Why was this study conducted?
Edited by BM Davies
Previous research¹ has demonstrated that patients with cervical myelopathy undergo an immune response. Additionally, proinflammatory proteins, called cytokines, are more present in cerebrospinal fluid in patients with cervical myelopathy and low back degenerative disc disease. Therefore, it is possible that some of these cytokines may be able to serve as blood markers of severity of cervical myelopathy.
How was the study conducted?
This was a comprehensive study involving both humans and animals to help investigate their research question.
In humans: Blood was collected from 40 patients with cervical myelopathy before surgery, 10 controls without myelopathy, and another group of 10 patients with myelopathy to serve as a validation group. From this blood they analyzed the presence of 4 cytokines.
In rats: These cytokines are also compared between healthy rats, and rats in which cervical myelopathy was recreated. The researchers also went on to administer a large dose of one of the cytokines (interleukin-6) in rats who did not have compression, so see what would happen. They looked at amount of motor function, pain sensitivity, tissue damage, and cytokine levels in the rats.
What was discovered?
Of the 4 cytokines examined, patients with cervical myelopathy had an increased concentration of interleukin-6 only. This was found in both groups of patients with cervical myelopathy. Interleukin-6 was moderately associated with mJOA scores and body mass index but not age or symptom duration. While interleukin-6 levels were higher than controls, they still were in the range of what is clinically considered “normal” suggesting that it was elevated but not THAT elevated.
Additionally, rats that had experimental compression of their cervical spinal cord had elevated levels of interleukin-6 in both their blood and cerebrospinal fluid. They also had lower motor function scores than rats without compression, increased pain sensitivity, and spinal cord damage. Interestingly, the rats that had an experimental dose of interleukin-6 had similar motor scores, pain sensitivity, and spinal cord damage to the rats with compression.
Why is this important?
This study importantly expands our knowledge of the disease process in patients with cervical myelopathy. Since the blood interleukin-6 levels were still in the “normal”, it may not be the best marker for diagnosing the disease, but it appears it could serve as an indicator of severity of the condition. It is also important because the study was done in a way that we can have substantial confidence that what they found was real. Science has a problem lately with being unable to replicate findings.² This study, on the other hand, replicated their own findings in humans and an animal model of cervical myelopathy.
Overall, this study highlights that inflammation may be an important component of cervical myelopathy, and therefore by extension anti-inflammatory therapy could have potential. There is still a lot more we need to explore with that though as some anti-inflammatory medicines can impair healing after a cervical fusion. Therefore, patients with cervical myelopathy shouldn’t start an anti-inflammatory regimen without consulting their surgeon!
Questions for discussion:
1. Have you noticed any benefits in motor function such as walking, grip, or balance while on anti-inflammatories?
Let us know in the comments!
1. Du S, Sun Y, Zhao B. Interleukin-6 Serum Levels Are Elevated in Individuals with Degenerative Cervical Myelopathy and Are Correlated with Symptom Severity. In: Med Sci Monit. Vol 24.2018:7405-7413.
2. Baker M. 1,500 scientists lift the lid on reproducibility. Nature News. 2016;533(7604):452.