Children with Developmental Apraxia of Speech Communication Profiles and Interventions Laura J. Ball, Ph. D. Munroe-Meyer Institute for Genetics and Rehabilitation.

Children with Developmental Apraxia of Speech Communication Profiles and Interventions

Laura J. Ball, Ph. D.

Munroe-Meyer Institute for Genetics and Rehabilitation

University of Nebraska Medical Center, Omaha

Demographics

Onset Course Gender Prevalence Aggregation

Research Classifications

Unitary Entity: isolate one characteristic that differentiates DAS from other childhood speech problems.

Syndrome does not require one “necessary and sufficient” dx criterion.

Subtypes:behavioral characteristics are associated with dx criteria for each of 2+ subtypes of the disorder.

Theoretical Perspective Shriberg et.al., (1997a, 97b, 97c) present a

schema for speech production in DAS with linguistic processing stages.1. Input processes (auditory-temporal,

perceptual)2. Organizational processes ( representational,

transformational)3. Output processes (selection-retrieval, pre-

articulatory sequencing)4. Articulatory execution.

DAS: Deficit in Input Processes?

Auditory-Temporal & Perceptual input processes are usually proposed from 2 general perspectives. Children with DAS have:1. Across-the-board deficits in language

processes.2. Specific deficits in either formulation or

transformation of appropriate phonological representations.

Robin et.al., (1993) noted that children had disordered prosody, suggesting that “impaired temporal perception could impact ability to gain information about durational aspects of prosody and add to the observed prosodic difficulties.”

DAS: Deficit in Organizational Processes?

Representational & Perceptual Organization

Velleman & Strand (1994) implicate representational processing. They suggest that children with DAS “could be seen as impaired in their ability to generate & utilize frames, which would otherwise provide the mechanisms for analyzing, organizing, & utilizing information from their motor, sensory, & linguistic systems for the production of spoken language.”

Maassen, Thoonen, & Gabreels (1993):

Children with DAS demonstrate a “phonological encoding disorder.”

Snow, Marquardt, & Davis (1992): Children

with DAS “demonstrate an apparent breakdown in the ability to perceive ‘syllableness’ and access & compare syllable representations with regard to position & structure.”

Groenen, Crul, Maassen, & Thoonen (1993): “weaker auditory memory traces” suggest perceptual discrimination tasks have diagnostic value. “The degree of dysfunction in speech production is related to the degree of dysfunction in speech perception.”

Transformational Organization

Morphophonemic, allophonic & sociolinguistic rules appear to be intact.

DAS: Deficit in Output Processes?

Pre-articulatory Sequencing

(most prevalent) attributes the variability observed in speech output to deficits in pre-articulatory sequencing of the spatio-temporal movements for speech sounds.

Selection-Retrieval

Phonetic variability involves a lower-level deficit in motor programming, rather than retrieval of phonemic units.

Walton & Pollack (1991) “motor theory”: “Although one could argue that there is a phonemic confusion in the speech of these children, one could also argue that their ability to demonstrate these contrasts is lost when their motor systems are taxed or challenged.”

DAS is a disorder of movement

Diagnostic Features

Speech Errors: Differ from errors of children with

developmental delay, phonological processes.

Resemble errors of adult acquired apraxia (contrast between voluntary and involuntary performance, variability of errors).

Differ from dysarthria, which has errors in phonation, resonance, articulation & prosody.

DAS impacts

all aspects

of communication

Why do we Communicate?

Light (1988) identified four purposes of social communication:

1. expression of wants or needs,

2. transfer of information,

3. social closeness, and

4. social etiquette.

Important Aspects

1. DAS as a disorder of movement

2. DAS as a disorder impacting all aspects of communication

DAS DefinedTypically defined in terms of sound

production error patterns, actually a disorder of movement.

Difficulty is noted with purposeful voluntary movements for speech, creating an inability to sequence speech movements in the absence of paralysis.

DAS is a disorder of

movement

Survey of SLPs

Participants regional SLP’s treating DAS

Profiles children actually in treatment

Perspective clinical awareness vs. “pure”

research version

Profiles

DAS & Communication: Characteristics

Decreased intelligibilityDisordered languageSocial withdrawalBehavioral aggressionAcademic failure

Important Aspects…gee, notice a pattern here?

