[ CLINICAL COMMENTARY ] JAMES M. ELLIOTT, PT, PhD1-3 • SUDARSHAN DAYANIDHI, PT, PhD4,5 • CHARLES HAZLE, PT, PhD6-8 • MARK A. HOGGARTH, MS1,9 JACOB MCPHERSON, PhD10 • CHERYL L. SPARKS, PT, PhD11 • KENNETH A. WEBER II, DC, PhD12 Advancements in Imaging Technology: Do They (or Will They) Equate to Advancements in Our Knowledge of Recovery in Whiplash? TTSYNOPSIS: It is generally accepted that up resolution to reveal currently elusive anatomical to 50% of those with a whiplash injury following lesions (or, perhaps more importantly, temporal a motor vehicle collision will fail to fully recover. changes in physiological responses to assumed Twenty-five percent of these patients will dem- lesions) in those patients at risk of poor recovery. onstrate a markedly complex clinical picture that Preliminary findings from 2 prospective cohort includes severe pain-related disability, sensory and studies in 2 different countries suggest that this motor disturbances, and psychological distress. is so, as evidenced by changes to the structure of t is generally accepted that A number of psychosocial factors have shown skeletal muscles in those who do not fully recover. up to 50% of those with a prognostic value for recovery following whiplash In this clinical commentary, we will briefly intro- from a motor vehicle collision. To date, no manage- duce the available imaging decision rules and the whiplash injury should expect ment approach (eg, physical therapies, education, current knowledge underlying the pathomechanics to recover within the first 2 to 3 psychological interventions, or interdisciplinary and pathophysiology of whiplash. We will then I strategies) for acute whiplash has positively influ- acknowledge known prognostic factors underlying months following a motor vehicle enced recovery rates. For many of the probable functional recovery. Last, we will highlight emerg- collision (MVC). Accordingly, approxi- pathoanatomical lesions (eg, fracture, ligamentous ing evidence regarding the pathobiology of muscle 15 rupture, disc injury), there remains a lack of avail- degeneration/regeneration, as well as advance- mately 50% will not fully recover, of able clinical tests for identifying their presence. ments in neuroimaging and musculoskeletal imag- whom approximately 25% will demon- Fractures, particularly at the craniovertebral and ing techniques (eg, functional magnetic resonance strate a markedly complex set of signs/ imaging, magnetization transfer imaging, spec- cervicothoracic junctions, may be radiographically symptoms that include severe pain-relat- troscopy, diffusion-weighted imaging) that may be occult. While high-resolution computed tomogra- ed disability,113 changes in the structure phy scans can detect fractures, there remains a used as noninvasive and objective complements to of neck muscle,29,32,34,39 sensory and motor lack of prevalence data for fractures in this popula- known prognostic factors associated with whiplash 114 89,108,115 tion. Conventional magnetic resonance imaging recovery, in particular, poor functional recovery. disturbances, muscle weakness, has not consistently revealed lesions in patients J Orthop Sports Phys Ther 2016;46(10):861-872. and psychological distress.114,116 Though with acute or chronic whiplash, a “failure” that doi:10.2519/jospt.2016.6735 there is evidence to suggest damage to a may be due to limitations in the resolution of avail- TTKEY WORDS: cervical spine, functional number of tissues (facet joints and cap- able devices and the use of standard sequences. magnetic resonance imaging (fMRI), magnetic sules, the intervertebral disc, ligaments, Journal of Orthopaedic & Sports Physical Therapy® Downloaded from www.jospt.org at on January 12, 2017. For personal use only. No other uses without permission. Copyright © 2016 Journal of Orthopaedic & Sports Physical Therapy®. All rights reserved. The technological evolution of imaging techniques resonance imaging (MRI) research, radiology/ 21 and sequences eventually might provide greater medical imaging, spinal pain vascular tissues, osseous structures), no definitive structural cause of the wide 1Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL. 2School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia. 3Zürich University of Applied Sciences, Zürich, Switzerland. 4Rehabilitation Institute of Chicago, Chicago, IL. 5Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, IL. 6Division of Physical Therapy, College of Health Sciences, University of Kentucky, Lexington, KY. 7Walsh University, North Canton, OH. 8Griffith University, Gold Coast, Australia. 