Childhood apraxia of speech (CAS) is a speech disorder in which a child’s brain has difficulty coordinating the complex oral movements needed to create sounds into syllables, syllables into words, and words into phrases. Typically, muscle weakness is not to blame for this speech disorder.
Parents of children with childhood apraxia of speech commonly say things like, "No one can understand my son," "It looks like he is trying to say the word, but can't get it out," and "He said that word one time, and then I never heard it again."
The most common description of a child with childhood apraxia of speech is that he is often very difficult to understand.
Childhood apraxia of speech is a motor speech disorder. There is something in the child's brain that does not allow messages to get to the mouth muscles to produce speech correctly.
In most cases, the cause is unknown. CAS is not a disorder that can be “outgrown,” rather children with CAS will not make progress without treatment.
There is little data available about how many children have childhood apraxia of speech. The number of children diagnosed with the disorder appears to be on the rise, but it is hard to measure how the incidence has changed over time.
Some factors influencing the rise in diagnosis include:
- Increased awareness of childhood apraxia of speech by professionals and families
- Increased availability of research on CAS
- Earlier-age evaluation and identification
According to the American Speech-Language-Hearing Association (ASHA, 2007), the three most common features in children with apraxia of speech are:
- Inconsistent errors on consonants and vowels in repeated productions of syllables or words (for example, a child says the same word differently each time he tries to produce it).
- Difficulty producing longer, more complex words and phrases.
- Inappropriate intonation and stress in word/phrase production (for example, difficulty with the timing, rhythm and flow of speech).
Some additional characteristics of speech production associated with childhood apraxia of speech include:
- Late development of the child's first words and sounds.
- A decreased sound inventory (for example, a lack of variety of consonant and vowel sounds expected at a certain age).
- Multiple and/or unusual sound errors.
- Vowel sound errors.
- Excessive movements of the mouth or attempting to position the mouth for sound production.
- Persistent or frequent regression in the number of words produced.
- Differences in performance of automatic speech (such as "hello" and "thank you") versus voluntary speech. In most cases, voluntary speech is more affected by apraxia of speech.
- Errors in the order of sound production in words (such as sounds omitted, switched, or added to words and within words).
An accurate diagnosis of childhood apraxia of speech requires a comprehensive speech and language evaluation by a speech-language pathologist (SLP). The SLP will evaluate your child's speech skills and expressive and receptive language abilities, while gathering information from your family about how your child communicates at home and in other situations.
It is important that the SLP evaluating your child has experience and expertise in diagnosing and working with childhood apraxia of speech so an accurate diagnosis can be made and other possible diagnoses are ruled out. For example, childhood apraxia of speech is often confused with a severe articulation disorder, since both diagnoses include poor speech intelligibility. Unfortunately, the approach taken to address an articulation disorder is vastly different than the approach for childhood apraxia of speech, and confusing the two could result in reduced therapy gains.
An assessment for childhood apraxia of speech must include an evaluation of your child's expressive and receptive language abilities; many children with this disorder demonstrate deficits in their language skills. In addition, gaps between receptive and expressive language skills, word order confusion, and difficulty with word recall are common in children with apraxia of speech. A thorough assessment of your child's abilities is needed so therapy goals can be developed based on his individual needs.
Treatment for apraxia of speech should be intensive and may last several years depending on the severity of your child’s disorder. Many children with childhood apraxia of speech benefit from:
- Multiple repetitions and repeated practice of sound sequences, words and phrases during therapy
- The use of visual prompting to show how speech sounds are made as sequences of sounds are combined into words
- Co-production, or having the child say the word at the same time as the SLP or caregiver
If your child only has a limited number of words in his vocabulary, therapy will initially focus on improving his functional communication skills. It is critical for your child to have positive experiences with communication. If producing words is too difficult for your child initially, positive interactions may be achieved through other modes of communication, such as sign language, picture communication boards and voice output communication devices. Using other modes of communication while working on speech production has been found to promote verbal skills and decrease frustration in children while communicating.
It is important for SLPs, teachers, parents, related professionals and all family members to be actively involved in the treatment process so your child with ataxia of speech can achieve maximum progress. Additional research on this disorder is needed to explore causal factors, diagnostic criteria and the effectiveness of various therapy approaches.
With commitment from professionals, researchers and families, children with apraxia of speech can make significant improvements to their speech and communication skills.