Abstract
Iatrogenic spinal cord injury is the most feared complication of scoliosis surgery. The importance of combined somatosensory evoked potentials (SEP) and motor evoked potentials (MEP) monitoring during spine surgery is well known. The current authors retrospectively evaluated the results of neurophysiological intraoperative monitoring (IOM) in a large population of patients who underwent surgical treatment for spinal deformity. Intraoperative monitoring of SEPs and transcranial electrical stimulation MEPs (TES-MEP) was performed in 172 successive patients who underwent surgical treatment of idiopathic (128 pts), congenital (15 pts) or syndromic (29 pts) scoliosis. The first 106 patients (Group 1) underwent only SEP monitoring, while the other 66 patients (Group 2) underwent combined SEP and TES-MEP monitoring, when the technique was introduced in the current authors’ institution. Halogenate anaesthesia (Sevoflurane, MAC 0.6–1.2) was performed in Group 1 cases, total intravenous anaesthesia (Propofol infusion, 6–10 mg/kg/h) in Group 2 patients. A neurophysiological “alert” was defined as a reduction in amplitude (unilateral or bilateral) of at least 50% for SEPs and of 65% for TES-MEPs compared with baseline. In Group 1, two patients (1.9%) developed postoperative neurologic deficits following surgical correction of spinal deformity, consisting of permanent paraparesis in one case and transient paraparesis secondary to spinal cord ischaemia in the other. Twelve patients presented intraoperative significant changes of neurophysiological parameters that improved following corrective actions by surgeons and anaesthesiologists, and did not show any postoperative neurologic deficits. In ten cases the alert was apparently unrelated to surgical manoeuvres or to pharmacological interventions and no postoperative neurologic deficits were noted. Considering the patients of Group 2, two patients (3.0%) presented transient postoperative neurologic deficits preceded by significant intraoperative changes in SEPs and TES-MEPs. In five cases a transient reduction in the amplitudes of SEPs (1 patient) and/or TES-MEPs (5 patients) was recorded intraoperatively with no postoperative neurologic deficits. In conclusion, in the current series of 172 patients the overall prevalence of postoperative neurologic deficit was 2.3% (4 patients). When combined SEP and TES-MEP monitoring was performed, the sensitivity and specificity of IOM for sensory-motor impairment was 100 and 98%, respectively. Combined SEP and TES-MEP monitoring must be regarded as the neurophysiological standard for intraoperative detection of emerging spinal cord injury during corrective spinal deformity surgery. Early detection affords the surgical team an opportunity to perform rapid intervention to prevent injury progression or possibly to reverse impending neurologic sequelae.
Similar content being viewed by others
References
Diab M, Smith AR, Kuklo TR, The Spinal Deformity Study Group et al (2007) Neural complications in the surgical treatment of adolescent idiopathic scoliosis. Spine 32:2759–2763
Qiu Y, Wang S, Wang B et al (2008) Incidence, risk factors of neurological deficits of surgical correction for scoliosis. analysis of 1373 cases at one Chinese institution. Spine 33:519–526
Vauzelle C, Stagnara P, Jouvinroux P (1973) Functional monitoring of spinal cord activity during spinal surgery. Clin Orthop 93:173–178
Mostegl A, Bauer R, Eichenbauer M (1988) Intraoperative somatosensory potential monitoring: a clinical analysis of 127 surgical procedures. J Spine 13(4):396–400
Tamaki T, Noguchi T, Takano H et al (1984) Spinal cord monitoring as a clinical utilization of the spinal evoked potential. Clin Orthop Relat Res 184:58–64
Padberg AM, Wilson-Holden TJ, Lenke LG, Bridwell KH (1992) Somatosensory and motor evoked potential monitoring without a wake-up test during idiopathic scoliosi surgery. Spine 23:1392–1400
