Chronic back pain and common false alarms from medical imaging

Key take aways:

• Research shows that medically used radiological imaging (X-ray, CT, MRI) results do not correlate with intensity or even the presence of pain.
• Degenerative changes are found equally in the spines of symptomatic and asymptomatic populations, increasing with age.
  

You know your back pain better than MRI's and X-rays

Have you ever walked out of your doctor's office feeling frustrated because they didn't bother to order imaging for your pain? You aren't alone – but the doctor actually may have a good reason not to order expensive tests.

People with pain rely on doctors to find the root cause of the problem, and we commonly assume that X-rays, CT scans, and MRI scans hold the keys to diagnosis and treatment. The surprising reality is that in many cases, imaging doesn't provide the answers we seek because there is more to chronic pain than a simple "mechanical glitch" in the spine. 

In study after study, research shows that pain and anatomical changes in the spine are unrelated. 

A longitudinal 10-year study published in 2017 found no correlation between low back pain and the prevalence of disk degeneration, disk bulging, or vertebral alignment findings such as spondylolisthesis (1). Moreover, degenerative changes are commonly found in the spinal imaging of asymptomatic populations, in addition to those suffering from back pain (2). A systematic meta-review of low back pain literature published in the American Journal of Neuroradiology showed that the prevalence of degenerative changes in the spine increases as we age, irrespective of pain status (3). 

It turns out, many diagnoses are, in fact, false alarms. Medical guidelines only indicate radiological imaging when intense neurological symptoms are present (4). But this does not stop many practitioners in the orthopedic specialties from ordering expensive and unnecessary imaging, which then leads to undue attention to defects in the spine that otherwise would cause no harm to their bearer whatsoever. 

MRI scans are also notorious for their poor quality control and the variability of results. In one study, a woman received MRI imaging across ten different imaging locations. A total of 49 distinct pathological findings were reported, only one repeating across examinations (5). This shows how unreliable a tool MRIs can be and adds to the pile of evidence showing that we should not be basing our pain treatments on their results.

What MRI's and X-rays do and do not tell us

When orthopedic specialists look at imaging, they view the bony and cartilaginous structures of the spine as well as the gelatinous discs that support the spinal column. A spine CT or MRI scan provides a good view of the physical structure around the spine but lacks detail when trying to understand the nervous system. 

These imaging scans are sufficient for us to find various macroscopic anatomical abnormalities, such as bulging or degenerated discs, vertebral misalignment, and osteoarthritic changes of the spinal joints. But – research clearly shows that these abnormalities rarely correlate with the presence or intensity of chronic pain!

To see the pain, we must look at the brain

To understand why spinal imaging can't capture the perception of pain, we can look at how normal acute pain works.

It goes something like this: When the nerves in our skin detect a potential threat (through, for example, pressure or heat), they send alarm signals to the brain. These alarm signals are relayed through the body like a game of telephone, from the nerves to the spinal cord to the brain. Because pain is so essential for our survival, the spinal cord naturally increases the volume of these danger signals, so the brain hears them loud and clear. The brain's interpretation of these alarm signals then combines the sensations coming from the peripheral body part with feelings and thoughts to create the full experience of pain. 

The pain experience is not in the spine; it is in the brain.

The brain interprets the sensory signals that are routed through the spinal cord, and what happens in your brain is not shown in standard medical imaging. Brain imaging requires more powerful and higher-resolution equipment than what is available to a typical orthopedist. 

Standard medical imaging gives little insight into how the nervous system functions as a whole and how we experience pain. The nervous system runs throughout our bodies—not just our spines—and our brain is the true master orchestrator of our conscious experiences, including that of pain perception. 

We can also look at the issue of imaging from another angle. In medicine, "normal" is formally defined as something not statistically significantly different from the values typical for a healthy individual of the same age group. However, most definitions of spine abnormality fail to recognize the effect of age and instead compare the spines of people of ages 50, 60, and 70 to the spines of a 20-year-old. This, of course, is absurd. 

In the past, degenerative spine changes have been termed "degenerative disc disease," but these changes are actually part of an ageing process that every spine goes through over its lifespan.

Should a natural progression that doesn't necessarily cause any functional problems be called a disease? Calling a natural aging process degenerative puts an undue negative spin on a natural structural change in the spine and may lead treatment down blind alleys.

What is causing our chronic pain symptoms is, in fact, something else altogether.

In our next post, we will be going into detail about the actual causes of chronic back pain. Sign up for our newsletter to make sure you don't miss it!

Reviewed by Dr. Melissa Farmer.

References:

1. The associations between magnetic resonance imaging findings and low back pain: A 10-year longitudinal analysis.
2. Magnetic Resonance Imaging of the Lumbar Spine in People without Back Pain.
3. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations.
4. Diagnosis and Treatment of Low Back Pain: A Joint Clinical Practice Guideline from the American College of Physicians and the American Pain Society.
5. Variability in diagnostic error rates of 10 MRI centers performing lumbar spine MRI examinations on the same patient within a 3-week period.

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