by B. Davies
If we took a hundred random individuals, over the age of 40 off the street, and performed a cervical MRI scan, as many as 56 would have imaging changes associated with myelopathy. However, fewer than 1 or 2 would actually have spinal cord injury and therefore actual myelopathy. These numbers may not be exact (although they were found in a recent study), but you get the gist. 
So a big question for researchers is what happens to the other 54 people…. Do they go on to get myelopathy? Is it just a question of time? Or will they remain unaffected?
There has only ever been one study looking at this by Joseph Bednarik. In that study they found that, given time, as many as 10 of the remaining 54 would get myelopathy .
In a follow up study published this month , Dr Bednarik has been looking at whether we can predict which of those 54 patients will develop myelopathy. They found that if a patient had had cervical radiculopathy, or electrophysiological signs of cord problems or more significant compression features on their MRI, they were more likely to develop myelopathy.
These findings need to be confirmed in larger studies, but they are interesting. For one, it suggests that features of cord injury (electrophysiology) come before any symptoms of myelopathy! We know that catching myelopathy early is important, but this is going to make things even more difficult!
1) Adamova, B., Kerkovsky, M., Kadanka, Z., Dusek, L., Jurova, B., Vlckova, E., & Bednarik, J. (2017). Predictors of symptomatic myelopathy in degenerative cervical spinal cord compression. Brain and Behavior, 7(9), e00797.
2) Bednarik, J., Kadanka, Z., Dusek, L., Kerkovsky, M., Vohanka, S., Novotny, O., et al. (2008). Presymptomatic spondylotic cervical myelopathy: an updated predictive model. European Spine Journal : Official Publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 17(3), 421–431.
3) Kovalova, I., Kerkovsky, M., Kadanka, Z., Nemec, M., Jurova, B., Dusek, L., et al. (2016). Prevalence and Imaging Characteristics of Non-Myelopathic and Myelopathic Spondylotic Cervical Cord Compression. Spine.
The conference was a great opportunity to promote DCM and Myelopathy.org to a diverse group of leading experts. It stimulated interesting discussions with the community, and hopefully it can continue to drive progress.
But of course a big thanks to you our community, because much of the information this is coming to light has come from you!! So keep participating and hopefully we can make a difference.
1. C.Munro et al. Online Symptom Checkers: A Novel Insight into the Challenges of Diagnosing Cervical Spondylotic Myelopathy
2. J. Tempest-Mitchell et al. Qualitative MRI reporting in Cervical Spondylotic Myelopathy influences patient referral to spinal services
3. B.Hilton et al. MRI compression is the focus of surgical decision making in Degenerative Cervical Myelopathy
4. O.Mowforth et al. The use of smart technology in patients with Degenerative Cervical Myelopathy
Amongst patients with CSM, most have a 'normal' looking spinal cord, but others can have changes, including high signal (aka the 'white spot') on T2 images, with or without low signal (black) on T1 images.
A group from North America (1), in the largest such study to date, having been looking specifically at changes within the spinal cord. Their theory was that the amount of spinal cord damage, and therefore the severity of disease and likelihood of improving after surgery, related to this sequence of changes. I.e. Normal cord was better than a white spot, but a white spot with corresponding blackness on T1 was worst of all. The white spot is thought to represent oedema, whereas the blackness loss of spinal cord tissue.
The authors analysed over 400 MRI scans of patients who went on to have surgery for CSM. Just as they thought, they found that these image changes did relate to the severity of myelopathy, and likelihood of responding to surgery.
More specifically, they found that the 'black' low signal on T1 images was the most important feature; most likely to be found in more severely affected patients, who responded less well to surgery. A 'white spot' on its own was only very slightly worse than normal looking cord, however 'white spots' at multiple levels was associated with more severe myelopathy.
This is a high-quality study, involving a large number of patients from across the globe. This is a very interesting study and moves the field forwards. The clinical relevance of a 'white spot' was uncertain, and a topic of constant debate; some studies had shown it was a sign of bad myelopathy, where as others that it was not indicative of severity (2). The finding here of the significance of one vs many white spots may explain these previously inconsistent findings. Regardless the relative, greater importance of low signal (black) on T1 images is new.
These image findings are not the be all and end all; some patients with spinal cord changes on their MRI do very well with surgery and vice versa. These findings therefore, at least for now, are only a guide.
1. A.Nouri et al. The Relationship Between MRI Signal Intensity Changes, Clinical Presentation, and Surgical Outcome in Degenerative Cervical Myelopathy: Analysis of a Global Cohort. Spine. May 2017.
