Abstract
Objective The accuracy of intraoperative neuromonitoring (IONM) during surgery for cervical
spondylotic myelopathy (CSM) to detect iatrogenic nervous system injuries while they
are reversible remains unknown. We evaluated a cohort of patients who had IONM during
surgery to assess accuracy.
Methods Patients who underwent surgical treatment of CSM that included IONM from January
2018 through August 2018 were retrospectively identified. A standardized protocol
was used for operative management. Clinical changes and postoperative neurological
deficits were evaluated.
Results Among 131 patients in whom IONM was used during their procedure, 42 patients (age
58.2 ± 16.3 years, 54.8% males) showed IONM changes and 89 patients had no change.
The reasons for IONM changes varied, and some patients had changes detected via multiple
modalities: electromyography (n = 25, 59.5%), somatosensory-evoked potentials (n = 14, 33.3%), motor evoked potentials (n = 13, 31.0%). Three patients, all having baseline deficits before surgery, had postoperative
deficits. Among the 89 patients without an IONM change, 4 showed worsened postoperative
deficits, which were also seen at last follow-up. The sensitivity of IONM for predicting
postoperative neurological change was 42.86% and the specificity was 68.55%. However,
most patients (124, 94.7%) in whom IONM was used showed no worsened neurological deficit.
Conclusion IONM shows potential in ensuring stable postoperative neurological outcomes in most
patients; however, its clinical use and supportive guidelines remain controversial.
In our series, prediction of neurological deficits was poor in contrast to some previous
studies. Further refinement of clinical and electrophysiological variables is needed
to uniformly predict postoperative neurological outcomes.
Keywords
cervical spondylotic myelopathy - degenerative cervical myelopathy - electromyography
- intraoperative neuromonitoring
