Brain Integrity with Trauma & Aging

Tuesday 13 May 2014

Lora Talley Watts¹, Justin Alexander Long¹, Jonathan Chemello¹, Qiang Shen¹, Shiliang Huang¹, and Timothy Duong^1
1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States

This study investigated the spatiotemporal dynamics of diffusion, T2 and fractional anisotropy associated with mild traumatic brain injury (TBI) following methylene blue treatment. Lesion volume, diffusion, T2 and fractional anisotropy changes and behavioral scores generally correlated well with the improvement by methylene blue treatment compared to placebo controls. However, despite the presence of some lesions on day 7 and 14, behavioral measures mostly returned to normal in both groups, suggesting that there is functional compensation in our mild TBI model. Multi-parametric MRI offers a range of biomarkers that are sensitive to different tissue types and to different stages of TBI.

Joseph H. Rosenberg¹, Jiachen Zhuo¹, Chandler R. Sours¹, Steven Roys¹, Elijah O. George¹, Kathirkamanthan Shanmuganathan¹, and Rao P. Gullapalli^1
1Deagnostic Radiology, University of Maryland School of Medicine, Baltimore, MD, United States

DKI parameters were evaluated in mild traumatic brain injury patients. Patients were compared to controls, and patients with symptomatic improvement between sub-acute and chronic injury stages were compared to those without. Patients showed alterations in DKI parameters in the genu of the corpus callosum. Patients experiencing later symptom improvement showed DKI alterations at the acute stage distinct from those whose symptoms did not improve. Commonly affected regions were the corpus callosum body and genu and bilateral anterior corona ratiata. These DKI alterations may indicate greater acute microstructural damage to white matter tracts in those without eventual symptomatic improvement.

Raquel Phillips¹, Vadim Zotev¹, Han Yuan¹, Kymberly Young¹, Chung Ki Wong¹, Brent Wurfel¹, Frank Krueger^1,2, Matthew Feldner^1,3, and Jerzy Bodurka^1,4
1Laureate Institute for Brain Research, Tulsa, OK, United States, ²Neuroscience Dept., George Mason University, Fairfax, VA, United States,³Department of Psychological Science, University of Arkansas, Fayetteville, AR, United States, ⁴College of Engineering, University of Oklahoma, Tulsa, OK, United States

Post-traumatic stress disorder (PTSD) is a chronic and disabling psychiatric condition. Individuals with PTSD suffer from the dysregulation of several types of emotion including fear, anxiety, and depression. Neurocircuit models of PTSD emphasize the role of the amygdala. We utilize advances in real-time functional magnetic resonance imaging neurofeedback (rtfMRI-nf) to directly modulate amygdala activity. This technique measures neuronal activity with sufficiently high temporal resolution that information from the amygdala is immediately available to form a feedback loop. We show that individuals with PTSD are able to use rtfMRI-nf training to enhance the control of the hemodynamic response of the amygdala.

Kavita Singh¹, Richa Trivedi¹, Maria M D’souza¹, Ajay Chaudhary², Pawan Kumar¹, Ram KS Rathore³, Rajendra P Tripathi¹, and Subash Khushu^1
1Institute of Nuclear Medicine & Allied Sciences, Delhi, Delhi, India, ²Dr. Ram Manohar Lohia Hospital, Delhi, Delhi, Delhi, India, ³Indian Institute of Technology, Kanpur, Kanpur, Uttar Pradesh, India

Aim our study was to assess the degenerative changes, secondary to TBI in subdivisional fibres of CC, corresponding to cortical brain area primarily injured in chronic moderate TBI patients. DTT was done in 18 TBI (A: frontal lobe injury,n=6; B: occipito-temporal lobe injury, n=5; C: fronto-parieto-temporal lobe injury, n=7) and 11 healthy participants. Diffusion metrices of 7 sub-divisions of CC (Witelson’s scheme) were acquired using in-house developed software. The study showed significantly reduced FA and increased MD in the sub-divisions of CC corresponding to cortical brain area primarily injured. Reduced FA and increased MD values may represent regional Wallerian Degeneration.

Chandler Sours^1,2, Haoxing Chen³, Steven Roys¹, and Rao P. Gullapalli^1,2
1Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States, ²Magnetic Resonance Research Center (MRRC), Baltimore, MD, United States, ³University of Maryland School of Medicine, Baltimore, Maryland, United States

We investigated the mechanisms of recovery following mild traumatic brain injury (mTBI) using discrete wavelet analysis of resting state fMRI and its relationship with post concussive syndrome (PCS). Our results demonstrate reduced strength of resting state coherence within the Default Mode Network in mTBI with PCS compared to those without PCS within multiple frequency ranges. These findings stress the importance of investigating resting state coherence using discrete wavelet analysis: however, further research is needed incorporating cardiac and respiratory monitoring as well as a sliding window analysis to fully characterize the dynamic properties of resting state coherence in mTBI patients.

