[Morphometry of the normal cadaveric cervical spinal cord]

We measured the cross-sectional area and diameters of the C7 segment in 80 cadaveric specimens obtained from patients without spinal cord lesions died at 60 to 79 years of age. We found considerable individual variation in the spinal cord size. The transverse area of the C7 segment varied from 33.3 mm2 to 67.7 mm2 (mean 48.4 +/- 6.9 mm2). The size of the cord had no correlation with body weight, and had some correlation with body height. But the individual variation in the cord size was considerably large even among the cases of the same height. This large variation in the cord size should be under consideration in morphometric analysis of the spinal cord. We showed the morphometric data based on the measurements of the cross-sectional area and diameters in each segment from C2 to Th1 in 14 cases. Although the size of the spinal cord varied markedly from case to case, the relative ratio of cross-sectional area in each segment to that of C3 was similar among the cases (C2; 1.01 +/- 0.04, C4; 1.02 +/- 0.03, C5; 1.09 +/- 0.04, C6; 1.09 +/- 0.06, C7; 1.07 +/- 0.06, C8; 0.98 +/- 0.05. Th1; 0.80 +/- 0.04). Based on our data, the proper cross-sectional area of each segment and of each individual may be calculable from measurement of a given single segment.