Reconsidering high intensity zones: its role in intervertebral disk degeneration and low back pain
Two pages on PainSci cite Sima 2024: 1. The Complete Guide to Low Back Pain 2. Pictures of spinal inflammation: a correlation kerfuffle
PainSci notes on Sima 2024:
High intensity zones (HIZ) are bright blotches on certain kinds of MRI scans that show inflammation, often seen with more conventional signs of spinal disc changes.
How often, though? Sima et al. designed an experiment to shed light on that, and whether the HIZs have an “independent relationship” with other signs of degeneration (that is, do they go together regardless of other factors). They looked at the lumbar MRIs and X-rays of 136 adult patients, and found 57 (42%) had some HIZ (inflammation). They designated the remainder as a kind of control group, and crunched some comparison numbers.
HIZ spots were six times likelier in spines with other signs of troubled discs, and those patients were three times likelier to have pain than the no-HIZ folks.
Sima et al. concluded that standard signs of disc degeneration are “related” to scannable signs of inflammation, regardless of other factors, and therefore:
“HIZ is likely a symptomatic and clinically meaningful diagnostic tool in the assessment of low back pain.”
The word “likely” is doing quite a lot of heavy lifting there. 🙂 But it’s not crazy. I think this is a solid experiment. It’s limited by examining backs at only one moment in time; it can only say “these things were found together once” (cross-sectional) and not “the HIZ came before the symptoms and so the relationship is probably causal” (longitudinal). But it seems a sensible design for a mere slice-of-time study. Worse cross-sectional studies has been used to justify much more overstated conclusions.
Speaking of sensible: the inevitable and sensible criticism of correlation findings like this is that “correlation does not imply causation,” and that is absolutely technically true, and its importance should never be underestimated. This data alone definitely cannot and does not “prove” that the HIZ is a cause of back pain, or that scanning for HIZ is necessarily a useful clinical tool.
This data is far from “alone,” however. For a bunch of context and analysis, see the blog post, “Pictures of spinal inflammation: a correlation kerfuffle.”
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.
PURPOSE: High intensity zones (HIZ) in the lumbar intervertebral disk (IVD) can be associated with degenerative changes which may ultimately manifest as low back pain (LBP). However, the relationship between the prevalence of HIZ and lumbar degenerative parameters is still unclear. The purpose of this study was to determine the prevalence of HIZ in the lumbar spine, analyze the independent relationship between HIZ and lumbar degenerative parameters measured on MRI and X-ray and determine the association between HIZ and the presence of LBP.
METHODS: A retrospective review of MRI data, X-ray data, and radiology reports for 136 consecutively recruited patients, above 18-years-age and with both lumbar MRI and X-ray scans was conducted. 57 patients with HIZ were identified. Patients without HIZ (n=79) made up the control group.
RESULTS: HIZ was prevalent in 41.9% of patients and in 11.0% of all lumbar IVDs. The odds of developing HIZ were 6.4 (Exp(B) 6.4, 95%CI [3.157-12.988]) and 3.0 (Exp(B) 3.0, 95%CI [1.603, 5.674]) times higher in IVDs with disk bulge/protrusion and nucleus degeneration, respectively. Odds of HIZ was also increased in disks with larger IVD angle (Exp(B) 1.1, 95%CI [1.034, 1.169]). The odds of patients presenting to imaging with LBP was 3.0 (OR 3.0, 95%CI [1.478-6.338]) times higher in the HIZ compared to the control group.
CONCLUSIONS: HIZ was prevalent in 41.9% of participants that were recruited in this study. Nucleus degeneration, disk bulge/protrusion and increased IVD angle were found to be independently associated with HIZ and since there is an increased likelihood of LBP, we posit that HIZ is likely a symptomatic and clinically meaningful diagnostic tool in the assessment of LBP.
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:
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