There is some debate among professionals in communication disorders on the correct terminology for apraxia. There are several terms for apraxia that professionals may use interchangeably: Childhood Apraxia of Speech (COS), Developmental Verbal Apraxia (DVA), and Developmental Verbal Dyspraxia (DVD). Both apraxia and dyspraxia contain the same root word “praxia” which is the execution of voluntary muscle movements. The “a” in apraxia means the absence of movement while the “dys” in dyspraxia means abnormal or difficult. Apraxia means without speech while the term dyspraxia means abnormal or difficult speech. Apraxia can also be developmental or acquired. Developmental Apraxia indicates speech did not develop or has not already been present versus Acquired Apraxia may result from brain injury or trauma.
(References: The Source for Childhood Apraxia of Speech by Robin Strode Downing and Catherine E Chamberlain)