title: Efficacy of Head Repositioning in Restoration of Electrophysiological Signals During Cervical Spine Procedures.
abstract: OBJECTIVE
  To evaluate the frequency of loss of neurophysiological potentials during head positioning, the usefulness of head repositioning to restore the potentials, and the effect on neurological outcome.
  
  
  METHODS
  We retrospectively reviewed consecutive cervical spine surgeries performed at the Israel Spine Center, Assuta Medical Center, during 2006 to 2013. Surgeries performed with neuromonitoring (transcranial-electric motor evoked potentials, somatosensory evoked potentials, electromyographic recordings) were included. Demographic data, medical history, findings at neurological examination and imaging, electrophysiological data recorded during surgery, and neurological outcomes were collected and analyzed.
  
  
  RESULTS
  Three hundred eighty-one patients met inclusion criteria. Loss of potentials detected in nine patients during patient positioning and repositioning was undertaken with the aim of restoring electrophysiological signals. In 5/9 patients, repositioning resulted in immediate reappearance of potentials; in 1/5, potentials were affected again during decompression. In 4/9, repositioning did not immediately restore electrophysiological signals; in ¼, potentials reappeared later during the decompression and in ¾, potentials had not recovered till the conclusion of surgery. There were new neurological deficits in 2/9, including one patient with loss of potential that was not restored with repositioning and the one in whom potential was restored but lost again during decompression.
  
  
  CONCLUSIONS
  Intraoperative neuro monitoring is an efficient tool to alert the surgical team to potential neurological damage. Head reposition often restores the electrophysiological signals with possible prevention of impending sequelae.
authors: *Department of Neurology, Barzilai Medical Center, Ashkelon, Israel; †Surgical Monitoring Services LTD, Beit Shemesh, Israel; ‡Department of Pediatric Neurosurgery, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; and §Israel Spine Center, Assuta Medical Center, Tel Aviv, Israel.
authors: Shmuel
authors: S
authors: Appel
authors: Akiva
authors: A
authors: Korn
authors: Tali
authors: T
authors: Biron
authors: Kobi
authors: K
authors: Goldstein
authors: Nahshon
authors: N
authors: Rand
authors: Michael
authors: M
authors: Millgram
authors: Yizhar
authors: Y
authors: Floman
authors: Ely
authors: E
authors: Ashkenazi
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000503:physiopathology / Q000601:surgery*; D019299:Decompression, Surgical / Q000379:methods*; D004576:Electromyography / Q000379:methods*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006257:Head; D006801:Humans; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods*; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D012189:Retrospective Studies