title: Neurophysiological monitoring of lumbar spinal nerve roots: A case report of postoperative deficit and literature review.
abstract: BACKGROUND
  Intraoperative neurophysiological monitoring (IONM) has proven to help reduce the probability of postoperative neurological deficit for spinal deformity correctional surgeries. However, in rare cases new deficits may still happen. We report a surgical case in which the patient had postoperative paralysis. We would like to call for more case reports with postoperative neurological deficits as they present difficult clinical cases.
  
  
  METHODS
  A 61-year-old male patient with severe thoracolumbar kyphoscoliosis underwent posterior spinal correction and fusion with segmental T10-L5 pedicle screws and rods instrumentation with IONM. The only intraoperative event was a pedicle breach at left L3 which was detected by triggered electromyography (EMG) testing, and the pedicle screw was repositioned. Left lower extremity paralysis was observed upon patient awakening. He received rehabilitation treatment and had limited recovery of muscle strength. Partial lumbar nerve root injury was likely the cause of the paralysis.
  
  
  CONCLUSIONS
  This is a case with new lumbar nerve root deficit, with positive EMG signal change, but negative somatosensory evoked potential (SSEP) and motor evoked potential (MEP) findings. We discuss the different neurophysiological modalities for monitoring lumbar spinal nerve root function. We review journal articles from the past two decades which reported lumbar root deficits, and list neuromonitoring events during the surgeries.
  
  
  CONCLUSIONS
  Multimodality monitoring with spontaneous and electrically triggered EMG combined with SSEP and MEP may provide the best chance to detect lumbar nerve root injuries.
authors.affiliation: Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Yuguang
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Neurological Monitoring Services, West Reading, PA, USA. Electronic address: bpw@neuromoninc.com.
authors.forename: Baoqing P
authors.initials: BP
authors.lastname: Wang
authors.affiliation: Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Junlin
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Spinal Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Yaolong
authors.initials: Y
authors.lastname: Deng
keywords: Case report; Electromyography; Evoked potential; Neuromonitoring; Postoperative deficit; Spinal nerve root