title: Intraoperative monitoring of motor-evoked potentials for supratentorial tumor surgery.
abstract: OBJECTIVE
  The purpose of this study was to assess the feasibility and clinical efficacy of motor evoked potential (MEP) monitoring for supratentorial tumor surgery.
  
  
  METHODS
  Between 2010 and 2012, to prevent postoperative motor deterioration, MEP recording after transcranial stimulation was performed in 84 patients with supratentorial brain tumors (45 males, 39 females; age range, 24-80 years; median age, 58 years). MEP monitoring results were correlated with postoperative motor outcome compared to preoperative motor status.
  
  
  RESULTS
  MEP recordings were stable in amplitude (<50% reduction in amplitude) during surgery in 77 patients (91.7%). No postoperative motor deficit was found in 66 out of 77 patients with stable MEP amplitudes. However, postoperative paresis developed in 11 patients. False negative findings were associated with edema in peri-resectional regions and postoperative bleeding in the tumor bed. MEP decrease in amplitude (>50%) occurred in seven patients (8.3%). However, no deficit occurred postoperatively in four patients following preventive management during the operation. Three patients had permanent paresis, which could have been associated with vascular injury during tumor resection.
  
  
  CONCLUSIONS
  MEP monitoring during supratentorial tumor surgery is feasible and safe. However, false negative MEP results associated with postoperative events may occur in some patients. To achieve successful monitoring, collaboration between surgeon, anesthesiologist and an experienced technician is mandatory.
authors.affiliation: Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea.
authors.forename: Jung Jae
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea.
authors.forename: Young Il
authors.initials: YI
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea.
authors.forename: Jae Taek
authors.initials: JT
authors.lastname: Hong
authors.affiliation: Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea.
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Sung
authors.affiliation: Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea.
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea.
authors.forename: Seung Ho
authors.initials: SH
authors.lastname: Yang
keywords: Brain tumor; Intraoperative monitoring; Motor-evoked potentials; Supratentorial; Surgery