Study Design. Systematic review.
Objective. To determine whether there are magnetic resonance imaging (MRI) characteristics in patients with cervical spondylotic myelopathy that affect treatment decisions or predict postsurgical outcomes or adverse events.
Summary of Background Data. Although the role of MRI in confirming the clinical diagnosis of cervical spondylotic myelopathy and directing surgical management is well established, its potential value as a prognostic tool is largely unknown.
Methods. A systematic search was conducted using PubMed and the Cochrane Collaboration Library for articles published between January 1, 1956, and November 20, 2012. The overall body of evidence with respect to each clinical question was determined on the basis of precepts outlined by the Grading of Recommendation Assessment, Development and Evaluation Working Group and recommendations made by the Agency for Healthcare Research and Quality.
Results. The initial search yielded 268 citations. Twenty publications met all inclusion criteria and were included in the review. Three of these assessed MRI predictors of clinical deterioration in the case of conservative treatment and 17 evaluated MRI anatomic or cord characteristics that could predict surgical outcome or adverse events. There is low evidence suggesting that a high signal intensity (SI) grade on T2WI is not associated with patient deterioration during conservative treatment. High SI grade on T2WI, along with compression ratio and canal diameter, was not an important predictor of outcome. There is low evidence identifying number of high SI segments on T2WI, low SI segments on T1WI, combined T1/T2 SI, and SI ratio as important negative predictors of surgical outcome.
Conclusion. On the basis of this review and on low-quality evidence, we have identified 3 important negative predictors of surgical outcome: number of high SI segments on T2WI, combined T1/T2 signal change, and SI ratio.
Evidence-Based Clinical Recommendations.
Recommendation 1. We suggest that when clinically feasible, surgeons rely on MRI to confirm the diagnosis of CSM and rely on clinical history and examination to determine progression and severity of disease.
Overall Strength of Evidence. Low
Strength of Recommendation. Weak
Recommendation 2. T2 signal may be a useful prognostic indicator when used in combination with low SI change on T1WI, or as a ratio comparing compressed with noncompressed segments, or as a ratio of T2 compared with T1WI. We suggest that if surgeons use MRI signal intensity to estimate the risk of a poor outcome after surgery, they use high SI change on T2WI in combination with other signal intensity parameters, and not in isolation.
Overall Strength of Evidence: Low
Strength of Recommendation: Weak
This systematic review identifies magnetic resonance imaging characteristics that affect treatment decisions or predict surgical outcomes. A high signal intensity (SI) grade on T2WI was not associated with patient deterioration during conservative treatment. A combined T1 T2 signal change, SI ratio, and a greater number of SI segments on T2WI were found to be negatively associated with outcome.
*University of Toronto, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
† Spectrum Research, Inc., Tacoma, WA
‡Divisions of Neurosurgery and Orthopedic Surgery, Spinal Program, University of Toronto, Toronto, Ontario, Canada
§Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
¶Institute of Medical Science, University of Toronto, Division of Neurosurgery, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada
‖Division of Neurosurgery and Spinal Program Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada; and
**Calgary Spine Program, Foothills Medical Centre, Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada.
Address correspondence and reprint requests to Michael G. Fehlings, MD, PhD, FRCSC, Toronto Western Hospital, Room 4W-449, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; E-mail: Michael.Fehlings@uhn.on.ca
Acknowledgment date: March 4, 2013. First revision date: May 13, 2013. Acceptance date: July 15, 2013.
The manuscript submitted does not contain information about medical device(s)/drug(s).
Supported by AOSpine North America, Inc. Analytic support for this work was provided by Spectrum Research, Inc., with funding from the AOSpine North America.
Relevant financial activities outside the submitted work: support for travel to meetings for the study or other purposes, fees for participation in review activities such as data monitoring boards, statistical analysis, end point committees, and the like, and payment for writing or reviewing the manuscript.