The value of preoperative magnetic resonance imaging in predicting postoperative recovery in patients with cervical spondylosis myelopathy: a meta-analysis

The imaging of cervical spondylotic myeloradiculopathy

This review provides a detailed description of the imaging features of cervical spondylotic myelopathy and radiculopathy, with a focus on MRI. Where relevant, we will outline grading systems of vertebral central canal and foraminal stenosis. Whilst post-operative appearances of the cervical spine are outside the scope of this paper, we will touch on imaging features recognised as predictors of clinical outcome and neurological recovery. This paper will serve as a reference for both radiologists and clinicians involved in the care of patients with cervical spondylotic myeloradiculopathy.

The Natural History of Degenerative Cervical Myelopathy

Degenerative cervical myelopathy (DCM) is the most frequent cause of spinal cord dysfunction and injury in the adult population and leads to significant loss of quality of life and economic impact from its associated medical care expenditures and loss of work. Surgical intervention is recommended for patients manifesting progressing neurological signs and symptoms of myelopathy, but the optimal management in individuals who have mild and clinically stable disease manifestations is controversial. Understanding the natural history of DCM is, thus, important in assessing patients and identifying those most appropriately indicated for surgical management. Despite the attempts to rigorously perform studies of the natural history of these patients, most published investigations suffer from methodological weaknesses or are underpowered to provide definitive answers. Investigations of particular patient subsets, however, provide some clinical guidance as to which patients stand most to benefit from surgery, and these may include those with lower baseline mJOA scores, evidence of segmental hypermobility, cord signal changes on MRI, abnormal somatosensory or motor-evoked potentials, or the presence of certain inflammatory markers. Clinicians should assess patients with mild myelopathy and those harboring asymptomatic cervical spinal cord compression individually when making treatment decisions and an understanding of the various factors that may influence natural history may aid in identifying those best indicated for surgery. Further investigations will likely identify how variables that affect natural history can be used in devising more precise treatment algorithms.

Preoperative T1 magnetic resonance imaging changes carry a poor postoperative prognosis in cervical myelopathy: A retrospective study of 182 patients

Background:

T2 scans are widely used to determine the prognosis for patients undergoing surgery for cervical myelopathy. In this study, we determined whether T1 MR changes in addition to T2 MR changes could have prognostic importance.

Methods:

This retrospective analysis involved 182 patients undergoing surgery for cervical myelopathy (2017–2020). There were 110 patients in Group 1 (only T2 MR changes) and 72 in Group 2 (both T1 and T2 MR changes). In addition, demographic, visual analog score (VAS), modified Japanese Orthopaedic Association (mJOA) scores, and operative details were recorded at 1 month, 3 months, 6 months, and 1 year postoperatively.

Results:

Notably, VAS scores were comparable at each point in time and were significantly better than the preoperative scores at 1 year postoperatively. Although mJOA scores were comparable at 1 month in both groups, they were better thereafter for Group 1 patients.

Conclusion:

The presence of T1 changes on the preoperative magnetic resonance imaging represented a poor prognostic indicator for the postoperative outcome compared to the presence of T2 changes alone.

ACR Appropriateness Criteria® Myelopathy: 2021 Update

Myelopathy is a clinical diagnosis with localization of the neurological findings to the spinal cord, rather than the brain or the peripheral nervous system, and then to a particular segment of the spinal cord. Myelopathy can be the result of primary intrinsic disorders of the spinal cord or from secondary conditions, which result in extrinsic compression of the spinal cord. While the causes of myelopathy may be multiple, the acuity of presentation and symptom onset frame a practical approach to the differential diagnosis. Imaging plays a crucial role in the evaluation of myelopathy with MRI the preferred modality. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

High cord signals on magnetic resonance and other factors predict poor outcomes of cervical spine surgery: A review

Background:

High cord signals (HCS) on preoperative/postoperative T1, T1 gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA), and T2 magnetic resonance (MR) studies, postoperative failure of HCS to regress and/or cord re-expansion, and a triangular cord configuration are poor prognostic factors for surgical patients with cervical spondylotic myelopathy (CSM).

