Abstract
BACKGROUND AND OBJECTIVES: In cervical spondylotic myelopathy (CSM), compression may not be evident in the neutral position, potentially leading to misdiagnosis and delayed treatment. We sought to assess the utility of flexion-extension MRI in revealing occult spondylotic compression in undifferentiated myelopathies with spinal cord T2 hyperintensity. METHODS: Adult patients with clinical myelopathy and cervical spinal cord T2 hyperintensities who had undergone flexion-extension cervical spine MRI over a >10-year period (December 31, 2012, to October 24, 2023) were retrospectively identified. Demographic, clinical, and radiologic data were collected and analyzed. RESULTS: Ninety patients who underwent flexion-extension MRI for possible CSM were identified. The median age was 58 years (range, 30-81), with 47 of 90 patients (52%) being male. CSM was the final diagnosis in 65 (85% had insidious onset; 12% had reverse Lhermitte phenomenon). Before flexion-extension MRI, 39 of 65 with CSM had an initially uncertain diagnosis and 26 of 65 (40%) were initially given alternative diagnoses, including 19 of 65 (29%) who received immunotherapy and one who underwent spinal cord biopsy. The median delay to diagnosis in these patients was 15 months (range, 0.5-155). Positional compression on flexion-extension MRI at sites of T2 signal hyperintensity was more likely with a final diagnosis of CSM (55/65 [85%]) than with an alternative myelopathy etiology (3/25 [12%]: multiple sclerosis, 2; progressive lateral sclerosis, 1) (p < 0.0001). The odds ratio for CSM in the presence of positional cord compression was 40.3 (95% CI 10.58-137.4; Fisher exact test p < 0.0001). The dynamic changes noted in CSM during flexion-extension MRI included the following: worse in extension, 47 (85%); worse in flexion, 4 (7.5%); worse in both, 4 (7.5%). Decompressive surgery was completed at Mayo Clinic in 46 of 65 patients with CSM (71%). Most reported symptomatic improvement alone (29/43, 67%), nearly a quarter (10/43, 23%) reported improvement in some symptoms but worsening of others, a minority (4/43, 9%) noted only symptom stability, and none described worsening alone (0/43, 0%); 3 were lost to follow-up. DISCUSSION: Flexion-extension MRI is a cost-effective, accessible technique that can reveal occult CSM or provide clarity when the diagnosis is uncertain, and its use may reduce misdiagnosis and allow earlier treatment of unrecognized CSM.