Childhood apraxia of speech (CAS) is a pediatric speech sound disorder affecting a child’s ability to plan the specific movements required to produce speech. CAS is also known historically and internationally as developmental apraxia of speech, developmental verbal apraxia, and developmental verbal dyspraxia. Apraxia is a difficulty in performing purposive movements in the absence of muscular weakness. This entry discusses the etiology of CAS, theories about how it manifests in a child’s speech and language system, and its characteristics, diagnosis, and treatment.

The motor, or movement, planning difficulty experienced by children with CAS leads to problems with coordinating and sequencing the fine-grained movements necessary for clear speech. Continuous speech requires rapid overlapping movements, or coarticulation. Given the difficulty with planning, coordinating, and sequencing movements, children with ...