While most people fully recover from whiplash injuries within the first few months, about 25 percent have long-term pain and disability that last many months or years.
Using special MRI imaging, scientists can now predict, within the first one to two weeks of injury, which patients will go on to develop chronic pain, disability, and post-traumatic stress disorder (PTSD).
The ability to identify these patients so early will allow faster and more specialized treatment, which could be particularly beneficial for PTSD sufferers.
More severe injury
Using a sophisticated MRI that measures the fat/water ratio in the muscles, scientists discovered unusual muscular changes in the chronic pain group one to two weeks after an injury. Imaging revealed large amounts of fat infiltrating the patients’ neck muscles, indicating rapid atrophy.
The presence of fat in the muscle does not appear to be related to a person’s body size or shape.
“We believe this represents an injury that is more severe than what might be expected from a typical low-speed car crash,” says lead investigator James Elliott, assistant professor of physical therapy and human movement sciences at Northwestern University Feinberg school of Medicine.
“This opens up a new door for research on whiplash. For a long time whiplash has been treated as a homogenous condition. Our study has shown these patients are not all the same; they have different clinical signs and symptoms.”
Risk of PTSD
Whiplash-associated disorders from motor vehicle collisions affect more than 4 million Americans annually, harming their quality of life and costing an estimated $30 billion for medical/rehabilitative care per year.
Published in the journal Spine, the new findings build on previous research which used standard MRI imaging and also showed large amounts of fat in neck muscles of whiplash patients at one and three months post injury. Those patients went on to develop chronic pain and disability.
Not everyone needs a MRI scan after a whiplash injury from a motor vehicle collision. However, the findings can be used to identify who is likely to develop post-traumatic stress disorder. This then could be used to justify the referral of the patient to a psychiatrist or psychologist, Elliott says. PTSD is caused by experiencing or witnessing a traumatic event.
“These patients have shown to not respond well to traditional rehabilitation such as physical therapy,” Elliott says. “It appears that they may require a more concerted effort for pain management from their physician and help from a psychologist.”
The findings may indicate the importance of changing standard imaging protocols to identify these individuals early and start accelerated treatment. Routine imaging does not reveal this fat infiltration in individuals with whiplash injuries.
A small preliminary study previously shows whiplash victims with chronic pain also have a high level of muscle fat in their lower legs, indicating muscle atrophy.
These patients may have partially damaged their spinal cord, Elliott says. They reported feeling fatigued and clumsy when walking, felt weakness in their legs, and had difficulty doing simple tasks like pushing hard on the gas pedal of a car or standing on their tiptoes.
“We haven’t found an effective treatment for these folks with chronic whiplash, and I think it’s because we haven’t really figured out what’s wrong with them,” Elliott says.
The findings help to demystify the condition and let individuals know their chronic pain is not all in their heads. A basic exam will not consistently show a fracture, herniated disc, or ligament tear.
“If you’re a whiplash patient with ongoing chronic pain, but no objective imaging finds anything wrong, people are frequently informed that nothing is wrong with them,” Elliott says “It’s been a huge problem.”
“That fat appears to be a response to an injury. What has actually been injured remains for us to find out. But now we know to look more deeply into the problem.”
Source: Northwestern University