The diagnostic accuracy of somatosensory evoked potentials in evaluating neurological deficits during 1036 posterior spinal fusions.

BACKGROUND: The goal of this study is to assess the sensitivity and specificity of somatosensory evoked potentials (SSEPs) in predicting perioperative neurological deficits during posterior spinal fusions (PSF).

METHODS: This study examined the diagnostic accuracy of significant changes of SSEPs and multimodal monitoring to evaluate and predict post-operative neurological deficits after PSF. All 1036 patients underwent PSF at the University of Pittsburgh Medical Center from 2010 to 2012. Statistical analysis was completed using SPSS version 22.

RESULTS: Of the 1036 patients included in the study, 35 (3.38%) patients had significant SSEP changes. Out of the 35 patients with significant SSEP changes, 22 (62.86%) patients had significant lower extremity (LE) SSEP changes. Ten (45.5%) of LE SSEP changes were loss of responses. Gender, obesity, and abnormal baselines did not significantly affect patient outcomes. Significant LE changes had an odds ratio of 13.18, 95% CI [3.44, 50.56], and LE loss of waveforms had an odds ratio of 19.48, 95% CI [3.76, 100.75].

CONCLUSIONS: Patients with perioperative neurological deficits are 13 times more likely to have LE significant changes, and 19 times more likely to have a LE loss of SSEP responses. Our study results indicate that LE significant changes or LE loss of waveforms in SSEPs can serve as a marker of perioperative neurological deficits.