Fig. 1

Cervical spine MRI images (Patient 1). a The sagittal cervical cord MRI image showed a clivo-axial angle of 118°, as well as a broad right paracentral disc bulge at C6–7 causing mild cord compression and canal stenosis, with an antero-posterior (AP) cervical canal diameter of 6 mm at that level. The cervical canal diameter from C3 to C7 was congenitally narrow at 8 mm. b A transverse image at C5–6. c A transverse image at C6–7 illustrating the site of cord compression