scholarly journals Anatomical Correlates of Age-Related Working Memory Declines

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Evan T. Schulze ◽  
Elizabeth K. Geary ◽  
Teresa M. Susmaras ◽  
James T. Paliga ◽  
Pauline M. Maki ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Working Memory ◽  
White Matter ◽  
Magnetic Resonance ◽  
Gray Matter Volume ◽  
Memory Task ◽  
White Matter Integrity ◽  
Resonance Imaging ◽  
Matter Volume ◽  
Aging Studies

Aging studies consistently show a relationship between decreased gray matter volume and decreased performance on working memory tasks. Few aging studies have investigated white matter changes in relation to functional brain changes during working memory tasks. Twenty-five younger and 25 older adults underwent anatomical magnetic resonance imaging (MRI) scans to measure gray matter volume, diffusion tensor imaging (DTI) to measure fractional anisotropy (FA) as a measure of white matter integrity, and functional magnetic resonance imaging (fMRI) while performing a working memory task. Significant increases in activation (fMRI) were seen in the left dorsal and ventral lateral prefrontal cortex with increased working memory load and with increased age (older showing greater bilateral activation). Partial correlational analyses revealed that even after controlling for age, frontal FA correlated significantly with fMRI activation during performance on the working memory task. These findings highlight the importance of white matter integrity in working memory performance associated with normal aging.

scholarly journals Multimodal Magnetic Resonance Imaging reveals alterations of sensorimotor circuits in restless legs syndrome

SLEEP ◽  
2019 ◽  
Vol 42 (12) ◽  
Author(s):  
Ambra Stefani ◽  
Thomas Mitterling ◽  
Anna Heidbreder ◽  
Ruth Steiger ◽  
Christian Kremser ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Gray Matter ◽  
Disease Duration ◽  
Gray Matter Volume ◽  
Resonance Imaging ◽  
Iron Storage ◽  
Matter Volume ◽  
The Right

Abstract Study Objectives Integrated information on brain microstructural integrity and iron storage and its impact on the morphometric profile is not available in restless legs syndrome (RLS). We applied multimodal magnetic resonance imaging (MRI) including diffusion tensor imaging, the transverse relaxation rate (R2*), a marker for iron storage, as well as gray and white matter volume measures to characterize RLS-related MRI signal distribution patterns and to analyze their associations with clinical parameters. Methods Eighty-seven patients with RLS (mean age 51, range 20–72 years; disease duration, mean 13 years, range 1–46 years, of those untreated n = 30) and 87 healthy control subjects, individually matched for age and gender, were investigated with multimodal 3T MRI. Results Volume of the white matter compartment adjacent to the post- and precentral cortex and fractional anisotropy (FA) of the frontopontine tract were both significantly reduced in RLS compared to healthy controls, and these alterations were associated with disease duration (r = 0.25, p = 0.025 and r = 0.23, p = 0.037, respectively). Corresponding gray matter volume increases of the right primary motor cortex in RLS (p < 0.001) were negatively correlated with the right FA signal of the frontopontine tract (r = −0.22; p < 0.05). Iron content evaluated with R2* was reduced in the putamen as well as in temporal and occipital compartments of the RLS cohort compared to the control group (p < 0.01). Conclusions Multimodal MRI identified progressing white matter decline of key somatosensory circuits that may underlie the perception of sensory leg discomfort. Increases of gray matter volume of the premotor cortex are likely to be a consequence of functional neuronal reorganization.

Precentral and cerebellar atrophic changes in moyamoya disease using 7-T magnetic resonance imaging

2019 ◽  
Vol 61 (4) ◽  
pp. 487-495
Author(s):  
Hyeong Cheol Moon ◽  
Byeong Ho Oh ◽  
Chaejoon Cheong ◽  
Won Seop Kim ◽  
Kyung Soo Min ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Moyamoya Disease ◽  
Gray Matter ◽  
Gray Matter Volume ◽  
Healthy Controls ◽  
Resonance Imaging ◽  
Matter Volume ◽  
Age Range

Background Chronic repeated transient ischemic changes are one of the common symptoms of moyamoya disease that could affect cortical and subcortical atrophy. Purpose We aimed to assess the cortical gray matter volume and thickness, white matter subcortical volume, and clinical characteristics using 7-T magnetic resonance imaging (MRI) and MR angiography (MRA). Material and Methods In this case-control study, whole-brain parcellation of gray matter and subcortical volumes were manually assessed in nine patients with moyamoya disease (18 hemispheres; median age = 34 years; age range = 10–60 years) and nine healthy controls (18 hemispheres; median age = 29 years; age range = 20–62 years) matched for age and sex, who underwent both 7-T MRI and MRA. The volumes were measured using high-resolution image (<1 mm) processing based on the Desikan-Killiany-Tourville (DKT) atlas, via an automated segmentation method (FreeSurfer version 6.0). Results The gray matter volume of the left precentral cortex and the white matter volume of the subcortical cerebellum were lower in both hemispheres in the patients with moyamoya disease compared to the healthy controls. Conclusion Gray matter atrophy in the precentral cortex and cerebellar white matter were detected in this 7-T MRI volumetric analysis study of patients with moyamoya disease who experienced repeated transient ischemic changes. Cortical atrophy in precentral cortex and cerebellum could explain the transient motor weakness in patients with moyamoya disease, as one of the early findings was that patients with moyamoya disease do not have detectable infarction changes on conventional MRI images.

scholarly journals Novel strain analysis informs about injury susceptibility of the corpus callosum to repeated impacts

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Allen A Champagne ◽  
Emile Peponoulas ◽  
Itamar Terem ◽  
Andrew Ross ◽  
Maryam Tayebi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Corpus Callosum ◽  
Diffusion Tensor ◽  
White Matter Integrity ◽  
White Matter Tract ◽  
Exposure Group ◽  
Resonance Imaging ◽  
High Exposure

Abstract Increasing evidence for the cumulative effects of head trauma on structural integrity of the brain has emphasized the need to understand the relationship between tissue mechanic properties and injury susceptibility. Here, diffusion tensor imaging, helmet accelerometers and amplified magnetic resonance imaging were combined to gather insight about the region-specific vulnerability of the corpus callosum to microstructural changes in white-matter integrity upon exposure to sub-concussive impacts. A total of 33 male Canadian football players (meanage = 20.3 ± 1.4 years) were assessed at three time points during a football season (baseline pre-season, mid-season and post-season). The athletes were split into a LOW (N = 16) and HIGH (N = 17) exposure group based on the frequency of sub-concussive impacts sustained on a per-session basis, measured using the helmet-mounted accelerometers. Longitudinal decreases in fractional anisotropy were observed in anterior and posterior regions of the corpus callosum (average cluster size = 40.0 ± 4.4 voxels; P &lt; 0.05, corrected) for athletes from the HIGH exposure group. These results suggest that the white-matter tract may be vulnerable to repetitive sub-concussive collisions sustained over the course of a football season. Using these findings as a basis for further investigation, a novel exploratory analysis of strain derived from sub-voxel motion of brain tissues in response to cardiac impulses was developed using amplified magnetic resonance imaging. This approach revealed specific differences in strain (and thus possibly stiffness) along the white-matter tract (P &lt; 0.0001) suggesting a possible signature relationship between changes in white-matter integrity and tissue mechanical properties. In light of these findings, additional information about the viscoelastic behaviour of white-matter tissues may be imperative in elucidating the mechanisms responsible for region-specific differences in injury susceptibility observed, for instance, through changes in microstructural integrity following exposure to sub-concussive head impacts.

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