Appraising Apraxia When a speech-sound disorder is severe, how do you know if it’s childhood apraxia of speech? Features
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Features  |   March 01, 2017
Appraising Apraxia
Author Notes
  • Edythe Strand, PhD, CCC-SLP, is emeritus speech-language pathologist in the Department of Neurology at the Mayo Clinic and emeritus professor in the Mayo College of Medicine. Her research has focused on developmental, acquired and progressive apraxia of speech, and degenerative dysarthria. She is an affiliate of ASHA Special Interest Groups 2, Neurogenic Communication Disorders; and 15, Gerontology. edythestrand@gmail.com
    Edythe Strand, PhD, CCC-SLP, is emeritus speech-language pathologist in the Department of Neurology at the Mayo Clinic and emeritus professor in the Mayo College of Medicine. Her research has focused on developmental, acquired and progressive apraxia of speech, and degenerative dysarthria. She is an affiliate of ASHA Special Interest Groups 2, Neurogenic Communication Disorders; and 15, Gerontology. edythestrand@gmail.com×
Article Information
Speech, Voice & Prosodic Disorders / Apraxia of Speech & Childhood Apraxia of Speech / Features
Features   |   March 01, 2017
Appraising Apraxia
The ASHA Leader, March 2017, Vol. 22, 50-58. doi:10.1044/leader.FTR2.22032017.50
The ASHA Leader, March 2017, Vol. 22, 50-58. doi:10.1044/leader.FTR2.22032017.50
Ann, a speech-language pathologist, plays on the floor with Jay, who is 3 going on 4. Jay speaks only 15 to 20 intelligible words. Though he attempts to communicate often, his speech is usually unintelligible.
His mother has brought him to Ann for a second opinion on his recent diagnosis of childhood apraxia of speech (CAS). As Ann continues observing Jay and forming clinical hypotheses, she is unsure if this diagnosis is correct. She knows she has a complex task ahead to either verify or rule out that diagnosis.
Haven’t we all felt unsure at times? Even after more than 40 years of practicing in the field of speech-language pathology, I still see children for whom I have to say, “I’m not sure.” This is likely a common feeling when we suspect CAS—for a number of reasons. First, our training doesn’t emphasize differential diagnosis and treatment of pediatric motor speech disorders as much as other pediatric communication disorders. Second, CAS typically occurs along with delays or impairment in phonology. It often shows up as both linguistic (phonologic) and motor-speech deficits. Teasing that out can be challenging.
In fact, one of the most significant challenges in differential diagnosis of speech-sound disorders is determining the contribution of motor-speech impairment, especially CAS. Interpretation of assessment data must take into account both linguistic and motoric context. Not an easy challenge!
Luckily, there is now more consensus about the characteristics of CAS. Choosing assessment tasks that reveal those characteristics will help you make a good clinical judgment about diagnosis.

Interpretation of assessment data must take into account both linguistic and motoric context. Not an easy challenge!

Characteristics of CAS
Labels, classifications and diagnoses are necessary so that we can communicate efficiently about a child’s collection of speech features. These terms may also guide our treatment choices. One problem with them, however, is the tendency to give a child one label. The reality is that most children have characteristics indicating more than one type of speech-sound disorder.
Our task in diagnosis, then, is determining the relative contribution of levels of impairment. For CAS, that often means determining whether the child’s speech disorder is primarily a linguistically based phonologic impairment, a motor-planning problem, or actual neuromuscular difficulties resulting in dysarthria.
Returning to the case at hand—Ann’s assessment of Jay—Ann knows that despite a fairly long history of debate about CAS, there’s now fairly good agreement about characteristics of the disorder. Some characteristics are not necessarily discriminative for that label, but others are (see boxes below). Ann considers the assessment tasks she will choose to gauge these characteristics.
CAS characters that are often present, but not discriminative, include:
  • Limited consonant and vowel repertoire.

  • Use of simple syllable shapes and frequent omission of sounds.

  • Numerous errors—poor standard scores on articulation tests.

  • Poor intelligibility.

