Skip to main content

Advertisement

SpringerLink
Log in

Improvement in intraoperative transcranial electrical motor-evoked potentials in tethered cord surgery: an analysis of 45 cases

  • Clinical Article - Spine
  • Published:
Acta Neurochirurgica Aims and scope Submit manuscript

Abstract

Background

Improvement of transcranial electrical motor-evoked potentials (TeMEPs) following untethering during tethered cord surgery (TCS) and its clinical significance have not been analyzed in the literature.

Methods

Forty-five consecutive cases of tethered cord were operated on with multimodality intraoperative neurophysiological monitoring (IONM) between February 2005 and January 2012. Intraoperative TeMEP change was classified as improvement, worsening or no change. Motor, sensory, bladder and bowel symptoms and signs were evaluated preoperatively, in the first week post-surgery and at the last follow-up (maximum of 2 years).

Results

Patient age ranged from 5 to 44 years (mean, 16 ± 10 years), with 30 children. Intraoperative MEPs improved in 23 (51 %), remained the same in 21 (46.7 %) and worsened in 1 (2 %) patient. Motor improvement occurred in 7 patients and clinical improvement in 17 patients in the immediate postoperative period. Postoperative neurological worsening occurred in one patient (2.2 %). Improved and stable MEPs correlated with the motor (p = 0.002) and clinical improvement (p = 0.02) in the immediate postoperative period. Follow-up was available in 35 patients (77.7 %), ranging from 5 to 24 months (median, 21 months; mean, 17.7 ± 6.8 months). There was late clinical improvement in 73.5 % of the patients in whom the intraoperative MEP had remained the same or improved. However, there was no statistically significant correlation between MEP change and long-term outcome.

Conclusions

Intraoperative MEP improvement occurs in about 50 % of the patients following successful untethering. This finding probably provides support to the ischemic theory of tethered cord syndrome.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

Abbreviations

TeMEP:

Transcranial electrical motor-evoked potential

TCS:

Tethered cord surgery

IONM:

Intraoperative neurophysiological monitoring

EMG:

Electromyography

MEP:

Motor-evoked potential

MRI:

Magnetic resonance imaging

SSEP:

Somatosensory-evoked potential

MRC:

Medical Research Council

CMAP:

Compound muscle action potential

References

  1. Albright AL, Pollack IF, Adelson PD, Solot JJ (1999) Outcome data and analysis in pediatric neurosurgery. Neurosurgery 45:101–106

    Article  CAS  PubMed  Google Scholar 

  2. Al-Holou WN, Muraszko KM, Garton HJ, Buchman SR, Maher CO (2009) The outcome of tethered cord release in secondary and multiple repeat tethered cord syndrome. J Neurosurg Pediatr 4:28–36

    Article  PubMed  Google Scholar 

  3. Beyazova M, Zinnuroglu M, Emmez H, Kaya K, Ozkose HZ, Baykaner MK, Erden Z, Orucoglu N, Ozturk GT, Erdogan Z (2010) Intraoperative neurophysiological monitoring during surgery for tethered cord syndrome. Turk Neurosurg 20:480–484

    PubMed  Google Scholar 

  4. Chen X, Sterio D, Ming X, Para DD, Butusova M, Tong T, Beric A (2007) Success rate of motor evoked potentials for intraoperative neurophysiologic monitoring: effects of age, lesion location, and preoperative neurologic deficits. J Clin Neurophysiol 24:281–285

    Article  PubMed  Google Scholar 

  5. Fulkerson DH, Satyan KB, Wilder LM, Riviello JJ, Stayer SA, Whitehead WE, Curry DJ, Dauser RC, Luerssen TG, Jea A (2011) Intraoperative monitoring of motor evoked potentials in very young children. J Neurosurg Pediatr 7:331–337

    Article  PubMed  Google Scholar 

  6. Hilibrand AS, Schwartz DM, Sethuraman V, Vaccaro AR, Albert TJ (2004) Comparison of transcranial electric motor and somatosensory evoked potential monitoring during cervical spine surgery. J Bone Joint Surg Am 86-A:1248–1253

    PubMed  Google Scholar 

  7. Hoving EW, Haitsma E, Oude Ophuis CM, Journée HL (2011) The value of intraoperative neurophysiological monitoring in tethered cord surgery. Childs Nerv Syst 27:1445–1452

    Article  PubMed Central  PubMed  Google Scholar 

  8. Husain AM, Shah D (2009) Prognostic value of neurophysiologic intraoperative monitoring in tethered cord syndrome surgery. J Clin Neurophysiol 26:244–247

    Article  PubMed  Google Scholar 

  9. James HE, Mulcahy JJ, Walsh JW, Kaplan GW (1979) Use of anal sphincter electromyography during operations on the conus medullaris and sacral nerve roots. Neurosurgery 4:521–523

    Article  CAS  PubMed  Google Scholar 

  10. Khealani B, Husain AM (2009) Neurophysiologic intraoperative monitoring during surgery for tethered cord syndrome. J Clin Neurophysiol 26:76–81

    Article  PubMed  Google Scholar 

  11. Kothbauer K, Schmid UD, Seiler RW, Eisner W (1994) Intraoperative motor and sensory monitoring of the cauda equina. Neurosurgery 34:702–707

