Imaging modalities such as magnetic resonance imaging (MRI) and computed tomography (CT) scans are useful tools that are commonly used to investigate and diagnose pathology in different regions of the body such as the cervical, thoracic or lumbar spine. Often times, treatment plans are established based on the pathologies detected with imaging modalities. This is particularly problematic, considering that abnormal findings are actually commonly found in asymptomatic subjects (patients who do not report any pain)¹ ² ³ ⁴ ⁵. This calls into question the validity of using the results of these imaging modalities to serve as the foundation for the development of treatment plans. In this article, I will present a variety of research studies examining the prevalence of abnormal imaging findings in patients who report no pain.
In a recent systematic review published in 2015 by Brinjikji et al., 33 articles were reviewed, providing imaging findings (CT scan or MRI) for 3110 asymptomatic individuals¹. Here is a summary of their results:
- The prevalence of disk degeneration in asymptomatic individuals increased from 37% to 96% when comparing 20-year-old individuals to 80-year-old individuals.
- Disk bulge prevalence increased from 30% to 84% when comparing 20-year-old individuals to 80-year-old individuals.
- Disk protrusion prevalence increased from 29% to 43% when comparing 20-year-old individuals to 80-year-old individuals.
- The prevalence of annular fissure increased from 19% to 29% when comparing 20-year-old individuals to 80-year-old individuals.
- Facet degeneration was rarely found in in younger individuals (prevalence of 4–9% in those 20 and 30 years of age). However, the prevalence of facet degeneration increased sharply with age.
- Spondylolisthesis was not commonly found in asymptomatic individuals until approximately 60 years of age (prevalence of 23%). In addition, the prevalence of spondylolisthesis increased substantially at 70 and 80 years of age.
- More than 50% of asymptomatic individuals 30–39 years of age had disk degeneration, height loss, or bulging
CERVICAL & THORACIC SPINE
Another recent cross-sectional study published in 2015 by Nakashima et al. determined the prevalence and distribution of abnormal findings on cervical spine magnetic resonance image (MRI)². The Japanese study included 1211 healthy, asymptomatic volunteers. The age of healthy volunteers ranged from 20 to 70 years, with approximately 100 individuals per decade, per sex. Approximately, 50% of the subjects had passive occupations (i.e. office work, teachers, or service providers), whereas 28% of the participants had physically demanding occupations (i.e. housekeepers, builders and manufacturers). Here is a summary of their results:
- Disc Bulging: most asymptomatic volunteers (87.6%) had significant disc bulging with an incidence of 73.3% in 20-year-old males and 78.0% in 20-year-old females. The frequencies increased with age from the 20s to the 50s, with a significant increase from the 30s to the 40s in males ( P < 0.05). The number of bulging discs in each subject also increased with age.
- Spinal Cord Compression: identified in 5.3% of subjects. There were no cases of spinal cord compression in the 20-year-old group. However, the prevalence of spinal cord compression increased with age, was more commonly found in males than in females across all ages, and was predominantly found at C5-C6 (41%) and C6-C7 (27%).
- Relationship between disc bulging, spinal cord compression and increased signal intensity: The frequency of spinal cord compression and increased signal intensity increased after 50 years of age, and the latter was accompanied by increased severity of disc bulging.
Moreover, similar findings have been found in other asymptomatic populations in previous studies³ ⁴. One study written by Siivola et al. examined whether or not subjects with persistent or recurrent neck and shoulder pain were more likely to have abnormal MRI findings of cervical spine than those without neck and shoulder pain³. This study comprised of 31 subjects between 24-27 years of age. 186 included a random sample of 826 high-school students who were initially examined when the students were 17–19 years, and again when they had reached 24–26 years of age. A total of 186 discs were analyzed via MRI and included in the data analysis. Their results demonstrated that pathological changes of the cervical spine in a young adult population (24 to 27 years of age) were equally common in symptomatic and asymptomatic subjects. However, a disc herniation was the only finding significantly associated with neck pain. Therefore, the study concluded that pathophysiological changes of the cervical spine on MRI cannot completely explain the occurrence of neck and shoulder pain in young adults³. In addition a study including 94 asymptomatic volunteers with a mean age of 48 years examined the degenerative MRI findings of the thoracic spine. They found that 90.4% of the subjects exhibited positive MRI findings, indicating degeneration at one or more intervertebral levels in the cervical spine. The prevalence of degenerative MRI findings at the thoracic spine were less common (46.8%)⁴.
