Alright this is Pain Science Part 2, where we will discuss the topic of imaging as well as the psychological impact of scans. In pain science part 1 we mentioned that debilitating pain can exist without structural cause for pain.
Look at these scans, which Person Do You Think Hurts the Worst and The Least?
Without knowing anything else about these patients, who do you think has the worst pain? Who do think these people are? What are their lives like? These will serve as a lesson about pain, context and people.
Remember pain is context specific, so it depends on the person and the circumstances around pain experience. We’ll come back to these shortly.
This was a study done on the prevalence of degenerative imaging findings in asymptomatic people. This is just one study of many. You can see on the chart as age increases, so do structural findings. Everything from basic degeneration to disc bulges and protrusions.
The results from this systematic review strongly suggest that when degenerative spine findings are incidentally seen, these findings should be considered as normal age-related changes rather than pathologic processes.
This is just one study on imaging findings. There are other studies that have found a larger association with imaging findings as a cause of pain. It really depends on the structural changes that occur and which ones can be contributory to pain. Based on my reviews, simple disc bulges, herniations and protrusions don’t necessarily mean they are the cause of pain.
In review of the previous imaging studies, it is clear there is a population of people with structural changes to their spine like disc bulges, degeneration, protrusions and disc wall fissures (or cracks.) without pain. Additionally, structural changes like torn rotator cuff tendons and meniscus tears in knees have been found in asymptomatic people. So it’s not just the spine.
So what could be causing pain in the other group of people who have the same structural changes?
Let’s look at a study that may provide some answers. Researchers randomly selected 131 Veterans Affairs outpatients ,aged 35 to 70, without low back pain in the past 4 months.
They compared initial MRI findings with MRI findings 3 years later. They also measured pain level changes over the course of 3 years.
The 3-year incidence of new pain was 67%. New structural changes were infrequently found over 3 years, and they did not demonstrate significant association
of any imaging finding with new onset back pain.
Only central canal stenosis and nerve root compression were positively correlated with new pain. Other studies have drawn a similar correlation to nerve root impingement as a probable cause of pain. The researchers stated a possible limitation to this study was sample size.
So if there wasn’t significant correlation of new MRI findings with new pain onset,
What was causing the new pain in the 67% of subjects? The researchers found something interesting that had a greater association for new pain. Sit tight, this will be revealed in a few minutes.
Again lets go back to the MRI scans – who do you think has THE least pain? Who has the MOST pain? Remember context matters.
The young mother has the most pain. At the time of this image she had complaints of significant back pain that profoundly limited her ability to function as a mother. The two athletes at the time of these scans had no pain. The physicality is clearly different between these three subjects. What is unknown about the mother is her mental health. Maybe there is more to her pain than the structure on the scan?
Structural compromise like a disc protrusion, bulge or degenerating disc can be present on a scan but without any pain associated with it. This is not the case for everyone, but the danger in our healthcare culture is assuming the structure in question on a scan is THE cause of back pain. What is the danger? The person who has difficulty recovering then elects to have back surgery, only to feel no better or maybe even worse after, because the structure in question was actually NOT the pain generator.
Additionally, some personality types may be more likely to become hypervigilant or overly consumed with the features on the scan creating a more complex psychologically magnified problem.