Somatosensory- and motor-evoked potential monitoring during spine and spinal cord surgery

Abstract

Objectives: Complex spinal surgery carries a significant risk of neurological damage. The aim of this study is to determine the reliability and applicability of multimodality motor-evoked potentials (MEPs) and somatosensory-evoked potentials (SEPs) monitoring during spine and spinal cord surgery in our institute. Methods: Recordings of MEPs to multipulse transcranial electrical stimulation (TES) and cortical SEPs were made on 52 patients during spine and spinal cord surgery under propofol/ fentanyl anaesthesia, without neuromuscular blockade. Results: Combined MEPs and SEPs monitoring was successful in 38/52 patients (73.1%), whereas only MEPs from at least one of the target muscles were obtained in 12 patients (23.1%); both MEPs and SEPs were absent in two (3.8%). Significant intraoperative-evoked potential changes occurred in one or both modalities in five (10%) patients. Transitory changes were noted in two patients, whereas three had persistent changes, associated with new deficits or a worsening of the pre-existing neurological disabilities. When no postoperative changes in MEP or MEP/SEP modalities occurred, it was predictive of the absence of new motor deficits in all cases. Conclusion: Intraoperative combined SEP and MEP monitoring is a safe, reliable and sensitive method to detect and reduce intraoperative injury to the spinal cord. Therefore, the authors suggest that a combination of SEP/MEP techniques could be used routinely during complex spine and/or spinal cord surgery.Spinal Cord (2007) 45, 86-91.

Lack of neuroprotection with pharmacological pretreatment in a paradigm for anticipated spinal cord lesions

“…Even though refinement of surgical procedures and intraoperative electrophysiological monitoring have helped to prevent damage to the SC during elective spine surgery, 2,3 excessive surgical manipulation of the SC is bound to result in SCI. 1,2 In search for pharmacological tools to reduce the risk of SCI under these circumstances, here we evaluated the capacity of several agents known to be neuroprotectant to modify functional and histological outcome in rats subjected to mild SC damage, a model simulating SCI that may occur during elective spine surgery.…”

“…1,2 In search for pharmacological tools to reduce the risk of SCI under these circumstances, here we evaluated the capacity of several agents known to be neuroprotectant to modify functional and histological outcome in rats subjected to mild SC damage, a model simulating SCI that may occur during elective spine surgery. Notably none of the drugs tested produced any detectable benefit.…”

“…1,2 Because of the lack of specific experimental models resembling neurological injury caused by elective spine surgery, we chose the animal model of mild contusion SCI for this study for two reasons: it reproduces the majority of iatrogenic injuries that could occur after elective spine surgery, and as an incomplete injury allows for the detection of beneficial and detrimental changes, as well as no changes at all in response to treatments. Furthermore, by starting pharmacological treatment before injury, we converted this model of traumatic SCI into a paradigm for anticipated SC lesions.…”

“…1,2 Efforts have been made to reduce the risk of mechanically induced damage to SC during elective spine surgery by intraoperative electrophysiological monitoring and the development of less traumatic and more hemostatic surgical techniques. 2,3 However, few attempts have been made to pharmacologically prevent or reduce this complication.…”

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“…LR between 1 and 2 and between 0.5-1 rarely alter pretest probability. 6 Despite traditional spinal IOM literature suggests that NIOM is effective in identifying patients at a high risk for sustaining new spinal cord injuries [7][8][9][10][11][12][13][14][15] as well as animal research has supported human experience, [16][17][18] there is a heterogeneity in IOM services and this should be reviewed to see what accounts for the difference in false-positive and false-negative cases in the literature.…”