title: [Transcranial motor evoked potentials monitoring for cerebral aneurysm surgery].
abstract: OBJECTIVE
  To evaluate the usefulness of transcranial motor evoked potential(MEP)monitoring for aneurysm surgery.
  
  
  METHODS
  Sixty-four patients undergoing aneurysm surgery were included in the study. We recorded MEP responses at craniotomy, when dissecting the aneurysm and surrounding tissue, after clipping, and during temporary clipping of the parent artery. We examined the relations between MEP wave pattern change and postoperative motor function.
  
  
  RESULTS
  In all of the patients MEPs were recordable for continuous neurophysiological monitoring of the vascular territory of interest throughout the surgery. In 16 patients, significant intraoperative MEP changes occurred. Of these patients, three patients presented with postoperative transient motor deficit. From the changes in MEP wave recording after aneurismal clipping and temporary occlusion of the parent artery. We speculated that the maximal time allowed for occlusion of the perforating arteries without ischemic damage is five minutes. Intraoperative MEP changes had a sensitivity of 100%(3/3)and specificity of 78.7%(48/61). The positive predictive value of postoperative motor deficit was 18.8%(3/16), and the negative predictive value was 100%(48/48). It was important to carry out MEP monitoring, so as not to produce false-negatives.
  
  
  CONCLUSIONS
  Intraoperative transcranial MEP monitoring is useful for predicting motor function after aneurysm surgery.
authors.affiliation: Department of Neurosurgery, Niigata City General Hospital and Medical Center, Kashiwazaki-city, Niigata, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamashita
authors.forename: Osamu
authors.initials: O
authors.lastname: Sasaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Suzuki
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Takao
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Nakamura
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Koike
mesh_terms: D000328:Adult; D000368:Aged; D003399:Craniotomy / Q000379:methods; D004558:Electric Stimulation / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods