Developmental (Childhood) apraxia of speech is a disorder of the nervous system that affects the ability to sequence and say sounds, syllables, and words. It is not due to muscular weakness or paralysis. The problem is in the brain's planning to move the body parts needed for speech (e.g., lips, jaw, tongue). The child knows what he or she wants to say, but the brain is not sending the correct instructions to move the body parts of speech the way they need to be moved. There is no known cause of the disorder.
The terms Apraxia and Dyspraxia are often used interchangeably, although there are subtle differences. Both terms refer to a disturbance of praxis, or in English, motor planning. Apraxia and Dyspraxia are terms referring to oral-motor planning deficits. Apraxia means no motor planning (no speech) and Dyspraxia means difficulty with motor planning (delay in speech). Children with these deficits have difficulties transmitting the speech message from their brain to their mouths. Children with significant weakness of the lips, tongue, and jaw may be diagnosed by a neurologist as having Dysarthria. Many children with cerebral palsy and multiple sclerosis have Dysarthria. While some children have had obvious brain damage (difficult birth, cerebral palsy, etc.), most of the cases of Dyspraxia which we treat these days are idiopathic; i.e. of unknown origin. Whether or not we know the cause, SLPs can treat the disorder.