Predictive value of intraoperative neurophysiological monitoring during cervical spine surgery: a prospective analysis of 1055 consecutive patients

Michael O. Kelleher F.R.C.S., M.D., Gamaliel Tan F.R.C.S., Roger Sarjeant B.Sc. and Michael G. Fehlings M.D., Ph.D., F.R.C.S.C.
View More View Less
  • Spinal Program, Krembil Neuroscience Centre, Toronto Western Hospital, University Health Network; and Division of Neurosurgery, Department of Surgery, University of Toronto, Ontario, Canada
Restricted access

Purchase Now

USD  $45.00

Spine - 1 year subscription bundle (Individuals Only)

USD  $369.00

JNS + Pediatrics + Spine - 1 year subscription bundle (Individuals Only)

USD  $600.00
Print or Print + Online

Object

Despite the growing use of multimodal intraoperative monitoring (IOM) in cervical spinal surgery, limited data exist regarding the sensitivity, specificity, and predictive values of such a technique in detecting new neurological deficits in this setting. The authors sought to define the incidence of significant intraoperative electrophysiological changes and new postoperative neurological deficits in a cohort of patients undergoing cervical surgery.

Methods

The authors conducted a prospective analysis of a consecutive series of patients who had undergone cervical surgery during a 5-year period at a university-based neurosurgical unit, in which multimodal IOM was recorded. Sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs) were determined using standard Bayesian techniques. The study population included 1055 patients (614 male and 441 female) with a mean age of 55 years.

Results

The IOM modalities performed included somatosensory evoked potential (SSEP) recording in 1055 patients, motor evoked potential (MEP) recording in 26, and electromyography (EMG) in 427. Twenty-six patients (2.5%) had significant SSEP changes. Electromyographic activity was transient in 212 patients (49.6%), and 115 patients (26.9%) had sustained burst or train activity. New postoperative neurological deficits occurred in 34 patients (3.2%): 6 had combined sensory and motor deficits, 7 had new sensory deficits, 9 had increased motor weakness, and 12 had new root deficits. Of these 34 patients, 12 had spinal tumors, of which 7 were intramedullary. Overall, of the 34 new postoperative deficits, 21 completely resolved, 9 partially resolved, and 4 had no improvement. The deficits that completely resolved did so on average 3.3 months after surgery. Patients with deficits that did not fully resolve (partial or no improvement) were followed up for an average of 1.8 years after surgery.

Somatosensory evoked potentials had a sensitivity of 52%, a specificity of 100%, a PPV of 100%, and an NPV of 97%. Motor evoked potential sensitivity was 100%, specificity 96%, PPV 96%, and NPV 100%. Electromyography had a sensitivity of 46%, specificity of 73%, PPV of 3%, and an NPV of 97%.

Conclusions

Combined neurophysiological IOM with EMG and SSEP recording and the selective use of MEPs is helpful for predicting and possibly preventing neurological injury during cervical spine surgery.

Abbreviations used in this paper: EMG = electromyography; IOM = intraoperative monitoring; MEP = motor evoked potential; NPV = negative predictive value; PPV = positive predictive value; SSEP = somatosensory evoked potential.

Spine - 1 year subscription bundle (Individuals Only)

USD  $369.00

JNS + Pediatrics + Spine - 1 year subscription bundle (Individuals Only)

USD  $600.00

Contributor Notes

Address correspondence to: Michael G. Fehlings, M.D., Ph.D., F.R.C.S.C., University of Toronto, 399 Bathurst Street, Suite 4W–499, Toronto, Ontario M5T 2S8, Canada. email: michael.fehlings@uhn.on.ca.
  • 1

    Accadbled F, , Henry P, , de Gauzy JS, & Cahuzac JP: Spinal cord monitoring in scoliosis surgery using an epidural electrode. Results of a prospective, consecutive series of 191 cases. Spine 31:26142623, 2006

