Utility of Flexion-extension MRI to Reveal Occult Cervical Spondylotic Compression in Those with Suspected Inflammatory or Undifferentiated Myelopathies

ObjectiveTo describe the utility of flexion-extension MRI in inflammatory and undifferentiated myelopathies with spinal cord T2-hyperintensity. BackgroundCervical spondylotic myelopathy can be misdiagnosed as inflammatory myelitis leading to unnecessary immunotherapy and delayed definitive surgical treatment. Design/MethodsMayo Clinic patients were identified retrospectively from 12/31/2012-10/24/2023. Inclusion criteria were: 1) Age ≥18 years; 2) Myelopathy; 3) Flexion-extension cervical spine MRI available; 4) Spinal cord T2-hyperintensity on MRI. ResultsNinety patients that underwent flexion-extension MRI were included, and the median age was 58 years (range, 30-81) with 47 (52%) of male sex. Cervical spondylotic myelopathy was the final diagnosis in 65 (85% had insidious onset; 12% had accompanying reverse Lhermitte’s phenomenon). In 55/65 (85%) the diagnosis of cervical spondylotic myelopathy was aided by evidence of increased cord compression during flexion-extension MRI (worse in extension, 47[85%]; worse in flexion, 4[7.5%]; both, 4[7.5%]). In 3/58 (5%) patients, positional cord compression occurred on Flexion-Extension MRI, but an alternative cause of myelopathy was found (Multiple sclerosis, 2; progressive lateral sclerosis, 1). Prior to the Flexion-Extension MRI being undertaken, 26/65 (40%) with cervical spondylotic myelopathy were initially assigned alternative diagnoses and 19 (29%) received immunotherapy for presumed inflammatory myelitis. The median delay to diagnosis in these patients was 15 months (range, 0.5-155). The median length of cord T2-hyperintensity on sagittal sequences was 1 vertebral segment (range, 1-5) and 33/53 (62%) had accompanying enhancement. In 46/65 (71%) decompressive surgery was undertaken at Mayo Clinic and 29/46 (63%) reported improvement, 14/46 (30%) noted stability and 3/46 (6%) worsened. ConclusionsCervical spondylotic myelopathy with spinal cord T2-hyperintensity was frequently misdiagnosed as myelitis in this series often leading to unnecessary immunotherapy and delayed definitive treatment. Flexion-Extension MRI is a straightforward MRI technique which can show positional cord compression and allow more rapid diagnosis and earlier treatment of unrecognized cervical spondylotic myelopathy.