    Article  CAS  PubMed  Google Scholar 

  12. Kothbauer KF, Deletis V (2010) Intraoperative neurophysiology of the conus medullaris and cauda equina. Childs Nerv Syst 26:247–253

    Article  PubMed  Google Scholar 

  13. Kumar GS, Rajshekhar V, Babu KS (2006) Intraoperative mapping of sacral nervous system (S2-4). Br J Neurosurg 20:396–402

    Article  PubMed  Google Scholar 

  14. Lang EW, Beutler AS, Chesnut RM, Patel PM, Kennelly NA, Kalkman CJ, Drummond JC, Garfin SR (1996) Myogenic motor-evoked potential monitoring using partial neuromuscular blockade in surgery of the spine. Spine 21:1676–1686

    Article  CAS  PubMed  Google Scholar 

  15. Lew SM, Kothbauer KF (2007) Tethered cord syndrome: an updated review. Pediatr Neurosurg 43:236–248

    Article  PubMed  Google Scholar 

  16. Lieberman JA, Lyon R, Feiner J, Diab M, Gregory GA (2006) The effect of age on motor evoked potentials in children under propofol/isoflurane anesthesia. Anesth Analg 103:316–321

    Article  CAS  PubMed  Google Scholar 

  17. Paradiso G, Lee GY, Sarjeant R, Hoang L, Massicotte EM, Fehlings MG (2006) 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 31:2095–2102

    Article  PubMed  Google Scholar 

  18. Phillips LH 2nd, Jane JA (1996) Electrophysiologic monitoring during tethered spinal cord release. Clin Neurosurg 43:163–174

    PubMed  Google Scholar 

  19. Pouratian N, Elias WJ, Jane JA Jr, Phillips LH 2nd, Jane JA Sr (2010) Electrophysiologically guided untethering of secondary tethered spinal cord syndrome. Neurosurg Focus 29:E3

    Article  PubMed  Google Scholar 

  20. Quiñones-Hinojosa A, Gadkary CA, Gulati M, von Koch CS, Lyon R, Weinstein PR, Yingling CD (2004) Neurophysiological monitoring for safe surgical tethered cord syndrome release in adults. Surg Neurol 62:127–133, discussion 133–135

    Article  PubMed  Google Scholar 

  21. Rajshekhar V, Velayutham P, Joseph M, Babu KS (2011) Factors predicting the feasibility of monitoring lower-limb muscle motor evoked potentials in patients undergoing excision of spinal cord tumors. J Neurosurg Spine 14:748–753

    Article  PubMed  Google Scholar 

  22. Sala F, Krzan MJ, Deletis V (2002) Intraoperative neurophysiological monitoring in pediatric neurosurgery: why, when, how? Childs Nerv Syst 18:264–287

    PubMed  Google Scholar 

  23. Schneider SJ, Rosenthal AD, Greenberg BM, Danto J (1993) A preliminary report on the use of laser-Doppler flowmetry during tethered spinal cord release. Neurosurgery 32:214–217, discussion 217–218

    Article  CAS  PubMed  Google Scholar 

  24. Shinomiya K, Fuchioka M, Matsuoka T, Okamoto A, Yoshida H, Mutoh N, Furuya K, Andoh M (1991) Intraoperative monitoring for tethered spinal cord syndrome. Spine 16:1290–1294

    Article  CAS  PubMed  Google Scholar 

  25. Tanaka S, Tashiro T, Gomi A, Takanashi J, Ujiie H (2011) Sensitivity and specificity in transcranial motor-evoked potential monitoring during neurosurgical operations. Surg Neurol Int 2:111

    Article  PubMed Central  PubMed  Google Scholar 

  26. von Koch CS, Quinones-Hinojosa A, Gulati M, Lyon R, Peacock WJ, Yingling CD (2002) Clinical outcome in children undergoing tethered cord release utilizing intraoperative neurophysiological monitoring. Pediatr Neurosurg 37:81–86

    Article  Google Scholar 

  27. Yamada S, Zinke DE, Sanders D (1981) Pathophysiology of “tethered cord syndrome. J Neurosurg 54:494–503

    Article  CAS  PubMed  Google Scholar 

  28. Yamada S, Won DJ, Yamada SM (2004) Pathophysiology of tethered cord syndrome: correlation with symptomatology. Neurosurg Focus 16:E6

    Article  PubMed  Google Scholar 

Download references

Acknowledgments

The authors thank Ms. Visali Jayaseelan, Department of Biostatistics, for helping with the statistical analysis. The authors also thank Mr. Benjamin Franklin and Ms. Delhi Rani for technical help in monitoring the patients and electrophysiological data collection.

Conflicts of interest

None.

Author information

Authors and Affiliations

  1. Department of Neurological Sciences, Christian Medical College, Vellore, 632004, India

    Ravindran Pratheesh, K. Srinivasa Babu & Vedantam Rajshekhar

Authors
  1. Ravindran Pratheesh
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. K. Srinivasa Babu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Vedantam Rajshekhar
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Vedantam Rajshekhar.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Pratheesh, R., Babu, K.S. & Rajshekhar, V. Improvement in intraoperative transcranial electrical motor-evoked potentials in tethered cord surgery: an analysis of 45 cases. Acta Neurochir 156, 723–731 (2014). https://doi.org/10.1007/s00701-014-1999-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00701-014-1999-7

Keywords

Search

Navigation