[Progress in perioperative neuromonitoring: preface and comments].

The aims of the neuromonitoring during perioperative period are 1) to detect the brain, spinal cord and peripheral nerve ischemia immediately and hence prevention from neuronal injury, 2) to measure the depth of anesthesia, especially sedative effect of anesthetics and 3) to evaluate brain death. For the detection of brain and spinal cord ischemia during operation, we have to bear in mind 1) whether we truly monitor the possible ischemic risk sites in the brain and spinal cord; 2) whether we know the false-negative and false-positive ratio of the neuromonitoring with account being taken of the effect of anesthetics, the patient's own pathologies, the body temperature etc. If we detect the abnormal change through neuromonitoring, we should immediately warn the surgeon to improve his subsequent procedures and confirm his decision to prevent neuronal damage. To understand these reviews, we have to know the fundamental basic knowledge such as International 10-20 System on EEG monitoring, the expression of negative wave and positive wave in evoked potential, the meaning of near-field potential and far-field potential, temporal dispersion and so on. In this issue, the recent progress in neuromonitoring is described by the specialists in each fields. I hope the anesthesiologists understand the significance of neuromonitoring and apply these techniques for the patient undergoing the neurological operation during perioperative periods.