    • Search Google Scholar
    • Export Citation
  • 2

    Ben-David B, , Haller G, & Taylor P: Anterior spinal fusion complicated by paraplegia. A case report of a false-negative somatosensory-evoked potential. Spine 12:536539, 1987

    • Search Google Scholar
    • Export Citation
  • 3

    Bose B, , Sestokas AK, & Schwartz DM: Neurophysiological monitoring of spinal cord function during instrumented anterior cervical fusion. Spine J 4:202207, 2004

    • Search Google Scholar
    • Export Citation
  • 4

    DiCindio S, , Theroux M, , Shah S, , Miller F, , Dabney K, & Brislin RP, : 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 28:18511856, 2003

    • Search Google Scholar
    • Export Citation
  • 5

    Djurasovic M, , Dimar JR II, , Glassman SD, , Edmonds HL, & Carreon LY: A prospective analysis of intraoperative electromyographic monitoring of posterior cervical screw fixation. J Spinal Disord Tech 18:515518, 2005

    • Search Google Scholar
    • Export Citation
  • 6

    El-Hawary R, , Sucato DJ, , Sparagana S, , McClung A, , Van Allen E, & Rampy P: Spinal cord monitoring in patients with spinal deformity and neural axis abnormalities: a comparison with adolescent idiopathic scoliosis patients. Spine 31:E698E706, 2006

    • Search Google Scholar
    • Export Citation
  • 7

    Flynn TB: Neurologic complications of anterior cervical discectomy in Louisiana. J La State Med Soc 136:68, 1984

  • 8

    Gunnarsson T, , Krassioukov AV, , Sarjeant R, & Fehlings MG: Real-time continuous intraoperative electromyographic and somatosensory evoked potential recordings in spinal surgery: correlation of clinical and electrophysiologic findings in a prospective, consecutive series of 213 cases. Spine 29:677684, 2004

    • Search Google Scholar
    • Export Citation
  • 9

    Guo L, , Quiñones-Hinojosa A, , Yingling CD, & Weinstein PR: Continuous EMG recordings and intraoperative electrical stimulation for identification and protection of cervical nerve roots during foraminal tumor surgery. J Spinal Disord Tech 19:3742, 2006

    • Search Google Scholar
    • Export Citation
  • 10

    Kothbauer K, , Deletis V, & Epstein FJ: Intraoperative spinal cord monitoring for intramedullary surgery: an essential adjunct. Pediatr Neurosurg 26:247254, 1997

    • Search Google Scholar
    • Export Citation
  • 11

    Kothbauer KF, & Novak K: Intraoperative monitoring for tethered cord surgery: an update. Neurosurg Focus 16:2 E8, 2004

  • 12

    Krassioukov AV, , Sarjeant R, , Arkia H, & Fehlings MG: Multimodality intraoperative monitoring during complex lumbosacral procedures: indications, techniques, and long-term follow-up review of 61 consecutive cases. J Neurosurg Spine 1:243253, 2004

    • Search Google Scholar
    • Export Citation
  • 13

    Lee JY, , Hilibrand AS, , Lim MR, , Zavatsky J, , Zeiller S, & Schwartz DM, : Characterization of neurophysiologic alerts during anterior cervical spine surgery. Spine 31:19161922, 2006

    • Search Google Scholar
    • Export Citation
  • 14

    Lesser RP, , Raudzens P, , Lüders H, , Nuwer MR, , Goldie WD, & Morris HH III, : Postoperative neurological deficits may occur despite unchanged intraoperative somatosensory evoked potentials. Ann Neurol 19:2225, 1986

    • Search Google Scholar
    • Export Citation
  • 15

    Linn S: A new conceptual approach to teaching the interpretation of clinical tests. J Stat Ed 12:3, 2004. (www.amstat.org/publications/jse/v12n3/linn.html) [accessed 29 October, 2007]