Other characteristics are becoming accepted as discriminative of a CAS diagnosis, which should help Ann feel more confident about using that label:
  • Difficulty moving from one articulatory configuration to another.

  • Groping and/or trial-and-error behavior.

  • Vowel distortions.

  • Prosodic errors.

  • Inconsistent voicing errors.

Ann remembers several articles in which researchers used a set of “behavioral markers” (characteristics commonly associated with CAS) to describe their participants. Children who exhibited at least four of the characteristics across at least three assessment tasks were included in the CAS group. She uses this as another tool to help her decide whether Jay may have CAS. The markers include:
  • Awkward movement transitions.

  • Groping and/or trial-and-error behavior.

  • Vowel or consonant distortion.

  • Inconsistent voicing errors.

  • Intrusive or word-final schwa.

  • Lexical stress errors.

  • Equal stress and/or segmentation.

  • Increased difficulty with multisyllabic words.

  • Inconsistency across repeated trials.

  • Slow rate.

Keep in mind, however, these characteristics are not all discriminative. For example, children with dysarthria may also have a slow rate. However, CAS may be likely when a number of these characteristics are observed somewhat frequently and across tasks. Now Ann needs to develop an assessment protocol that will demonstrate if Jay exhibits any of these discriminating characteristics and to what extent.
Assessment protocols
Assessment protocols for children with severe speech-sound disorders will likely differ a bit depending on a child’s age, attention and cooperation levels, and the severity of the speech disorder (see chart below showing different assessment approaches for different levels of speech delay).
Ann begins by taking a good medical and developmental history of Jay: His mom reports that he met most developmental milestones except for speaking, although he does have some mild fine- and gross-motor delays. He did very little babbling, with only a couple of consonants and only one vowel (a schwa). Ann knows that parents of children with CAS often report little babbling behavior, with perhaps only a couple of consonants and maybe even only one vowel, while parents of children with phonologic impairment will more often report babbling with a number of different vowels.
Gross- and fine-motor delays are often noted in children with CAS, but less so for children with only phonologic problems. This is not true all the time—but tends to be more frequent in children with CAS. Jay has no history of drooling and no difficulty with chewing or swallowing, as often seen in dysarthria.
Ann then takes a language sample to observe Jay’s speech characteristics. After playing with him to establish rapport, she brings out toys designed to elicit age-appropriate vocabulary and phonemes. Jay attempts verbal communication frequently, but uses a limited number of words. Ann notes the following words used correctly in context:
  • “Hi” with a distorted vowel

  • “Ma” in attempt to say man (again with a distorted vowel)

  • “Mo” for more

  • “No”

  • “Boy” with a distorted vowel

  • “Puppy” with a distorted weak vowel, and segmentation and equalized stress

  • “Mom”

  • “Me” with distorted vowel

  • “Do” for go, which perceptually sounded in between /d/ and /t/

  • “Mo ee” for monkey with segmentation and equalized stress

  • “Baby” with vowel distortions and segmentation

  • “Moo”

  • “Bye” with a distorted vowel

  • “Dow” for down, with a distorted vowel

Gross- and fine- motor delays are often noted in children with CAS, but less so for children with only phonologic problems.

