SY6.3 Intraoperative Neurophysiological Monitoring in Posterior Fossa Surgery

Abstract

Intraoperative monitoring (IOM) is rapidly emerging as a service standard during spinal cord surgery. In particular, potential operative damage to the spinal cord during correction of scoliosis and resection of spinal tumors can be effectively minimized with IOM. Monitoring of the dorsal columns can be achieved with somatosensory evoked potentials, but extensive experience has validated the efficacy of motor evoked potentials in detecting corticospinal tract injury. Utilization of multipulse transcranial electrical stimulation, coupled with D-wave monitoring [1], has appeared to be most extensively employed compared to other methods of spinal monitoring. Compound muscle action potential evoked from pedicle screw stimulation have also contributed in ensuring spinal integrity during scoliosis surgery, as have the electromyography monitoring of root compromise during lumbosacral spinal operations. These methods are now combined as multimodal IOM in the clinical setting. The field of spinal IOM has been extended to include thoracic aneurysm surgery and dorsal rhizotomy in the management of spastic paraparesis. Recent advances in the understanding of anesthetic interactions and spinal electrophysiology has added to our experience in spinal IOM [2 4]. State-of-the-art Image guidance [5], combined with IOM, with be the way forward in providing a significantly safer operative environment for patients with surgically amenable spinal disorders. Each of these aspects will be updated, reviewed and critically commented on.