A review of intraoperative monitoring for spinal surgery

Mark M Stecker, Mark M Stecker

Abstract

Background: Intraoperative neurophysiologic monitoring (IONM) is a technique that is helpful for assessing the nervous system during spine surgery.

Methods: This is a review of the field describing the basic mechanisms behind the techniques of IONM. These include the most often utilized trancranial motor evoked potentials (Tc-MEPs), somatosensory evoked potentials (SSEPs), and stimulated and spontaneous EMG activity. It also describes some of the issues regarding practices and qualifications of practitioners.

Results: Although the anatomic pathways responsible for the Tc-MEP and SSEP are well known and these clinical techniques have a high sensitivity and specificity, there is little published data showing that monitoring actually leads to improved patient outcomes. It is evident that IONM has high utility when the risk of injury is high, but may be only marginally helpful when the risk of injury is very low. The monitoring team must be well trained, be able to provide the surgeon feedback in real time, and coordinate activities with those of the surgical and anesthesia teams.

Conclusions: Although IONM is a valuable technique that provides sensitive and specific indications of neurologic injury, it does have limitations that must be understood. Maintaining a high quality of practice with appropriately trained personnel is critical.

Keywords: Intraoperative neurophysiologic monitoring; motor evoked potentials; somatosensory evoked potentials; spine.

Figures

Figure 1
Figure 1
Illustration of the responses to a single-pulse transcranial electrical stimulation in the (a) awake and (b) anesthetized patients. (c) Shows the effect of multipulse stimulation in the anesthetized patient
Figure 2
Figure 2
Illustrations of the anatomy underlying the upper (a) and lower (b) somatosensory evoked potentials
Figure 3
Figure 3
Illustration of the physiology of the (a) F-wave and (b) H-reflex
Figure 4
Figure 4
Illustration of the effect that the a priori probability P(I) has on the probability that a warning is associated with true injury when a warning is made with every injury (100% sensitive) and varying levels of false-positive warnings P(W/NI). W = warning, I = injury, NI = no injury, P(W/NI) is the conditional probability of a warning when there is no injury

