Early natural course of transient encephalopathy after coronary artery bypass grafting

Objective: A decline of neuropsychological performance is an unwanted side effect of coronary artery bypass grafting (CABG) with extracorporeal circul ation. There is little data on the neuropsychological changes during the fi rst 2 wks after CABG. Design, Setting, Patients: In this prospective observational study at our u niversity medical center, a group of 67 patients who underwent routine CABG was selected for absence of comorbidity (such as carotid stenosis, previou s stroke, dementia, and advanced general medical disorders) and examined. I n this selected group of patients, no focal deficit was seen throughout the study. A total of 20 hospitalized patients with different types of periphe ral neuropathy and free from drugs interfering with cognition served as a c ontrol group for the practice effects of the neuropsychological testing. Measurements and Main Results: Seven standard tests covering different neur opsychological domains were used as a composite battery. Examinations took place before surgery and serially at days 3, 6, and 9 after CABG; general n eurologic examination was done every day, including the first postoperative day. We observed a definite decline in all tests at day 3 (p < .01) and pr ogressive recovery thereafter up to or even beyond preoperative values with in 9 days (p < .01). Transient depression as indicated by self-rated scores occurred in some patients. Conclusion: We observed a uniform, but transient, deterioration in performa nce on a battery of frequently repeated standardized neuropsychological tes ts early after CABG. Our data on the early natural course may help to bette r evaluate treatment efforts aimed at preventing or reducing after-surgery neuropsychological alterations.