Does mild cognitive impairment increase the risk of developing postoperative cognitive dysfunction?

Background: Increasingly, postoperative cognitive dysfunction (POCD) is recognized as a complication after surgery in the elderly. We sought to determine whether patients with mild cognitive impairment (MCI) would have an accelerated progression of dementia postoperatively when compared with the patients without MCI. Methods: The Center for Brain Health at the New York University (NYU) Medical Center maintains records of volunteers who undergo a series of neurological assessments. We reviewed records of 670 patients who received at least 2 evaluations and whose surgery occurred before the second assessment. Longitudinal differences of several cognitive domains were examined. Results: Individuals with MCI and surgery had a greater decline in performance on the Digit Span Forward test compared with those with MCI without surgery on their postoperative evaluation (F_3,158 = 3.12, P = .03). No performance changes were detected in the normal subjects. Conclusion: These preliminary findings suggest that surgery negatively impacts attention/concentration in patients with MCI but not in normal individuals. This is the first study that identified a specific subgroup of patients who are predisposed to POCD.