References

    1. Amassian V. Animal and human motor system neuorphysiology related to intraoperative monitoring. In: Deletis V, Shils J, editors. Neurophysiology in Neurosurgery. San Diego California: Academic Press; 2002. pp. 3–23.
    1. Anderson DG, Wierzbowski LR, Schwartz DM, Hilibrand AS, Vaccaro AR, Albert TJ. Pedicle screws with high electrical resistance: A potential source of error with stimulus-evoked EMG. Spine (Phila Pa 1976) 2002;27:1577–81.
    1. Baars JH, Kalisch D, Herold KF, Hadzidiakos DA, Rehberg B. Concentration-dependent suppression of F-waves by sevoflurane does not predict immobility to painful stimuli in humans. Br J Anaesth. 2005;95:789–97.
    1. Bar-On Z, Zeilig G, Blumen N, Ohry A, Azaria M. Paraplegia following surgical correction of scoliosis with Cotrel-Dubousset instrumentation. Bull Hosp Jt Dis. 1995;54:32–4.
    1. Bell CM, Bajcar J, Bierman AS, Li P, Mamdani MM, Urbach DR. Potentially unintended discontinuation of long-term medication use after elective surgical procedures. Arch Intern Med. 2006;166:2525–31.
    1. Bigelow DC, Patterson T, Weber R, Stecker MM, Judy K. Comparison of endotracheal tube and hookwire electrodes for monitoring the vagus nerve. J Clin Monit Comput. 2002;17:217–20.
    1. Bose B, Wierzbowski LR, Sestokas AK. Neurophysiologic monitoring of spinal nerve root function during instrumented posterior lumbar spine surgery. Spine (Phila Pa 1976) 2002;27:1444–50.
    1. Burke D, Hicks R, Stephen J, Woodforth I, Crawford M. Assessment of corticospinal and somatosensory conduction simultaneously during scoliosis surgery. Electroencephalogr Clin Neurophysiol. 1992;85:388–96.
    1. 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. 2001;95:161–8.
    1. Calancie B, Madsen P, Lebwohl N. Stimulus-evoked EMG monitoring during transpedicular lumbosacral spine instrumentation.Initial clinical results. Spine (Phila Pa 1976) 1994;19:2780–6.
    1. Chen ZY, Wong HK, Chan YH. Variability of somatosensory evoked potential monitoring during scoliosis surgery. J Spinal Disord Tech. 2004;17:470–6.
    1. Chung I, Glow JA, Dimopoulos V, Walid MS, Smisson HF, Johnston KW, et al. Upper-limb somatosensory evoked potential monitoring in lumbosacral spine surgery: A prognostic marker for position-related ulnar nerve injury. Spine J. 2009;9:287–95.
    1. Darden BV, 2nd, Hatley MK, Owen JH. Neurogenic motor evoked-potential monitoring in anterior cervical surgery. J Spinal Disord. 1996;9:485–93.
    1. de Blas G, Barrios C, Regidor I, Montes E, Burgos J, Piza-Vallespir G, et al. Safe pedicle screw placement in thoracic scoliotic curves using t-EMG: Stimulation threshold variability at concavity and convexity in apex segments. Spine (Phila Pa 1976) 2012;37:E387–95.
    1. Delank KS, Delank HW, Konig DP, Popken F, Furderer S, Eysel P. Iatrogenic paraplegia in spinal surgery. Arch Orthop Trauma Surg. 2005;125:33–41.
    1. Deletis V. Intraoperative neuorphysiology and methodologies used to monitor the functional integrity of the motor system. In: Deletis V, Shils J, editors. Neurophysiology in Neurosurgery. San Diego, California: Academic Press; 2002. pp. 25–51.
    1. Deletis V, Isgum V, Amassian VE. Neurophysiological mechanisms underlying motor evoked potentials in anesthetized humans. Part 1. Recovery time of corticospinal tract direct waves elicited by pairs of transcranial electrical stimuli. Clin Neurophysiol. 2001;112:438–44.
    1. 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. 2007;16(Suppl 2):S209–15.
    1. 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 (Phila Pa 1976) 2006;31:E698–706.
    1. Fehlings MG, Brodke DS, Norvell DC, Dettori JR. The evidence for intraoperative neurophysiological monitoring in spine surgery: Does it make a difference? Spine (Phila Pa 1976) 2010;35:S37–46.
    1. Forbes HJ, Allen PW, Waller CS, Jones SJ, Edgar MA, Webb PJ, et al. Spinal cord monitoring in scoliosis surgery.Experience with 1168 cases. J Bone Joint Surg Br. 1991;73:487–91.
    1. Hendey GW, Barth BE, Soliz T. Overnight and postcall errors in medication orders. Acad Emerg Med. 2005;12:629–34.
    1. Holland NR, Lukaczyk TA, Riley LH, 3rd, Kostuik JP. Higher electrical stimulus intensities are required to activate chronically compressed nerve roots.Implications for intraoperative electromyographic pedicle screw testing. Spine (Phila Pa 1976) 1998;23:224–7.
