What Is the Key Point for Intraoperative Monitoring in Cerebral Aneurysm Surgery

Intraoperative monitoring, which has advanced in the 21st century, consists of the motor evoked potential(MEP)and visual evoked potential(VEP). Transcranial stimulation has become the mainstream of MEP from cortical stimulation, and reports of MEP monitoring for the face and lower limbs are increasing. The biggest problem with VEP is poor reproducibility due to inhalation anesthetics. With the increase use of of MEP, total intravenous anesthesia has become common and reproducibility has improved, making it a clinically useful method. I will mention the key points of current intraoperative monitoring in cerebral aneurysm surgery. 1. Selection of type of intraoperative monitoring: Is MEP cortical stimulation or transcranial stimulation, upper limb or lower limb? What is VEP? What is somatosensory evoked potential? 2. What to do when the waveform deteriorates or disappears? Remove the clip after clipping. If the blood flow is temporarily occluded, release the occlusion as soon as possible. When the deterioration improves after this maneuver, it should be stopped until the waveform is restored. 3. Pitfall and coping method: Anesthesia method. Changes in the stimulation threshold of the transcranial stimulation MEPs. Deterioration/disappearance of MEP waveform after release of brain traction.