Use of Flexion-Extension MRI to Reveal Occult Spondylotic Compression in Undifferentiated Cervical Myelopathies With...

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.

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.

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.

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.