Use of moniteoring systems during microneurosurgery

In the past two years, we have used some kinds of monitoring systems during microneurosurgical procedure in our hospital. We evaluate the indications and utilities of such systems. ① ABR and evoked potentials directly recorded from the VII th nerve were very useful to monitor auditory functions during microvascular decompression operations. ② T-SEP and EMG recorded from the direct stumulation of the VII th nerve were very useful for the rapid identification of the cranial nerves, especially in the operation of widely spread posterior fossa tumors. ③ VEP is supposed to be useful for thte surgical procedure of para-optic nerve.