Could It Be Both? Distinguishing Between Autism and Childhood Apraxia of Speech

Parents frequently ask how to distinguish between autism and childhood apraxia of speech (CAS), or how to determine if a child with autism could also have CAS. This can be difficult to determine if the child is showing signs of both—especially if they are not yet talking very much. So, what makes diagnosing CAS among children with autism so difficult? Is a child more likely to have CAS if they also have autism (and vice versa)? Are these labels even important? How can I advocate for accurate diagnosis and appropriate treatment for my child? This article brings you answers based on the best available research evidence and personal clinical experience.

Note: Many individuals and families prefer different word choices in reference autism. This article uses person-first language (e.g., child with autism) and identity-based language (e.g., autistic child) to honor these different preferences. The terms “autism spectrum disorder” and “autism” are used interchangeably.

What Are the Signs?

There are many different reasons why some children have difficulty talking. Some warning signs associated with autism and CAS are listed below. Similar features commonly shared by both disorders are starred. Note that not all children who have autism or CAS will display all of these warning signs, and that no single sign is proof of either disorder.

Signs associated with CAS:1-2

  • In infancy, produces fewer word-like productions while babbling*
  • Late to begin talking*
  • Produces the wrong sounds or distorted sounds in words
  • Sometimes says the same words differently
  • Has more difficulty saying longer words than shorter words
  • Places unusual emphasis on parts of words or words in sentences*

 

Signs associated with autism spectrum disorder:3-4

  • In infancy, low rate of babbling*
  • Does not respond to their name by 9 months of age
  • Uses few gestures (e.g., should wave by 12 months, point by 18 months)
  • Engages in little back-and-forth play or eye contact
  • Late to begin talking*
  • Overuses or frequently repeats words and phrases
  • Has a unique voice that sounds more robotic or singsong than other children*
  • Has a strong preference for the same routines
  • Is unusually sensitive to light, sound, or touch
  • Engages in repetitive movements (e.g., rocking their body, flicking their hands)
  • Has difficulty interacting with others or knowing how others are feeling

 

If your child displays some of the warning signs above, the next step is to get an evaluation from qualified professionals. Talk to a speech-language pathologist with experience in autism and CAS, as well as your pediatrician. Your child’s pediatrician may refer you to a specialist for further evaluation.

Is Childhood Apraxia of Speech More Common Among Children with Autism Spectrum Disorder?

Unfortunately, the most we can say based on current research evidence is “maybe.” There has just not been enough research conducted in this area, and the existing research tells a conflicting story. Depending on the study, estimates range from no greater likelihood of CAS among children with autism,5 to a very high rate of co-occurrence.6 Reasons for the wide range of estimates most likely come down to the different methods used by the studies. The children involved in these studies were very different in terms of their speech, language, and cognitive skills, as well as how the researchers conceptualized and diagnosed CAS.

Clinically, speech-language pathologists report suspecting CAS in 1 in 6 autistic children on their caseloads7—far greater than the number of children generally thought to have CAS.8 However, only about half of the children suspected to have co-occurring disorders were confirmed as having CAS.7 This discrepancy highlights how challenging it can be to definitively diagnosis CAS among children with autism.

According to the most recent diagnostic criteria,9 speech or language delay is not a core characteristic of autism. Yet, many autistic children have delays in language and about a third are minimally verbal.11-13 It is possible that speech production disorders such as CAS present a roadblock to early language development. However, it is very unlikely that there is just one reason why a particular child has difficulty acquiring language. Research has identified numerous foundational skills in addition to speech production ability that could influence language development, including attention, imitation, sensory-motor development, social motivation and cognitive skills.14-18

Irrespective of the precise number of children who present with both autism and CAS, clinicians and researchers are sure that some children do have both disorders.19-20 Given the potential risks, screening for autism and apraxia is highly recommended for all children who show signs of either disorder.6

Why Might Childhood Apraxia of Speech Occur More Often Among Children with Autism?

