Extensive high signal intensity area on T2-weighted MRI in the spinal cord is associated with spinal segment instability and potentially worse clinical outcomes in patients with cervical spondylotic myelopathy.

Background: Patients with cervical spondylotic myelopathy often have increased signal intensity area (ISI) in the spinal cord on T2-weighted magnetic resonance imaging. The ISI is usually located at the level of the spinal cord compression, most often at the intervertebral segments, but in some patients, it extends to the level of the adjacent vertebral body. The purpose of this study was to elucidate the clinical characteristics associated with extensive ISI in the spinal cord and its potential impact on surgical outcomes.

Methods: Patients with cervical spondylotic myelopathy who underwent posterior decompression surgery at our hospital from 2015 to 2021 were included in this study. ISI was found in 65 patients in a total of 78 intervertebral segments. Patients were divided into two groups according to the extent of ISI; the intervertebral disc group (D group; 34 patients, 44 %) and the vertebral body group (B group; 44 patients, 56 %), each consisting of patients with ISI within or beyond the intervertebral disc level. Radiographic and clinical parameters were analyzed and compared between the two groups.

Results: A greater degree of C2-7 lordosis (p = 0.01), higher percentage of intervertebral segments with instability (p = 0.04), and longer symptom duration (p = 0.001) were significantly associated with the B group. Although the differences did not reach statistical significance, the percentage of intervertebral segments with spondylolisthesis was higher (p = 0.08) and the JOA recovery rate was lower (p = 0.11) in the B group compared to the D group.

Conclusions: Patients with cervical spondylotic myelopathy who have extensive ISI are associated with spinal segment instability, prolonged symptom duration, and potentially worse surgical outcomes.