An award-winning approach to timely diagnosis of degenerative cervical myelopathy—and why it matters


Blog Fehlings DCM

Although degenerative cervical myelopathy (DCM) is the leading cause of spinal cord impairment in adults, the condition is relatively little-known among the general public. It is also frequently misdiagnosed by medical professionals. In order to facilitate earlier surgical intervention where needed, Dr Michael Fehlings, Dr Lindsay Tetreault, and study team are proposing a new step-wise approach to diagnosing DCM. The paper has been named winner of the Best Paper 2022 Award from the Global Spine Journal (GSJ), which will be awarded at the forthcoming Global Spine Congress in Prague. Here, Fehlings outlines why DCM should be among the top public healthcare priorities globally.

Degenerative cervical myelopathy (DCM) is a condition under which the cervical spinal cord is subjected to progressive compression as patients get older. As a result of age-related changes to the spine the spinal canal narrows, leading to a reduction of the space available for the spinal cord. This in turn can subject the neural tracts to increasing amounts of pressure.

The symptoms caused by DCM are manyfold and can have significant negative effects on quality of life. Apart from numbness in both hands, paresthesia, and gait impairment they can also include motor weakness of the upper and lower extremities as well as bladder and bowel dysfunction.

According to figures collated by my colleagues Mark Kotter and Benjamin Davies as part of the AO Spine RECODE-DCM project, DCM currently affects up to three percent of adults around the world. However, shifting demographics and aging populations, especially in high income countries, mean that we can expect a substantial increase over the coming years in the proportion of patients aged 50 and above who suffer from musculoskeletal conditions.

Among these, DCM is the most serious, making it one of the most pressing issues we’re currently facing from a public health perspective. In fact, the RECODE-DCM project is campaigning for DCM to be categorized as a specific disease entity by the International Classification of Diseases (ICD) in recognition of the fact that it is of particular importance for public health.

Early intervention is key in Degenerative Cervical Myelopathy

However, awareness, both among the general public as well as among most medical professionals, of DCM is relatively low. That’s not to say that the condition can’t be treated very well once properly identified. Good diagnostic tests as well as safe and effective treatment methods are readily available.

In fact, patients who undergo surgery will improve by an average two points on the modified Japanese Orthopaedic Association (mJOA) scale, which is used to grade the severity of DCM. mJOA scores between 15 and 17 represent mild cases of myelopathy, while scores between 12 and 14 represent moderate cases. A score of between 0 and 11 represents severe DCM. An improvement of two points can therefore mean a significant improvement.

While many patients with milder forms of DCM may not actually require surgery, it is still imperative that the condition is diagnosed promptly. As early intervention prevents further deterioration, this is especially true for patients within the moderate spectrum on the mJOA scale, who are most at risk for further decline. Indeed, in cases where surgery is required, intervention will lead to improvement in approximately four out of five patients.

The problem is that DCM is difficult to diagnose for a number of reasons. Firstly, the symptoms are by no means similar in every patient. Pain, for example, is a common indicator. However, around 50 percent of DCM patients do not report any pain at all—which of course doesn’t mean that there isn’t a problem. In other cases, pain can become so pronounced that it masks other symptoms: some patients focus on their DCM-induced neck pain so much that they remain unaware of other developing issues such as gait impairment or dysfunction of the hands.
DCM-induced symptoms are also frequently ascribed to other conditions. For example, a tingling sensation or numbness in both hands can often be a tell-tale sign for DCM. But these symptoms are regularly ascribed by physicians to carpal tunnel syndrome, potentially delaying a correct diagnosis by months or even years. Other conditions with symptoms similar to those of DCM include amyotrophic lateral sclerosis (ALS), peripheral nerve entrapment, and vitamin B12 deficiency.

New stepwise method speeds up diagnosis of DCM

The good news is that better diagnoses and earlier medical intervention aren’t very difficult to facilitate. One of the main prerequisites is a more systematic approach to diagnosing the condition. I am therefore proposing a step-by-step routine which every physician can apply when faced with potential cases of DCM.

The idea is to start with the basics and then gradually escalate the diagnostic process as required. For example, a detailed patient history will in many cases yield initial hints that point to DCM. The next step would be a series of open-ended and myelopathy-specific questions, in combination with a few easy tests that can be performed within minutes by any physician. These include an assessment of the patient’s gait as well as the Hoffman test, a simple identifier of possible issues with the cervical cord. A more comprehensive physical examination should also be performed.

If these measures support the suspicion that a patient may indeed be suffering from DCM, then appropriate tests can be ordered to rule in or out other diagnoses. These include imaging of the cervical spinal axis and cord through radiography, computed tomography (CT) or magnetic resonance imaging (MRI). Other advanced imaging techniques as well as electrophysiological tests can also be used to diagnose patients with DCM.

We need to spread the word of DCM

The other critical element in regard to correctly diagnosing more DCM patients is to increase everybody’s knowledge on the subject. In fact, the RECODE-DCM project has named raising awareness of DCM—both among healthcare professionals and among the general public—as its main research priority for the future. We simply need to spread the word, and not just among orthopedic specialists and neurosurgeons. We also urgently need to educate other specialists as well as family physicians and caregivers about the condition itself as well as the best ways of correctly diagnosing it. Our aim must be to reach those medical professionals who will regularly be the first point of contact for undiagnosed DCM patients.

The most important symptoms for heart attacks and strokes are common knowledge nowadays. Many lay people are aware of them and will react appropriately when faced with a patient displaying them. My aim would be for us as a society to reach a point where the same can be said for the most common DCM symptoms. If you hear a family member complaining about numbness in their hands, or if you notice a friend walking less steadily than the last time you saw them, then, in an ideal world, DCM should be among the first things you think about as a possible cause.

Read the awarded paper:

Tetreault L, Kalsi-Ryan S, Benjamin Davies, et al. Degenerative Cervical Myelopathy: A Practical Approach to Diagnosis. Global Spine Journal. 2022;12(8):1881-1893. doi:10.1177/21925682211072847

About the author:

Professor Michael G Fehlings, PhD, MD, FACS, FRCSC, is a Professor of Neurosurgery at the University of Toronto. He is the Vice Chair Research in the Department of Surgery, Co-Director of the University of Toronto Spine Program, holds the Robert Campeau Foundation / Dr. C.H. Tator Chair in Brain and Spinal Cord Research at the University Health Network, is a Scientist at the McEwen Centre for Regenerative Medicine, and a Senior Scientist at the Krembil Brain Institute. His main clinical interests are in spinal neurosurgery, and his research focus is on molecular mechanisms underlying spinal cord injury. Michael Fehlings is a Steering Committee member of the AO Spine Knowledge Forum Spinal Cord Injury and Chairperson of the AO ITC Clinical Science Advisory Commission.

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The articles included in the AO Spine Blog represent the opinion of individual authors exclusively and not necessarily the opinion of AO Spine or AO Foundation.