    1. Isley MR, Pearlman RC. Credentialing and competency policy statement for intraoperative neuromonitoring. [Last Accessed on 2012 Apr 17]. Available online at: .
    1. Jahangiri FR, Holmberg A, Vega-Bermudez F, Arlet V. Preventing position-related brachial plexus injury with intraoperative somatosensory evoked potentials and transcranial electrical motor evoked potentials during anterior cervical spine surgery. Am J Electroneurodiagnostic Technol. 2011;51:198–205.
    1. Journee H. Motor EP physiology, risks and specific anesthetic effects. In: Nuwer MR, editor. Handbook of Clinical Neurophysiology. Vol. 8. Amsterdam, NL: Elsevier; 2008. pp. 218–34.
    1. Kalkman CJ, Drummond JC, Kennelly NA, Patel PM, Partridge BL. Intraoperative monitoring of tibialis anterior muscle motor evoked responses to transcranial electrical stimulation during partial neuromuscular blockade. Anesth Analg. 1992;75:584–9.
    1. Kelleher MO, Tan G, Sarjeant R, Fehlings MG. Predictive value of intraoperative neurophysiological monitoring during cervical spine surgery: A prospective analysis of 1055 consecutive patients. J Neurosurg Spine. 2008;8:215–21.
    1. Khan A, Pearlman RC, Bianchi DA, Hauck KW. Experience with two types of electromyography monitoring electrodes during thyroid surgery. Am J Otolaryngol. 1997;18:99–102.
    1. Komanetsky RM, Padberg AM, Lenke LG, Bridwell KH, Russo MH, Chapman MP, et al. Neurogenic motor evoked potentials: A prospective comparison of stimulation methods in spinal deformity surgery. J Spinal Disord. 1998;11:21–8.
    1. Kothbaurer K. Motor evoked potential monitoring for intramedullary spinal cord surgery. In: Deletis V, Shils J, editors. Neurophysiology in Neurosurgery. San Diego, California: Academic Press; 2002. pp. 73–92.
    1. Krammer MJ, Wolf S, Schul DB, Gerstner W, Lumenta CB. Significance of intraoperative motor function monitoring using transcranial electrical motor evoked potentials (MEP) in patients with spinal and cranial lesions near the motor pathways. Br J Neurosurg. 2009;23:48–55.
    1. Langeloo DD, Journee HL, de Kleuver M, Grotenhuis JA. Criteria for transcranial electrical motor evoked potential monitoring during spinal deformity surgery A review and discussion of the literature. Neurophysiol Clin. 2007;37:431–9.
    1. Leppanen RE, Abnm D. American Society of Neurophysiological M. Intraoperative monitoring of segmental spinal nerve root function with free-run and electrically-triggered electromyography and spinal cord function with reflexes and F-responses. A position statement by the American Society of Neurophysiological Monitoring. J Clin Monit Comput. 2005;19:437–61.
    1. Loder RT, Thomson GJ, LaMont RL. Spinal cord monitoring in patients with nonidiopathic spinal deformities using somatosensory evoked potentials. Spine (Phila Pa 1976) 1991;16:1359–64.
    1. MacEwen 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.
    1. Malhotra NR, Shaffrey CI. Intraoperative electrophysiological monitoring in spine surgery. Spine (Phila Pa 1976) 2010;35:2167–79.
    1. Manninen PH. Monitoring evoked potentials during spinal surgery in one institution. Can J Anaesth. 1998;45:460–5.
    1. Minahan RE, Riley LH, 3rd, Lukaczyk T, Cohen DB, Kostuik JP. The effect of neuromuscular blockade on pedicle screw stimulation thresholds. Spine (Phila Pa 1976) 2000;25:2526–30.
    1. Montes E, De Blas G, Regidor I, Barrios C, Burgos J, Hevia E, et al. Electromyographic thresholds after thoracic screw stimulation depend on the distance of the screw from the spinal cord and not on pedicle cortex integrity. Spine J. 2012;12:127–32.
    1. More RC, Nuwer MR, Dawson EG. Cortical evoked potential monitoring during spinal surgery: Sensitivity, specificity, reliability, and criteria for alarm. J Spinal Disord. 1988;1:75–80.
    1. Nash CL, Jr, Lorig RA, Schatzinger LA, Brown RH. Spinal cord monitoring during operative treatment of the spine. Clin Orthop Relat Res. 1977;126:100–5.
    1. 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 (Phila Pa 1976) 2002;27:825–30.
    1. Nuwer MR, Dawson EG, Carlson LG, Kanim LE, Sherman JE. 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.
    1. Parker SL, Amin AG, Farber SH, McGirt MJ, Sciubba DM, Wolinsky JP, et al. Ability of electromyographic monitoring to determine the presence of malpositioned pedicle screws in the lumbosacral spine: Analysis of 2450 consecutively placed screws. J Neurosurg Spine. 2011;15:130–5.
