scholarly journals Diffusion tensor imaging tractography study in bipolar disorder patients compared to first-degree relatives and healthy controls

2017 ◽  
Vol 71 (10) ◽  
pp. 706-715 ◽  
Author(s):  
Ananya Mahapatra ◽  
Sudhir K. Khandelwal ◽  
Pratap Sharan ◽  
Ajay Garg ◽  
Nalini K. Mishra
2015 ◽  
Vol 161 (2-3) ◽  
pp. 329-339 ◽  
Author(s):  
Hidayet E. Arat ◽  
Virginie-Anne Chouinard ◽  
Bruce M. Cohen ◽  
Kathryn E. Lewandowski ◽  
Dost Öngür

2020 ◽  
pp. 025371762097528
Author(s):  
Velprashanth Venkatesan ◽  
Christoday R J Khess ◽  
Umesh Shreekantiah ◽  
Nishant Goyal ◽  
K. K. Kshitiz

Background: Patients with bipolar disorder demonstrate increased sensitivity to appetitive/rewarding stimuli even during euthymia. On presentation of arousing pictures, they show a peculiar response, suggesting heightened vigilance. While responding to looming arousing cues, studies show subjects with anxiety spectrum disorders exhibit increased reaction time (RT), explained by the “looming-vulnerability model.” This study aimed to investigate the responses to looming arousing cues in euthymic bipolar patients and their first-degree relatives, as compared to healthy controls. Method: A looming appetitive and aversive cue paradigm was designed for assessing the RT of patients to process appetitive and aversive cues. The behavioral inhibition/activation and sensitivity to reward/punishment amongst the groups were also assessed. Results: The bipolar group showed significantly longer RT to process appetitive cues irrespective of the looming condition. Aversive cues elicited significantly longer RT in both the bipolar group and in first-degree relatives, but only when presented with the looming condition. Significant looming bias was elicited in the bipolar group which suggested a particular cognitive style to looming cues. A composite measure of RT along with sensitivity to reward/punishment distinguishes the bipolar group and their first-degree relatives from the healthy controls. Conclusion: The looming vulnerability model may provide important insights for future exploration of cognitive endophenotypes in bipolar disorder.


Author(s):  
Shawn D’Souza ◽  
Lisa Hirt ◽  
David R Ormond ◽  
John A Thompson

Abstract Gliomas are neoplasms that arise from glial cell origin and represent the largest fraction of primary malignant brain tumours (77%). These highly infiltrative malignant cell clusters modify brain structure and function through expansion, invasion and intratumoral modification. Depending on the growth rate of the tumour, location and degree of expansion, functional reorganization may not lead to overt changes in behaviour despite significant cerebral adaptation. Studies in simulated lesion models and in patients with stroke reveal both local and distal functional disturbances, using measures of anatomical brain networks. Investigations over the last two decades have sought to use diffusion tensor imaging tractography data in the context of intracranial tumours to improve surgical planning, intraoperative functional localization, and post-operative interpretation of functional change. In this study, we used diffusion tensor imaging tractography to assess the impact of tumour location on the white matter structural network. To better understand how various lobe localized gliomas impact the topology underlying efficiency of information transfer between brain regions, we identified the major alterations in brain network connectivity patterns between the ipsilesional versus contralesional hemispheres in patients with gliomas localized to the frontal, parietal or temporal lobe. Results were indicative of altered network efficiency and the role of specific brain regions unique to different lobe localized gliomas. This work draws attention to connections and brain regions which have shared structural susceptibility in frontal, parietal and temporal lobe glioma cases. This study also provides a preliminary anatomical basis for understanding which affected white matter pathways may contribute to preoperative patient symptomology.


2021 ◽  
Vol 10 (2) ◽  
pp. 205846012199347
Author(s):  
Romulo V de Oliveira ◽  
João S Pereira

Background Diffusion tensor imaging has emerged as a promising tool for quantitative analysis of neuronal damage in Parkinson disease, with potential value for diagnostic and prognostic evaluation. Purpose The aim of this study was to examine Parkinson disease-associated alterations in specific brain regions revealed by diffusion tensor imaging and how such alterations correlate with clinical variables. Material and Methods Diffusion tensor imaging was performed on 42 Parkinson disease patients and 20 healthy controls with a 1.5-T scanner. Manual fractional anisotropy measurements were performed for the ventral, intermediate, and dorsal portions of the substantia nigra, as well as for the cerebral peduncles, putamen, thalamus, and supplementary motor area. The correlation analysis between these measurements and the clinical variables was performed using χ2 variance and multiple linear regression. Results Compared to healthy controls, Parkinson disease patients had significantly reduced fractional anisotropy values in the substantia nigra ( P < .05). Some fractional anisotropy measurements in the substantia nigra correlated inversely with duration of Parkinson disease and Parkinson disease severity scores. Reduced fractional anisotropy values in the substantia nigra were also correlated inversely with age variable. fractional anisotropy values obtained for the right and left putamen varied significantly between males and females in both groups. Conclusion Manual fractional anisotropy measurements in the substantia nigra were confirmed to be feasible with a 1.5-T scanner. Diffusion tensor imaging data can be used as a reliable biomarker of Parkinson disease that can be used to support diagnosis, prognosis, and progression/treatment monitoring.


2017 ◽  
Vol 34 ◽  
pp. 96-98 ◽  
Author(s):  
M. Puligheddu ◽  
I. Laccu ◽  
G. Gioi ◽  
P. Congiu ◽  
M. Figorilli ◽  
...  

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