    • Search Google Scholar
    • Export Citation
  • 16

    Lo YL, , Dan YF, , Tan YE, , Nurjannah S, , Tan SB, & Tan CT, : Intraoperative motor-evoked potential monitoring in scoliosis surgery: comparison of desflurane/nitrous oxide with propofol total intravenous anesthetic regimens. J Neurosurg Anesthesiol 18:211214, 2006

    • Search Google Scholar
    • Export Citation
  • 17

    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 the lower and upper extremities. Spine 28:194203, 2003

    • Search Google Scholar
    • Export Citation
  • 18

    May DM, , Jones SJ, & Crockard HA: Somatosensory evoked potential monitoring in cervical surgery: identification of pre- and intraoperative risk factors associated with neurological deterioration. J Neurosurg 85:566573, 1996

    • Search Google Scholar
    • Export Citation
  • 19

    Morota N, , Deletis V, , Constantini S, , Kofler M, , Cohen H, & Epstein FJ: The role of motor evoked potentials during surgery for intramedullary spinal cord tumors. Neurosurgery 41:13271336, 1997

    • Search Google Scholar
    • Export Citation
  • 20

    Owen JH: The application of intraoperative monitoring during surgery for spinal deformity. Spine 24:26492662, 1999

  • 21

    Padberg AM, & Thuet ED: Intraoperative electrophysiologic monitoring: considerations for complex spinal surgery. Neurosurg Clin N Am 17:205226, 2006

    • Search Google Scholar
    • Export Citation
  • 22

    Paradiso G, , Lee GY, , Sarjeant R, , Hoang L, , Massicotte EM, & Fehlings MG: Multimodality intraoperative neurophysiologic monitoring findings during surgery for adult tethered cord syndrome: analysis of a series of 44 patients with long-term follow-up. Spine 31:20952102, 2006

    • Search Google Scholar
    • Export Citation
  • 23

    Quiñones-Hinojosa A, , Gulati M, , Lyon R, , Lyon R, , Gupta N, & Ying-ling C: Spinal cord mapping as an adjunct for resection of intramedullary tumors: surgical technique with case illustrations. Neurosurgery 51:11991207, 2002

    • Search Google Scholar
    • Export Citation
  • 24

    Quiñones-Hinojosa A, , Lyon R, , Ames CP, & Parsa AT: Neuromonitoring during surgery for metastatic tumors to the spine: intraoperative interpretation and management strategies. Neurosurg Clin N Am 15:537547, 2004

    • Search Google Scholar
    • Export Citation
  • 25

    Schwartz DM, , Sestokas AK, , Hilibrand AS, , Vaccaro AR, , Bose B, & Li M, : Neurophysiological identification of position-induced neurologic injury during anterior cervical spine surgery. J Clin Monit Comput 20:437444, 2006

    • Search Google Scholar
    • Export Citation
  • 26

    Sebastian C, , Raya JP, , Ortega M, , Olalla E, , Lemos V, & Romero R: Intraoperative control by somatosensory evoked potentials in the treatment of cervical myeloradiculopathy. Results in 210 cases. Eur Spine J 6:316323, 1997

    • Search Google Scholar
    • Export Citation
  • 27

    Shi YB, , Binette M, , Martin WH, , Pearson JM, & Hart RA: Electrical stimulation for intraoperative evaluation of thoracic pedicle screw placement. Spine 28:595601, 2003

    • Search Google Scholar
    • Export Citation
  • 28

    Thuet ED, , Padberg AM, , Raynor BL, , Bridwell KH, , Riew KD, & Taylor BA, : Increased risk of postoperative neurologic deficit for spinal surgery patients with unobtainable intraoperative evoked potential data. Spine 30:20942103, 2005

    • Search Google Scholar
    • Export Citation
  • 29

    Wiedemayer H, , Sandalcioglu IE, , Armbruster W, , Regel J, , Schaefer H, & Stolke D: False negative findings in intraoperative SEP monitoring: analysis of 658 consecutive neurosurgical cases and review of published reports. J Neurol Neurosurg Psychiatry 75:280286, 2004

    • Search Google Scholar
    • Export Citation

Metrics