Nuwer MR, Dawson EG, Carlson LG et al (1995) Somatosensory evoked potential spinal cord monitoring reduces neurologic deficits after scoliosis surgery: results of a large multicenter survey. Electroencephalogr Clin Neurophysiol 96:6–11
Scoliosis Research Society (1992) Position Statement on Somatosensory Evoked Potential Monitoring of Neurological Spinal Cord Function. Scoliosis Research Society 1992
Luk KDK, Hu Y, Wong YW, Cheung KMC (2001) Evaluation of various evoked potenial techniques for spinal cord monitoring during scoliosis surgery. Spine 26(16):1772–1777
Sutter M, Deletis V, Dvorak J et al (2007) Current opinions and recommendations on multimodal intraoperative monitoring during spine surgeries. Eur Spine J 16(2):S232–S237
Pajewski TN, Arlet V, Phillips LH (2007) Current approach on spinal cord monitoring: the point of view of the neurologist, the anesthesiologist and the spine surgeon. Eur Spine J 16(2):S115–S129
Schwartz DM, Sestokas AK (2002) A systems-based algorithmic approach to intraoperative neurophysiological monitoring during spinal surgery. Semin Spine Surg 14:136–145
Mac Ewen GD, Bunnel WP, Sriram K (1975) Acute neurological complications in the treatment of scoliosis. A report of the Scoliosis Research Society. J Bone Joint surg 57-A(3):404–408
Ginsburg HH, Shetter AG, Raudzens PA (1985) Postoperative paraplegia with preserved intraoperative somatosensory evoked potentials. J Neurosurg 63:296–300
Pelosi L, Lamb J, Grevitt M et al (2002) Combined monitoring of motor and somatosensory evoked potentials in orthopaedic spinal surgery. Clin Neurophysiol 113:1082–1091
Noonan KJ, Walker T, Feinberg JR et al (2002) Factors related to false- versus true-positive neuromonitoring changes in adolescent idiopathic scoliosis surgery. Spine 27(8):825–830
Seyal M, Mull B (2002) Mechanisms of signal change during intraoperative somatosensory evoked potential monitoring of the spinal cord. J Clin Neurophysiol 19(5):409–415
Luk KDK, Hu Y, Wong YW, Leong JCY (1999) Variability of somatosensory-evoked potentials in different stages of scoliosis surgery. Spine 24(17):1799–1804
Ku ASW, Hu Y, Irwin MG et al (2002) Effect of sevoflurane/nitrous oxide versus propofol anaesthesia on somatosensory evoked potential monitoring of the spinal cord during surgery to correct scoliosis. Br J Anaesth 88:502–507
Chen Z (2004) The effects of isoflurane and propofol on intraoperative neurophysiological monitoring during spinal surgery. J Clin Monit Comput 18:303–308
Pelosi L, Stevenson M, Hobbs GJ et al (2001) Intraoperative motor evoked potentials to transcranial electrical stimulation during two anaesthetic regimens. Clin Neurophysiol 112:1076–1087
Sloan TO, Heyer EJ (2002) Anesthesia for intraoperative neurophysiologic monitoring of the spinal cord. J Clin Neurophysiol 19(5):430–443
Wiedemayer H, Fauser B, Sandalcioglu IE et al (2002) The impact of neurophysiological intraoperative monitoring on surgical decisions: a critical analysis of 423 cases. J Neurosurg 96:255–262
Devlin VJ, Schwartz DM (2007) Intraoperative neurophysiologic monitoring during spinal surgery. J Am Acad Orthop Surg 15:549–560
Schwartz DM, Auerbach JD, Dormans JP et al (2007) Neurophysiological detection of impending spinal cord injury during scoliosis surgery. J Bone Joint Surg Am 89:2440–2449
Ofiram E, Lonstein JE, Skinner S, Perra JH (2006) The disappearing evoked potentials: a special problem of positioning patients with skeletal dysplasia. Case report. Spine 31:E464–E470
Schwartz DM, Drummond DS, Hahn M et al (2000) Prevention of positional brachial plexopathy during surgical correction of scoliosis. J Spinal Disord 13(2):178–182
Conflict of interest
None.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Pastorelli, F., Di Silvestre, M., Plasmati, R. et al. The prevention of neural complications in the surgical treatment of scoliosis: the role of the neurophysiological intraoperative monitoring. Eur Spine J 20 (Suppl 1), 105–114 (2011). https://doi.org/10.1007/s00586-011-1756-z
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00586-011-1756-z