Post Cardiac Surgery Neurocognitive Decline: Correlations Between Neuropsychological Tests and Functional MRI Techniques

Postoperative cognitive decline (POCD) is a frequent complication after cardiac surgery. It is estimated that 40-70% of all cardiac patients show cognitive dysfunction during the first post-surgical week. Six weeks after surgery, this incidence decreases to 10-40% and the figure remains stable over the long-term. The investigators will recruit 50 patients undergoing elective valve surgery and each patient will receive complete evaluation a) preoperative, one week before surgery; b) early postoperative, before hospital discharge; and c) late postoperative, 8 weeks follow up. The investigators will apply Diffusion Tensor Imaging, 1Proton-Magnetic Resonance Spectroscopy and Morphometry studies with correlation to neuropsychological test battery to evaluate POCD.