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Successful Motor Evoked Potential Monitoring in Cervical Myelopathy : Related Factors and the Effect of Increased Stimulation Intensity

  • Shim, Hyok Ki (Department of Neurosurgery and Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine) ;
  • Lee, Jae Meen (Department of Neurosurgery and Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine) ;
  • Kim, Dong Hwan (Department of Neurosurgery and Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine) ;
  • Nam, Kyoung Hyup (Department of Neurosurgery and Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine) ;
  • Choi, Byung Kwan (Department of Neurosurgery and Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine) ;
  • Han, In Ho (Department of Neurosurgery and Medical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine)
  • 투고 : 2020.04.10
  • 심사 : 2020.06.08
  • 발행 : 2021.01.01

초록

Objective : Intraoperative neurophysiological monitoring (IONM) has been widely used during spine surgery to reduce or prevent neurologic deficits, however, its application to the surgical management for cervical myelopathy remains controversial. This study aimed to assess the success rate of IONM in patients with cervical myelopathy and to investigate the factors associated with successful baseline monitoring and the effect of increasing the stimulation intensity by focusing on motor evoked potentials (MEPs). Methods : The data of 88 patients who underwent surgery for cervical myelopathy with IONM between January 2016 and June 2018 were retrospectively reviewed. The success rate of baseline MEP monitoring at the initial stimulation of 400 V was investigated. In unmonitorable cases, the stimulation intensity was increased to 999 V, and the success rate final MEP monitoring was reinvestigated. In addition, factors related to the success rate of baseline MEP monitoring were investigated using independent t-test, Wilcoxon rank-sum test, chi-squared test, and Fisher's exact probability test for statistical analysis. The factors included age, sex, body mass index, diabetes mellitus, smoking history, symptom duration, Torg-Pavlov ratio, space available for the cord (SAC), cord compression ratio (CCR), intramedullary increased signal intensity (SI) on magnetic resonance imaging, SI length, SI ratio, the Medical Research Council (MRC) grade, the preoperative modified Nurick grade and Japanese Orthopedic Association (JOA) score. Results : The overall success rate for reliable MEP response was 52.3% after increasing the stimulation intensity. No complications were observed to be associated with increased intensity. The factors related to the success rate of final MEP monitoring were found to be SAC (p<0.001), CCR (p<0.001), MRC grade (p<0.001), preoperative modified Nurick grade (p<0.001), and JOA score (p<0.001). The cut-off score for successful MEP monitoring was 5.67 mm for SAC, 47.33% for the CCR, 3 points for MRC grade, 2 points for the modified Nurick grade, and 12 points for the JOA score. Conclusion : Increasing the stimulation intensity could significantly improve the success rate of baseline MEP monitoring for unmonitorable cases at the initial stimulation in cervical myelopathy. In particular, the SAC, CCR, MRC grade, preoperative Nurick grade and JOA score may be considered as the more important related factors associated with the success rate of MEP monitoring. Therefore, the degree of preoperative neurological functional deficits and the presence of spinal cord compression on imaging could be used as new detailed criteria for the application of IONM in patients with cervical myelopathy.

