title: Intraoperative Loss of Tibialis Anterior Transcranial Electrical Motor Evoked Potentials Predicted Postoperative Footdrop.
abstract: BACKGROUND
  Footdrop secondary to L5 root injury is a rare complication associated with lumbar surgery. It is unclear whether intraoperative neuromonitoring can detect such an injury.
  
  
  METHODS
  A 54-year-old man who had had bilateral chronic L5 radiculopathy underwent L4-S1 lumbosacral decompression and fusion. During surgery, the patient lost transcranial electrical motor evoked potentials (tceMEPs) from the left tibialis anterior (TA) at the time of L5-S1 intervertebral cage placement. Neither intraoperative free-run electromyography nor somatosensory evoked potentials detected any changes. In addition, contralateral TA tceMEPs remained stable. Postoperatively, the patient presented with left-sided footdrop that has persisted for >1 year.
  
  
  CONCLUSIONS
  Intraoperative TA tceMEPs could detect L5 root iatrogenic injury.
authors.affiliation: Department of Neurology, Geisinger Medical Center, Danville, Pennsylvania, USA; Department of Audiology and Speech Pathology, Bloomsburg University of Pennsylvania, Bloomsburg, Pennsylvania, USA. Electronic address: qyue@bloomu.edu.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yue
authors.affiliation: Department of Neurology, Geisinger Medical Center, Danville, Pennsylvania, USA; Department of Audiology and Speech Pathology, Bloomsburg University of Pennsylvania, Bloomsburg, Pennsylvania, USA.
authors.forename: Tyson
authors.initials: T
authors.lastname: Hale
authors.affiliation: Department of Neurology, Geisinger Medical Center, Danville, Pennsylvania, USA.
authors.forename: Aaron
authors.initials: A
authors.lastname: Knecht
authors.affiliation: Department of Neurology, Geisinger Medical Center, Danville, Pennsylvania, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Laidacker
mesh_terms: D019299:Decompression, Surgical / Q000009:adverse effects*; D019054:Evoked Potentials, Motor; D020233:Gait Disorders, Neurologic / Q000175:diagnosis* / Q000209:etiology* / Q000517:prevention & control; D006801:Humans; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods*; D007796:Laminectomy / Q000009:adverse effects; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013123:Spinal Fusion / Q000009:adverse effects*; D016896:Treatment Outcome
keywords: Electromyography (EMG); Footdrop; Somatosensory evoked potential (SSEP); Tibialis anterior (TA); Transcranial electrical motor evoked potential (tceMEP)