New Study: Some Chronic Whiplash Patients Have Spinal Cord Injuries
I’ve been treating patients with “whiplash” for decades. One of the things that has always stood out to me is that in some chronic pain patients, many aspects of their symptoms look like an incomplete spinal cord injury. The problem? Their MRI imaging doesn’t show spinal cord damage, until now. Let’s dig in.
Whiplash and MRI
Traumatic neck injury aka whiplash is more common than you would think. One problem is that for most of these patients who end up with chronic neck and/or headache pain, there is no or little MRI evidence of a problem. Hence these poor patients are often kicked from specialist to specialist without any diagnosis. The good news is that more often than not, they find a doctor offering interventional spine care and finally get a diagnosis and some relief. However, some are never helped. A few of these remaining patients have cranial-cervical instability and get help through procedures like our novel PICL technique. However, still, others have a collection of weird neurologic symptoms. These are the patients who are the subject of this new paper.
A long time ago, Jim Eliott worked with us as a physical therapist. He ultimately moved on to get his Ph.D. and perform some really interesting research on upper neck muscle atrophy. During all of that, Jim got more and more expertise in novel MRI techniques. That plus a conviction that these poor souls who still have symptoms may have something demonstrably wrong with them led to this new paper.
Traditional MRI allows us to see soft tissues, which is a big advance over x-ray. However, there are new MRI protocols that use the same technology that allow us to see more. One of those is called MT-MRI (magnetization transfer). Let’s dive in there.
All MRI imaging works by applying a strong magnet which causes the water molecules to become aligned and when that magnetic field is shut off, they flip back to their normal state while generating energy in the process that’s picked up by the machine and turned into an image. Magnetization transfer MRI (MT-MRI) uses specialized protocols that can detect damage to neurologic tissues at a molecular level. The actual physics is complex but is discussed here.
Parts of the Spinal Cord
Your spinal cord has different parts. One of those is called the spinothalamic tract, which is responsible for the transmission of pain, temperature, and touch sensation to the brain (thalamus). So if you were trying to give someone chronic pain by damaging their spinal cord, this would be a prime target. Meaning damaging the spinothalamic tract would cause strange signals to go to the part of the brain that perceives pain. So things that wouldn’t normally be painful could become painful.
The New Study
This new study used MT-MRI to look at various parts of the spinal cord in 30 recovered whiplash patients, 32 who had mild issues, and 14 severe patients (1). In the spinothalamic tract, there were significant differences in the MT-MRI signal between the recovered/mild and the severe group. Ultimately, the authors concluded that they were able to detect subtle spinal cord damage in some severe chronic whiplash patients.
Why This is a Big Deal
We now have many different studies showing everything from brain atrophy to muscle atrophy in patients with chronic pain who otherwise would have their MRIs read as “normal”. In fact, in medical school, we had an inside joke for this phenomenon. An abbreviation for a normal finding is WNL (Within Normal Limits). However, we often joked that WNL really meant “we never looked”. This seems to be the case with many MRI studies. Either the radiologist failed to notice subtle existing findings consistent with where the patient hurts or the wrong type of imaging or analysis was used.
This new study now adds to those new ways of looking for why people have chronic pain after a whiplash injury. In fact, I intend to try to use it on a few patients who have problematic clinical presentations and who don’t respond or respond in a limited way to advanced care.
Can You Go Out and Get One of these Studies Today?
Nope. However, I’ll be working with a radiologist I trust to help figure out how to apply these very specific MRI protocols in real patients. At some point, I’ll report my progress and maybe some case studies.
I love the phrase, “You ‘ain’t seen nothing yet”. That applies here because artificial intelligence is still in its infancy. These new technologies will eventually be applied to look at MRI data in ways that frankly, we humans are just too slow and stupid to understand. For example, we now create images from the data generated by an MRI machine, but we likely lose gobs of important information in the process. In the future, as AI gets better, I suspect that we will create programs smart enough to look at that raw data and call diagnoses far more accurately than we humans can. In medicine, this will advance the quality of the care we deliver just like the first MRI scanners advanced diagnosis back in the 80s.
The upshot? MT-MRI could be a new and useful way to get to a diagnosis in those patients who have had a whiplash-type injury who have symptoms not explained by their traditional neck MRI. What’s really exciting here is that by finding new ways to use the tools we already have, we’re seeing some amazing technologies emerge that can help people who are hard to diagnose finally get a real diagnosis.
(1) Hoggarth MA, Elliott JM, Smith ZA, Paliwal M, Kwasny MJ, Wasielewski M, Weber KA 2nd, Parrish TB. Macromolecular changes in spinal cord white matter characterize whiplash outcome at 1-year post motor vehicle collision. Sci Rep. 2020 Dec 17;10(1):22221. doi: 10.1038/s41598-020-79190-5. PMID: 33335188; PMCID: PMC7747591.