Sara B. Rosenbaum BA, Presenter: Nothing to Disclose

Namhee Kim PhD, Abstract Co-Author: Nothing to Disclose

Tova Gardin, Abstract Co-Author: Nothing to Disclose

Molly Zimmerman, Abstract Co-Author: Nothing to Disclose

Richard Lipton, Abstract Co-Author: Nothing to Disclose

Michael L. Lipton MD, PhD, Abstract Co-Author: Nothing to Disclose

It is known that a subset of mTBI patients experience persistent functional impairment and post-concussion symptoms (PCS). In this study, we use acute DTI to predict HRQoL and PCS at one year post-injury.

17 patients were recruited from a large emergency center. DTI (3.0 T, b=1000, 32 directions) was performed within two weeks of injury. PCS (Rivermead PCS Questionnaire (RPQ)) and HRQoL (Sickness Impact Profile (SIP)) were administered one year later and served as outcome measures. Voxelwise assessment (p(individual voxel)<0.05, p(cluster size)<0.01) was used to identify voxels with abnormally high fractional anisotropy (FA), compared to 40 healthy controls, in each patient. Mean FA, axial diffusivity (AD) and radial diffusivity (RD) across these voxels was determined for each patient and served as predictor variables. Partial correlation analysis (controlled for premorbid intelligence) was used to assess imaging predictors of the outcome measures.

Mean FA across voxels with abnormally high FA predicts better outcomes on two measures of HRQoL, mobility control (SIP-MC; R= -0.514, p= 0.024) and psychological functioning (SIP-PAC; R=-0.599; p=.007, respectively), as well as cognitive PCS (RPQ; R=-0.576, p=0.01). (Note that lower SIP and RPQ scores indicate better outcomes.) AD, RD and MD were also significantly associated with the outcome measures. 

Regions of abnormally high FA predict better HRQoL and lesser PCS one year after mTBI. High FA may thus index functional changes that mitigate evolution of mTBI pathology or enhance recovery. High AD and RD in the setting of high FA indicates that diffusion along the principal axis of the diffusion tensor (AD) is likely the major determinant of abnormally high anisotropy. This is consistent with neuroplastic change in response to injury, which confers better functional and symptom outcomes.

DTI may reveal evidence of compensatory mechanisms, which portend better functional and symptom outcomes after mTBI. These mechanisms could be exploited to enhance recovery.

Rosenbaum, S, Kim, N, Gardin, T, Zimmerman, M, Lipton, R, Lipton, M, Abnormally High Anisotropy Predicts Health Related Quality of Life (HRQoL) and Post Concussion Symptoms (PCS) at One Year Post-mTBI.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12032897.html