Using special magnetic resonance imaging (MRI), researchers have identified which patients will go on to develop chronic pain, disability, and post-traumatic stress disorder (PTSD) 1 to 2 weeks following whiplash injuries.
This is the earliest these patients have ever been identified, according to James Elliott, MD, Northwestern University Feinberg school of Medicine, Chicago, Illinois, and colleagues. The ability to identify these patients so early will enable faster and more specialised treatment, which could be particularly beneficial for the PTSD.
While most people should expect to fully recover from whiplash injuries within the first few months, about 25% have long-term pain and disability that lasts many months or years.
After 1 to 2 weeks of the injury, the researchers found unusual muscular changes in the chronic pain group using a sophisticated MRI that measures the fat/water ratio in the muscles. The 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,” said Dr. Elliott. “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.”
The current finding, published on March 17 in the journal Spine, builds on previous research by Dr. Elliott, which found a large amount of fat in neck muscles of whiplash patients at 1 and 3 months post injury using standard MRI imaging. 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, these findings help physicians understand water/fat MRI, in tandem with other clinical signs/symptoms can be used to identify who is likely to develop PTSD. This then could be used to justify the referral of the patient to a psychiatrist or psychologist, said Dr. Elliott.
“These patients have shown to not respond well to traditional rehabilitation such as physical therapy,” he said. “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.