False Negative and Positive Motor Evoked Potentials in One Patient: Is Single Motor Evoked Potential Monitoring Reliable Method?: A Case Report and Literature Review

Study Design. A case report and literature review. Objective. To report a false negative and delayed positive motor-evoked potential (MEP) in 1 patient. Summary of Background Data. An unreliable MEP can result in fatal outcomes because surgeons have recently begun to depend on the MEP for intraoperative decision-making. Methods. We report a case of a false MEP during scoliosis surgery that showed false negative and positive MEPs during a series of operations. Results. A 23-year-old man with a history of spondyloepiphyseal dysplasia presented with severe kyphoscoliosis. The initial neurologic examination did not reveal any neurologic abnormalities. Surgical correction and fusion were performed with transcranial MEP monitoring. During the entire procedure, the MEP did not reveal any signs of cord injury. However, lower limb paralysis and paresthesia was observed when the patient awakened. After 2 additional surgical procedures to recover the neurologic deficit, the MEP did not show any signs of cord injury but the patient's neurologic status had recovered slightly. At postoperative day 8, the neurologic status recovered, and a third operation was performed to fix the long rods. However, there were abnormal amplitudes in both lower limbs but the patient's neurologic status was almost normal. Conclusion. From our experience of false negative and positive MEP in 1 patient, it is concluded that undesirable events can occur with use of MEP in scoliosis or other spinal surgery. Therefore, we warn the surgeons too heavily rely on the MEP monitoring, and propose a further prospective study as well as use of alternative method that can improve the reliability of single MEP.

[1]  J. Ransohoff,et al.  Somatosensory Evoked Potentials During Decompression and Stabilization of the Spine: Methods and Findings , 1979, Spine.

[2]  Vedran Deletis,et al.  Neurophysiological mechanisms underlying motor evoked potentials in anesthetized humans. Part 2. Relationship between epidurally and muscle recorded MEPs in man , 2001, Clinical Neurophysiology.

[3]  S. Hyun,et al.  Combined motor- and somatosensory-evoked potential monitoring for spine and spinal cord surgery: correlation of clinical and neurophysiological data in 85 consecutive procedures , 2009, Spinal Cord.

[4]  M. Grafe,et al.  Preservation of evoked potentials in a case of anterior spinal artery syndrome. , 1990, Electroencephalography and clinical neurophysiology.

[5]  R. Maxwell,et al.  The Initial Use of Free-running Electromyography to Detect Early Motor Tract Injury during Resection of Intramedullary Spinal Cord Lesions , 2005, Neurosurgery.

[6]  P. Lanteri,et al.  Motor Evoked Potential Monitoring Improves Outcome after Surgery for Intramedullary Spinal Cord Tumors: A Historical Control Study , 2006, Neurosurgery.

[7]  L. Pelosi,et al.  Combined monitoring of motor and somatosensory evoked potentials in orthopaedic spinal surgery , 2002, Clinical Neurophysiology.

[8]  C. L. Nash,et al.  Spinal cord monitoring during operative treatment of the spine. , 1977, Clinical orthopaedics and related research.

[9]  A. Legatt.  Current Practice of Motor Evoked Potential Monitoring: Results of a Survey , 2002, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[10]  T. Yamamoto,et al.  Corticospinal direct response in humans: identification of the motor cortex during intracranial surgery under general anaesthesia. , 1988, Journal of neurology, neurosurgery, and psychiatry.

[11]  N. Epstein,et al.  Surgical treatment of spinal cord astrocytomas of childhood. A series of 19 patients. , 1982, Journal of neurosurgery.

[12]  Y. Péréon,et al.  Somatosensory- and motor-evoked potential monitoring without a wake-up test during idiopathic scoliosis surgery: an accepted standard of care. , 1999, Spine.

[13]  D. Burke,et al.  Assessment of corticospinal and somatosensory conduction simultaneously during scoliosis surgery. , 1992, Electroencephalography and clinical neurophysiology.

[14]  J Schramm,et al.  Modification of cortical stimulation for motor evoked potentials under general anesthesia: technical description. , 1993, Neurosurgery.

[15]  D. Burke,et al.  Cotrel-dubousset instrumentation in children using simultaneous motor and somatosensory evoked potential monitoring. , 1996 .

[16]  F. Miller,et al.  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 , 2003, Spine.

