Geographical knowledge in patients with Alzheimer's disease.

Geographical knowledge, a measure of remote memory for visuospatial information, was studied in mildly and moderately demented patients who met NINCDS-Alzheimer's Disease and Related Disorders Association criteria for Alzheimer's disease. Alzheimer's disease patients were moderately impaired on a test that emphasizes locating gross features of US geography and profoundly impaired in locating cities on a map of the region of the United States in which they resided. The possibility that performance on tests of geographical knowledge can be used to predict impending difficulties of demented patients in wayfinding is discussed.