Defined as a motor-speech disorder, childhood apraxia of speech causes difficulty in the programming and planning of speech movements. In most cases the child’s expressive speech is seriously deficient, absent or severely unclear. Usually developmental in nature, childhood apraxia of speech also can be acquired.
To differentially diagnose apraxia, speech-language pathologists use what are generally known as its main characteristics: vowel distortion, inconsistent sound substitution (a “t” for a “k” one time, and a “v” for a “k” the next), omission of initial consonants, limited sound repertoire, limited early sound play and babbling, superior imitative skills with inferior volitional skills, significant intelligibility breakdowns with motoric complexity, prosody, and a greater understanding of language than the ability to use it expressively.
“Children with apraxia don’t produce speech sounds well on demand,” Amy Nelson, MA, CCC-SLP, senior staff speech-language pathologist at the Alfred I. DuPont Children’s Hospital, in Wilmington, DE, told ADVANCE. “Sequencing oral-motor movement is difficult for them. Their phonetic repertoire is limited, their prosody is deviant, and their errors are very inconsistent.”
As children babble, they learn how to coordinate the movement of their articulators with the outflow of breath as well as the movement of their vocal folds, explained Amy Skinder-Meredith, PhD, CCC-SLP, of the University of Minnesota at Duluth. Babbling is an opportunity that allows babies to receive rich sensory feedback as they are playing and experimenting with muscles used for speech.
“It’s been observed that typically developing children will babble with an intonation pattern that matches the language they will use,” she said.
Prosody, which involves the suprasegmental elements of speech, typically occurs naturally during a child’s experiences with babbling. Often shaped by emotions, prosody includes emphasis, intonation, loudness, duration, pitch range and stress. Prosody is affected when children struggle to place their articulators. Disordered prosody is a common characteristic of apraxia.
“When we’re trying to make sure a child gets a sound, we model the sound they’re missing by putting stress on a syllable that shouldn’t receive stress or emphasizing the sound that typically doesn’t get emphasis,” she stated. “But as soon as possible, you want to start working toward more natural prosody.”
Although the child may never get to a normal rate of speech, clinicians should continue treatment until the prosody of speech is close to normal.
Children who have problems with speech sound production and language are at high risk for having other academic problems, including difficulty with reading and writing and other higher-level language difficulties, outcome and longitudinal studies have found.
“We have to start focusing on written language very early and not just spoken language,” said Claire Waldron, PhD, CCC-SLP, on faculty at Radford University in Radford, VA. “We make literacy a very strong part of our intervention program, even with preschool children.”
Short-term goals specify the types of behavior that need to change, while long-term goals are broad and relate to a child’s effectiveness as a communicator.
Because children with apraxia of speech differ from one another, goals should be individualized, said Dr. Waldron. When treatment is being planned, goals for oral and written language should be broad and congruent with what the children are expected to do in school.
“I’m not going to wait until they say all their sounds perfectly before I have expectations about their narrative production or their ability to have normal conversation discourse with their friends,” she noted. “I tend to take a broad look at their social, academic and pragmatic needs and not just their phonological needs.”