[17]  B. Stein.  Intramedullary spinal cord tumors. , 1983, Clinical neurosurgery.

[18]  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.

[19]  W. Mess,et al.  Assessment of spinal cord integrity during thoracoabdominal aortic aneurysm repair. , 2002, The Annals of thoracic surgery.

[20]  S. Jones,et al.  Two cases of quadriparesis following anterior cervical discectomy, with normal perioperative somatosensory evoked potentials , 2003, Journal of neurology, neurosurgery, and psychiatry.

[21]  H. Morton,et al.  Stimulation of the cerebral cortex in the intact human subject , 1980, Nature.

[22]  D. Burke,et al.  Corticospinal volleys evoked by anodal and cathodal stimulation of the human motor cortex. , 1990, The Journal of physiology.

[23]  T. Sloan,et al.  Anesthesia for Intraoperative Neurophysiologic Monitoring of the Spinal Cord , 2002, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[24]  V. Deletis.  Intraoperative monitoring of the functional integrity of the motor pathways. , 1993, Advances in neurology.

[25]  R. Betz,et al.  Neurologic Injury in the Surgical Treatment of Idiopathic Scoliosis: Guidelines for Assessment and Management , 2009, The Journal of the American Academy of Orthopaedic Surgeons.

[26]  D Burke,et al.  Anodal and cathodal stimulation of the upper-limb area of the human motor cortex. , 1992, Brain : a journal of neurology.

[27]  I. Whittle,et al.  Recording of spinal somatosensory evoked potentials for intraoperative spinal cord monitoring. , 1986, Journal of neurosurgery.

[28]  V. Deletis,et al.  Monitoring of scoliosis surgery with epidurally recorded motor evoked potentials (D wave) revealed false results , 2006, Clinical Neurophysiology.

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

[30]  Vedran Deletis,et al.  Intraoperative neurophysiological monitoring of the spinal cord during spinal cord and spine surgery: A review focus on the corticospinal tracts , 2008, Clinical Neurophysiology.

[31]  J. Schramm,et al.  Transcranial high-frequency repetitive electrical stimulation for recording myogenic motor evoked potentials with the patient under general anesthesia. , 1996, Neurosurgery.

[32]  J. Zentner,et al.  Noninvasive motor evoked potential monitoring during neurosurgical operations on the spinal cord. , 1989, Neurosurgery.

[33]  D. M. Schwartz,et al.  Influence of nitrous oxide on posterior tibial nerve cortical somatosensory evoked potentials. , 1997, Journal of spinal disorders.

[34]  V Deletis,et al.  Intraoperative spinal cord monitoring for intramedullary surgery: an essential adjunct. , 1997, Pediatric neurosurgery.

[35]  J. R. Bowen,et al.  Neurophysiological detection of impending spinal cord injury during scoliosis surgery. , 2007, The Journal of bone and joint surgery. American volume.

[36]  D. M. Schwartz,et al.  Efficacy of spinal cord monitoring in scoliosis surgery in patients with cerebral palsy. , 1996, Journal of spinal disorders.

[37]  C. O'Donovan,et al.  Intraoperative monitoring. , 2005, Archives of neurology.

[38]  M. Janusz,et al.  Intraoperative spinal cord monitoring during descending thoracic and thoracoabdominal aneurysm surgery. , 2002, The Annals of thoracic surgery.

[39]  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.

[40]  Dietmar Stolke,et al.  The impact of neurophysiological intraoperative monitoring on surgical decisions: a critical analysis of 423 cases. , 2002, Journal of neurosurgery.

[41]  R. Lesser,et al.  Anterior spinal cord injury with preserved neurogenic ‘motor’ evoked potentials , 2001, Clinical Neurophysiology.

[42]  C. Kalkman,et al.  Assessment of spinal cord ischemia by means of evoked potential monitoring during thoracoabdominal aortic surgery. , 2000, Seminars in vascular surgery.

[43]  V. Amassian,et al.  Single and multiple-unit analysis of cortical stage of pyramidal tract activation. , 1954, Journal of neurophysiology.

[44]  V. Deletis,et al.  Motor-evoked potential monitoring for intramedullary spinal cord tumor surgery: correlation of clinical and neurophysiological data in a series of 100 consecutive procedures. , 1998, Neurosurgical focus.