children with developmental apraxia of speech communication profiles and interventions laura j....
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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.