Magnetization transfer and diffusion tensor MRI show gray matter damage in neuromyelitis optica

Background: Although aquaporin-4 (AQP4) is widely expressed in the human brain cortex, lesions are rare in neuromyelitis optica (NMO) spectrum disorders (NMOSD). Recently, however, several studies have demonstrated occult structural brain atrophy in NMO. Objective: This study aims to investigate magnetic resonance imaging (MRI) patterns of gray matter (GM) and white matter (WM) abnormalities in patients with NMOSD and to assess the visual pathway integrity during disease duration correlation of the retinal nerve fiber layer (RNFL) and pericalcarine cortex thickness. Methods: Twenty-one patients with NMOSD and 34 matched healthy controls underwent both high-field MRI (3T) high-resolution T1-weighted and diffusion-tensor MRI. Voxel-based morphometry, cortical analyses (Freesurfer) and diffusion-tensor imaging (DTI) analyses (TBSS-FSL) were used to investigate brain abnormalities. In addition, RNFL measurement by optic-coherence tomography (OCT) was performed. Results: We demonstrate that NMOSD is associated with GM and WM atrophy, encompassing more frequently the motor, sensory and visual pathways, and that the extent of GM atrophy correlates with disease duration. Furthermore, we demonstrate for the first time a correlation between RNFL and pericalcarine cortical thickness, with cortical atrophy evolving over the course of disease. Conclusions: Our findings indicate a role for retrograde and anterograde neurodegeneration in GM atrophy in NMOSD. However, the presence atrophy encompassing almost all lobes suggests that additional pathomechanisms might also be involved.

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Brain Substrates of Time-Based Prospective Memory Decline in Aging: A Voxel-Based Morphometry and Diffusion Tensor Imaging Study

Cerebral Cortex ◽

10.1093/cercor/bhaa232 ◽

2020 ◽

Vol 31 (1) ◽

pp. 396-409

Author(s):

Alexandrine Morand ◽

Shailendra Segobin ◽

Grégory Lecouvey ◽

Julie Gonneaud ◽

Francis Eustache ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

White Matter ◽

Prospective Memory ◽

Gray Matter ◽

Diffusion Tensor ◽

Imaging Study ◽

Age Related ◽

Young Subjects ◽

Anterior Prefrontal Cortex ◽

And Diffusion

Abstract Time-based prospective memory (TBPM) allows us to remember to perform intended actions at a specific time in the future. TBPM is sensitive to the effects of age, but the neural substrates of this decline are still poorly understood. The aim of the present study was thus to better characterize the brain substrates of the age-related decline in TBPM, focusing on macrostructural gray matter and microstructural white matter integrity. We administered a TBPM task to 22 healthy young (26 ± 5.2 years) and 23 older (63 ± 5.9 years) participants, who also underwent volumetric magnetic resonance imaging and diffusion tensor imaging scans. Neuroimaging analyses revealed lower gray matter volumes in several brain areas in older participants, but these did not correlate with TBPM performance. By contrast, an age-related decline in fractional anisotropy in several white-matter tracts connecting frontal and occipital regions did correlate with TBPM performance, whereas there was no significant correlation in healthy young subjects. According to the literature, these tracts are connected to the anterior prefrontal cortex and the thalamus, 2 structures involved in TBPM. These results confirm the view that a disconnection process occurs in aging and contributes to cognitive decline.

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Neural correlates of symptom severity in obsessive-compulsive disorder using magnetization transfer and diffusion tensor imaging

Psychiatry Research Neuroimaging ◽

10.1016/j.pscychresns.2020.111046 ◽

2020 ◽

Vol 298 ◽

pp. 111046

Author(s):

Suzan Maleki ◽

Yann Chye ◽

Xiaoliu Zhang ◽

Linden Parkes ◽

Samuel R. Chamberlain ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

Obsessive Compulsive Disorder ◽

Symptom Severity ◽

Diffusion Tensor ◽

Magnetization Transfer ◽

Neural Correlates ◽

Obsessive Compulsive ◽

Compulsive Disorder ◽

And Diffusion

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Quantitative spinal cord MRI in radiologically isolated syndrome

Neurology Neuroimmunology & Neuroinflammation ◽

10.1212/nxi.0000000000000436 ◽

2018 ◽

Vol 5 (2) ◽

pp. e436 ◽

Cited By ~ 23

Author(s):

Paula Alcaide-Leon ◽

Kateryna Cybulsky ◽

Stephanie Sankar ◽

Courtney Casserly ◽

General Leung ◽

...

Keyword(s):

Spinal Cord ◽

Diffusion Tensor ◽

Magnetization Transfer ◽

Cross Sectional Study ◽

Magnetization Transfer Ratio ◽

Cross Sectional ◽

Sequence Of Events ◽

Radiologically Isolated Syndrome ◽

And Diffusion

ObjectivesTo assess whether quantitative spinal cord MRI (SC-MRI) measures, including atrophy, and diffusion tensor imaging (DTI) and magnetization transfer imaging metrics were different in radiologically isolated syndrome (RIS) vs healthy controls (HCs).MethodsTwenty-four participants with RIS and 14 HCs underwent cervical SC-MRI on a 3T magnet. Manually segmented regions of interest circumscribing the spinal cord cross-sectional area (SC-CSA) between C3 and C4 were used to extract SC-CSA, fractional anisotropy, mean, perpendicular, and parallel diffusivity (MD, λ⊥, and λ||) and magnetization transfer ratio (MTR). Spinal cord (SC) lesions, SC gray matter (GM), and SC white matter (WM) areas were also manually segmented. Multivariable linear regression was performed to evaluate differences in SC-MRI measures in RIS vs HCs, while controlling for age and sex.ResultsIn this cross-sectional study of participants with RIS, 71% had lesions in the cervical SC. Of quantitative SC-MRI metrics, spinal cord MTR showed a trend toward being lower in RIS vs HCs (p = 0.06), and there was already evidence of brain atrophy (p = 0.05). There were no significant differences in SC-DTI metrics, GM, WM, or CSA between RIS and HCs.ConclusionThe SC demonstrates minimal microstructural changes suggestive of demyelination and inflammation in RIS. These findings are in contrast to established MS and raise the possibility that the SC may play an important role in triggering clinical symptomatology in MS. Prospective follow-up of this cohort will provide additional insights into the role the SC plays in the complex sequence of events related to MS disease initiation and progression.

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