ASHA Glossary: Primary Progressive Aphasia (PPA)
A focal dementia (or focal cortical atrophy syndrome) characterized by gradual loss of language function in the context of relatively well-preserved memory, visual processing, and personality until the advanced stages. Symptoms usually begin with word-finding problems and progress to impaired grammar (syntax) and comprehension (sentence processing and semantics). Symptoms associated with impaired speech production, such as dysarthria and apraxia of speech, can also accompany PPA. Typically, a diagnosis of PPA is made following a 2-year decline in language function not accompanied by any marked decline in other cognitive functions. (However, a 2-year hiatus in making a definitive diagnosis should not delay proactive management of the aphasia and general life planning.) Structural and physiological abnormalities are typically noted only in the left hemisphere language-related cortices (i.e., frontal, parietal, and temporal regions). PPA is not due to neoplastic, vascular, or metabolic etiologies nor to infectious disease (Mesulam, 2001; Rogers, 2004).
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