Study design: The authors measured the transverse area and diameters of the cadaveric cervical spinal without evidence of nervous system pathology and also investigated factors related to spinal cord size.
Objectives: This study attempted to provide basic data that affords an accurate morphometric analysis of the human cervical spinal cord.
Summary of background data: Several postmortem morphometric studies of the spinal cord have been performed, but the measurements are different among the reports, and no authorized standard has been established.
Methods: The authors measured the transverse area and diameters of the C7 segment in 152 cadaveric specimens and investigated the cord size in relation to age, body height, body weight, and brain weight. Of these, 14 cases were selected and their segments from C2 to T1 were measured.
Results: There was a considerable individual variation in spinal cord size. The transverse area of the C7 segment varied from 33.3 mm2 to 74.0 mm2 (mean 49.6 +/- 7.4 mm2). The cord size showed a strong correlation with brain weight, and to a lesser degree with age and body height. Although the size of the spinal cord varied from case to case, the relative ratio of the transverse area of each segment to that of the C3 segment was almost the same among the cases examined.
Conclusions: This large variation in cord size should be taken under consideration in morphometric analyses of the spinal cord. When the pathologic cord conditions such as compression or atrophy exist, the normally expected transverse area of the affected segment in each individual is calculable from measurement of a given single normal segment.