Intraoperative neuromonitoring as real-time diagnostic for cerebral ischemia in endovascular treatment of ruptured brain aneurysms

Objective: To evaluate the diagnostic accuracy of intraoperative neurophysiological monitoring (IONM) during endovascular treatment (EVT) of ruptured intracranial aneurysms (rIA). Methods: IONM and clinical data from 323 patients who underwent EVT for rIA from 2014-2019 were retrospectively reviewed. Significant IONM changes and outcomes were evaluated based on visual review of data and clinical documentation. Results: Of the 323 patients undergoing EVT, significant IONM changes were noted in 30 patients (9.29%) and 46 (14.24%) experienced postprocedural neurological deficits (PPND). 22 out of 30 (73.33%) patients who had significant IONM changes experienced PPND. Univariable analysis showed changes in somatosensory evoked potential (SSEP) and electroencephalogram (EEG) were associated with PPND (p-values: <0.001 and <0.001, retrospectively). Multivariable analysis showed that IONM changes were significantly associated with PPND (Odd ratio (OR) 20.18 (95%CI:7.40-55.03, p-value: <0.001)). Simultaneous changes in both IONM modalities had specificity of 98.9% (95% CI: 97.1%-99.7%). While sensitivity when either modality had a change was 47.8% (95% CI: 33.9%-62.0%) to predict PPND. Conclusions: Significant IONM changes during EVT for rIA are associated with an increased risk of PPND. Significance: IONM can be used confidently as a real time neurophysiological diagnostic guide for impending neurological deficits during EVT treatment of rIA. (c) 2024 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.