PainSci summary of Nakashima 2015?This page is one of thousands in the PainScience.com bibliography. It is not a general article: it is focused on a single scientific paper, and it may provide only just enough context for the summary to make sense. Links to other papers and more general information are provided at the bottom of the page, as often as possible. ★★★★★?5-star ratings are for sentinel studies, excellent experiments with meaningful results. Ratings are a highly subjective opinion, and subject to revision at any time. If you think this paper has been incorrectly rated, please let me know.
There is now a well-established pattern of studies that use MRI or x-ray that show a surprising number of abnormalities MRI in healthy people, but this is the first large study of this kind for the neck. Almost 90% of 1200 subjects had bulging intervertebral discs. Although bulging discs were more common in older people, even people in their 20s were affected, about 75% of them.
On the other hand, spinal compression and irritation (increased signal intensity) was relatively rare in healthy subjects (only 5% and 2%). Those abnormalities are obviously much more likely to cause problems (myelopathy). Nevertheless, it’s still surprising that a defect as serious as pinching the spinal cord can be asymptomatic in as many as 1 in 20 people! My hunch would have been “zero.”
~ Paul Ingraham
original abstract†Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
STUDY DESIGN: Cross-sectional study.
OBJECTIVE: The purpose of this study was to determine the prevalence and distribution of abnormal findings on cervical spine magnetic resonance image (MRI).
SUMMARY OF BACKGROUND DATA: Neurological symptoms and abnormal findings on MR images are keys to diagnose the spinal diseases. To determine the significance of MRI abnormalities, we must take into account the (1) frequency and (2) spectrum of structural abnormalities, which may be asymptomatic. However, no large-scale study has documented abnormal findings of the cervical spine on MR image in asymptomatic subjects.
METHODS: MR images were analyzed for the anteroposterior spinal cord diameter, disc bulging diameter, and axial cross-sectional area of the spinal cord in 1211 healthy volunteers. The age of healthy volunteers prospectively enrolled in this study ranged from 20 to 70 years, with approximately 100 individuals per decade, per sex. These data were used to determine the spectrum and degree of disc bulging, spinal cord compression (SCC), and increased signal intensity changes in the spinal cord.
RESULTS: Most subjects presented with disc bulging (87.6%), which significantly increased with age in terms of frequency, severity, and number of levels. Even most subjects in their 20s had bulging discs, with 73.3% and 78.0% of males and females, respectively. In contrast, few asymptomatic subjects were diagnosed with SCC (5.3%) or increased signal intensity (2.3%). These numbers increased with age, particularly after age 50 years. SCC mainly involved 1 level (58%) or 2 levels (38%), and predominantly occurred at C5-C6 (41%) and C6-C7 (27%).
CONCLUSION: Disc bulging was frequently observed in asymptomatic subjects, even including those in their 20s. The number of patients with minor disc bulging increased from age 20 to 50 years. In contrast, the frequency of SCC and increased signal intensity increased after age 50 years, and this was accompanied by increased severity of disc bulging.
One article on PainScience.com cites Nakashima 2015 as a source:
- PS Save Yourself from Neck Pain! — A complete guide to chronic neck pain and the disturbing sensation of a “crick”
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- A Bayesian model-averaged meta-analysis of the power pose effect with informed and default priors: the case of felt power. Gronau 2017 Comprehensive Results in Social Psychology.
- Association of Spinal Manipulative Therapy With Clinical Benefit and Harm for Acute Low Back Pain: Systematic Review and Meta-analysis. Paige 2017 JAMA.
- Incidence of Spontaneous Resorption of Lumbar Disc Herniation: A Meta-Analysis. Zhong 2017 Pain Physician.
- How much is too much? (Part 1) International Olympic Committee consensus statement on load in sport and risk of injury. Soligard 2016 Br J Sports Med.
- Chiropractic spinal manipulative therapy for migraine: a three-armed, single-blinded, placebo, randomized controlled trial. Chaibi 2016 Eur J Neurol.