Although research has not confirmed whether CAS is more common among children with autism, there are several ideas about why this could be the case. First, the disorders could share a common cause, such as genetic factors21 or brain-related differences.22 It is also possible that one disorder causes or influences the severity of the other. Some research has found a connection between early ability to produce speech sounds and later language outcomes for children with autism.23-25 If a child is already struggling to develop verbal skills, difficulty with speech production may make this even more difficult. However, at this time we also cannot rule out the possibility that autism and CAS simply co-occur for unrelated reasons among some children. For many autistic children, speech skills are typical or even exceptional in comparison to their peers without autism.5

What Makes Accurate Diagnosis Difficult?

CAS is diagnosed by a speech-language pathologist, based on how a child produces sounds, words, and sentences. Many characteristics of CAS can overlap with those of other types of speech sound disorders (e.g., increased difficulty producing longer and more complex words, making many sound errors).

Some of the characteristics that are relatively unique to CAS include:26

  • Inconsistent errors: The same word/sound produced differently over repeated tries.
  • Lengthened or disrupted transitions between sounds and syllables: Pauses between sounds, “stretched out” sounds, or “fumbling” between sounds.
  • Inappropriate prosody: Atypical rhythm of speech, caused by placing emphasis on the incorrect parts of words, or incorrect words in phrases.

Importantly, the same characteristics that distinguish CAS from other speech disorders among children without autism are thought to be the same for autistic children. 27 Again, there is limited information on this topic, but so far researchers do not suspect that CAS looks differently among children who also have autism. However, some factors commonly associated with autism can interfere with a clinician’s ability to diagnose CAS.

It can be difficult to accurately diagnose CAS if a child…28

  1. does not yet use enough speech to judge articulation. Although it is possible to suspect CAS among children who use very little speech, they must be able to produce at least a handful words for the clinician to definitively diagnosis CAS. Some autistic children use mostly self-directed speech (i.e., speaking without clear engagement with another person). Self-directed speech may be quieter in volume, difficult to understand, or not generative in nature (e.g., repeating lines from a TV show; see below).
  2. has poor repetition skills or heightened repetition. A common technique used in assessment and treatment of CAS is word imitation. Some autistic children have difficulty processing speech or “tuning in to speech” which makes it difficult to listen to and repeat what is heard. Alternatively, many autistic children are excellent imitators. Other children with autism might use repetition in unexpected ways, such as reciting lines from TV shows or other sources, overusing the same few phrases, or repeating what was just said when the context does not require it. For everyone, imitated speech is usually produced more clearly than non-imitated speech. An assessment that consists of little non-imitated speech runs the risk of overestimating speech ability or potentially overlooking CAS.
  3. has difficulty understanding task demands or displays limited social motivation. Some children with autism have reduced language skills, cognitive capabilities, and/or social motivation. Speech assessment is most effective if the child clearly understands what they are expected to do and are fully engaged in the assessment tasks.
  4. uses limited eye contact or demonstrates poor attention. Word repetition is a common technique used for diagnosis and treatment of CAS. If a child is unable to focus on and gather information from the clinician’s face, they may need other ways of learning the correct movements needed to produce sounds and words.
  5. is more sensitive to touch. Everyone has different preferences when it comes to touch, and some autistic children fall on the extremes, demonstrating hypersensitivity or very low sensitivity to touch. For children with heightened sensitivity to touch, they may be unable to tolerate an oral exam (which is needed to rule out potential problems with the function of the tongue, lips, and other oral structures). Likewise, hands-on cues are common in many assessment and treatment approaches for CAS. If these kinds of cues cause a child discomfort or distress, alternative methods will be needed.
  6. demonstrates interfering behaviors or decreased compliance. Not all children with autism demonstrate behaviors that interfere with traditional speech assessment and treatment, but special consideration is often needed to ensure the demands, environment, and approach encourage participation and do not cause distress.
  7. uses atypical prosody. Atypical prosody, or rhythm of speech, is associated with both autism and CAS. If a child with autism is observed to use unusual prosody but shows few other characteristics of CAS, careful consideration is needed to arrive at the correct diagnosis.

Regardless of whether a child presents with co-occurring disorder(s), diagnosis of CAS should always be made based on a cluster of characteristics, rather than just one or two.

Do These Labels Even Matter?