1. DAS as a disorder of movement

2. DAS as a disorder impacting all aspects of communication

Screening for DAS Address increase in referrals &

diagnoses of DAS among preschool population

Short administration time Organize, streamline assessment

process Increase assessment efficiency

Morehouse & Linderman, 2000

Screening for Developmental Apraxia of Speech (SDAS) Oral Motor Movements Phoneme Stimulability Intelligibility Checklist of DAS Characteristics Increasing Word Length Multisyllabic Words Across Trials Interpretation & Recommendations

Morehouse & Linderman, 2000

Assessment of DAS (Strand, 1998)

Neuromuscular Muscle strength, tone, & coordinationReflexesSensory function

Structural FunctionStructures, tissue characteristics, &

sensationRange of motion, strength, coordination,

speed, & ability to vary muscle tension.

Motor Speech Production

Simple to complex phonetic sequencing:

CV, VC, CVC (vary the vowel) monosyllabic words multisyllabic words phrases sentences of increasing length

Assess at Level of Breakdown

Examine any vowels NOT heard in spontaneous speech

Examine CV/VC combinations, also omitting those heard in spontaneous speech

Examine CVC productions, omitting those heard in spontaneous speech same 1st & last phoneme different 1st & last phoneme

simultaneous production with examiner

direct imitationdelayed imitation

Examine Words of Increasing Examine Words of Increasing LengthLength

•simultaneous production with examiner

•direct imitation•delayed imitation

Examine Multisyllabic Words

Respiration Laryngeal function Resonance: Large number

hyper- nasal hypo- nasal mixed nasality

Physiological functioning for Physiological functioning for speech productionspeech production

Articulation & Phonology What evaluation procedures would

be most appropriate to address the needs of children with DAS?

What evaluation procedures would be most appropriate to address the needs of children with motor-based speech disorders?

Intelligibility & Comprehensibility

What are the most appropriate means of assessing intelligibility in young children?

How might you get a measure of a child’s comprehensibility vs. intelligibility?

Intelligibility/Comprehensibility

Index of Augmented Speech Comprehensibility in Children (I-ASCC) (Dowden, 1997)

A non-standardized clinical measure to assess comprehensibility.

I-ASCC Hierarchy

Present a picture with a verbal cue such as “What is this?”

Present a picture and provide contextual cues such as “It’s a food you might eat. What is it?”

Present a picture plus an embedded model such as “It’s pizza. Now you say it.”

Intelligibility

Judge listens to taped utterances without contextual cues and transcribes.

Comprehensibility

After listening to & judging the entire set of utterances without contextual cues, the listener rewinds the tape, reads a contextual cue and transcribes again.

Contextual Cues Something children eat at snack time. Something children use during craft

time. Something children eat for lunch. Clothing young girls wear outside. What you see children doing with a

book.

Language What current methods exist to measure

expressive language in unintelligible children?

What are the most appropriate assessment procedures for assessing both receptive and expressive language in children with DAS?

Clinically, consider of ALL of the following:

Movement skills

Receptive & expressive language skills

Physical structures and functions

Comprehensibility

Communication repertoires in use

Differential Diagnosis

Determine which characteristics are most readily apparent. Are there dominant speech characteristics?

Dysarthria vs. DAS Fluency disorder vs. DAS Phonological disorder vs. DAS Developmental articulation vs. DAS

Research Questions

What attributes of overall communication disabilities are found in children with DAS?

Do clusters based on communication disabilities exist for children with DAS?

MethodsN=36 children with DAS

Screening: DAS Screening Instrument

(Blakeley, 1980)

Child Social Interaction Scales (Adapted from Booth-Butterfield and Gould, 1986; Duran, 1992; Wiemann, 1977; Canary and Spitzberg, 1987; McCrosky, 1982; Christophel, 1990; and Burgoon, 1976.)

Criteria for Inclusion

Committee of 3 DAS experts rated “degree of DAS”

A mean score 3, considered DAS

Articulation and Phonology

Do children with DAS use phonological processes? Examine consistency of productions.

Khan-Lewis Phonological Analysis

Articulation & prosody Goldman-Fristoe Test of Articulation Consider impact on language skills &

reading development

Language sample if intelligibility allows Comprehensive receptive & expressive Morphology & syntax

Test of Auditory Comprehension of

Language (III) (1998) Peabody Picture Vocabulary Test (IIIA/B)

LanguageLanguage

Communication

Social communication skills

Behavioral communication repertoires

Academic communication skills Social Skills Rating System

(Gresham and Elliott, 1990)

Assessment Procedures Contributing to DAS Profile Identification

Profile Communication Aspects

Intelligibility & Comprehensibility

Language (receptive & expressive)

Social

Behavioral

Academic

Cluster Analysis Measure used to examine large data set

and determine if there are patterns of similarity among the variables.

