We describe the clinical history of a 49-year old woman, who demonstrated progressive personality changes more than twenty years after radiation of a pituitary adenoma (prolactinoma), with apathy, loss of initiative, memory deficits, postural instability, dysarthria and faecal incontinence. Neuropsychological assessment showed impulsivity, loss of overview, desinhibition, fluctuating deficits of attention, and memory disturbances. MRI-scanning of the brain revealed a cystic lesion along the right ventricle. The clinical picture and the findings of the other investigations are typical for dementia due to radiation encephalopathy. Such a long period between radiation and cognitive deterioration is rare, although it has been described before.
