetics and Orthotics International ◽

10.1177/0309364616684216 ◽

2017 ◽

Vol 41 (5) ◽

pp. 507-511

Author(s):

Sang Yoon Lee ◽

Si Hyun Kang ◽

Don-Kyu Kim ◽

Kyung Mook Seo ◽

Hee Joon Ro ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Diffusion Tensor Imaging ◽

Magnetic Resonance ◽

Primary Motor Cortex ◽

Corticospinal Tract ◽

Diffusion Tensor ◽

Brain Magnetic Resonance Imaging ◽

Resonance Imaging ◽

Transtibial Amputation

Background:After amputation, the brain is known to be reorganized especially in the primary motor cortex. We report a case to show changes in the corticospinal tract in a patient with serial bilateral transtibial amputations using diffusion tensor imaging.Case Description and Methods:A 78-year-old man had a transtibial amputation on his left side in 2008 and he underwent a right transtibial amputation in 2011. An initial brain magnetic resonance imaging with a diffusion tensor imaging was performed before starting rehabilitation on his right transtibial prosthesis, and a follow-up magnetic resonance imaging with diffusion tensor imaging was performed 2 years after this.Findings and Outcomes:In the initial diffusion tensor imaging, the number of fiber lines in his right corticospinal tract was larger than that in his left corticospinal tract. At follow-up diffusion tensor imaging, there was no definite difference in the number of fiber lines between both corticospinal tracts.Conclusion:We found that side-to-side corticospinal tract differences were equalized after using bilateral prostheses.Clinical relevanceThis case report suggests that diffusion tensor imaging tractography could be a useful method to understand corticomotor reorganization after using prosthesis in transtibial amputation.

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