What is Primary Progressive Aphasia?
Gorno-Tempini and colleagues in 2011 provided the most recent consensus on the definition of primary progressive aphasia, or PPA. Specifically, they defined PPA as aphasia of insidious onset that results in a gradual progression of word finding, object naming, or word comprehension impairments in spontaneous conversation or on formal language measures. The limitations in activities of daily living experienced by individuals with this diagnosis must be attributed to language impairment during the initial phase of the disease. In other words, it must be a primary language issue in the first stages of the disease. The individual should have intact premorbid language function.
In addition, the pattern of deficits in PPA cannot be accounted for by other non-degenerative nervous system or medical disorders. Other cognitive deficits do exist, but language remains the most impaired throughout the course of the disease. There should be an absence of episodic and non-verbal memory impairment, and visual perceptual impairments in the early stages of the disease. In addition, there is typically an absence of behavioral disturbance at onset. If behavioral issues are present, they should not be the main complaint or main cause of functional impairment.
Michael de Riesthal, Ph.D., CCC-SLP, is an Assistant Professor in the Department of Hearing and Speech Sciences (Vanderbilt University School of Medicine), and Director of Pi Beta Phi Rehabilitation Institute at the Vanderbilt Bill Wilkerson Center. His clinical and research interests include the management of neurologic speech, language, and cognitive disorders.