Significance of the neurological level of injury as a prognostic predictor for motor complete cervical spinal cord injury patients

Abstract

Objective: To investigate the usefulness of the combination of neurological findings and magnetic resonance imaging (MRI) as a prognostic predictor in patients with motor complete cervical spinal cord injury (CSCI) in the acute phase.Design: A cross-sectional analysisSetting: Department of Orthopaedic Surgery, Spinal Injuries CenterParticipants/Methods: Forty-two patients with an initial diagnosis of motor complete CSCI (AIS A, n = 29; AIS B, n = 13) within 72 h after injury were classified into the recovery group (Group R) and the non-recovery group (Group N), based on the presence or absence of motor recovery (conversion from AIS A/B to C/D) at three months after injury, respectively. The Neurological Level of Injury (NLI) at the initial diagnosis was investigated and the presumptive primary injured segment of the spinal cord was inferred from MRI performed at the initial diagnosis. We investigated whether or not the difference between the presumptive primary injured segment and the NLI exceeded one segment. The presence of a difference between the presumptive primary injured segment and the NLI was compared between Groups R and N.Results: The number of cases with the differences between the presumptive primary injured segment and the NLI was significantly higher in Group N than in Group R.Conclusion: The presence of differences between the presumptive primary injured segment and the NLI might be a poor improving prognostic predictor for motor complete CSCI. The NLI may be useful for predicting the recovery potential of patients with motor complete CSCI when combined with the MRI findings.

Keywords: Ascending myelopathy; Cervical spinal cord injury; Motor complete spinal cord injury; Neurological level of injury; Prognostic predictor.

Figure 1

Case presentation: C6/7 skeletal level injury with NLI-gap. The presumptive primary injured segment was determined to be the C8 segment of the spinal cord, as the skeletal level of injury was C6/7, which is estimated to affect the C8 segment of the spinal cord. Given the neurological findings, the NLI was determined to be C5. Since the difference between the presumptive primary injured segment and the NLI exceeded one segment, this case was considered to have NLI-gap. If the NLI had been C7, then the case would have been considered to not have NLI-gap.

Figure 2

Rate of NLI-gap in Groups N and R. NLI-gap was noted in 26 of 28 cases (92.9%) in Group N and 3 of 14 cases (21.4%) in Group R. The rate of patients with NLI-gap was significantly higher in Group N than in Group R. *P < 0.0001, Chi-square test.

Figure 3

Rate of bone injury in Groups N and R. Bone injury was noted in 24 of 28 cases (85.7%) in Group N, and 5 of 14 cases (35.7%) in Group R. The rate of patients with bone injury was significantly higher in Group N than in Group R. *P = 0.0024, Chi-square test.

Figure 4

Rate of NLI-gap in Groups N and R in the initially AIS A patients. NLI-gap was detected in 25 of 26 cases (96.2%) in Group N and 0 of 3 cases (0.0%) in Group R. The rate of patients with NLI-gap was significantly higher in Group N than in Group R. *P = 0.0011, Chi-square test.

Figure 5

Rate of bone injury in Groups N and R in the initially AIS A patients. Bone injury was noted in 21 of 25 cases (84.0%) in Group N, and 0 of 3 cases (0.0%) in Group R, showing a statistically significant difference. *P = 0.0107, Chi-square test.