Both autism and CAS require specialized approaches to improve communication skills, with best outcomes when interventions are provided early in development. It can be uncomfortable or triggering when labels are used to describe your child, but, when appropriately used, these labels can help children gain access to specialized treatments. Labels like “autism” and “CAS” can also give those who work with your child greater understanding about their needs and abilities.

Examples of Suspected Childhood Apraxia of Speech and Autism Spectrum Disorder

It can be difficult to distinguish between childhood apraxia of speech (CAS) and autism spectrum disorder, especially when children are not yet talking very much. Below are three real-life examples of cases in which both autism spectrum disorder and CAS were suspected. Since autism and CAS require specialized treatment approaches, it is important to get accurate diagnoses to plan the most effect treatment.

Note that there are many reasons why children may have difficulty talking, and all children will look differently. If your child sounds like one of the examples described below, talk to a speech-language pathologist with experience in autism and CAS, as well as your pediatrician. Your child’s pediatrician may refer you to a specialist for further testing.

Child 1: Mia

Mia is a four-year-old girl, who was diagnosed with autism at two years old. She consistently uses a few words, including “ou” (for “outside”), “ma” (for “mom”), “wa” (for “water”), “no,” and “mmhm” (for “yes”), and she uses signs for “more” and “all done.” She sometimes repeats words when asked to do so, but most often she does not respond. Mia’s parents describe her as generally happy, easily excitable, and gentle. They also noted that she is sensitive to loud sounds and often fixates on bright lights. When excited or overstimulated, she might flap her arms, yell, or cover her ears. Mia tends to use her body to communicate more than her words—if she wants something she will find a way to get it! She likes to do certain play routines by herself (e.g., stacking blocks and knocking them over) and does not usually look at someone or interact in a back-and-forth way unless she needs them (e.g., getting a push on the swing). Mia’s parents are concerned that although she receives daily speech and language therapy, she does not seem to be making much progress with her verbal development. Could she have CAS?

Mia’s parents are absolutely right to question if there could be potentially overlooked reasons as to why her language is developing slowly. They worked with a speech-language pathologist with expertise in autism and CAS to plan a comprehensive speech assessment. The assessment was completed over several short sessions to give Mia many different opportunities to produce words without overwhelming her. Across sessions, Mia said 20 different words and repeated most at least twice. She repeated the words largely the same way each time and while she always shortened longer words, she produced almost all vowels correctly. However, she was only able to correctly use a few consonant sounds and was not able to produce enough longer words for the clinician to be able to judge her ability to use correct word stress. In the end, the speech-language pathologist determined that it was possible but unlikely that Mia had CAS. She recommended re-evaluation for a possible speech production disorder after Mia developed more speech and consistent ability to repeat words. The family and clinician also determined that changes were needed to Mia’s communication treatment plan given her recent lack of progress. The clinician recommended that therapy focus on strengthening her foundational communication skills, such as joint attention and engagement, rather than “drilling” words. The clinician also recommended practicing more signs and introducing a picture-based communication system to help her develop more language. They agreed to revisit the plan after three months to make sure Mia was making progress with the adjusted approach and to make further adjustments as needed.

Child 2: Craig

Craig is an 8-year-old boy, who was diagnosed with autism at age four. He was late to start talking, but with several years of intensive therapy, his language really took off. His parents have always had difficulty understanding his speech when he launches into a story or tries to say complex words, but they currently describe him as a “chatterbox.” Although Craig has gotten very good at acting things out or using gestures when people do not understand him, he also gets very frustrated when he is misunderstood. His previous therapist tried to work on articulation but stopped doing so because he would burst into tears, turn over furniture, and rip up papers when he was asked to repeat words or was given corrections. Should Craig be re-evaluated for CAS?

