Priority 2 from the Degenerative Cervical Myelopathy PSP

UNCERTAINTY: What is the natural history of DCM? What is the relationship between DCM and asymptomatic spinal cord compression or canal stenosis? What factors influence the natural history of the disease?  (JLA PSP Priority 2)
Overall ranking 2
JLA question ID 0097/2
Explanatory note The pattern of progression in DCM is highly variable and not well defined. In a systematic review by Karadimas et al (2013), moderate evidence suggested that 20% to 62% of patients deteriorate by at least 1 point on the Japanese Orthopedic Association scale at 3 to 6 years after initial assessment. This conclusion was largely based on longitudinal nonsurgical cohorts and studies comparing operative versus nonoperative management. This systematic review also evaluated risk factors associated with disease progression. There was low to insufficient evidence on this topic, preventing the development of meaningful recommendations. In a systematic review by Wilson et al (2013), low evidence suggested that, in non-myelopathic patients with cervical canal stenosis and cord compression, approximately 8% at 1-year and 23% at a 44-months will develop clinical evidence of myelopathy. Important predictors of the onset of DCM included presence of symptomatic radiculopathy, prolonged SEPs and MEPs and EMG signs of anterior horn cell lesion (low to moderate evidence). There was no consensus with respect to the presence of T2 signal changes on magnetic resonance imaging. Further studies are required to better define the natural history of DCM and relevant predictors of disease development and progression. 

Systematic reviews on the topic rated the level of evidence as low to moderate.
Tetreault LA, Karadimas S, Wilson JR, Arnold PM, Kurpad S, Dettori JR, Fehlings MG. The Natural History of Degenerative Cervical Myelopathy and the Rate of Hospitalization Following Spinal Cord Injury: An Updated Systematic Review. Global Spine J. 2017 Sep;7(3 Suppl):28S-34S.
Karadimas SK, Erwin WM, Ely CG, Dettori JR, Fehlings MG. Pathophysiology and natural history of cervical spondylotic myelopathy. Spine (Phila Pa 1976). 2013 Oct 15;38(22 Suppl 1):S21-36.
Wilson JR, Barry S, Fischer DJ, Skelly AC, Arnold PM, Riew KD, Shaffrey CI, Traynelis VC, Fehlings MG. Frequency, timing, and predictors of neurological dysfunction in the nonmyelopathic patient with cervical spinal cord compression, canal stenosis, and/or ossification of the posterior longitudinal ligament. Spine (Phila Pa 1976). 2013 Oct 15;38(22 Suppl 1):S37-54.
Fehlings MG, Tetreault LA, Riew KD, Middleton JW, Aarabi B, Arnold PM, Brodke DS, Burns AS, Carette S, Chen R, Chiba K, Dettori JR, Furlan JC, Harrop JS, Holly LT, Kalsi-Ryan S, Kotter M, Kwon BK, Martin AR, Milligan J, Nakashima H, Nagoshi N, Rhee J, Singh A, Skelly AC, Sodhi S, Wilson JR, Yee A, Wang JC. A Clinical Practice Guideline for the Management of Patients With Degenerative Cervical Myelopathy: Recommendations for Patients With Mild, Moderate, and Severe Disease and Nonmyelopathic Patients With Evidence of Cord Compression. Global Spine J. 2017 Sep;7(3 Suppl):70S-83S.

Health Research Classification System category
Extra information provided by this PSP
Original uncertainty examples

What is the natural history of DCM without surgical intervention?  ~ Is it reversible? ~ What proportion with asymptomatic cervical cord compression develops DCM? Why do some asymptomatic cervical cord compressions never develop DCM? ~ What are the outcomes of unsymptomatic stenosis? ~ How long is the neurological plateau after an exacerbation of DCM? ~ What is the rate of deterioration with patients with DCM?

Submitted by Spinal Surgeons x 44, Other healthcare professionals x 15, People with DCM and their supporters x 11 
PSP information
PSP unique ID 0097
PSP name Degenerative Cervical Myelopathy
Total number of uncertainties identified by this PSP. 76  (To see a full list of all uncertainties identified, please see the detailed spreadsheet held on the JLA website)
Date of priority setting workshop 20 November 2019