Mark A Hoggarth MS, Presenter: Nothing to Disclose

James Matthew Elliott PhD, Abstract Co-Author: Owner, Pain Id, LLC

Todd B. Parrish PhD, Abstract Co-Author: Co-owner, Pain Id, LLC

Whiplash Associated Disorder (WAD) has been commonly treated as a homogenous condition but there remains little evidence that doing so will improve functional recovery in the long-term. No structural mechanism of WAD has been found leading to the assertion that chronic WAD is primarily and uniquely found in the psychologically weak-willed. However, recent evidence has identified degenerative changes in neck muscles specific to those with chronic WAD, suggesting a biological contribution. Precise mechanisms, however, remain elusive. Magnetization Transfer (MT) imaging is a method of investigating white matter integrity in multiple pathologies, including demyelination in the spinal cord. MT ratio (MTR) analysis in the spinal cord could refine diagnosis in WAD. The goal of this work is threefold: 1) introduce quantitative MTR methods by which patients with WAD can be characterized; 2) promote quantitative metrics in the study of WAD; 3) present degeneration in regional spinal cord pathways which may be present in a subpopulation of persons with chronic WAD.

15 subjects, 5 chronic WAD, 5 recovered and 5 controls were recruited into this study. Images were gathered perpendicular to the cervical spinal cord at the superior aspect of the fifth vertebra using MEDIC MRI. The MT pulse was 1.5kHz off-resonance with Flip angle/duration of 5400/10ms. Scan time was 8 minutes for MT and non-MT imaging. Ventral, dorsal, and lateral (left & right) aspects of the cord were segmented, and MTRs were calculated. The range in MTR values (dMTR) was then recorded.

dMTR differences were significant between WAD versus control and recovered groups (P < 0.01) . Average dMTR values were dMTR: 18.87, recovered: 7.45 and control: 6.59. Control and recovered were not distinguishable (P = 0.37).

A quantitative imaging technique was introduced and preliminary findings suggest that the group of concern demonstrates reductions of magnetization transfer ratios in spinal cord white matter pathways. Recovered and healthy controls do not have such findings. These findings provide foundation for larger-scaled work.

50% of people with a whiplash injury from a motor vehicle collision will never fully recover and 25% have complex clinical presentations. This work contributes to the understanding of potential neurological pathologies in the spinal cord underlying chronic WAD.

Hoggarth, M, Elliott, J, Parrish, T, Quantitative Magnetic Resonance Imaging for Spinal Cord Degeneration in Whiplash Associated Disorders.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011415.html