Progressive Aphasia: Three Explanations

Progressive aphasia is a disorder in which speech, comprehension, reading, and writing slowly deteriorate. There is debate in the literature about whether progressive aphasia is a distinct clinical entity or part of a dementia process. Three main explanations have been proposed. The literature on progressive aphasia is reviewed in the context of these explanations, and the most significant findings are presented. Particular attention is given to the differential diagnosis of progressive aphasia and to the various types of progressive aphasia.