Jay utters numerous other unintelligible words and word combinations. He does point and use naturalistic gestures to help get his message across. Ann notes a phonemic inventory of /m/, /d/ and /b/, and a phonetic inventory of /h/ and /p/. She knows that an observation of reduced phonetic and phonemic inventories is not necessarily discriminative (see “Distinguishing CAS From Phonologic Impairment” below). Jay’s reduced number of vowels and consonants and the distorted vowels in known targets provides evidence of—or at least red flags for—CAS.
Although Jay is cooperative, Ann decides not to give him an articulation test or formal test of expressive language because he had such little speech output. She does, however, complete formal receptive language testing, on which he scores in the average range.
The structural-functional exam helps Ann confirm her initial assessment that Jay does not have dysarthria. To assess for oral nonverbal apraxia (ONVA), she models and then has Jay blow, kiss the air, smack his lips, and cough. Jay shows awkward, inaccurate movement toward the goal, with success only for his smacking lips. This suggests the presence of ONVA and a greater likelihood of CAS.
Ann’s next move is to conduct a dynamic motor-speech exam (MSE), a key tool in assessing CAS (see “Using Dynamic Assessment to Evaluate for CAS” below). An MSE reveals what happens when the child tries to repeat something they don’t typically say (especially characteristics such as groping, trial-and-error behavior and segmentation). Ann includes most vowels in the assessment, varying the co-articulatory context using earlier-developing phonemes. She samples across syllable types and includes some bisyllables to examine use of stress. Given Jay’s age, she decides to sample about 20 words: hi, up, pin, papa, banana, boo, on, dad, mommy, peekaboo, me, eat, hop, baby, no, out, bus, uh oh, toy, at, mine, daddy.
Although she had never done a dynamic MSE, Ann has read that it will be helpful because it better discerns the presence of CAS, as well as severity and prognosis. She begins by telling Jay: “I’m going to ask you to try to repeat some words. I know that some of these may be hard for you to say right now. You don’t have to say it right. I just need to watch how you try.”
She lets him know that if he has any trouble, she will help him. She encourages him to watch her face, and then try to say what she says. She then says each word, while he watches her face. If he falters or responds incorrectly, she provides cues, usually starting with a simple one. If he still has trouble, she provides additional help. For example, she may:
  • Repeat the word a bit more slowly, encouraging Jay to watch her face again.

  • Use a gestural cue (for example, bringing her fingers coming together to show lip closure; pointing to rounded lips).

  • Add a tactile cue.

  • Say the word together (simultaneously) a few times to see if that helps Jay be more accurate.

Ann then repeats the word without cueing to see if his response is closer than his first try. She continues this throughout all the words she has chosen to sample. She takes notes on the kinds of errors (for example, vowel and/or consonant distortions; prosodic errors; voicing errors) to see if he exhibits characteristics of CAS. She also notes how much cueing he needs to be accurate or to improve his initial try at the words. This gives her more information regarding severity and prognosis.
Jay is willing and able to attempt direct imitation of Ann’s chosen words, but some children may not be. In that case, we may have to say we cannot determine or rule out CAS, because the child cannot yet attempt direct imitation of any words. The clinician may choose, though, to say “suspected CAS” or “there are red flags for CAS” if there are CAS characteristics in the child’s spontaneous speech.
Ann notices that Jay’s accuracy almost always improves with cueing, approaching correct production even with some of the vowel distortions. Based on this, Ann believes that Jay’s speech could improve quickly with treatment focused on improving movement accuracy and incorporating motor-learning principles. Even though his spontaneous speech indicates a severe speech delay, his responses to dynamic assessment indicate less severity and a more favorable prognosis.
Ann writes a quick diagnostic statement to summarize her clinical thinking (see “Examples of Diagnostic Statements for CAS” below for other examples):
Jay is exhibiting a severe delay in speech acquisition due primarily to deficits in planning/programming movements for speech (CAS). He also exhibits a delay in phonologic development, and a significant delay in expressive language. Receptive language is in the average range. There is no overt evidence for cognitive impairment. He exhibits good communicative intent and good pragmatic language skills. There is no evidence for dysarthria.
Diagnosis and treatment
Now comes the task of explaining the diagnosis and proposed treatment plan to Jay’s mother. Ann tells Jay’s mother that she agrees Jay has CAS, which she explains is due to difficulty with planning and programming speech movements. Ann explains the vocal, muscular and brain-related mechanics of producing speech sounds, providing even more technical details when Jay’s mother asks for more information.
Jay’s mother has two more important questions: First she asks what caused this to happen. Ann explains that CAS can sometimes result from identifiable neurologic problems (such as strokes), but that often we don’t know the cause. She is careful to assure Jay’s mother that speech-language treatment will likely improve his speech significantly. Jay’s mother also asks if Jay will be able to talk by kindergarten. Ann says that with frequent treatment focused on motor-speech skills, Jay will likely be using many words—and even sentences—by kindergarten.

