Intraoperative neuromonitoring loss in abnormal magnetic resonance imaging signal intensity from patients with cervical compressive myelopathy

Abstract

Purpose: Our objective of this study was to evaluate if cervical compressive myelopathy (CCM) patients with preoperative abnormal magnetic resonance imaging (MRI) might easily lead to intraoperative neuromonitoring (IONM) loss.

Method: A consecutive series of 152 CCM patients who underwent cervical cord decompression were enrolled in this study between December 2013 and February 2017. All patients with abnormal MRI signal intensity were divided into 2 groups (group 1: T2-WIs hyperintensity; group 2: both T2-WIs hyperintensity and T1-WIs hypointensity). Relevant IONM changes were identified as significant transcranial motor evoked potentials (MEP) loss associated with surgical decompression of cervical cord.

Results: There were 121 patients in group 1, and then 6 cases showed IONM degeneration; 31 patients in group 2, and then 13 cases showed IONM degeneration (6/121 versus 13/31, p=0.000). Moreover, one case presented transient new spinal deficits after surgery, no permanent spinal deficit in group 1; 5 cases presented transient new spinal deficits, 2 cases showed permanent spinal deficit in group 2. And in group 2 the MEP amplitude before and after decompression had significant difference (134μV±30.2 versus 65μV±26.2, *p<0.05).

Conclusion: Our results suggest that the IONM degenerations or postoperative spinal deficits are more likely to appear on patients with abnormal T2-WIs and T1-WIs. Appropriate and timely interventions are probably useful for IONM recovery.

Keywords: Cervical compressive myelopathy (CCM); Intraoperative neuromonitoring (IONM); Magnetic resonance imaging (MRI); T1-WIs hypointensity; T2-WIs hyperintensity.