[Acute change in behavior of an elderly patient due to epilepsy].
A man aged 69 years with a history of a cerebrovascular accident showed progressively strange behaviour in two weeks. There were no signs of a neurological disorder. Psychiatric examination revealed psychotic symptoms. The electro encephalogram revealed epileptic activity at the site of the old infarct. The diagnosis was 'psychotic disorder due to a non-convulsive status epilepticus'. Treatment with anti-epileptics was followed by clinical recovery. An epileptic insult must be thought of in every elderly patient with unexplained changed behaviour. A cerebrovascular accident is the main risk factor for developing an insult in elderly.