Schematic representation of the six-point epidural spinal cord compression scale (ESCC) grading scale. A grade of 0 indicates bone-only disease; 1a, epidural impingement, without deformation of the thecal sac; 1b, deformation of the thecal sac, with spinal cord abutment; 1c, deformation of the thecal sac with spinal cord abutment, but without cord compression. 2, Spinal cord compression, but with CSF visible around the cord. 3, Spinal cord compression, with cerebral spinal fluid (CSF) visible around the cord.