Apraxia of speech (AOS), also called verbal apraxia, is a speech sound disorder affecting an individual's ability to translate conscious speech plans into motor plans, which results in limited and difficult speech ability. By the definition of apraxia, AOS affects volitional (willful or purposeful) movement pattern. However, AOS usually also affects automatic speech.[1]
Individuals with AOS have difficulty connecting speech messages from the brain to the mouth.[2] AOS is a loss of prior speech ability resulting from a brain injury such as a stroke or progressive illness.
Developmental verbal dyspraxia (DVD), also known as childhood apraxia of speech (CAS) and developmental apraxia of speech (DAS),[3][4] is an inability to utilize motor planning to perform movements necessary for speech during a child's language learning process. Although the causes differ between AOS and DVD, the main characteristics and treatments are similar.[2][5]