David C Zhu¹, Tracey Covassin¹, Sally Nogle¹, Scarlett Doyle¹, Doozie Russell¹, Randy Pearson¹, Jeffrey Monroe¹, Christine Liszewski¹, J. Kevin DeMarco¹, and David Kaufman^1
1Michigan State University, East Lansing, MI, United States

Resting-state fMRI (rs-fMRI) and diffusion tensor imaging (DTI) were applied to understand the dynamics of functional and structural connectivity of the default-mode network (DMN) after concussion. The functional connectivity within DMN was significantly higher on Day 1 comparing to Days 7 and 30 after concussion. Noticeable change in structural connectivity and gross anatomy were not seen. This sequential change of DMN functional connectivity was not seen in the control group. Based on our results, the functional connectivity of DMN measured with sequential rs-fMRI can potentially serve as a biomarker to monitor the dynamically changing brain function after sports-related concussion.

Shin-Lei Peng^1,2, Julie Dumas³, Denise Park^1,4, Peiying Liu¹, Francesca Filbey⁴, Carrie McAdams¹, Amy Pinkham^1,5, Bryon Adinoff^1,6, Rong Zhang⁷, and Hanzhang Lu^1
1UT Southwestern Medical Center, Dallas, TX, United States, ²National Tsing Hua University, Taiwan, ³University of Vermont College of Medicine, VT, United States, ⁴University of Texas Dallas, TX, United States, ⁵Southern Methodist University, TX, United States, ⁶VA North Texas Health Care System, Dallas, TX, United States, ⁷Texas Health Presbyterian Hospital Dallas, TX, United States

In this study, we provide evidence that the brain of older adults works ¡§harder¡¨ when compared to younger adults, as manifested by an age-related increase in cerebral metabolic rate of oxygen (CMRO2) (N=118). We further showed that, prior to the typical menopausal age of 51 years old, female and male groups have similar rates of CMRO2 increase (P=0.003). However, for the entire age range, women have a slower rate of CMRO2 change, when compared to men (P<0.001). Our data also revealed a possible circadian rhythm of CMRO2 in that brain metabolic rate is greater at noon than in the morning.

C. M. Barth¹, R. S. Wilson², A. Capuano², S. Zhang², D. A. Bennett², and K. Arfanakis^1
1Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois, United States, ²Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, Illinois, United States

The purpose of this study was to test the hypotheses that: a) more frequent cognitive activity in late life is associated with higher microstructural integrity in brain white matter (WM), and b) microstructural integrity in WM mediates the relation between late life cognitive activity and cognition. Diffusion tensor imaging data were collected for a community-dwelling sample of 397 older, non-demented adults. It was demonstrated that fractional anisotropy in a number of WM regions was significantly associated with frequency of late life cognitive activity. Also, FA in those WM regions partially mediated the relationship between late life cognitive activity and cognition.

Sina Aslan^1,2, Sandra B Chapman², Jeffrey S Spence², Molly Keebler², Nyaz Didehbani², and Hanzhang Lu^3
1Advance MRI, LLC, Frisco, Texas, United States, ²Center for BrainHealth, University of Texas at Dallas, Dallas, Texas, United States, ³Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States

This study investigates that engaging in complex mental activity offer promising ways to enhance brain integrity to promote successful cognitive aging. Using three MRI-based measurements, i.e. pCASL MRI, fcMRI, and DTI, we examined brain changes across three time points pre, mid, and post-training (12-weeks) in a randomized sample who received cognitive training versus a control group. We found significant training-related brain state changes at rest; specifically, (1) increases in global and regional CBF, particularly in the default mode and central executive networks, (2) greater connectivity in these same networks, and (3) increased white matter integrity in the left uncinate fasciculus.

Johan Westborg¹, Danielle Van Westen^1,2, Markus Nilsson³, Jimmy Lätt², Filip Szczepankiewicz⁴, Sebastian Palmqvist⁵, Erik Stomrud⁵, Lennart Minthon⁵, Katarina Nägga⁵, and Oskar Hansson^5
1Department of Diagnostic Radiology, Lund University, Lund, Sweden, ²Center for Medical Imaging and Physiology, Skane University Hospital, Lund, Sweden, ³Lund University Bioimaging Center, Lund University, Lund, Sweden, ⁴Department of Medical Radiation Physics, Lund University, Lund, Sweden,⁵Clinical Memory Research Unit, Clinical Sciences, Lund University, Malmö, Sweden

Our aim was to disentangle the contribution of microstructural change and partial volume effects (PVE) to the reduction of the fractional anisotropy (FA) in the corpus callosum, observed in ageing. Using tractography, we show that the FA reduction with age becomes non-significant when the voxel-count in the tract segments is corrected for. An observed FA reduction in older (>71 years) subjects with ventricular enlargement was primarily driven by increased callosal atrophy. We did not observe microstructural change separate from atrophy and increased PVE.