키워드

참고문헌

  1. Appel S, Biron T, Goldstein K, Ashkenazi E : Effect of intra- and extraoperative factors on the efficacy of intraoperative neuromonitoring during cervical spine surgery. World Neurosurg 123 : e646-e651, 2019 https://doi.org/10.1016/j.wneu.2018.11.244
  2. Avadhani A, Rajasekaran S, Shetty AP : Comparison of prognostic value of different MRI classifications of signal intensity change in cervical spondylotic myelopathy. Spine J 10 : 475-485, 2010 https://doi.org/10.1016/j.spinee.2010.03.024
  3. Ayoub C, Zreik T, Sawaya R, Domloj N, Sabbagh A, Skaf G : Significance and cost-effectiveness of somatosensory evoked potential monitoring in cervical spine surgery. Neurol India 58 : 424-428, 2010 https://doi.org/10.4103/0028-3886.66454
  4. Benuska J, Plisova M, Zabka M, Horvath J, Tisovsky P, Novorolsky K : The influence of anesthesia on intraoperative neurophysiological monitoring during spinal surgeries. Bratisl Lek Listy 120 : 794-801, 2019
  5. Bose B, Sestokas AK, Schwartz DM : Neurophysiological monitoring of spinal cord function during instrumented anterior cervical fusion. Spine J 4 : 202-207, 2004 https://doi.org/10.1016/j.spinee.2003.06.001
  6. Calancie B, Harris W, Brindle GF, Green BA, Landy HJ : Threshold-level repetitive transcranial electrical stimulation for intraoperative monitoring of central motor conduction. J Neurosurg 95(2 Suppl) : 161-168, 2001
  7. Charalampidis A, Jiang F, Wilson JR, Badhiwala JH, Brodke DS, Fehlings MG : The use of intraoperative neurophysiological monitoring in spine surgery. Global Spine J 10(1_suppl) : 104S-114S, 2020 https://doi.org/10.1177/2192568219859314
  8. Chen X, Sterio D, Ming X, Para DD, Butusova M, Tong T, et al. : 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, 2007 https://doi.org/10.1097/WNP.0b013e31802ed2d4
  9. Cho YE, Shin JJ, Kim KS, Chin DK, Kuh SU, Lee JH, et al. : The relevance of intramedullary high signal intensity and gadolinium (Gd-DTPA) enhancement to the clinical outcome in cervical compressive myelopathy. Eur Spine J 20 : 2267-2274, 2011 https://doi.org/10.1007/s00586-011-1878-3
  10. Choi JH, Shin JJ, Kim TH, Shin HS, Hwang YS, Park SK : Does intramedullary signal intensity on MRI affect the surgical outcomes of patients with ossification of posterior longitudinal ligament? J Korean Neurosurg Soc 56 : 121-129, 2014 https://doi.org/10.3340/jkns.2014.56.2.121
  11. Clark AJ, Safaee M, Chou D, Weinstein PR, Molinaro AM, Clark JP 3rd, et al. : Comparative sensitivity of intraoperative motor evoked potential monitoring in predicting postoperative neurologic deficits: nondegenerative versus degenerative myelopathy. Global Spine J 6 : 452-458, 2016 https://doi.org/10.1055/s-0035-1565258
  12. Cole T, Veeravagu A, Zhang M, Li A, Ratliff JK : Intraoperative neuromonitoring in single-level spinal procedures: a retrospective propensity score-matched analysis in a national longitudinal database. Spine (Phila Pa 1976) 39 : 1950-1959, 2014 https://doi.org/10.1097/brs.0000000000000593
  13. Eggspuehler A, Sutter MA, Grob D, Jeszenszky D, Porchet F, Dvorak J : Multimodal intraoperative monitoring (MIOM) during cervical spine surgical procedures in 246 patients. Eur Spine J 16(Suppl 2) : 209-215, 2007 https://doi.org/10.1007/s00586-007-0424-9
  14. Fouyas IP, Statham PF, Sandercock PA : Cochrane review on the role of surgery in cervical spondylotic radiculomyelopathy. Spine (Phila Pa 1976) 27 : 736-747, 2002 https://doi.org/10.1097/00007632-200204010-00011
  15. Geng T, Zhu X, Xu C : Changes of T2WI high signal of spinal magnetic resonance imaging correlated with the 1-year postoperative improvement rate in patients with cervical spondylotic myelopathy. Int J Clin Exp Med 12 : 13472-13479, 2019
  16. Gerling MC, Radcliff K, Isaacs R, Bianco K, Jalai CM, Worley NJ, et al. : Two-year results of the prospective spine treatment outcomes study: an analysis of complication rates, predictors of their development, and effect on patient derived outcomes at 2 years for surgical management of cervical spondylotic myelopathy. World Neurosurg 106 : 247-253, 2017 https://doi.org/10.1016/j.wneu.2017.06.147
  17. Halawa I, Reichert K, Sommer M, Paulus W : Increasing pulse widths and intensity increase the efficacy of high frequency rTMS in inducing excitatory aftereffects. bioRxiv, 2019 [Epub ahead of print]
  18. 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 86 : 1248-1253, 2004 https://doi.org/10.2106/00004623-200406000-00018
  19. Hirabayashi K, Miyakawa J, Satomi K, Maruyama T, Wakano K : Operative results and postoperative progression of ossification among patients with ossification of cervical posterior longitudinal ligament. Spine (Phila Pa 1976) 6 : 354-364, 1981 https://doi.org/10.1097/00007632-198107000-00005
  20. Ito Z, Matsuyama Y, Shinomiya K, Ando M, Kawabata S, Kanchiku T, et al. : Usefulness of multi-channels in intraoperative spinal cord monitoring: multi-center study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research. Eur Spine J 22 : 1891-1896, 2013 https://doi.org/10.1007/s00586-013-2722-8
  21. Journee HL, Polak HE, de Kleuver M, Langeloo DD, Postma AA : Improved neuromonitoring during spinal surgery using double-train transcranial electrical stimulation. Med Biol Eng Comput 42 : 110-113, 2004 https://doi.org/10.1007/BF02351019