Results in “dendrogram” (see diagram) which depicts the total data set and each stage of grouping the most similar data points (or in this case, children with DAS) into clusters.

Cluster Analysis

Confirmatory measure of profiles previously obtained (Ball & Beukelman, 1998).

Classifies sample into smaller number of mutually exclusive groups based on similarity.

Variables analyzed simultaneously to discover underlying structure.

Significant Discriminant Functions

Profile Identification Procedures

Discriminant Function Structure Weights

Articulation-oriented Function 1Articulation -.531 DAS .488 Intelligibility .481 MLU .452 PCC .413

Language-oriented Function 2 Parent/behavior -.453Language comprehension .434Receptive Vocabulary .363Phonological skills .347

Cluster One, n = 12

high # articulation errors high social skill ratings high DAS scores (very DAS) few consistent phonological processes low intelligibility low vocabulary scores high disruptive behaviors low receptive language scores small MLU low PCC

Cluster Two, n = 12

high # articulation errors high social skills ratings less DAS many consistent phonological processes low intelligibility high vocabularyscores few disruptive behaviors high receptive language scores high MLU high PCC

Cluster Three, n = 1

high # articulation errors many consistent phonological processes more DAS low intelligibility low vocabulary scores less socially interactive many behavioral disruptions low receptive language skills low MLU low PCC

Cluster Four, n = 11

low # articulation errors few consistent phonological processes less DAS high intelligibility high vocabulary scores less socially interactive few behavioral disruptions high receptive language scores high MLU high PCC

I II IV

High Articulation Err; Low Language X X

Low Articulation Err; High Language X

High Behavior Probs.; Low Language X X

Low Behavior Probs.; High Language X

Cluster Status on Significant Variables

-4

-2

0

2

4

6

8

DAS Articulation PhonologyIntelligibility Receptive Vocabulary Parent/socialParent/behavioral Teacher/social Teacher/behavioralRecpetive Language MLU %Consonants Correct

Cluster I Cluster II Cluster III Cluster IV

Intervention

Motor Learning TheoryMotor learning occurs as a result of

experience & practice

Relevant factors: Precursors to Motor Learning Conditions of Practice Knowledge of Results Effects of Rate

Motor Learning: PrepracticeThe prepractice portion of a therapy

session involves:

Motivation make the tasks seem important set goals with the child with standard

to achievenot just “do the best you can”

Focused Attention

General Idea of Task understand task clearly ways they will learn keep instructions simple; focus on

1-2 important aspects of movement.

DO NOT OVERINSTRUCT

Observational Learning modeling & demonstration with

pictures, videotapes, and live demos

show the child the movements a few times covering all stimuli being targeted in the session

be wary of verbal instructions

Establish Reference of Correctness

auditory feedback i.e., for /pa/, may have lip closure

as correct to begin, then later move to correct articulation

Motor Learning: Practice

Knowledge of Performance Knowledge of Results

summary immediate

Repetitive Practice mass distributed

Knowledge of Performance (KP)

Feedback about the correctness of a particular movement pattern re: accuracy of production. e.g., “I heard you say ….”

Knowledge of Results (KR)

Feedback about the outcome of a movement pattern re: environmental goal. e.g., “Yes, you got it!” “No, that’s not

quite it.”

Avoid extraneous activity (speaking, movements by clinician/child) during the period between the response & when you deliver KR, also after KR

Summary KR is better than immediate KR, better to wait until several (easier wait 15, difficult wait 3-5) responses are obtained

Conditions of Motor Speech Practice (DAS)

Repetitive Practice need enough trials/session to allow

motor learning to occur & become habituated to automatic

use reinforcements that don’t take time develop activities that facilitate repeated

opportunities for production of target movement patterns

Mass vs. Distributed Practice

decision depends on severity and type mass yields quick development of

accurate production distributed requires longer time, but

get better generalization direct imitation delayed imitation

Examine Sentences of Increasing Length

direct imitation with repeated attempts

Speech Practice for DAS

Intensive treatment is required Large number of movement repetitions

required (no fewer than 20) Come to neutral position between attempts

(rest), do NOT divide into component parts Progress through hierarchy of task difficulty Treat rhythm, stress & intonation to

coincide with articulation drills

Augmentative and Alternative Communication

Children with DAS

Integrating AAC and Natural Speech

Extent of AAC use depends upon the communication load that can be carried by natural speech.