Methods:

Here, we reviewed the negative prognostic import of high Grades/Types and more extensive locations of preoperative/postoperative HCS on T1, T1 Gd-DTPA, and T2 MR studies in surgical patients with CSM. Additional predictors of poor operative outcomes included postoperative failure of HCS to regress, cord re-expansion at the site of a HCS, and the triangular vs. teardrop or boomerang cord configuration. The Types/Grades of HCS on MR follow:Type/Grade 0 – no/absent signal changes; Type/Grade 1 – mild/light/fuzzy/obscure/low cord signal (LCS) changes; Type/Grade 2 – sharp/intense/well-defined HCS; and Type/Grade 3 – mixed/HCS. The definitions of location/extent of LCS/HCS were: focal (1 level), multifocal (with skip areas), and multisegmental (continuous over >1 segment), while cord configuration was categorized as triangular, teardrop, or boomerang.

Results:

On MR studies, preoperative/postoperative Types/Grades 0–1 changes correlated with better prognoses (e.g., improved Japanese Orthopedic Association (JOA) scores or Nurick Grades), while Types/Grades 2–3 correlated with poorer outcomes. Multiple poor prognostic indicators also included; failure of postoperative HCS on MR to regress (particularly if multisegmental), postoperative cord re-expansion at the site of a prior HCS, and triangular cord configuration.

Conclusions:

Grade/Types 2–3 HCS on T1, T1 Gd-DTPA, and T2-weighted MR images on preoperative/postoperative MR studies, failure of HCS to regress (multisegmental), cord re-expansion at the site of a prior HCS, and a triangular cord configuration (atrophy) all contributed to poorer outcomes for CSM surgery.

The Relationship Between MRI Signal Intensity Changes, Clinical Presentation, and Surgical Outcome in Degenerative Cervical Myelopathy: Analysis of a Global Cohort

STUDY DESIGN

Retrospective analysis of prospective data.

OBJECTIVE

To assess the relationship between MRI signal intensity changes, clinical presentation, and surgical outcome in degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

Several studies have sought to assess the extent of spinal cord dysfunction and the potential for postoperative neurological recovery through the evaluation of spinal cord signal change on T2-weighted (T2WI) and T1-weighted images (T1WI). There remains ambiguity if T2WI and T1WI signal changes (1) relate to baseline severity, and (2) predict neurological recovery after surgical treatment.

METHODS

Four hundred nineteen MRIs from two prospective multicenter studies were examined. Images were assessed for the presence, levels, and location of spinal cord signal intensity changes and compared with clinical data. Signal changes were also evaluated for the prediction of 2-year postoperative outcome using mJOA parameters.

RESULTS

MRIs were categorized by T1WI and T2WI signal change: no signal change (28.9%), T2WI hyperintensity-only (T2WI-only, 51.8%), and T2WI-hyperintensity and T1WI-hypointensity (T1WI+T2WI, 19.3%). T2WI-hyperintensity was present at multiple levels in 27% of patients overall. Baseline severity increased from no signal change to T2WI-only to T2WI+T1WI (P < 0.0001), and there was an incremental increase in the frequency of signs/symptoms. There were no differences in outcomes between no signal change and T2WI-only groups. The presence of T1WI-hypointensity correlated with reduced recovery ratio (P = 0.03) and likelihood of an optimal surgical outcome (P = 0.005), adjusting for baseline mJOA. A greater number of T2WI-hyperintensity levels was also associated with worse baseline severity (P < 0.0001) and recovery ratio (P = 0.001).

CONCLUSION

This analysis of a global cohort of DCM patients shows a stepwise trend toward increasing impairment from no signal change to T2WI-hypertensity to T1WI-hypointensity. T1WI signal change indicates more permanent injury, portending decreased functional recovery. T2WI-hyperintensity alone does not predict outcomes. Multiple levels of T2WI-hyperintensity suggest additional tissue injury, correlating with worse clinical impairment and recovery potential.

LEVEL OF EVIDENCE

2.