2. L.Tetreault et al. A Systematic Review of MRI Characteristics that Affect Treatment Decision-Making and Predict Clinical Outcome in Patients with Cervical Spondylotic Myelopathy. Spine August 2013
By J Tempest Mitchell
When considering whether to undergo surgery for treatment of CSM, one of the biggest questions that people want answered is what the risks are, and how likely they are to occur. Well, they’re in luck- a team from China have just completed a large-scale study, looking at previous research on the topic, to try and find out exactly that (1)!
Overall, the researchers looked at over 100 previous studies, and more than 8500 patients who underwent surgery to treat CSM, and found that just over 20% experienced some degree of complications from the surgery: in other words, twenty out of every hundred patients had some form of issues afterwards. Whilst this percentage may initially seem quite high, it is important to remember that CSM surgery can be life-changing, and that many of these side effects may be only temporary or minor compared to the damage that the disease itself can cause.
So what sort of complications did patients experience?
The most common of the complications examined in the study was difficulty or pain on swallowing, which nearly 17% of the patients studied reported on the first day after surgery (although the data doesn’t tell us how long this effect lasted beyond that first day). The next most common complication was axial (neck) pain, which was reported by 15.6% of patients.
Other problems seen after surgery were:
· Damage to the nerve C5, which supplies part of the upper arm (5.3%)
· Hoarseness (4.0%)
· Graft subsidence, an issue where the graft sinks into the bones of the spine, causing distortion (3.7%)
· Dislodgement of the graft (3.4%)
· Infection (2.8%)
· Failure of the bones in the spine to fuse (2.6%).
Two rarer, but potentially more serious complications seen were infection of the CSF (the fluid surrounding the spinal cord) in 1.9% of patients and epidural haematoma (bleeding between the outer lining of the spinal cord and brain, and the skull) in 1.1%.
These complication rates varied slightly, depending on the subtype of myelopathy from which patients were suffering, and also the exact operation type. In particular, patients with myelopathy caused by OPLL (a condition in where a flexible structure known as the posterior longitudinal ligament thickens and become less elastic) had a higher risk of damage to the C5 nerve and CSF infection after surgery.
This information is useful to allow patients to make an informed decision. It should be remembered that despite these possible problems, overall surgery for CSM has been shown effective to stop disease progression.
dsMRI is a modified form of the normal imaging technique, first introduced in the 1980s. This form of dynamic MRI imaging can be carried out in the same, standard, MRI machines we use now. Images are still taken with the patient lying down in the scanner (‘supine’), but rather than just take one series of images, the spine is imaged through a range of different neck positions (‘dynamic’), so its effect on the spinal cord can be seen. The major drawer back for patients is the imaging takes even longer (the researchers in this article estimate this would be an additional 15 minutes) and holding the different neck positions may not be possible for patients, as it could exacerbate their symptoms.
Do you suffer from CSM or know someone who does? Then share your experiences to help researchers understand the disease
In this article, the researchers found thirteen previous studies comparing dsMRI to traditional MRI techniques in the diagnosis of CSM. They found that on average, dsMRI was able to identify compression that was either missed or underestimated by traditional techniques in around 20% of patients. This suggests that dsMRI may be able to measure spinal cord compression with a higher degree of sensitivity.
It should be noted that the types of studies conducted so far are at risk of bias which means that the conclusions of this study can only be hesitant. Nevertheless, these findings are interesting as they have identified clear examples of where a standard MRI may not identify any compression, yet dsMRI does. And of course, many doctors rely on ‘MRI compression’ to make their diagnosis.
Additionally given ‘basic’ MRI imaging has been shown to poorly predict the severity of CSM and therefore response to surgery, could dsMRI change this and better inform patients?
One thing is certain, more investigation is required!
(1) Nanfung Xu et al. Does Dynamic Supine Magnetic Resonance Imaging Improve the Diagnostic Accuracy of Cervical Spondylotic Myelopathy? A Review of the Current Evidence, World Neurosurgery http://dx.doi.org/10.1016/j.wneu.2017.01.047.
By looking at MRI scans, the team were able to identify a larger amount of fatty tissue in two neck muscles, directly above and below the point of spinal cord compression. A larger build-up of fat cells was found to be linked to heightened symptoms of CSM, such as taking longer to walk 30m, and more difficulty with movement. They also found that patients with unevenness in one of their other neck muscles reported greater neck pain, and associated problems.
The increase of fat cells in muscle can be linked to a number of causes, but is most often seen as a normal part of the ageing process. Previous research has already found that we can reduce this age-related build-up of fat using physical activity and regular exercise (2), so the Canadian team speculate that a scheme of targeted neck exercises might help to improve the results of surgery in the treatment of CSM.
It’s important to remember however, that this research is still in its early days, and that so far, and a number of questions remain unanswered:
- Can neck exercises reverse fat infiltration?
- if so, what type of exercises are appropriate?
- Does this improve patient symptoms?
- Is it a consequence of CSM, or related to its origins?
