Diagnostic Accuracy of Somatosensory Evoked Potentials and Electroencephalography During Endovascular Treatment of Unruptured Cerebral Aneurysms.

OBJECTIVE: Endovascular treatment (EVT) of unruptured cerebral aneurysms (UCA) offers a safer alternative to clipping. However, it is still associated with an increased risk for Postprocedural Neurological deficit (PPND). Prompt recognition using intraoperative neurophysiologic monitoring (IONM) and intervention can reduce the incidence and impact of new postoperative neurological complications. We aim to evaluate the diagnostic accuracy of IONM in predicting PPND after EVT of UCA. METHODS: We included 414 patients who underwent EVT for UCA from 2014 to 2019. The sensitivities, specificities, and diagnostic odds ratio of somatosensory evoked potentials and electroencephalography monitoring methods were calculated. We also determined their diagnostic accuracy using receiver operating characteristic plots. RESULTS: The highest sensitivity of 67.7% (95% confidence interval {CI}, 34.9%-90.1%) was obtained when either modality had a change. Simultaneous changes in both modalities have the highest specificity of 97.8% (95% CI, 95.8%-99.0%). The area under the receiver operating characteristic curve was 0.795 (95% CI, 0.655-0.935) for changes in either modality. CONCLUSIONS: IONM with somatosensory evoked potentials alone or in combination with electroencephalography has high diagnostic accuracy in detecting periprocedural complications and resultant PPND during EVT of UCA.

Role of Intraoperative Neurophysiologic Monitoring in Internal Carotid Artery Injury During Endoscopic Endonasal Skull Base Surgery.

OBJECTIVE: In the present study, we investigated the role of intraoperative neuromonitoring (IONM) in internal carotid artery (ICA) injury during endoscopic endonasal skull base surgery (EESBS). METHODS: The study group included all 13 patients who had experienced an ICA injury during EESBS with IONM from 2004 to 2017. The medical records were reviewed for the perioperative data. The IONM reports were reviewed to evaluate the baseline somatosensory evoked potentials (SSEP), electroencephalography (EEG), and brainstem auditory evoked potentials (BAEP) and their significant changes related to ICA injury and/or the subsequent surgical/endovascular interventions. RESULTS: All 13 patients had undergone SSEP and 7 patients had BAEP monitoring during surgery. EEG was added during emergent angiography following the surgery for 5 patients. Two patients showed significant SSEP changes, and one showed significant SSEP and EEG changes, indicating cerebral hypoperfusion. Of these 3 patients, patient 1 had experienced irreversible SSEP loss with postoperative stroke. Patients 2 and 3 had SSEP and/or EEG changes that had recovered to baseline after interventions without postoperative deficits. Despite ICA injury, 10 patients showed no significant SSEP and/or EEG changes, and all 7 patients with BAEP monitoring showed no significant BAEP changes, indicating adequate cerebral and brainstem perfusion, respectively. The injured ICA was sacrificed in 4 patients, of whom 3 showed stable SSEP and 1 had experienced irreversible SSEP loss. IONM correlated with the postoperative neurologic examination findings in all cases, adequately predicting the neurologic outcomes after ICA injury. CONCLUSION: SSEP and EEG monitoring can accurately detect cerebral hypoperfusion and provide real-time feedback during surgery. SSEP and EEG changes predicted for neurologic outcomes and guide surgical decisions regarding the preservation or sacrifice of the ICA. Comprehensive multimodality monitoring according to the surgical risks can serve to detect and guide the management of ICA injury in EESBS.