There is a substantial amount of evidence to support the presence of degenerative changes in asymptomatic individuals. Furthermore, the above findings suggest that even in young adults, degenerative changes may be incidental and not necessarily causally related to the patient’s presenting symptoms. Therefore, it is possible that the latter findings are normal age-related changes rather than pathologic processes.
That being said, there is some research to suggest that perhaps the severity of these degenerative changes is more likely associated with pain than the sheer presence of them. For instance, the previously mentioned study by Siivola et al. found that a disc herniation was the only finding significantly associated with neck pain. Although disc bulges are commonly found among asymptomatic individuals, it is possible that a herniation of the disc is more likely to produce pain as it has completely breached the outer annulus, increasing the likelihood of a nerve root compression and/or irritation⁶. In addition, another study of 1043 volunteers between the ages of 18 and 55 years with low back pain demonstrated a positive correlation between the severity of lumbar interverterbral degenerative disc disease and low back pain, with the L4-L5 and L5-S1 segments being the most commonly affected⁵.
To conclude, it would be ill-advised to make an interventional decision based on degenerative changes found on MRI alone. The clinical presentation of the patient, as well as the objective findings of the physical evaluation, must absolutely be considered. Moreover, it is crucial to use proper clinical judgement when interpreting MRI results, and particularly when explaining these results to patients.
Anthony Teoli MScPT
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DISCLAIMER: This blog is not meant for diagnostic or treatment purposes. It should not substitute for professional diagnosis and treatment. This blog was not created to provide physiotherapy consultations, nor was it created to obtain new clients. The content of this blog is a resource for information only. This blog was created to serve as an information resource for both the general population and health professionals. For any further questions or concerns regarding imaging results, please consult your doctor.
1. Brinjikji, W., Luetmer, P. H., Comstock, B., Bresnahan, B. W., Chen, L. E., Deyo, R. A., Halabi, S., … Jarvik, J. G. (2015). Systematic Literature Review of Imaging Features of Spinal Degeneration in Asymptomatic Populations. AJNR Am J Neuroradiol, 36(4): 811–816.
2. Nakashima, H., Yukawa, Y. Suda, K, Yamagata, M, Ueta, T., & Kato, F. (2015). Abnormal Findings on Magnetic Resonance Images of the Cervical Spines in 1211 Asymptomatic Subjects. Spine, 40(6): 392-398.
3. Siivola, S. M., Levoska, S., Tervonen, O., Ilkko, Ero., Vanharanta, H., & Keinänen-Kiukaanniemi, S. (2002). MRI changes of cervical spine in asymptomatic and symptomatic young adults. European Spine Journal, 11(4): 358-363.
4. Matsumoto, M., Okada, E., Ichihara, D., Watanabe, K., Chiba, K., Toyama, Y., Fujiwara, H., … Takahata, T. (2010). Age-Related Changes of Thoracic and Cervical Intervertebral Discs in Asymptomatic Subjects. Spine, 35(14): 1359-1364.
5. Cheung, K. M. C., Karpinnen, J., Chan, D., Ho, D. W. H., Song, Y. Sham, P., Cheah, K. S. E., … Luk, K. D. K. (2009). Prevalence and Pattern of Lumbar Magnetic Resonance Imaging Changes in a Population Study of One Thousand Forty-Three Individuals. Spine, 34(9): 934-940.
6. Shelerud, R. A. (2017). Bulging disk vs. herniated disk. MayoClinic. Retrieved from: http://www.mayoclinic.org/diseases-conditions/herniated-disk/expert-answers/bulging-disk/faq-20058428