It should be remembered that neck exercises will not remove the compression behind CSM and that at present, this can only be treated with surgery. Additionally some suggest extensive neck therapy before surgical treatment can make symptoms worse. (3) More work will need to be done to see whether the possible benefits of exercise are actually seen in patients, and if so, which types of exercises are most useful. However, if the suggestions made in this paper are found to be accurate, then this could be a simple way for patients to change the way that they prepare for surgery, in order to improve results.
(1) Fortin M, Dobrescu O, Courtemanche M, Sparrey CJ, Santaguida C, Fehlings MG,Weber MH. Association Between Paraspinal Muscle Morphology, Clinical Symptoms and Functional Status in Patients With Degenerative Cervical Myelopathy. Spine (PhilaPa 1976). 2016 May 23
(2) Hamrick, Mark W., Meghan E. McGee-Lawrence, and Danielle M. Frechette. “Fatty Infiltration of Skeletal Muscle: Mechanisms and Comparisons with Bone Marrow Adiposity.” Frontiers in Endocrinology 7 (2016): 69. PMC. Web. 15 Feb. 2017
(3) Rhee JM, Shamji MF, Erwin MW, Bransford RJ, Yoon T, Smith JS, Kim HJ, Ely CG, Dettori JR, Patel AA, Kalsi-Ryan S. Nonoperative management of cervical myelopathy: a systematic review. Spine
It has been well shown in many studies that Cervical Spondylotic Myelopathy (CSM) is a chronic and debilitating condition that reduces quality of life (1). However, until recently no one has studied how this compares to other common chronic conditions.
The study also found that the mental impairment caused by CSM was worse than for any of the other conditions, surpassed only by back pain and sciatica.
This was a well conducted, large, multi-centre study which successfully demonstrated that CSM carries a greater physical and mental disease burden than many other conditions, including cancer, diabetes and chronic lung disease. With a growing elderly population causing the prevalence of CSM to rise (3), the average age of a CSM patient is 57 (2), this study has made the important point that the condition is affecting an increasing number of people and to a greater extent than many better known diseases.
With this in mind, it is only fair to say that CSM deserves to receive a far larger share of medical attention than it does at present.
1. Al-Tamimi YZ, Guilfoyle M, Seeley H, Laing RJ. Measurement of long-term outcome in patients with cervical spondylotic myelopathy treated surgically. Eur Spine J . 2013 Nov;22(11):2552–7.
2. Oh T, Lafage R, Lafage V, Protopsaltis T, Challier V, Shaffrey C, et al. Comparing Quality of Life in Cervical Spondylotic Myelopathy with Other Chronic Debilitating Diseases Using the SF-36 Survey. World Neurosurg. 2017 Jan 5;
3. Wang MC, Kreuter W, Wolfla CE, Maiman DJ, Deyo RA. Trends and variations in cervical spine surgery in the United States: Medicare beneficiaries, 1992 to 2005. Spine. 2009 Apr 20;34(9):955-961-963.
This group followed up 135 patients with CSM, of which some patients underwent surgery and some did not. They found that the blood pressure of patients undergoing surgery improved (lowered) after surgery, whereas those who did not, remained the same.
You of course might say, well 'stress and pain' are a result of CSM, surely if they improve after surgery, my blood pressure will go down? Well the group measured pain, and found that the improvement of blood pressure did not relate to pain, but instead severity of CSM...
This puts the cat amongst the pigeons. Why should CSM cause high blood pressure?
That remains an unanswered question. This study did not measure stress, additionally some limitations in the study, particularly the number of patients, may have hidden a relationship with pain.
However there is some theory to the idea that CSM could affect your blood pressure. Control of blood pressure is naturally dependent on many things. Partly it relies on some very small nerve fibres called your 'Sympathetic Nervous System'. Although this nervous system is separate to your spinal cord, there is some communication which could be potentially disrupted in CSM. If we look at patients who have a traumatic spinal cord injury, their blood pressure is often unstable as a result. So there could be something more to this than simply pain or stress! We will have to watch this space! But be prepared to reduce your blood pressure medication after surgery if that is applicable.
We are committed to raising awareness of CSM. We have been working with Cambridge TV to produce a documentary about the condition. This includes interviews from patients at the September CSM day, hosted at the University of Cambridge. Part 1 aired a few weeks ago, but now Part 2 is ready for viewing. Thanks to all at Cambridge TV for putting together this excellent summary of the disease, its impact and the future of treatment. Hope you enjoy. Let us know what you think!
As we have been reiterating throughout this blog, CSM is massively under-recognised. We are working to raise the profile of the disease, and have been very grateful for the support of Cambridge TV who have made a 2-part documentary about the disease. See part 1 here. This includes interviews of patients and their supporters from our CSM Day at the University of Cambridge
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