[Postoperative cognitive dysfunction].

Memory loss and lack of concentration are symptoms that frequently occur in patients who have undergone a surgical procedure. Although cognitive function can be assessed using neuropsychological tests, diagnosing postoperative cognitive decline (POCD) reliably appears to be difficult. Therefore, the true incidence of POCD is unknown. Severe POCD, which is apparent even without neuropsychological testing, is predominantly reported after cardiac and hip-replacement surgery. In these cases, POCD probably reflects micro embolic brain injury. Apart from the nature of the surgical procedure, advanced age is the most important risk factor for POCD. The anaesthetic technique used is not a determinant: the risks of POCD occurring appear to be similar following both general and local anaesthesia.