title: Somatosensory evoked potentials versus locoregional anaesthesia in the monitoring of cerebral function during carotid artery surgery: preliminary results of a prospective study.
abstract: OBJECTIVE
  to relate changes in somatosensory-evoked potentials (SEPs) with onset of neurological deficits in patients having carotid endarterectomy (CEA) under locoregional anaesthesia.
  
  
  METHODS
  a prospective study of 50 consecutive patients.
  
  
  RESULTS
  SEPs yielded an accuracy of 98%, specificity 100%, and sensitivity 89%. In all concordant cases the onset of a neurological deficit in awake patients corresponded to a 30--40% reduction in amplitude of N20-P25 waveforms. After shunting, the N20-P25 took 2--3 min to return to normal.
  
  
  CONCLUSIONS
  SEPs are associated with a 2% false negative rate. Their threshold for detecting cerebral ischaemia is lower than the currently reported value for patients under general anaesthesia. The time needed for evoked potentials (2--3 min) to return to normal after shunting limits their usefulness in verifying effective shunting.
authors.affiliation: I Cattedra di Chirurgia Vascolare, University of Rome La Sapienza, Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Sbarigia
authors.forename: A
authors.initials: A
authors.lastname: Schioppa
authors.forename: M
authors.initials: M
authors.lastname: Misuraca
authors.forename: M A
authors.initials: MA
authors.lastname: Panico
authors.forename: C
authors.initials: C
authors.lastname: Battocchio
authors.forename: C
authors.initials: C
authors.lastname: Maraglino
authors.forename: F
authors.initials: F
authors.lastname: Speziale
authors.forename: P
authors.initials: P
authors.lastname: Fiorani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local; D016894:Endarterectomy, Carotid; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity