Mbaba AN, Ogolodom MP*, Abam R, Ijeruh OY, Okpaleke MS, Maduka BU, Iwuagwu OC
Background: A wide range of variation in the termination of the spinal cord in normal adult population has been observed. Studies abound in foreign literature on the termination of the spinal cord but there is dearth of data concerning this subject in our environment. A good knowledge of the normal level of termination of the conus medullaris in our setting is imperative in every day medical practice.
Aim of the study: To determine the vertebral levels of termination of the spinal cord in living adult population in Port Harcourt Metropolis, Rivers State, Nigeria using MRI and to compare findings with previous similar studies.
Materials and Methods: A retrospective cross-sectional design was adopted in this study and was conducted in a single radio-diagnostic center with MRI scanner in Port Harcourt metropolis, Rivers State, Nigeria. Ethical approval was obtained from the Research Review Committee Board of the study center and the retrieved data were treated with utmost confidentiality and used for the purpose of this study only. Both T1W and T2W mid sagittal, spin-echo MR images were analyzed. The terminations of the conus medullaris were identified on sagittal images and were defined as the most distal point of the cord that could be visualized on the sagittal image. A line perpendicular to the long axis of the cord was drawn and extended to the adjacent vertebra. This location was recorded in relation to the upper, middle, or lower third of the adjacent vertebral body or the adjacent intervertebral disc. The obtained data were analyzed using SPSS version 22.
Results: Out of the 177 study population, greater numbers of the spinal cords terminated at middle third of L1 74 (males: 35 (36.47%) and females: 39 (48.75%)) as highest and the least terminated at the L3U, which is 1 (male: 1 (1.04%). Maximum numbers of the cases were within the age group 46-55 years old, 54 (Middle third of L1=29 (16.38%, upper third of L2=6 (3.39%) and lower third of L2=4 (2.26%) and the least were within the age group 15-25 years, which is 6 (middle third of L1=3 (1.69%), middle third of L2=I (1.04%) and T12/L1 disc=1 (1.04%)).
Conclusion: The average level of termination of the spinal cord in our study is at the middle third of L1 vertebral body. No gender difference in spinal cord termination. It is hoped that the finding of this study will serve as a useful guide for medical practitioners in our setting.