Diagnostic accuracy of evoked potentials for functional impairment after contusive spinal cord injury in adult rats

• SSEPs and MEPs are sensitive and specific predictors of motor deficits following simulated iatrogenic SCI.
• Significant changes in SSEPs resulting from simulated iatrogenic SCI are not always accompanied by motor deficits.
• MEPs are exceptionally responsive to contusive spinal cord injuries, and are highly specific predictors of motor deficits following simulated iatrogenic SCI.
• The laboratory animal model described here is highly representative of the circumstances and outcomes associated with clinical iatrogenic SCI.

Iatrogenic spinal cord injury (SCI) is a cause of potentially debilitating post-operative neurologic complications. Currently, intra-operative neurophysiological monitoring (IONM) via somatosensory evoked potentials and motor-evoked potentials is used to detect and prevent impending SCI. However, no empirically validated interventions exist to halt the progression of iatrogenic SCI once it is detected. This is in part due to the lack of a suitable translational model that mimics the circumstances surrounding iatrogenic SCI detected via IONM. Here, we evaluate a model of simulated contusive iatrogenic SCI detected via IONM in adult female Sprague-Dawley rats. We show that transient losses of somatosensory evoked potentials responses are 88.24% sensitive (95% confidence interval [CI] 63.53–98.20) and 80% specific (95% CI 51.91–95.43) for significant functional impairment following simulated iatrogenic SCI. Similarly, we show that transient losses in motor-evoked potentials responses are 70.83% sensitive (95% CI 48.91–87.33) and 100% specific (95% CI 62.91–100.00) for significant functional impairment following simulated iatrogenic SCI. These results indicate that our model is a suitable replica of the circumstances surrounding clinical iatrogenic SCI.