title: Neurologic findings in coronary artery bypass patients: perioperative or preexisting?
abstract: OBJECTIVE
  This prospective study compares the incidence of preexisting neurologic findings in elective cardiac surgery patients presenting with and without coronary atherosclerosis.
  
  
  METHODS
  This single-center study was conducted at a tertiary care hospital.
  
  
  METHODS
  After Review Board approval and obtaining written informed consent, 11 patients undergoing valvular heart surgery, 9 patients undergoing similar valvular procedures with concomitant coronary artery bypass surgery, and 4 patients undergoing coronary artery bypass surgery alone were enrolled. Preoperatively, all patients underwent a structured neurologic assessment, and the latter four additionally had preoperative magnetic resonance imaging.
  
  
  RESULTS
  The patients, 9 of 24 of whom were female, were aged 46 to 78 years and, other than ischemic heart disease, had medical histories that were similar between groups, with the exception of one patient having scleroderma. None of the patients had a clinical history of neurologic or cerebrovascular disease. Nine percent (1 of 11) of the valve-only patients showed subtle preoperative neurologic abnormalities, compared with 89% (eight of nine) of the valve patients having concomitant coronary surgery and 100% (four of four) of coronary artery bypass-only patients. Additionally, brain imaging scans of all four coronary bypass patients showed nonspecific changes reported as scattered punctate areas of high signal less than 3 to 4 mm in diameter.
  
  
  CONCLUSIONS
  This survey shows that both subtle neurological abnormalities and magnetic resonance imaging lesions can be found in a high percentage of patients with coronary atherosclerosis. Furthermore, this study indicates that without a standardized preoperative neurological examination, postoperative neurologic dysfunction cannot necessarily be ascribed to perioperative events.
authors.affiliation: Department of Anaesthesia, London Health Sciences Center, University of Western Ontario, London, Ontario, Canada.
authors.forename: D L
authors.initials: DL
authors.lastname: Baird
authors.forename: J M
authors.initials: JM
authors.lastname: Murkin
authors.forename: D L
authors.initials: DL
authors.lastname: Lee
mesh_terms: D000368:Aged; D001927:Brain Diseases / Q000175:diagnosis; D003071:Cognition; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009420:Nervous System / Q000503:physiopathology*; D011446:Prospective Studies