Extent of AAC use will vary from child to child.

Extent of AAC use will vary for a child depending on the communication goal.

Lindblom Model of MutualityRich

Information from the acoustic signal(Intelligibility)

Poor Poor Signal-Independent Rich

Information

Lower Comprehensibility

Higher Comprehensibility

Intelligibility Estimates

Mother 85%

Grandmother 30%

School SLP 30%

Classroom teacher 50%

AAC Specialist 25-30%

AAC Use & Intelligibility of Children with DAS

N = 36 children confirmed with DAS

M = 6 years, 1 month age

M = 44% intelligibility

Range of intelligibility from 0 to 97%

N = 1 child using AAC at time of evaluation for DAS

Use of AAC systems by Children with DAS

(Cumley, 1997)

Participants were children with severe phonological disorder and/or DAS

N = 16 Children3 yrs, 5 months to 7 yrs, 5 months

ProceduresDAS children with a range of

intelligibility were taught to use an AAC technique

Children engaged in play situations

Interactions were video recorded and analyzed

Research Design

ABA Design:1. No AAC Board Present

2. Treatment Condition with AAC Board Present

3. Post-treatment Condition with AAC Board Present

Results

Increase comprehensible messages Increased successful communication

repairs Children with most severe speech

disorders used AAC most frequently

AAC use did not decrease the number of speech attempts!!!

AAC use reduced the number of gestures.

AAC was used primarily to resolve communication breakdowns.

Communication Goals

ConversationSmall talk

Information sharing

Language learning

ParticipationEducation & Recreation

Social memberships

Establishing & maintaining

Wants & Needs

Multimodal Considerations

Communicative contexts

Communicative goals

Intent of communication situation

Immediate & future communication needs

Support development of skills

Theme-specific boards Picture/symbol dictionary Remnant books Voice output communication aids Collaborate roles & responsibilities for

each partner Establish initiation & repair of

breakdowns)

Focus on Communicative Competence

AAC Strategies

Sign

Low-tech (situation specific)

Portable digitized speech devices (situation specific)

Portable general purpose devices

AAC Evaluation

Why children with DAS are difficult to augment typically ambulatory have developed alternative, often unique

communication strategies may have intact cognitive skills language development ongoing may have poor literacy skills

AAC Device Specifications Portability Comprehensive system

high tech low tech

Cover extensive vocabulary demands Minimize sequencing demands Teach sequencing skills Allow & facilitate language development

Family Concerns re: DAS Qualitative Research Project

Garn-Nunn & Katz, 2000

Obtained postings daily from APRAXIA-KIDS listserve

Apparent Themes Diagnosis Treatment Securing Treatment Personal

Family Diagnostic Concerns 26% of postings Varying descriptive terms Nature of problem Concomitant problems Importance of Early Diagnosis SLP crucial to success

Garn-Nunn & Katz, 2000

Family Treatment Concerns 28% of postings Importance of speech motor practice Sign language, AAC facilitate speech early Parents intensively involved with treatment Changing nature of treatment Educational concerns

Garn-Nunn & Katz, 2000

Family Concerns: Securing Treatment Services

22% of postings Intensive treatment, long period of time Secure different sources of treatment IEP procedures, goals, availability of

services Private insurance issues Parent advocacy training, IDEA

Garn-Nunn & Katz, 2000

Family Personal 17% of postings Success stories, thanks,

encouragement Failures, venting Explaining DAS to others & to child Local support groups

Garn-Nunn & Katz, 2000

Case Study Walt, 10 year 6 month old male Regular 4th grade classroom

Intelligibility <50% to unfamiliar listener

Diagnosed with DAS in 1998 8 years of traditional articulation-

oriented speech therapy Past evaluation, recommendations

Assessment Results Language

TACL-3 PPVT-III Receptive subtests from CELF-R MLU

Articulation/Phonology

GFTA KLPA Screening Test for Developmental

Apraxia of Speech (Blakeley, 1980) Percent of Consonants Correct Motor Speech Tasks

