Application Of Cranial Peg-screw Electrode Motor Evoked Potentials Under Partial Neuromuscular Blocking During Anterior Circulating Cerebral Aneurysm Surgery

Background:The disadvantages of transcranial electric stimulation was performed for intraoperative monitoring in aneurysm microsurgery, summarized as follows:First, TES-MEPs needed the high-intensity to elicit myogenic MEPs, may result the false negative of MEPs monitoring. Second, the stimulus may induce the movement or seizure of the patient as an adverse event under total intravenous anesthesia(TIVA), it would affect the operating through a microscope. Third, there is controversy regarding how to interpret MEPs changes, the "Threshold-level" method revealed it’s superiority preliminary.Objective:We investigated the patients who were undergoing the anterior circulating cerebral aneurysm clipping with keyhole microsurgery. Anesthesia was maintained as TIVA-based combined with low-dose sevoflurane and partial neuromuscular blocking. Adopted the cranial peg-screw electrode electrical stimulation (CPSE-MEPs) technology and "Threshold-level" method of alarm criteria for intraoperative MEPs real-time monitoring. To reduce the complications related to MEPs, at the same time, improve the success rate of the monitoring. To derive a more easy to implement, safe, reliable and accurate intraoperative MEPs monitoring method.Methods:From January2012to March2013,18consecutive patients with cerebral aneurysms located anterior circulation. CPSE-MEPs was adopted as the method of intraoperative monitoring. The relationship between the change in the MEPs threshold level and the postoperative neurologic function was prospectively observed. To analyze the feasibility, safety, sensitivity of CPSE-MEPs monitoring for detecting coticospinal tract integrity, as well as the impact of the surgical procedures, under TIVA-based combined with low-dose sevoflurane and partial neuromuscular blocking.Results:Three cases could not be elicited recordable MEPs,15cases successfully been elicited MEPs, there were12cases could monitor bilateral MEPs. No complication which associated with evoked potentials monitoring appeared. Two cases showed postoperative motor deficit, manifested significant MEPs change, it presented the sensitivity of100%(2/2). Twelve cases manifested no interoperative evoked potential change and no postoperative motor deficit.Conclusions:For the patients with anterior circulating cerebral aneurysms underwent keyhole surgery. The CPSE-MEPs is an easy to implement, safe, reliable and accurate MEPs monitoring method under TIVA-based combined with low-dose sevoflurane and partial neuromuscular blocking.