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.

Inclusion Criteria:

• Patients undergoing elective valve surgery in Ospedale del Cuore, Fondazione G. Monasterio, Massa, Italy will prospectively enter the study.

Exclusion Criteria:

• History of head trauma, seizures, stroke, carotid artery stenosis (>70%)
• History of any major surgery with general anesthesia
• Preoperative MMSE score less than 23 to exclude patients with dementia and mild cognitive impairment (MCI)
• Subjects who will be unable to complete the baseline neuropsychological battery due to cognitive impairment, psychiatric disease, substance abuse, blindness, or poor knowledge of Italian language
• Any major neurological complication after CABG surgery (stroke, seizures, encephalopathy not resolving within few postoperative days)
• if any contraindications to MRI safety, indicated in local MRI safety protocol

Patients undergoing elective valve surgery in Ospedale del Cuore, Fondazione G. Monasterio, Massa, Italy and matching inclusion/exclusion criteria will prospectively enter the study.