Evaluation of Various Evoked Potential Techniques for Spinal Cord Monitoring During Scoliosis Surgery

Study Design. This prospective study compared the outcomes of different evoked potential (EP) techniques for intraoperative spinal cord monitoring. Objectives. To evaluate the reliability of different EP techniques administered during scoliosis surgery. Summary of Background Data. A number of different methods of intraoperative spinal cord monitoring are available. Because each has its own advantages and limitations, multimodal spinal cord monitoring has been proposed to improve monitoring reliability. Materials and Methods. Cortical somatosensory-evoked potential (CSEP), cortical motor-evoked potential (CMEP), spinal somatosensory-evoked potential (SSEP), and spinal cord-evoked potential (SCEP) were applied simultaneously to 30 patients undergoing surgical correction for spinal deformity. The presence of the EP waveforms and their reproducibilities over separate tests were compared. In addition, the monitoring outcomes were evaluated with the clinical results. Results. Of the 30 patients, CSEP waveforms were successfully recorded in 28 cases (93%), SCEP in 25 cases (83%), CMEP in 24 cases (80%), and SSEP in 21 cases (70%). Latencies of each EP technique showed no significant variability. However, amplitudes showed significant differences between different techniques. SCEP and CMEP showed clearer waveforms of greater amplitude that could be detected faster than CSEP and SSEP waveforms. SCEP and SSEP waveforms were more easily influenced by the surgical procedure. Conclusion. CSEP and CMEP are recommended for routine monitoring, so that both ascending and descending tracts are monitored. If adequate signals for either of these proposed monitoring methods cannot be easily obtained, SSEP can substitute for CSEP, whereas SCEP can substitute for CMEP.

[1]  G. Klem,et al.  Simple technique for monitoring intraoperative spinal cord function. , 1981, Neurosurgery.

[2]  C. Marsden,et al.  A method of monitoring function in corticospinal pathways during scoliosis surgery with a note on motor conduction velocities. , 1986, Journal of neurology, neurosurgery, and psychiatry.

[3]  M. Nuwer,et al.  Somatosensory evoked potential spinal cord monitoring reduces neurologic deficits after scoliosis surgery: results of a large multicenter survey. , 1995, Electroencephalography and clinical neurophysiology.

[4]  T. Andoh,et al.  Effects of anesthetics on somatosensory and motor evoked potentials in humans , 1998 .

[5]  M A Green,et al.  Spinal Cord Monitoring During Spinal Surgery Using Somatosensory Spinal Evoked Potentials , 1983, Journal of pediatric orthopedics.

[6]  M R Nuwer,et al.  Spinal cord monitoring with somatosensory techniques. , 1998, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[7]  American Electroencephalographic Society Guidelines for Intraoperative Monitoring of Sensory Evoked Potentials1 , 1987, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[8]  H. Tsuji,et al.  Spinal Cord Monitoring as a Clinical Utilization of the Spinal Evoked Potential , 1984, Clinical orthopaedics and related research.

[9]  L. Pelosi,et al.  Neurological complications of anterior spinal surgery for kyphosis with normal somatosensory evoked potentials (SEPs) , 1999, Journal of neurology, neurosurgery, and psychiatry.

[10]  K. Bridwell,et al.  Sensitivity and Specificity of Somatosensory and Neurogenic‐Motor Evoked Potentials in Animals and Humans , 1988, Spine.

[11]  J C Leong,et al.  Variability of somatosensory-evoked potentials in different stages of scoliosis surgery. , 1999, Spine.

[12]  J. Daube.  Intraoperative monitoring by evoked potentials for spinal cord surgery: the pros. , 1989, Electroencephalography and clinical neurophysiology.

[13]  P. Sponseller,et al.  Efficacy of Multimodality Spinal Cord Monitoring During Surgery for Neuromuscular Scoliosis , 1995, Spine.

[14]  R H Britt,et al.  Spinal and Cortical Somatosensory Evoked Potential Monitoring During Corrective Spinal Surgery with 108 Patients , 1986, Spine.

[15]  M. Nuwer,et al.  Spinal Cord Monitoring: Results of the Scoliosis Research Society and the European Spinal Deformity Society Survey , 1991, Spine.

[16]  J. Kostuik,et al.  The Use of Mechanically Elicited Electromyograms to Protect Nerve Roots During Surgery for Spinal Degeneration , 1994, Spine.

[17]  S Matsuoka,et al.  IFCN recommended standards for short latency somatosensory evoked potentials. Report of an IFCN committee. International Federation of Clinical Neurophysiology. , 1994, Electroencephalography and clinical neurophysiology.

[18]  C. Vauzelle,et al.  Functional monitoring of spinal cord activity during spinal surgery. , 1973, Clinical orthopaedics and related research.

[19]  W. Levy.  Spinal evoked potentials from the motor tracts. , 1983, Journal of neurosurgery.

[20]  A. Sances,et al.  Spinal cord evaluation by cortical evoked responses. , 1979, Archives of neurology.

[21]  D. Burke,et al.  Surgical monitoring of motor pathways. , 1998, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[22]  M Crawford,et al.  Direct comparison of corticospinal volleys in human subjects to transcranial magnetic and electrical stimulation. , 1993, The Journal of physiology.

[23]  S. Jones,et al.  Spinal and sub-cortical evoked potentials following stimulation of the posterior tibial nerve in man. , 1978, Electroencephalography and clinical neurophysiology.

[24]  R. Hicks,et al.  Cotrel‐Dubousset Instrumentation in Children Using Simultaneous Motor And Somatosensory Evoked Potential Monitoring , 1996, Spine.