Purpose: Forms of intraoperative neurophysiologic monitoring (IONM), including somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs), have been widely used in the field of neurosurgery. This study aimed to evaluate the diagnostic efficacy of IONM in identifying intraoperative events and predicting postoperative neurologic deficits in neurovascular intervention.
Methods: From January 2013 to December 2016, we retrospectively reviewed patients who underwent neurovascular intervention under general anesthesia with the use of IONM. Associations between significant changes in MEPs or SSEPs which were defined as a decrease more than 50% in amplitude and/or an increase more than 10% in latency and any identifiable intraoperative events and/or postoperative neurologic deficits were determined. The sensitivity and specificity values for both MEPs and SSEPs were calculated.
Results: In total, 578 patients (175 men and 403 women) were included. Their mean age was 59.5 years. SSEP changes occurred in 1% (n = 6), and MEP changes occurred in 1.2% (n = 7). Four patients suffered postoperative neurologic deficits, and identifiable intraoperative events were observed in seven patients. Both SSEP and MEP changes were significantly associated with identifiable intraoperative events and/or postoperative neurologic deficits (p < 0.001, Fisher's exact test). The calculated sensitivity and specificity of MEP monitoring were 50 and 99.5%, respectively. The sensitivity and specificity of SSEP monitoring were both 100%.
Conclusion: Intraoperative SSEP monitoring might be a reliable and sensitive method to surveil neurologic complications during neurovascular intervention. Intraoperative MEP monitoring appears to be feasible. However, it is unclear whether MEP monitoring has any additive benefit over SSEP monitoring.
Keywords: Endovascular surgery; Intraoperative monitoring; Motor evoked potential; Neurophysiologic monitoring; Somatosensory evoked potential.