Intraoperative Monitoring of Spinal Cord Function in Spinal Cord Tumor and Syringomyelia.

Intraoperative spinal cord monitoring using spinal evoked potentials was performed in 8 cases with spinal cord tumor and 2 cases with syringomyelia.Some neurological changes were seen in five cases and we discussed about these five cases. In one case with intramedullary spinal cord tumor the amplitude decresed to 50%, and did not recover after interrupting the operation.In one case with epidural lipoma the amplitude decreased to 70% during resection of the tumor, but it recovered 10 minutes after interrupting resection. No apparent amplitude change was seen in three cases. The patient with the amplitude decrease to 50% developed marked muscle weakness and sensory disturbance.Some neurological changes were seen in the other cases, but they were not so serious.