Social Communication

Social Skills Rating System(Gresham & Elliott, 1990) (AGS)

Child Social Interaction Scale

Intelligibility/Comprehensibility I-ASCC

AAC Assessment for WaltExamine current communication and

communication needs parent & child interview speech evaluation results communication abilities

understands symbols for communication emerging literacy skills

Physical Status ambulatory, active good fine motor control hearing and vision WNL

Walt’s Communication Device

Lightweight & portable Durable Extensive vocabulary Support emerging literacy skills Support developing language Allow for novel message generation Good quality voice output for

communication in a variety of contexts

Walt’s Communication System

DynaMyte (DynaVox Systems, Inc) Topic Boards Letter Board Remnant book Natural speech

Classroom Recommendations

Provide multiple avenues of communication

Computer supported literacy options Phonetic based word generation (Intellikeys) Story reading (Living Books, Intellikeys) Story writing (Write:Outloud, CoWriter) Organizational software (Inspiration)

Speech Therapy Recommendations

Frequent treatment sessions (daily) Brief treatment sessions (15 min) Motor learning concepts stressed

knowledge of results knowledge of performance distributed practice

Provide tactile, visual, & verbal feedback

References Bradford & Dodd (1996). Do all speech-disordered children

have motor deficits? Clinical Linguistics and Phonetics, 10(2), 77-101.

Davis, B. (1998a). Differential diagnosis of developmental apraxia. Newsletter: ASHA Special Interest Division 1: Language Learning and Education, 5(2), 4-7.

Hayden, D.(1994). Differential diagnosis of motor speech dysfunction in children. Clinics in Communication Disorders, 4(2), 119-141.

Hayden & Square (1999). Verbal Motor Production Assessment for Children (VMPAC). The Psychological Corporation: A Harcourt Assessment Company

More References

Cumley, G. (1997). Introduction of an augmentative and alternative modality: Effects on the quality and quantity of communication interactions of children with severe phonological disorders. Unpublished Doctoral Dissertation, University of Nebraska-Lincoln.

Davis, B., Jakielski, K., & Marquardt, T. (1998). Developmental apraxia of speech: Determiners of differential diagnosis. Clinical Linguistics and Phonetics, 12(1), 25-45.

Dowden, P. (1997). Augmentative and Alternative Communication Decision Making for Children with Severely Unintelligible Speech. AAC, 13(1), 48-58.

More References

Hall, P., Jordan, L., & Robin, D. (1993). Developmental apraxia of speech: Theory and clinical practice. Austin, TX: Pro-ed.

McNeil, M., Robin, D., & Schmidt, R. (1997). Apraxia of Speech: Definition, differentiation, and treatment. In M. McNeil (Ed.), Clinical management of sensorimotor speech disorders (p. 394). New York: Thieme.

Shriberg, L., Austin, D., Lewis, B., McSweeny, J., & Wilson, D. (1997a). The Percentage of Consonants Correct (PCC) metric: Extensions and reliability data. JSLHR, 40(4), 708-722.

More ReferencesShriberg, L., Aram, D., & Kwiatkowski, J. (1997a).

Developmental apraxia of speech I: Descriptive and theoretical perspectives. JSLHR, 40(2), 273-285.

Shriberg, L., Aram, D., & Kwiatkowski, J. (1997b). Developmental apraxia of speech II: Toward a diagnostic marker. JSLHR, 40(2), 286-312.

Shriberg, L., Aram, D., & Kwiatkowski, J. (1997c). Developmental apraxia of speech III: A subtype marked by inappropriate stress. JSLHR, 40(2), 313-337.

Strand, E. (1998). Treatment of developmental and acquired apraxia of speech. In D. Beukelman & K. Yorkston (Eds.), Motor speech disorders. Baltimore: Brookes.

More ReferencesStrand, E. A. (1995). Treatment of motor speech disorders in

children. Seminars in Speech and Language, 16(2), 126-139.

Shriberg, L., Austin, D., Lewis, B., McSweeny, J., & Wilson, D. (1997b). The Speech Disorders Classification System (SDCS): Extensions and lifespan reference data. JSLHR, 40(4), 723-740.

Caruso & Strand (1999). Clinical Management of Motor Speech Disorders in Children. NY: Thieme.

Beukelman, D., & Mirenda, P. (1998). Augmentative and Alternative Communication. (2nd ed.). Baltimore: Brookes.