9Department of Biomedical Engineering, Northwestern University, Chicago, IL. 10Department of Biomedical Engineering, College of Engineering and Computing, Florida International University, Miami, FL. 11Rehabilitation Center of Expertise, OSF Healthcare, Peoria, IL. 12Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA. Dr Elliott is funded by the National Institutes of Health (NICHD/NCMRR grant 1 R01 HD079076-01A1). Dr Elliott’s relevant financial activities outside the body of work include a 35% ownership/investment in a medical consulting start-up, Pain ID, LLC. The authors certify that they have no affiliations with or financial involvement in any organization or entity with a direct financial interest in the subject matter or materials discussed in the article. Address correspondence to Dr James M. Elliott, Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, 645 North Michigan Avenue, Suite 1100, Chicago, IL 60540. E-mail: [email protected] Copyright ©2016 Journal T of Orthopaedic & Sports Physical Therapy® 862 | october 2016 | volume 46 | number 10 | journal of orthopaedic & sports physical therapy 46-10 Elliott.indd 862 9/14/2016 8:36:23 PM and varied symptomatology has been guidelines, as well as introduce techno- prior patient history, probable etiology, realized with available imaging appli- logical advances in our understanding of signs and symptoms, and results of prior cations.38,83-85,94,95,105 Recent prospective the underlying mechanisms of muscle de- imaging. These categories are referred studies from 2 different countries have, generation/regeneration. We will also in- to as “clinical conditions,” with subcat- however, identified changes in the neck troduce and propose the use of advanced, egories described as “variants.” Most ap- muscle structure (eg, muscle fatty infil- but available, functional magnetic reso- plicable within the ACR-AC for patients trates [MFIs]) of those with poor func- nance imaging (fMRI) sequences of the with apparent acute WAD is the clinical tional recovery,32,25 suggesting a core brain and spinal cord as having potential condition category of “suspected spine biological contribution to outcomes. scope in measuring the pain experience trauma.”22 The criteria for determina- While interesting, the precise mecha- for patients with whiplash injury. The tion of whether imaging is indicated and nisms underlying these muscular chang- intention is to facilitate development of the recommended modality are based es and their defined influence on recovery productive interdisciplinary collabora- upon the Canadian cervical spine rule remain largely unknown. tions that will propel research in the field (CCSR) and the National Emergency X- A number of psychosocial factors (eg, of whiplash and WAD into a new era of Radiography Utilization Study low-risk coping, expectations, anxiety, and de- understanding—and legitimacy on a pa- rule (NEXUS-LRR) (APPENDIX, available pression) have demonstrated prognostic tient-by-patient basis. Such efforts have at www.jospt.org), along with sugges- value in whiplash recovery.15 However, potential to generate more efficient man- tions of neurological or cervical vascular despite the presence and recognition of agement strategies for patients, perhaps injury. these factors, there remains a paucity of interrupting the progression and associat- The CCSR and NEXUS-LRR were best-evidence treatment options to sub- ed sequelae of chronic pain-related states. developed for the purposes of identify- stantially influence the rate of functional ing which patients needed imaging in recovery.61,67,79 IMAGING CLINICAL the emergency department for immedi- It is important to be aware of a num- DECISION RULES ate decision making and those for whom ber of emerging mechanistic models for diagnostic procedures were less war- whiplash recovery. These include, but linicians, including physical ranted. The investigations giving rise to are not limited to, (1) maladaptive be- therapists, are required in the these criteria were undertaken because liefs and cognition,120 (2) stress system Ccourse of routine care to make in- of acknowledgment of negative findings dysregulation,74,75,123 (3) genetic vulner- dividual judgments for initial and fur- in an overwhelming majority of imaging ability,12,13 and (4) mild injury involv- ther diagnostic tests (possibly including studies in acute cervical trauma and of ing the peripheral and central nervous imaging) for the patients they manage. the accompanying unwarranted expenses systems.32,34-36,40,42,128-130 This includes not only acutely injured and use of emergency department time This clinical commentary will not re- patients presenting