Objective Signs of Spinal Cord Injury After Rear-End Collisions
One of the challenges of understanding auto injuries is showing the jury proof that the clients injuries are real. Any objective proof that whiplash is a real phenomena is critical in getting your clients the care they need and the compensation they deserve. A new study1 from Northwestern University adds some important new information in our understanding of the anatomy and physiology of auto injuries.
In this report by Elliott et al, the researchers performed MRI of the cervical spine and legs, with particular focus on the muscle fat of the neck and calves, and the motor pathways of the spinal cord. The patients also had the strength of their plantar flexors tested as a measure of their central nervous system function. In previous studies, researchers2,3 have found that patients with automotive-related neck injuries showed signs of fatty infiltration of the muscles of the. Other research4 by the same authors has found that patients with neck pain but with no trauma did not have signs of fatty infiltration, indicating that nerve injury is the cause of the phenomena.
The authors of this paper sought to corroborate that research and to see if there was a correlation between MRI findings, pain, and nerve function in the rest of the body. The study was small: only three patients with auto injury pain were examined and one control patient who had been in a 10 mph auto collision, but who had fully recovered three months after the crash. The patients who were in pain had reported symptoms lasting between 3.5 months and 3 years; these patients had significant disability from their injuries.
The authors found the following when comparing the patients to the recovered subject:
- The subjects in pain had a significantly higher amount of muscle fat in the cervical spine: 30% for the injured subjects vs. 10.5% for the pain-free subject.
- The patients in pain had a dramatically higher percentage of fatty infiltration in the legs compared to the recovered subject: 15.6% muscle fat vs. 7.6% muscle fat.
- The patients suffering from pain had significantly reduced plantar flexor strength: a reduction of about 40% compared to the healthy subject.
- All three patients with chronic pain showed signs of decreased myelin in the spinal cord that were consistent with spinal cord injuries.
- "In all three chronic cases we found that the expression of lower leg muscle fat infiltration corresponded to altered cervical spinal cord pathway integrity and reductions in the ability to maximally generate plantar flexion torques and muscle fatigue."
The authors conclude: "These findings provide preliminary evidence to suggest that the expression of neck and lower extremity muscle fatty infiltrates and reduced central activation in this small sample of patients with chronic WAD could very-well be the result of an initial mild injury involving the spinal cord..." While this is a small study and needs to be replicated with a larger group of test subjects, this article confirms a number of important findings:
- Auto injury patients with chronic pain show objective indications of nerve damage in the cervical spine.
- The effects of this nerve damage can alter muscles and nerve function in the lower extremities, in this case affecting plantar flexion strength.
- MRI of the muscles of the cervical spine can be effective at documenting fatty infiltration.
Again, this study had a very small number of test subjects, but it does provide more evidence that there are real, physiological changes associated with chronic pain in auto injury patients.
- Elliott JM, Dewald JP, Hornby TJ, et al. Mechanisms Underlying Chronic Whiplash: Contributions from an Incomplete Spinal Cord Injury? Pain Medicine 2014;Aug 19.
- Elliott J, Pedler A, Kenardy J, et al. The temporal development of fatty infiltrates in the neck muscles following whiplash injury: An association with pain and posttraumatic stress. PLoS ONE 2011;6:e21194.
- Elliott J, Sterling M, Noteboom JT, et al. The clinical presentation of chronic whiplash and the relationship to findings of MRI fatty infiltrates in the cervical extensor musculature: a preliminary investigation. European Spine Journal 2009;18(9):1371-8.
- Elliott J, Sterling M, Noteboom JT, et al. Fatty infiltrate in the cervical extensor muscles is not a feature of chronic, insidious-onset neck pain. Clinical Radiology 2008;63(6):681-7.