  22. Khan MH, Smith PN, Balzer JR, Crammond D, Welch WC, Gerszten P, et al. : Intraoperative somatosensory evoked potential monitoring during cervical spine corpectomy surgery: experience with 508 cases. Spine (Phila Pa 1976) 31 : E105-E113, 2006 https://doi.org/10.1097/01.brs.0000200163.71909.1f
  23. Kim DG, Jo SR, Park YS, Hyun SJ, Kim KJ, Jahng TA, et al. : Multi-channel motor evoked potential monitoring during anterior cervical discectomy and fusion. Clin Neurophysiol Pract 2 : 48-53, 2017 https://doi.org/10.1016/j.cnp.2016.12.006
  24. Lall RR, Lall RR, Hauptman JS, Munoz C, Cybulski GR, Koski T, et al. : Intraoperative neurophysiological monitoring in spine surgery: indications, efficacy, and role of the preoperative checklist. Neurosurg Focus 33 : E10, 2012
  25. Lee JM, Kim DH, Kim HS, Choi BK, Han IH : The applicability of intraoperative neuromonitoring in patients with preoperative motor weakness during spine surgery. Korean J Spine 13 : 9-12, 2016 https://doi.org/10.14245/kjs.2016.13.1.9
  26. Lee JY, Hilibrand AS, Lim MR, Zavatsky J, Zeiller S, Schwartz DM, et al. : Characterization of neurophysiologic alerts during anterior cervical spine surgery. Spine (Phila Pa 1976) 31 : 1916-1922, 2006 https://doi.org/10.1097/01.brs.0000228724.01795.a2
  27. Ney JP, van der Goes DN, Watanabe JH : Cost-effectiveness of intraoperative neurophysiological monitoring for spinal surgeries: beginning steps. Clin Neurophysiol 123 : 1705-1707, 2012 https://doi.org/10.1016/j.clinph.2012.01.020
  28. Nuwer MR, Emerson RG, Galloway G, Legatt AD, Lopez J, Minahan R, et al. : Evidence-based guideline update: intraoperative spinal monitoring with somatosensory and transcranial electrical motor evoked potentials: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and the American Clinical Neurophysiology Society. Neurology 78 : 585-589, 2012 https://doi.org/10.1212/WNL.0b013e318247fa0e
  29. Park MK, Lee SJ, Kim SB, Lee KW, Lee HJ, Han EY, et al. : The effect of positive changes during intraoperative monitoring of the functional improvement in patients with cervical compressive myelopathy. Clin Interv Aging 13 : 1211-1218, 2018 https://doi.org/10.2147/CIA.S163467
  30. Rajshekhar V, Velayutham P, Joseph M, Babu KS : 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, 2011 https://doi.org/10.3171/2011.1.SPINE10310
  31. Sala F, Palandri G, Basso E, Lanteri P, Deletis V, Faccioli F, et al. : Motor evoked potential monitoring improves outcome after surgery for intramedullary spinal cord tumors: a historical control study. Neurosurgery 58 : 1129-1143; discussion 1129-1143, 2006 https://doi.org/10.1227/01.NEU.0000215948.97195.58
  32. Smith PN, Balzer JR, Khan MH, Davis RA, Crammond D, Welch WC, et al. : Intraoperative somatosensory evoked potential monitoring during anterior cervical discectomy and fusion in nonmyelopathic patients--a review of 1,039 cases. Spine J 7 : 83-87, 2007 https://doi.org/10.1016/j.spinee.2006.04.008
  33. Taunt CJ Jr, Sidhu KS, Andrew SA : Somatosensory evoked potential monitoring during anterior cervical discectomy and fusion. Spine (Phila Pa 1976) 30 : 1970-1972, 2005 https://doi.org/10.1097/01.brs.0000176321.02963.72
  34. Traynelis VC, Abode-Iyamah KO, Leick KM, Bender SM, Greenlee JD : Cervical decompression and reconstruction without intraoperative neurophysiological monitoring. J Neurosurg Spine 16 : 107-113, 2012 https://doi.org/10.3171/2011.10.SPINE11199
  35. Uchida K, Nakajima H, Sato R, Kokubo Y, Yayama T, Kobayashi S, et al. : Multivariate analysis of the neurological outcome of surgery for cervical compressive myelopathy. J Orthop Sci 10 : 564-573, 2005 https://doi.org/10.1007/s00776-005-0953-1
  36. Uchida K, Nakajima H, Takeura N, Yayama T, Guerrero AR, Yoshida A, et al. : Prognostic value of changes in spinal cord signal intensity on magnetic resonance imaging in patients with cervical compressive myelopathy. Spine J 14 : 1601-1610, 2014 https://doi.org/10.1016/j.spinee.2013.09.038
  37. Wang S, Tian Y, Wang C, Lu X, Zhuang Q, Peng H, et al. : Prognostic value of intraoperative MEP signal improvement during surgical treatment of cervical compressive myelopathy. Eur Spine J 25 : 1875-1880, 2016 https://doi.org/10.1007/s00586-016-4477-5
  38. Wei L, Wei Y, Tian Y, Cao P, Yuan W : Does three-grade classification of T2-weighted increased signal intensity reflect the severity of myelopathy and surgical outcomes in patients with cervical compressive myelopathy? A systematic review and meta-analysis. Neurosurg Rev 43 : 967-976, 2020 https://doi.org/10.1007/s10143-019-01106-3
  39. Xu R, Ritzl EK, Sait M, Sciubba DM, Wolinsky JP, Witham TF, et al. : A role for motor and somatosensory evoked potentials during anterior cervical discectomy and fusion for patients without myelopathy: analysis of 57 consecutive cases. Surg Neurol Int 2 : 133, 2011 https://doi.org/10.4103/2152-7806.85606
  40. Zileli M, Borkar SA, Sinha S, Reinas R, Alves OL, Kim SH, et al. : Cervical spondylotic myelopathy: natural course and the value of diagnostic techniques -WFNS Spine Committee Recommendations. Neurospine 16 : 386-402, 2019 https://doi.org/10.14245/ns.1938240.120