Background and purpose: Perioperative stroke risk following carotid endarterectomy (CEA) is reported to be approximately 2-3%. The diagnostic accuracies of intraoperative EEG and SSEP monitoring during CEA have been studied separately. However, to date, the effectiveness of simultaneous EEG and SSEP monitoring during CEA has only been evaluated in small study populations. This study examined the diagnostic accuracy of combined EEG and SSEP monitoring in a large (N = 1165) patient population.
Methods: This study included 1165 patients who underwent CEA from 2000 to 2012 at the University of Pittsburgh Medical Center. The sensitivities, specificities, and diagnostic odds ratio of EEG and SSEP monitoring methods were examined separately and together. Receiver operating characteristic curves were plotted to assess sensitivity and specificity of single and combined Intraoperative monitoring (IONM) methods.
Results: Maximum sensitivity was obtained with multimodality monitoring with an IONM change in either EEG or SSEP of 50.00 (95% CI, 30.66-69.34). The specificity of simultaneous EEG and SSEP changes was 93.95 (95% CI, 92.28-95.35%). Maximum area under ROC curve obtained for IONM change in either EEG or SSEP was 0.660 (95% CI, 0.547-0.773, p-value 0.004).
Conclusion: The diagnostic accuracy of multimodality IONM during CEA is higher than an approach using single modality IONM. Simultaneous EEG and SSEP monitoring improves the likelihood of detecting periprocedural strokes after CEA. Neuro protective therapies to prevent periprocedural strokes can be based on changes in SSEP and EEG during CEA.
Keywords: Carotid endarterectomy; Carotid stenosis; EEG; Intraoperative neurophysiological monitoring; Somatosensory evoked potential; Stroke.