Abstract
Background: Multimodal intraoperative neuromonitoring is recommended during corrective spinal surgery, and has been widely used in surgery for spinal deformity with successful outcomes. Despite successful outcomes of corrective surgery due to increased safety of the patients with the usage of spinal cord monitoring in many large spine centers, this modality has not yet achieved widespread popularity. We report the analysis of prospectively collected intraoperative neurophysiological monitoring data of 354 consecutive patients undergoing corrective surgery for adolescent idiopathic scoliosis (AIS) to establish the efficacy of multimodal neuromonitoring and to evaluate comparative sensitivity and specificity.
Materials and Methods: The study group consisted of 354 (female = 309; male = 45) patients undergoing spinal deformity corrective surgery between 2004 and 2008. Patients were monitored using electrophysiological methods including somatosensory-evoked potentials and motor-evoked potentials simultaneously.
Results: Mean age of patients was 13.6 years (±2.3 years). The operative procedures involved were instrumented fusion of the thoracic/lumbar/both curves, Baseline somatosensory-evoked potentials (SSEP) and neurogenic motor-evoked potentials (NMEP) were recorded successfully in all cases. Thirteen cases expressed significant alert to prompt reversal of intervention. All these 13 cases with significant alert had detectable NMEP alerts, whereas significant SSEP alert was detected in 8 cases. Two patients awoke with new neurological deficit (0.56%) and had significant intraoperative SSEP + NMEP alerts. There were no false positives with SSEP (high specificity) but 5 patients with false negatives with SSEP (38%) reduced its sensitivity. There was no false negative with NMEP but 2 of 13 cases were false positive with NMEP (15%). The specificity of SSEP (100%) is higher than NMEP (96%); however, the sensitivity of NMEP (100%) is far better than SSEP (51%). Due to these results, the overall sensitivity, specificity and positive predictive value of combined multimodality neuromonitoring in this adult deformity series was 100, 98.5 and 85%, respectively.
Conclusion: Neurogenic motor-evoked potential (NMEP) monitoring appears to be superior to conventional SSEP monitoring for identifying evolving spinal cord injury. Used in conjunction, the sensitivity and specificity of combined neuromonitoring may reach up to 100%. Multimodality monitoring with SSEP + NMEP should be the standard of care.
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References
McEwen GD, Bunnell WP, Sriram K. Acute neurological complications in the treatment of scoliosis: A report of the Scoliosis Research Society. J Bone Joint Surg Am 1975;57:404–8.
Wilber RG, Thompson GH, Shaffer JW. Postoperative neurological deficits in segmental spinal instrumentation: A study using spinal cord monitoring. J Bone Joint Surg Am 1984;66:1178–87.
Bridwell KH, Lenke LG, Baldus C, Blanke K. Major intraoperative neurologic deficits in pediatric and adult spinal deformity patients: Incidence and etiology at one institution. Spine 1998;23:324–31.
Leung YL, Grevitt M, Henderson L. Cord monitoring changes and segmental vessel ligation in the “at risk” cord during anterior spinal deformity surgery. Spine 2005;30:1870–4.
Schwartz DM, Drummond DS, Ecker ML. Influence of rigid spinal instrumentation on the neurogenic motor evoked potential. J Spinal Disord 1996;9:439–45.
Jones SJ, Buonamassa S, Crockard HA. Two cases of quadriparesis following anterior cervical discectomy, with normal perioperative somatosensory evoked potentials. J Neurol Neurosurg Psychiatry 2003;74:273–6.
Owen JH. Necessity of using somatosensory-evoked potentials and motor evoked potentials to monitor spinal cord function during surgery for spinal deformity. Am Soc Neurophysiol Monitoring 1993;1:7–12.
Nuwer MR, Dawson EG, Carlson LG, Somatosensory evoked potential spinal cord monitoring reduces neurologic deficits after scoliosis surgery: Results of a large multicenter survey. Electroencephalogr Clin Neurophysiol 1995;96:6–11.
Vauzelle C, Stagnara P, Jouvinroux P. Functional monitoring of spinal cord activity during spinal surgery. Clin Orthop Relat Res 1973;93:173–8.
Nash CL Jr, Lorig RA, Schatzinger LA. Spinal cord monitoring during operative treatment of the spine. Clin Orthop Relat Res 1977;126:100–5.
Quraishi NA, Lewis SJ, Kelleher MO. Intraoperative multimodality monitoring in adult spinal deformity: Analysis of a prospective series of one hundred two cases with independent evaluation. Spine 2009;34:1504–12.
Lesser RP, Raudzens P, Lüders H. Postoperative neurological deficits may occur despite unchanged intraoperative somatosensory evoked potentials. Ann Neurol 1986;19:22–5.
Chen ZY, Wong HK, Chan YH. Variability of somatosensory evoked potential monitoring during scoliosis surgery. J Spinal Disord Tech 2004;17:470–6.
MacDonald DB, Al Zayed Z, Khoudeir I, Stigsby B. Monitoring scoliosis surgery with combined multiple-pulse transcranial electric motor and cortical somatosensory evoked potentials from lower and upper extremities. Spine 2003;28:194–203.
Macdonald DB, Al Zayed Z, Al Saddigi A. Four-limb muscle motor evoked potential and optimized somatosensory evoked potential monitoring with decussation assessment: Results in 206 thoracolumbar spine surgeries. Eur Spine J 2007;16:S171–87.
Schwartz DM, Auerbach JD, Dormans JP. Neurophysiological detection of impending spinal cord injury. J Bone Joint Surg Am 2007;89:2440–9.