The speech-language pathologist and Craig’s family agreed that a speech evaluation would be a good idea. Up until now, the focus of Craig’s therapy was on developing his language skills. Now that his language has improved, the difficulty he is having with articulation is more apparent and it is causing him frustration. In the evaluation, the clinician used strategies to take some of the pressure off Craig and reduce his frustration (e.g., had him “teach” puppets how to say words, asked him to repeat made up words instead of real words, included lots of breaks, completed the evaluation over many short sessions). She also consulted with a behavioral therapist to find more ways for him to participate without becoming frustrated. The speech-language pathologist determined that there was clear evidence of CAS and devised a plan to work on speech while minimizing distress. The clinician decided to focus on practicing a small set of made-up words in short, play-based sessions. This way, Craig could still work on producing accurate speech movement gestures and imitating different word stress patterns, but without the frustration of being corrected on words he already “knew” how to say. The clinician worked with Craig’s teacher to find time to pop into the classroom to work on his speech goals for ten minutes per day, rather than pulling him out of the classroom for longer, potentially frustrating sessions. The team decided to monitor frustration levels and to re-evaluate his progress in a few months to make sure improvements were carrying over into his everyday speech.

Child 3: Andres

Andres is three-year-old boy who has difficulty talking. He did not say his first word until age 2 and his parents note that even as a 1-year-old, his babbling was more like the “ooo’s” and “ahhh’s” of a younger child. At three, his speech is always difficult to understand even for those who interact with him daily. He uses a few simple words (e.g., “da” for dad, “oh” for “no,” and “ee” for “eat”) and attempts to say other things but his sounds “get jumbled up.” He is very expressive and has clear intent to communicate. His parents describe him as a “busy guy;” it can be difficult to get him to sit still and follow directions. Andres was diagnosed with a “developmental delay” has been receiving speech therapy to help with his communication skills. His pediatrician suspects autism and refers him to a specialist.

It is always a good idea to consider all possible reasons why a child is having difficulty talking. Andres was late to begin talking and is still difficult to understand, but he does not show other warning signs that might indicate autism. Still, he saw a developmental pediatrician who ruled out autism after performing an evaluation. The doctor used tests like the Checklist for Autism Spectrum Disorder, which has been shown not to overdiagnosis autism among children who also have speech disorders (Tierney et al., 2015). Andres already receives therapy from a speech-language pathologist, but it is unclear if the therapist has experience with CAS. It would be a good idea to also complete a speech evaluation with a speech-language pathologist who has expertise in CAS to determine if a more specific diagnosis is appropriate. It is possible that when Andres started therapy, he was not talking enough for the therapist to evaluate him for a specific speech sound disorder. Now, Andres uses a few words without being prompted and tries to repeat words when asked. Although Andres has a high activity level, with the right approach, enough information should be able to be gathered from an evaluation to diagnose or rule out CAS.

Summary

As shown by the case examples, it is important for children to receive the correct diagnoses to receive appropriate, effective treatment. Treatment for both autism and speech disorders such as CAS work best when delivered early. However, children are never “too old” to receive an evaluation or a different type of treatment.

Mia’s case shows that it is normal for even highly experienced speech-language pathologists to recommend follow-up evaluation if there is not currently enough information to make a confident diagnosis. It is important to continue to work on these foundational communication skills and re-evaluate frequently.

On the other hand, Andres’s example highlights that even young children are able to be diagnosed with CAS if they can engage in assessment tasks and repeat words. Autism and speech and language disorders can present similarly in young children who are not yet talking very much. However, there are signs that qualified professionals can use to effectively tell them apart.

As seen in the case of Craig, autistic children can display the full range of speech disorder severity, just as children without autism. Although Craig had relatively mild CAS, it impacted his communication, caused frustration, and needed to be addressed in treatment. Few children respond to CAS treatment in the same ways, and clinicians may need to modify research-based treatment approaches given a child’s strengths and needs. Since there is very little research about how to treat CAS among children with autism, clinicians and families should pay close attention to whether improvements are being made and adjust the treatment plan as needed.

What Does CAS Treatment Look Like for Children Who Also Have Autism?

Regardless of whether a child has autism, speech therapy will look different depending on individual needs. Autistic children often participate in many types of therapies and have important goals related to life skills, language, and behavior. Although therapy priorities may shift over time, it is important to keep working on communication skills and re-evaluate the therapy plan often to address changing needs. It is not uncommon for children with autism and CAS to participate in several therapy sessions per week or even multiple sessions each day.

