Cervical spinal cord--smaller than considered?

ABSTRACT

STUDY DESIGN: One hundred two patients with symptoms of cervical radiculopathy, were retrospectively analyzed and their cervical spinal cord diameters obtained. OBJECTIVES: To measure the cervical spinal cord in vivo and to compare the findings with those previously reported in the literature. SUMMARY OF BACKGROUND DATA Traditionally, autopsy data have served as the linchpin of cervical cord measurements. However, several studies obtained by realtime radiographic methods have failed to confirm such measurements. METHODS: The spinal cord was retrospectively measured in 102 patients. All patients underwent myelogram and postmyelogram computed tomographic scan. Anteroposterior and transverse diameters of the spinal cord were measured from C2 to T1 at the level of each intervertebral disc. The depth of the anterior median fissure and cross-sectional area were measured as well. Plain myelographic films were reviewed but demonstrated no findings contrary to postmyelogram computed tomographic measurements. RESULTS: There was no statistically significant difference in the spinal cord measurements in relation to age or sex. There was an increase in the transverse diameter but not in the anteroposterior diameter in the midcervical spinal enlargement. The anteroposterior diameter decreased linearly. The transverse diameter and the cross-sectional area increased to a maximum at C5, as did the depth of the anterior median fissure. The cervical spinal cord diameter was documented to be 15-20% smaller than has commonly been determined by autopsy data. CONCLUSIONS: Postmyelogram computed tomographic measurements are smaller than those obtained from autopsy data.