How is CAS diagnosed?
What speech characteristics indicate CAS?
What does the label “suspected CAS” mean?
Can CAS occur with other types of disorders?

How is CAS diagnosed?

There are many types of speech problems in children. The speech-language pathologist will complete an evaluation to understand the type of speech disorder a child has, a process known as differential diagnosis. Accurate differential diagnosis is important because it guides the therapist in selecting the correct method of treatment.

Talking requires complex and well-coordinated movements of the lips, tongue and other structures involved in speaking.  The muscles  must move in the right direction with the correct speed and force to produce sounds for understandable speech. The brain controls the planning and programming of these muscle movements. When the speech-language pathologist observes signs of difficulty with planning and programming movements for speech, the child is given the diagnosis of CAS. CAS is simply a label for this specific type of speech disorder.  

In order for the speech-language pathologist to observe and evaluate the child’s speech motor planning and programming skills the child will need to:

Have joint attention and the intent to communicate, meaning he/she initiates communication through pointing, gesturing, attempts to say words, or by other means

Be able to attempt to imitate at least simple syllables or words. Observing what happens when the child tries to imitate speech is how the therapist observes motor planning and programming.

If the child does not have intentional communication and does not attempt to imitate, the diagnosis of CAS is not possible.  For these children, it is more likely that other factors like joint attention or listening comprehension should be the initial focus of treatment.

When the child can attempt imitation of speech, then a dynamic motor speech examination is the best method to diagnose CAS. A dynamic motor speech assessment evaluates the child’s ability to plan and program movements necessary for speech production. It also reveals how the child benefits from cues provided by the therapist, an indicator of the expected rate of treatment progress.

It is important to understand that CAS is both under diagnosed (some children who have it are not diagnosed) and over diagnosed (some children who do not have it are given the diagnosis).  In both instances, incorrect diagnosis can result in a therapy plan that is not addressing the primary, underlying cause of the communication problem.

What speech characteristics indicate CAS?

The following characteristics are the best indicators of CAS:

Speech movements are inaccurate, clumsy, or awkward as the child attempts to imitate syllables and words. The child may have groping movements or show signs that speech is effortful.

Distortions of vowel sounds which can make the word sound “off” even if the consonant sounds are correct. Vowel errors can limit intelligibility, or how well speech is understood, and therefore are often the focus of CAS treatment.

Equal stress and segmentation of syllables, making speech sound unnatural or “robot-like”.

Voicing errors that make it difficult to tell the difference between words like “bat” and “pat”.

The following characteristics occur from a variety of speech sound disorders and are not good indicators of CAS:

Using only a few consonants or vowel sounds

Omitting sounds in words

A low score on a standardized test because of numerous sound errors

Poor intelligibility, meaning it is difficult to understand the child.

If your child has been given a diagnosis of CAS based on these symptoms, you should have a follow-up discussion with your speech-language pathologist.  Remember, CAS is a rare disorder, and the speech-langauge pathologist may be unfamiliar with the best methods of assessment.  You may want to talk to your therapist about your research and share resources you have found, such as this website.

What does the label “suspected CAS” mean?

This label may be appropriate to use when a child shows one or two characteristics of CAS but cannot participate in a motor speech examination for the clinician to confirm or rule out CAS.  This is most common with very young children. If your child receives a diagnosis of “suspected CAS”, here are some questions to ask the therapist:

What speech characteristics do you see that indicate CAS? Compare those symptoms to the to the above information.

How will you determine if it is CAS? The clinician should be able to give you a specific plan to further assess your child, which might include additional assessment and/or observing the child’s response to CAS treatment methods.

What will you do differently since my child might have CAS? Clinicians who suspect a child of having CAS may try treatment methods designed to treat CAS and see how the child responds. You may also be referred to another speech-language pathologist with more experience in assessment and treatment of CAS.

The following situations may indicate a need for further discussion with your therapist or even a second opinion:

The therapist tells you that children under 3 cannot be diagnosed with CAS. Although it is often more challenging to assess young children, there is no minimum age for diagnosis and age alone does not rule out or qualify a child for a diagnosis

Your therapist refers you to a physician for the diagnosis. Speech-language pathologists are the most qualified professionals to diagnose and treat CAS.

Your child is given the label of suspected CAS, but there is no plan for further assessment or a trial of treatment methods for CAS.

The child is given the label for an extended time (longer than 6 months) and you are not given any addition information or updates about the diagnosis.

Can CAS occur with other types of disorders?

CAS can occur in isolation with no identifiable underlying neurological disorder (known as idiopathic CAS), or it can occur with other developmental and neurological disorders. Children with CAS may also have delays in expressive language skills and in development of the rules that govern how sounds are used in a language (known as phonology). 

CAS occurs more often in children with certain disorders, such as Galactosemia and Down Syndrome. Although children with autism were once thought to be more at risk for CAS, research indicates that is not the case.   

When CAS occurs in isolation, assessment and treatment can focus just on the CAS.  When CAS occurs with other developmental disorders, it is important that the diagnosis and treatment of CAS take into consideration other developmental skills.  

Here are some questions to ask your therapist if your child has both CAS and another developmental or neurological disorder:

What characteristics observed in the assessment indicate that CAS is part of my child’s diagnosis?

What factors are most limiting my child’s successful communication at this time?

Based on the assessment results, what needs to be the focus of treatment for my child for the next 3 to 6 months?

Treatment Depends on Severity

Learn more

Explaining How CAS is Diagnosed

Watch Video

Examples of CAS and Other Types of Speech Sound Disorders

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