For children who are working on foundational communication skills such as attention and engaging with other people, speech and language therapy will likely address these skills prior to working on saying specific words and phrases. For children who have a good grasp on foundational skills and are using some speech, therapy may work on building a core vocabulary of frequently used words and phrases. As children are able to repeat more words and respond to feedback about how to correctly produce speech, therapy may begin dedicating more time to practicing specific speech movements within words and phrases.

A specialized, motor-based approach is thought to be most effective to improve speech skills among children with CAS. Unfortunately, there is little research about whether the evidence-based CAS interventions that are effective for children without autism will have the same results for autistic children. Some studies suggest adapting traditional CAS treatment to be more play-based and incorporating teaching strategies known to be effective for children who have autism.19 Research also supports using approaches that allow for lots of speech practice and incorporating the child’s interests and strengths, such as music.20 Clinical evidence is most important in making treatment decisions. If a treatment is not working, it needs to be adjusted!

Speech-language pathologists may also include augmentative and alternative communication (AAC) in the treatment plan. AAC is commonly used with children with have low verbal skills and either autism or CAS. Parents do not need to worry about this type of technology replacing or slowing down speech development; research shows that AAC provides important access to language and may actually facilitate spoken language development.29-30

Overall, the most important thing about treatment for children with autism is that it changes as they develop more skills and display different needs.

How Can I Advocate for My Child to Get an Accurate Diagnosis and Effective Treatment?

Tips for Evaluation:

  1. Seek out an evaluation from an experienced speech-language pathologist and ask lots of questions. Ask not only “Is it possible that my child has CAS?” but also “How do you know?” Ask the therapist about their specific experience with CAS and autism. Also ask your child’s pediatrician if referrals to other specialists might be helpful.
  2. Discuss the evaluation plan. Ahead of the evaluation, ask the speech-language pathologist to discuss their plan with you. If you are specifically interested in whether your child has CAS, make this goal known ahead of time. Ask “What assessments will you use to evaluate my child’s speech?” “Do you expect to be able to collect enough data to make a diagnosis?”
  3. Share what your child needs to be most successful. Children with and without autism may need different things for a therapist to get the most information from an evaluation. You know your child best, so speak up about the things you know about them. You might share that your child needs (1) testing completed over multiple, short sessions, rather than one long session, (2) observations and testing to be completed in a familiar place such as your home, or if not possible, extra time to get to know the therapist and the new setting, (3) lots of breaks during the evaluation, and (4) modifications to improve sensory regulation and engagement (e.g., sitting on a therapy ball or cushion, dimmed lights, breaks to jump on a trampoline). It is also helpful to share your child’s preferred activities and specific things that motivate them, as well as how they show when they are excited or frustrated.
  4. Expect to need follow-up evaluations. As children grow older and develop new skills, it is common to re-evaluate speech and language needs. Language, reading, and learning problems commonly co-occur with both autism and CAS, so follow-up evaluations are also needed to monitor how these skills are progressing.

Tips for Treatment:

  1. Share with the therapist the goals that are most important to you and your child and ask how the treatment plan will address them. For example, there might be certain words or phrases that are important to your child to say clearly (e.g., “no,” “see ya later, alligator,” favorite TV character). You might be concerned about rising frustration levels and want to make a plan for improving other communication strategies. You might also be interested in getting more involved in therapy, especially if there are special techniques or technologies that the therapist uses that you want to implement at home. The treatment process should be collaborative and address the goals most important to your child and your family.
  2. Decide how progress will be monitored, how often you will meet to discuss progress, and what will be changed if progress is not happening as expected. This is especially important for children who are not yet talking very much or who have not received a specific diagnosis. If the treatment is not working, it needs to be adjusted! Asking these questions at the beginning of treatment helps everyone stay on the same page and course-correct more quickly if needed.
  3. Share your observations and experiences. Are you noticing improvements? Are there important goals that have not yet been met? Have any problem behaviors emerged? It can be common for children with both CAS and autism to have difficulty carrying over skills learned in therapy to everyday life. The clinician needs to know how things are going outside of the therapy room in order to provide the best treatment.
References
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