Intravenous anaesthesia and repetitive transcranial magnetic stimulation monitoring in spinal column surgery.

BACKGROUND Transcranial magnetic stimulation with motor evoked potential monitoring is a non-invasive method for monitoring motor tracts during surgery. However, anaesthetic agents such as propofol and volatile agents reduce responses to single transcranial magnetic stimulation. We assessed an intravenous technique for anaesthesia to allow motor evoked potentials (MEPs) to be monitored using repetitive transcranial magnetic stimulation (rTMS). METHODS We applied three-pulse rTMS (TriStim) in 11 patients undergoing spinal column surgery after spinal column injury and recorded the latency and peak-to-peak amplitude of MEPs. Anaesthesia was maintained with propofol and remifentanil. RESULTS MEPs were monitored successfully intraoperatively in all patients. CONCLUSIONS It is possible to monitor intraoperative MEP using rTMS during anaesthesia with propofol and remifentanil.