We have to stay apprised of commonly accepted characteristics associated with different speech-sound disorder labels, recognizing that phonologic disorders and CAS are both usually present.

Ann also points out that labels can change. Over time, due to continued neural maturation and treatment, a child may progress to exhibiting only a few residual articulation errors, with no vowel distortions, groping or prosodic errors. At that point, the label CAS is not appropriate—although it may be appropriate to note the history of CAS, which may be important to later difficulties with literacy or learning and pronouncing difficult, novel, multisyllabic words.
SLPs have a challenging job. To come to a differential diagnosis, we need to take into account cognitive development and disorders; language and phonologic development and disorders; and motor-speech development and disorders. We need to understand how cognition, language (including phonology) and motor-speech skills interact in young children who are still developing speech and language.
We have to stay apprised of commonly accepted characteristics associated with different speech-sound disorder labels, recognizing that phonologic disorders and CAS are both usually present. What we do is complex, but there are many sources for help, including available research, the ASHA website (see, for example, the ASHA Practice Portal page on CAS), and our colleagues with more experience.
For Ann, who was at first unsure, choosing a set of assessment tasks allowed her to confidently confirm that Jay has CAS. She left the clinic that day satisfied, recognizing that her job may be challenging, but also brings many rewards.
Distinguishing CAS from Phonologic Impairment

What might tip you off to childhood apraxia of speech (CAS)? Vowel distortions, segmentation and/or equal stress; awkward movement transitions; and trial-and-error behavior in words and phrases are typical.

In comparison, children with only phonological impairment may make substitution errors or exhibit phonologic processes that are fairly consistent. The movements for those incorrect sounds will be accurate though, and rate and prosody are typically good. If the child is older, you can further examine phonologic performance via an articulation test.

Low standard scores do not discriminate CAS from phonologic impairment, but the clinician will be able to observe whether some errors are distortions (seen more often in CAS) versus well-articulated sound substitutions (more common in phonologic impairment).

Using Dynamic Assessment to Evaluate for CAS

In this type of evaluation, the clinician provides cueing as the child repeatedly attempts to produce an utterance. These cues may be slowing the rate of the model, visual cues (“watch my face”) or tactile cues.

Scoring reflects the child’s change in performance as a result of cueing. This approach can help identify children with CAS. When clinicians provide more support through cueing, the child may be more willing to attempt to say the word or phrase.

Even when simple cues are offered (for example, “Watch me,” or a gestural cue, such as a hand gesture to close the mouth more), a child may more actively attempt the correct movement.

This then allows clinicians to see groping, segmentation, awkward movements, stress errors or other characteristics associated with CAS that may occur infrequently or not at all in spontaneous utterances or in noncued repetitions.

Examples of Diagnostic Statements for CAS

While our work settings often dictate formats for documentation, these examples of diagnostic statements show how clinicians might summarize different presentations of childhood apraxia of speech.

Example One: The child’s severe delay in speech acquisition is due primarily to deficits in motor planning/programming skill consistent with childhood apraxia of speech. Characteristics include numerous inaccurate movement trajectories leading to consonant and particularly vowel distortions, groping for articulatory configurations, inconsistent voicing errors, segmentation of all attempts at bisyllablic words, and inconsistency across repeated attempts at target words. He also exhibits a significant delay in phonologic skill and a severe deficit in expressive language. Receptive language is in the low-average range. There is no evidence of cognitive impairment, social or pragmatic language deficits, or dysarthria.

Example Two: This child exhibits a moderate phonologic impairment characterized by fronting and consistent typical substitution errors for later-developing sounds. In addition, he exhibits a slightly slower rate, more difficulty with multisyllabic words with occasional segmentation, and occasional vowel distortions, providing evidence for a mild contribution of difficulty with praxis for speech, indicative of mild childhood apraxia of speech. There is no evidence for dysarthria. There is no evidence for receptive or expressive language delay or cognitive impairment.

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March 2017
Volume 22, Issue 3