scholarly journals Cognitive Function and 3-Tesla Magnetic Resonance Imaging Tractography of White Matter Hyperintensities in Elderly Persons

2015 ◽  
Vol 5 (3) ◽  
pp. 387-394 ◽  
Author(s):  
William Reginold ◽  
Angela C. Luedke ◽  
Angela Tam ◽  
Justine Itorralba ◽  
Juan Fernandez-Ruiz ◽  
...  

Background/Aims: This study used 3-Tesla magnetic resonance imaging (MRI) tractography to determine if there was an association between tracts crossing white matter hyperintensities (WMH) and cognitive function in elderly persons. Methods: Brain T2-weighted fluid-attenuated inversion recovery (FLAIR) and diffusion tensor MRI scans were acquired in participants above the age of 60 years. Twenty-six persons had WMH identified on T2 FLAIR scans. They completed a battery of neuropsychological tests and were classified as normal controls (n = 15) or with Alzheimer's dementia (n = 11). Tractography was generated by the Fiber Assignment by Continuous Tracking method. All tracts that crossed WMH were segmented. The average fractional anisotropy and average mean diffusivity of these tracts were quantified. We studied the association between cognitive test scores with the average mean diffusivity and average fractional anisotropy of tracts while controlling for age, total WMH volume and diagnosis. Results: An increased mean diffusivity of tracts crossing WMH was associated with worse performance on the Wechsler Memory Scale-III Longest Span Forward (p = 0.02). There was no association between the fractional anisotropy of tracts and performance on cognitive testing. Conclusion: The mean diffusivity of tracts crossing WMH measured by tractography is a novel correlate of performance on the Wechsler Memory Scale-III Longest Span Forward in elderly persons.

2003 ◽  
Vol 182 (5) ◽  
pp. 439-443 ◽  
Author(s):  
J. Burns ◽  
D. Job ◽  
M. E. Bastin ◽  
H. Whalley ◽  
T. Macgillivray ◽  
...  

BackgroundThere is growing evidence that schizophrenia is a disorder of cortical connectivity Specifically, frontotemporal and frontoparietal connections are thought to be functionally impaired. Diffusion tensor magnetic resonance imaging (DT–MRI) is a technique that has the potential to demonstrate structural disconnectivity in schizophrenia.AimsTo investigate the structural integrity of frontotemporal and frontoparietal white matter tracts in schizophrenia.MethodThirty patients with DSM–IV schizophrenia and thirty matched control subjects underwent DT–MRI and structural MRI. Fractional anisotropy – an index of the integrity of white matter tracts – was determined in the uncinate fasciculus, the anterior cingulum and the arcuate fasciculus and analysed using voxel-based morphometry.ResultsThere was reduced fractional anisotropy in the left uncinate fasciculus and left arcuate fasciculus in patients with schizophrenia compared with controls.ConclusionsThe findings of reduced white matter tract integrity in the left uncinate fasciculus and left arcuate fasciculus suggest that there is frontotemporal and frontoparietal structural disconnectivity in schizophrenia.


2015 ◽  
Vol 13 (3) ◽  
pp. 261-276 ◽  
Author(s):  
Maria Eugenia Caligiuri ◽  
Paolo Perrotta ◽  
Antonio Augimeri ◽  
Federico Rocca ◽  
Aldo Quattrone ◽  
...  

2009 ◽  
Vol 172 (2) ◽  
pp. 117-120 ◽  
Author(s):  
Adam M. Brickman ◽  
Amir Zahra ◽  
Jordan Muraskin ◽  
Jason Steffener ◽  
Christopher M. Holland ◽  
...  

2021 ◽  
Vol 15 ◽  
Author(s):  
Wha Jin Lee ◽  
Cindy W. Yoon ◽  
Sung-Woo Kim ◽  
Hye Jin Jeong ◽  
Seongho Seo ◽  
...  

Early- and late-onset Alzheimer’s disease (AD) patients often exhibit distinct features. We sought to compare overall white matter connectivity and evaluate the pathological factors (amyloid, tau, and vascular pathologies) that affect the disruption of connectivity in these two groups. A total of 50 early- and 38 late-onset AD patients, as well as age-matched cognitively normal participants, were enrolled and underwent diffusion-weighted magnetic resonance imaging to construct fractional anisotropy-weighted white matter connectivity maps. [18F]-THK5351 PET, [18F]-Flutemetamol PET, and magnetic resonance imaging were used for the evaluation of tau and related astrogliosis, amyloid, and small vessel disease markers (lacunes and white matter hyperintensities). Cluster-based statistics was performed for connectivity comparisons and correlation analysis between connectivity disruption and the pathological markers. Both patient groups exhibited significantly disrupted connectivity compared to their control counterparts with distinct patterns. Only THK retention was related to connectivity disruption in early-onset AD patients, and this disruption showed correlations with most cognitive scores, while late-onset AD patients had disrupted connectivity correlated with amyloid deposition, white matter hyperintensities, and lacunes in which only a few cognitive scores showed associations. These findings suggest that the pathogenesis of connectivity disruption and its effects on cognition are distinct between EOAD and LOAD.


Author(s):  
Rasheda A. Chowdhury ◽  
Michael T. Debney ◽  
Andrea Protti ◽  
Balvinder S. Handa ◽  
Kiran H. K. Patel ◽  
...  

Background Survivors of myocardial infarction are at increased risk of late ventricular arrhythmias, with infarct size and scar heterogeneity being key determinants of arrhythmic risk. Gap junctions facilitate the passage of small ions and morphogenic cell signaling between myocytes. We hypothesized that gap junctions enhancement during infarction–reperfusion modulates structural and electrophysiological remodeling and reduces late arrhythmogenesis. Methods and Results Infarction–reperfusion surgery was carried out in male Sprague‐Dawley rats followed by 7 days of rotigaptide or saline administration. The in vivo and ex vivo arrhythmogenicity was characterized by programmed electrical stimulation 3 weeks later, followed by diffusion‐weighted magnetic resonance imaging and Masson's trichrome histology. Three weeks after 7‐day postinfarction administration of rotigaptide, ventricular tachycardia/ventricular fibrillation was induced on programmed electrical stimulation in 20% and 53% of rats, respectively (rotigaptide versus control), resulting in reduction of arrhythmia score (3.2 versus 1.4, P =0.018), associated with the reduced magnetic resonance imaging parameters fractional anisotropy (fractional anisotropy: −5% versus −15%; P =0.062) and mean diffusivity (mean diffusivity: 2% versus 6%, P =0.042), and remodeling of the 3‐dimensional laminar structure of the infarct border zone with reduction of the mean (16° versus 19°, P =0.013) and the dispersion (9° versus 12°, P =0.015) of the myofiber transverse angle. There was no change in ECG features, spontaneous arrhythmias, or mortality. Conclusions Enhancement of gap junctions function by rotigaptide administered during the early healing phase in reperfused infarction reduces later complexity of infarct scar morphology and programmed electrical stimulation–induced arrhythmias, and merits further exploration as a feasible and practicable intervention in the acute myocardial infarction management to reduce late arrhythmic risk.


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