Multimodal intraoperative neurophysiological monitoring in AcoA aneurysms surgery: Personal experience

The treatment of AcoA aneurysms represents, actually, a great challenge for both neurosurgeon and neuroradiologist. Multimodal neurophysiologic monitoring is frequently used in aneurysm surgery for assessing the level of cerebroprotective anaesthesia and monitoring ischemia. The aim of this study was to determine the efficacy of electroencephalogram, somatosensory evoked potentials and motor evoked potentials for the detection and prediction of perforators ischemia during the AcoA aneurysms surgery, since in the literature there are no specific studies in this regard. From October 2009 to October 2012, 18 patients treated for surgical clipping of AcoA aneurysms underwent multimodal intraoperative neurophysiological monitoring. EEG, SEPs of bilateral median and tibial nerves, TcMEPs were recorded in all patients. A successful intraoperative monitoring of EEG, SEPs and MEPs was possible in all patients. In 5 cases impairments of the neurophysiological parameters were observed. Tibial nerve SEP changes occurred in 2 cases after the definitive aneurysm clipping and in 2 cases after the temporary clipping. In the case where a grade 3 SEP change was noted, the clip was promptly removed. In the remained cases, in the first instance the systemic blood pressure was increased, but in 3 cases a change in surgical maneuvers was necessary. In 3 cases TcMEP variations were noted, too. No post-operative deficits were seen as well as any radiological signs of ischemia. The findings of this our suggest that multimodal intraoperative neurophysiological monitoring is safe and reliable for detecting blood flow insufficiency in AcoA surgery.