Kim DH, Zaremski J, Kwon B. Risk factors for false positive transcranial motor evoked potential monitoring alerts during surgical treatment of cervical myelopathy. Spine 2007;32:3041–6.
de Haan P, Kalkman CJ, de Mol BA, Ubags LH, Veldman DJ, Jacobs MJ. Efficacy of Tc motor-evoked potentials to detect spinal cord ischemia during operations for thoraco-abdominal aneurysms. J Thorac Cardiovasc Surg 1997;113:87–101.
Pelosi L, Lamb J, Grevitt M, Mehdian SM, Webb JK, Blumhardt LD. Combined monitoring of motor and somatosensory evoked potentials in orthopaedic spinal surgery. Clin Neurophysiol 2002;113:1082–91.
Scoliosis Research Society. Position statement: Somatosensory evoked potential monitoring of neurologic spinal cord function during spinal surgery. Scoliosis Res Soc 1992.
Schwartz DM, Sestokas AK. Systems based algorithmic approach to intraoperative neurophysiological monitoring during spinal surgery. Semin Spine Surg 2002;14:136–45.
Deletis V. Intraoperative neurophysiology and methodologies used to monitor the functional integrity of the motor system. In: Deletis V, Shils JL, editors. Neurophysiology in neurosurgery: A modern intraoperative approach. New York: Academic Press; 2002. p. 25–6.
Schwartz DM, Drummond DS, Hahn M, Ecker ML, Dormans JP. Prevention of positional brachial plexopathy during surgical correction of scoliosis. J Spinal Disord 2000;13:178–82.
Schwartz DM, Sestokas AK, Hilibrand AS, Vaccaro AR, Bose B, Li M, et al.. Neurophysiological identification of position-induced neurologic injury during anterior cervical spine surgery. J Clin Monit Comput 2006;20:437–44.
Seyal M, Mull B. Mechanisms of signal change during intraoperative somatosensory evoked potential monitoring of the spinal cord. J Clin Neurophysiol 2002;19:409–15.
Fehlings MG; Spine Focus Panel. Summary statement: The use of methylprednisolone in acute spinal cord injury. Spine 2001;26:S55.
York DH. A critical evaluation of the 50% criterion in SEP monitoring. Proceedings of the American Society of Neurophysiological Monitoring Annual Meeting, St. Louis, Missouri, 1995.
Hilibrand AS, Schwartz DM, Sethuraman V, Vaccaro AR, Albert TJ. Comparison of transcranial electric motor and somatosensory evoked potential monitoring during cervical spine surgery. J Bone Joint Surg Am 2004;86:1248–53.
Padberg AM, Wilson-Holden TJ, Lenke LG, Bridwell KH. Somatosensory- and motor- evoked potential monitoring without a wake-up test during idiopathic scoliosis surgery: An accepted standard of care. Spine 1998;23:1392–400.
Noonan KJ, Walker T, Feinberg JR, Nagel M, Didelot W, Lindseth R. Factors related to false- versus true-positive neuromonitoring changes in adolescent idiopathic scoliosis surgery. Spine 2002;27:825–30.
DiCindio S, Theroux M, Shah S. Multimodality monitoring of transcranial electric motor and somatosensory-evoked potentials during surgical correction of spinal deformity in patients with cerebral palsy and other neuromuscular disorders. Spine 2003;28:1851–5.
Calancie B, Harris W, Broton JG, Alexeeva N, Green BA. “Threshold-level” multipulse transcranial electrical stimulation of motor cortex for intraoperative monitoring of spinal motor tracts: Description of method and comparison to somatosensory- evoked potential monitoring. J Neurosurg 1998;88:457–70.
Noonan KJ, Walker T, Feinberg JR, Nagel M, Didelot W, Lindseth R. Factors related to false-versus true positive neuromonitoring changes in adolescent idiopathic scoliosis surgery. Spine 2002;27:825–30.
Bejjani GK, Nora PC, Vera PL, Broemling L, Sekhar LN. The predictive value of intraoperative somatosensory-evoked potential monitoring: Review of 244 procedures. Neurosurgery 1998;43:491–8.
Ginsberg HH, Shetter AG, Raudzens PA. Postoperative paraplegia with preserved intraoperative somatosensory-evoked potentials. J Neurosurg 1985;63:296–300.
Kai Y, Owen JH, Kenke LG, Bridwell KH, Oakley DM, Sugioka Y. Use of sciatic neurogenic motor-evoked potentials versus spinal potentials to predict early-onset neurologic deficits when intervention is still possible during over distraction. Spine 1993;18:1134–9.
Pelosi L, Lamb J, Grevitt M, Mehdian SM, Webb JK, Blumhardt LD. Combined monitoring of motor and somatosensory evoked potentials in orthopaedic spinal surgery. Clin Neurophysiol 2002;113:1082–91.
Lee JY, Hilibrand AS, Lim MR, Zavatsky J, Zeiller S, Schwartz DM, et al.. Characterization of neurophysiologic alerts during anterior cervical spine surgery. Spine 2006;31:1916–22.
Owen JH, Laschinger J, Bridwell K, Shimon S, Nielsen C, Dunlap J, et al.. Sensitivity and specificity of somatosensory- and neurogenic motor-evoked potentials in animals and humans. Spine 1988;13:1111–8.
Owen JH, Sponsellor PD, Szymanski J, Hurdle M. Efficacy of multimodal spinal cord monitoring during surgery for neuromuscular scoliosis. Spine 1995;20:1480–8.
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Kundnani, V.K., Zhu, L., Tak, H.H. et al. Multimodal intraoperative neuromonitoring in corrective surgery for adolescent idiopathic scoliosis: Evaluation of 354 consecutive cases. IJOO 44, 64–72 (2010). https://doi.org/10.4103/0019-5413.58608
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DOI: https://doi.org/10.4103/0019-5413.58608