    1. 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.
    1. Quinones-Hinojosa A, Lyon R, Zada G, Lamborn KR, Gupta N, Parsa AT, et al. Changes in transcranial motor evoked potentials during intramedullary spinal cord tumor resection correlate with postoperative motor function. Neurosurgery. 2005;56:982–93. discussion 982-93.
    1. Romstock J, Strauss C, Fahlbusch R. Continuous electromyography monitoring of motor cranial nerves during cerebellopontine angle surgery. J Neurosurg. 2000;93:586–93.
    1. Roy EP, 3rd, Gutmann L, Riggs JE, Jones ET, Byrd JA, Ringel RA. Intraoperative somatosensory evoked potential monitoring in scoliosis. Clin Orthop Relat Res. 1988;229:94–8.
    1. 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. 2006;58:1129–43. discussion 1129-43.
    1. Schieppati M, Ducati A. Effects of stimulus intensity, cervical cord tractotomies and cerebellectomy on somatosensory evoked potentials from skin and muscle afferents of cat hind limb. Electroencephalogr Clin Neurophysiol. 1981;51:363–72.
    1. Schwartz DM, Auerbach JD, Dormans JP, Flynn J, Drummond DS, Bowe JA, et al. Neurophysiological detection of impending spinal cord injury during scoliosis surgery. J Bone Joint Surg Am. 2007;89:2440–9.
    1. Schwartz DM, Sestokas AK, Dormans JP, Vaccaro AR, Hilibrand AS, Flynn JM, et al. Transcranial electric motor evoked potential monitoring during spine surgery: Is it safe? Spine (Phila Pa 1976) 2011;36:1046–9.
    1. 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.
    1. Sherrington C. The integrative action of the nervous system. New Haven, CT: Yale University Press; 1906.
    1. Slimp JC. Electrophysiologic intraoperative monitoring for spine procedures. Phys Med Rehabil Clin N Am. 2004;15:85–105.
    1. Sloan T. Anesthesia and motor evoked potential monitoring. In: Deletis V, Shils J, editors. Neurophysiology in Neurosurgery. San Diego, California: Academic Press; 2002. pp. 452–74.
    1. 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 1039 cases. Spine J. 2007;7:83–7.
    1. Stecker MM, Baylor K, Wolfe J, Stevenson M. Acute nerve stretch and the compound motor action potential. J Brachial Plex Peripher Nerve Inj. 2011;6:4.
    1. Stecker MM, Cheung AT, Patterson T, Savino JS, Weiss SJ, Richards RM, et al. Detection of stroke during cardiac operations with somatosensory evoked responses. J Thorac Cardiovasc Surg. 1996;112:962–72.
    1. Stecker MM, Robertshaw J. Factors affecting reliability of interpretations of intra-operative evoked potentials. J Clin Monit Comput. 2006;20:47–55.
    1. Sutter MA, Eggspuehler A, Grob D, Porchet F, Jeszenszky D, Dvorak J. Multimodal intraoperative monitoring (MIOM) during 409 lumbosacral surgical procedures in 409 patients. Eur Spine J. 2007;16(Suppl 2):S221–8.
    1. Szelenyi A, Langer D, Beck J, Raabe A, Flamm ES, Seifert V, et al. Transcranial and direct cortical stimulation for motor evoked potential monitoring in intracerebral aneurysm surgery. Neurophysiol Clin. 2007;37:391–8.
    1. Toleikis RJ. Neurophysiological monitoring during pedicle screw placement. In: Deletis V, Shils J, editors. Neurophysiology in Neurosurgery. San Diego, California: Academic Press; 2002. pp. 231–64.
    1. Toleikis JR. American Society of Neurophysiological Monitoring. Intraoperative monitoring using somatosensory evoked potentials. A position statement by the American Society of Neurophysiological Monitoring. J Clin Monit Comput. 2005;19:241–58.
    1. Toleikis JR, Skelly JP, Carlvin AO, Burkus JK. Spinally elicited peripheral nerve responses are sensory rather than motor. Clin Neurophysiol. 2000;111:736–42.
    1. Toleikis JR, Skelly JP, Carlvin AO, Toleikis SC, Bernard TN, Burkus JK, et al. The usefulness of electrical stimulation for assessing pedicle screw placements. J Spinal Disord. 2000;13:283–9.
    1. Ulkatan S, Neuwirth M, Bitan F, Minardi C, Kokoszka A, Deletis V. Monitoring of scoliosis surgery with epidurally recorded motor evoked potentials (D wave) revealed false results. Clin Neurophysiol. 2006;117:2093–101.
    1. Uribe JS, Kolla J, Omar H, Dakwar E, Abel N, Mangar D, et al. Brachial plexus injury following spinal surgery. J Neurosurg Spine. 2010;13:552–8.

Source: PubMed

Szponzorok és közreműködők

Egészségi állapot

Kábítószer-beavatkozások

3
Iratkozz fel