Analysis of the Relationship Between the Epidural Spinal Cord Compression (ESCC) Scale and Paralysis Caused by Metastatic Spine Tumors

STUDY DESIGN. A retrospective, single-institute, and radiographic study. OBJECTIVE. To evaluate the relationship between the epidural spinal cord compression (ESCC) scale and the severity of metastatic spine tumor–induced paralysis. SUMMARY OF BACKGROUND DATA. The ESCC scale is used to evaluate the grade of spinal cord compression on T2-weighted magnetic resonance imaging (MRI). However, few studies have investigated the relationship between such MRI findings and paralysis. METHODS. The subjects were 467 patients with metastatic spine tumors and grade 1b or worse spinal cord compression according to the ESCC scale. Evaluations using this scale were performed by three spine surgeons, and results that were obtained by two or more surgeons were adopted. We also examined patients whose spinal cord compression deteriorated by one grade or more to American Spinal Injury Association (ASIA) grade C or worse within the first 3 weeks after MRI. RESULTS. The kappa coefficients for inter- and intraexaminer variability were 0.90 and 0.95, respectively. ASIA grade D or worse paralysis developed in at least 50% of the patients with ESCC grade 1b or worse spinal cord compression at the C1-T2 and at least 50% of those with ESCC grade 1c or worse spinal cord compression at the T3-L5. The frequency of ASIA grade C or worse paralysis was high among the patients with ESCC grade 2 or worse spinal cord compression at the C7-L1. Nineteen patients experienced rapid deterioration of one grade or more to ASIA grade C or worse paralysis within the first 3 weeks after MRI. Of these, paralysis occurred in at least 30% of the patients with anterolateral or circumferential cord compression combined with ESCC grade 2 or 3 compression at the C7-L1. CONCLUSION. The severity of paralysis was not correlated with the ESCC scale. Patients with anterolateral or circumferential ESCC grade 2 or 3 cord compression at the C7-L1 are at high risk of rapidly progressive paralysis. Level of Evidence: 4