General characteristics of treatable, reversible, and untreatable dementias.

The modification of cognitive function with age has been the focus of numerous studies. Most of the research has suggested that these changes, at least in the majority of individuals, occur only at a very advanced stage; however, those conditions that are treatable and potentially reversible are acute in onset and often associated with acute confusional states. Therefore, physicians should be aware of the possibility of reversible causes of cognitive change in their elderly patients, including certain medications responsible for memory loss and other organ system diseases. In addition, the authors stress that not all memory loss in geriatric patients is due to Alzheimer's disease and that when history and physical examination provide evidence of hypertension and magnetic resonance imaging provides evidence of leukoaraiosis, a diagnosis of vascular dementia should be considered.