title: Detection of stroke during cardiac operations with somatosensory evoked responses.
abstract: OBJECTIVE
  The objectives of this study were to determine if monitoring of intraoperative somatosensory evoked potentials could be used to detect stroke during cardiac operations and to establish indicators of cerebral ischemia based on changes in these potentials.
  
  
  METHODS
  Twenty-five patients undergoing cardiac operations underwent preoperative and postoperative neurologic examinations as well as intraoperative recording of somatosensory evoked potentials. Detailed analysis of the waveforms of these potentials was performed.
  
  
  RESULTS
  Two of the 25 patients had intraoperative strokes. These patients and only these patients had changes in their somatosensory evoked potentials during the operation suggesting cerebral ischemia. The unilateral disappearance of the cortical somatosensory evoked potential waves correlated significantly with the clinical outcome of stroke (p < 0.004). Ischemic changes were detected in real time and were related to the removal of the aortic crossclamp in one patient and to the initiation of cardiopulmonary bypass in the other.
  
  
  CONCLUSIONS
  Somatosensory evoked potentials can detect intraoperative stroke during cardiac operations. Acute, unilateral decreases in amplitude of the cortical potential are more useful than changes in latency in detecting intraoperative stroke.
authors.affiliation: Department of Neurology, University of Pennsylvania, Philadelphia, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Stecker
authors.forename: A T
authors.initials: AT
authors.lastname: Cheung
authors.forename: T
authors.initials: T
authors.lastname: Patterson
authors.forename: J S
authors.initials: JS
authors.lastname: Savino
authors.forename: S J
authors.initials: SJ
authors.lastname: Weiss
authors.forename: R M
authors.initials: RM
authors.lastname: Richards
authors.forename: J E
authors.initials: JE
authors.lastname: Bavaria
authors.forename: T J
authors.initials: TJ
authors.lastname: Gardner
mesh_terms: D000328:Adult; D000368:Aged; D001831:Body Temperature; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000209:etiology; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative