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Ray Kent Symposium Differentiating Motor Planning

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Title: Ray Kent Symposium Differentiating Motor Planning


1
Ray Kent Symposium Differentiating Motor
Planning Phonologic Impairment in Severe
Speech Disorders
  • Edy Strand
  • Department of Neurology
  • Associate Professor, Mayo College of Medicine

2
Purpose - Scope
  • Task
  • Speak on the topic of differentiating motor
    planning phonologic impairment in severe speech
    sound disorders in children

3
In our hour today
  • Definitions and Descriptions of phonologic
    impairment versus motor speech impairment
    (apraxia versus dysarthria)
  • Discussion of diagnostic markers
  • Discussion of issues that influence our clinical
    thinking in differential diagnosis
  • Review of Assessment Tasks
  • Interpretation of observations toward coming to a
    differential diagnosis

4
Purposes of Assessment(McNeil Kennedy, 1984)
  • Screening Detect or confirm a problem requiring
    further assessment
  • Differential Diagnosis
  • Specify severity and prognosis
  • Plan Treatment
  • Measure change that occurs as a result of
    treatment

5
  • Severe Speech Sound Disorders
  • Differential Diagnosis
  • Phonologic Impairment Motor Speech Impairment
  • CAS Dysarthria
  • Severe Speech Sound Disorders
  • Differential Diagnosis
  • Phonologic Impairment Motor Speech Impairment
  • CAS Dysarthria
  • Severe Speech Sound Disorders
  • Differential Diagnosis
  • Phonologic Impairment Motor Speech Impairment
  • CAS Dysarthria
  • Severe Speech Sound Disorders
  • Differential Diagnosis
  • Phonologic Impairment Motor Speech Impairment
  • CAS Dysarthria
  • Severe Speech Sound Disorders
  • Differential Diagnosis
  • Phonologic Impairment Motor Speech Impairment
  • CAS Dysarthria
  • Severe Speech Sound Disorders
  • Differential Diagnosis
  • Phonologic Impairment Motor Speech Impairment
  • CAS Dysarthria

6
Phonology
  • The term phonological disorders is frequently
    used to refer to the entire range of
    developmental communication disorders in which
    sound production is principally affected.
  • Specifically, phonologic disorders are a subset
    of sound production disorders in which linguistic
    and cognitive factors are thought to be central
    to the observed difficulties.

7
Childhood Apraxia of Speech (CAS)
  • CAS is a speech disorder, due to delays or
    deviances in those processes involved in planning
    and programming movement sequences for speech.
  • Children with CAS will have difficulty reaching
    and maintaining specific articulatory
    configurations, as well as difficulty moving from
    one articulatory configuration to the next.

8
  • Unless they have a coexisting dysarthria, they
    will not have difficulty moving muscles with the
    correct range, speed and force for non-speech
    activity, including chewing or swallowing.
  • Respiration and phonation will be unimpaired as
    the primary difficulty is planning movement to
    reach articulatory configurations.
  • While a great many of these children also have
    linguistic (phonologic, semantic, syntactic)
    deficits, the term apraxia relates to their
    movement difficulties.

9
Dysarthria
  • This is a collective term for a group of related
    motor speech disorders resulting from disturbed
    muscular control of the speech mechanism.
  • Dysarthria is manifest as disrupted or distorted
    oral communication due to paralysis, weakness,
    abnormal tone or incoordination of the muscles
    used in speech.

10
  • Processes of phonation, respiration, resonance,
    articulation and prosody are affected.
  • Movements may be impaired in force, timing,
    endurance, direction and range of motion.
  • In some types of dysarthria involuntary movements
    (dyskinesias) occur, disrupting articulatory
    output.
  • Sites of lesion include bilateral cortical
    damage cranial nerves involvement spinal nerve
    involvement (respiration) basal ganglia and
    cerebellum.

11
Dysarthria Characteristics
  • Slurred speech
  • Imprecise articulatory contacts
  • Weak respiratory support and low volume
  • Incoordination of the respiratory stream
  • Hypernasality
  • Involuntary dyskinesias of the oral facial
    muscles
  • Spasticity or flaccidity of the oral facial
    muscles

12
What do we do to come to a differential diagnosis?
  • Review the history, examine the structure and
    function of the speech mechanism, and observe
    habitual speech/language skill
  • Form clinical hypotheses regarding the nature of
    the speech disorder
  • Test those hypotheses through our specifically
    chosen and/or constructed assessment tasks

13
What do we do to come to a differential diagnosis?
  • Assessment tasks allow us to make observations
    of
  • Spontaneous speech and language
  • Elicited speech
  • Standardized tests
  • Non standardized tasks or measurements
  • Tally, describe, or measure aspects of speech
    production

14
What do we do to come to a differential diagnosis?
  • Compare speech characteristics observed with
  • Normative data
  • Developmental scales
  • Accepted diagnostic (behavioral) markers for
    specific categories of speech disorders

15
Diagnostic Markers
  • Diagnostic markers
  • Physiologic markers (e.g. Ach receptor
    antibodies for MG)
  • Behavioral Markers
  • observed in habitual performance
  • observed in carefully controlled contexts

16
Diagnostic Markers
  • No physiologic markers for many diagnoses
  • dementia autism
  • schizophrenia SLI
  • learning disabilities asthma
  • These diagnoses are made primarily by clinical
    observation and meeting a number of clinical
    inclusionary and/or exclusionary criteria.

17
Diagnostic Markers Motor Planning versus
Phonologic Impairment
  • For years, the literature repeatedly noted no
    consensus regarding accepted characteristics of
    CAS
  • This was considered a very controversial
    diagnostic label
  • When one read the literature, however, very
    similar descriptions were given by most people.

18
Diagnostic Markers in CAS
  • There was one important area of disagreement
  • While many described CAS as a motor planning
    disorder, and did not include linguistic
    parameters in the inclusionary criteria for the
    label
  • Others have included linguistic deficits (e.g.
    phonemic sequencing errors) as part of the
    description of the disorder (e.g. Aram Nation,
    1982 Lewis et al, 2004 Shriberg et al.,
    1997a,b,c Velleman, 1994)

19
Diagnostic Markers
  • The behavioral characteristics that have been
    suggested for the identification of motor
    planning impairment (CAS) over the years may be
    useful as potential behavioral/clinical markers

20
Speech Characteristics - CAS
  • Difficulty with achieving initial articulatory
    configurations
  • Difficulty moving from one articulatory
    configuration to another
  • Groping and/or trial and error behavior
  • Presence of vowel distortions
  • Limited consonant and vowel repertoire

21
Speech Characteristics - CAS
  • Use of simple syllable shapes
  • Frequent omission of sounds
  • Increased errors with increased word length and
    phonetic complexity
  • Difficulty completing a movement gesture for a
    phoneme easily produced in a simple context, but
    not in a longer one
  • Connected speech poorer than isolated word
    production

22
Markers Essential to the Phenotype
  • Difficulty achieving and maintaining articulatory
    configurations
  • Presence of vowel distortions
  • Altered suprasegmentals
  • lexical and sentential stress
  • overall prosodic contours
  • Altered timing between sounds and syllables
  • Inconsistent error patterns

23
ASHA position statement CAS
  • CAS is a neurological childhood speech sound
    disorder in which the precision and consistency
    of movement underlying speech are impaired in the
    absence of neuromuscular deficits
  • Features consistent with a deficit in the
    planning and programming of movements for speech
  • Inconsistent consonant and vowel errors
  • Lengthened and disrupted coarticulatory
    transitions
  • Inappropriate prosody

24
  • So far weve reviewed
  • How to approach coming to a differential
    diagnosis of motor planning impairment
  • The behavioral diagnostic markers for CAS
  • Lets take a brief look at some of the issues that
    affect our clinical thinking in differential
    diagnosis of motor planning versus phonologic
    impairment in children with speech sound
    disorders.

25
Many issues influence our clinical thinking in
differential diagnosis of MSD
  • 1. Theoretical perspectives regarding the
    co-emergence of language and movement in speech
    acquisition
  • 2. Knowledge base
  • 3. Previous work and current practices in
    nosology/classification
  • 4. Clinical Issues - Current clinical practices

26
1. Theoretical issues regarding the co-emergence
of language and movement in speech acquisition
  • This is not a new discussion
  • As best as I can tell, you and I agree that
    models of language formulation and speech
    production have had a relatively independent
    coexistence. Developments in one area have had
    rather small impact in the other. What Id like
    you to do is the following

27
  • a) Identify major constructs that you believe to
    hold promise for the amalgamation of these two
    classes of models
  • b) Suggest how the major contemporary models of
    speech production differ in their relation to
    models of language formulation
  • c) Consider the prospects for change. What will
    it take to stimulate interaction between language
    theorists and speech production theorists?

28
Co-emergence of language and movement
  • A number of researchers have addressed this issue
    of how language and speech interact during
    development (e.g. Smith and Goffman, 2004
    Stockman, 2004 Kent, 2004 Strand, 2002)
  • This impacts differential diagnosis in a number
    of ways

29
For example
  • Kent, (1984) noted that development of speech
    must be understood in relation to language
    structures on one hand, and the organization of
    movement sequences on the other.
  • He posited a theory that was based in terms of
    musculoskeletal and neural maturation, (rather
    than in terms of conventional linguistic
    contrasts)
  • His theory described speech development with a
    system designed to reflect articulatory movement
    and vocal tract anatomy which changes during
    this period of acquisition

30
  • Kent, (2004) argued for the notion that cognition
    exerts strong influences on speech motor control
    which should be viewed as a cognitive-motor
    accomplishment.
  • He cited evidence from the motor learning
    literature to show the cognitive influences on
    motor performance and learning
  • He cited neurophysiologic evidence that motor
    systems are activated by observing or imagining
    movement
  • And, he noted that both perceptual and motor
    learning are affected by cognitive and emotional
    context

31
  • Smith and Goffman (2004)
  • They ask How can we relate the physiology of
    muscle activation to the units of language?
  • They note that there is no single level of
    linguistic processing acting at the language
    motor interface this makes modeling hard
  • They posit that bidirectional influences of
    language and motor factors interact and change
    over time

32
2 Using the Knowledge Base
  • Neuromotor and structural development
  • Kent (1999) Motor Control Neurophysiology
    Functional Development
  • Kent, (1976 1990 1991 1992 1995)
  • Cognitive and language development
  • Phonological development
  • The use of evidenced based practice
  • to judge validity and reliability
  • as well as the sensitivity and specificity of our
    measures

33
  • Our understanding of theoretical constructs as
    well as a broad knowledge base impacts our
    actions and decisions in differential diagnosis
  • How we construct assessment tasks
  • Our development of new standardized tests
  • Our choices among tests already available (for
    that specific child and our clinical hypotheses
    regarding the nature of that childs speech
    disorder)
  • How we interpret observations made over different
    contexts

34
3. Nosology/Classification
  • This has been the topic of research in childhood
    speech disorders for some time (e.g. Dodd, 1995
    Shriberg,1994 2003)
  • Not trivial label reflects underlying
    impairment which mandates a particular type of
    treatment approach
  • This is particularly relevant to differential
    diagnosis of motor planning impairment, as there
    had been a lack of agreement about the
    characteristics associated with the CAS
    classification

35
4. Current clinical practices
  • a) Review some of the literature regarding
    measurements that may be helpful toward the
    determination of differential diagnosis
  • b) Review basic assessment procedures for
    differential diagnosis
  • c) Comment on standardized tests currently
    available and their psychometric adequacy
  • d) Argue for more dynamic assessment in motor
    speech disorders
  • e) Review some data regarding the construct
    validity of a new dynamic measure of motor speech
    skill

36
a) Measurement that may be helpful to
differential diagnosis of MSD in Kids
  • Maximum Performance Tests (MPT)(Kent, Kent
    Rosenbek, 1987)
  • MPTs examine the upper limits of performance for
    speech tasks
  • Their review summarized the published normative
    data, identified primary task variables and
    provided guidelines for data interpretation
  • Other researchers have also contributed to this
    literature including Rvachew, Hodge Ohber,
    2005 Thoonen et al, 1999 Potter, 2007)

37
  • Acoustic and physiological measures of
  • variability (e.g. Shriberg, Green, Campbell,
    Mcsweeny, Scheer, 2003 Smith Goffman, 1998),
  • Duration (e.g. Shriberg, Campbell, Karlsson,
    Brown, Mcsweeny, Nadler, 2003)
  • Temporal spatial patterns (e.g., Gibbon, 1999
    Moore, 2001 Murdoch, Attard, Ozanne, Stokes,
    1995 Nijland, Maassen, van der Meulen, Gabreels,
    Kraaimaat, Schreuder , 2003).

38
  • Application of some of these methods has led to
    the identification of subtle motor involvement
    among a wider range of children with speech
    abnormalities,
  • including those with specific language impairment
    (Goffman, 1999)
  • and articulation/phonologic disorder for whom
    motor speech involvement had not necessarily been
    suspected (Gibbon, 1999).
  • These measures may prove increasingly useful in
    the examination of speech and nonverbal oral
    movements in young children and therefore be
    helpful in differential diagnosis of motor
    planning as well as movement execution impairment.

39
b) Clinical Procedures in Assessment
  • History
  • Language Assessment
  • Sound System Description
  • Independent analysis (assessment of the childs
    system independent of the adult system
  • Relational analysis (assessment of the childs
    system in relation to the target (adult) system
  • Assessment of the Motor systems

40
Assessment of Motor Systems
  • Examination of Neuromuscular Condition
  • Structural functional Exam
  • Motor Speech Examination
  • Examination of Physiological subsystems

41
Motor Speech Exam (MSE)
  • Allows the clinician to observe changes in
    performance associated with variations in
    linguistic and motor complexity.
  • And, is probably the most appropriate tool for
    determining the presence of motor planning and
    programming deficits (CAS)
  • Allows one to examine behavioral markers when the
    child is trying to imitate movement gestures for
    specific utterances

42
Motor Speech Examination
  • Examine the childs ability to sequence movement
    for phonetic sequences in various contexts
  • Vowels
  • CV VC CVC
  • Monosyllabic, bisyllabic, polysyllabic
  • Phrase
  • Sentences of increasing length

43
MSE An Argument for Dynamic Testing
  • A dynamic approach to testing motor speech skill
    will facilitate determining severity, prognosis,
    and help with treatment planning.
  • Cues
  • Tactile
  • Temporal
  • slow rate
  • Vary the temporal relationship between the
    stimulus and the response

44
Motor Speech Examination
  • Direct Imitation (if wrong) ? Simultaneous,
    slower movement
  • Simultaneous (if wrong) ? Tactile cues
  • Simultaneous (if right) ? Direct Imitation
  • Direct Imitation (if right) ? Add delay

45
Motor Speech Examination
  • This varying the temporal relationship is just a
    TOOL to determine
  • How much help does the child need to reach the
    articulatory configuration and move into the
    subsequent ones Severity
  • Helps determine what phonetic segments, syllabic
    shapes, and length the stimuli should be

46
Standardized Tests for Motor Speech Skill
  • There are only a few standardized measures of
    motor speech skill currently available (McCauley
    Strand, in press)
  • Vary in content and scope
  • Most are limited in psychometric adequacy
  • Only one examines the effect of visual and
    tactile cueing on the childs response and then
    for fewer than half of the test items

47
DEMSS
  • Strand, McCauley Stoeckel (2004 in
    preparation) demonstrated initial construct
    validity and reliability for a new dynamic motor
    speech examination The Dynamic Evaluation of
    Motor Speech Skill
  • Purpose
  • Facilitate differential diagnosis of motor
    planning and programming deficits for speech
    production (CAS)
  • Determine severity and prognosis for improvement
  • Focuses solely on motor speech skill
  • Systematically varies the length, vowel content,
    syllable shapes, prosodic content, and phonetic
    complexity within the utterances sampled

48
DEMSS
  • The test examines parameters frequently
    associated with the diagnosis of apraxia of
    speech
  • Movement accuracy
  • Vowel production
  • Consistency
  • Prosody
  • The test uses a multidimensional scoring system
    to examine the childs response to different
    levels of cueing

49
DEMSS
  • In order to demonstrate the construct validity of
    this test, we have previously reported the
    results of a hierarchical agglomerative Cluster
    Analysis, using the DEMSS accuracy, vowel,
    prosody, and consistency scores, as variables.
  • Purpose - identify groups of children with
    similar profiles of performance on the DEMSS

50
Subjects
  • 82 Consecutive children between the ages of 36
    and 71 months who were referred for speech
    evaluations at the Mayo Clinic for concerns
    regarding speech deficits.
  • Exclusionary Criteria
  • structural deficits (e.g., cleft palate)
  • hearing loss
  • ESL
  • autism
  • developmental delay beyond MMI

51
Procedure
  • All children completed a comprehensive testing
    battery
  • Receptive Language Testing
  • Expressive Language Testing
  • Language Sample
  • MLU
  • phonetic and phonemic inventories
  • observations re grammar and syntax
  • Structural Functional Exam
  • Test for Oral Non-Verbal Praxis
  • Articulation Testing
  • DEMSS

52
Procedure
  • A diagnosis was made at the time of testing,
    based on all observations (including those made
    during administration of the DEMSS)
  • However, DEMSS subscores and total scores were
    not calculated until later and were not used in
    making the diagnosis.

53
Hierarchical Agglomerative Nesting Cluster
Analysis
  • Algorithm starts with each study subject forming
    his or her own cluster
  • For each pair of clusters a measure of
    dissimilarity is calculated.
  • The two most similar clusters are then merged
    together.
  • The algorithm repeats until there are only two
    remaining clusters and stops after merging these
    two clusters into one single cluster consisting
    of all subjects.

54
(No Transcript)
55
DEMSS
  • That study was a first step in an effort to
    develop a valid, reliable and dynamic tool to
    diagnose deficits in planning and programming
    movement gestures for volitional speech
    production in children.
  • We are now
  • Completing an item analysis as part of a revision
    of the instrument
  • We want to follow the lead of Dr. Kent and others
    and include some measures of maximum performance
  • Repeat studies to demonstrate construct validity
    and reliability
  • Establish normative data

56
Interpretation of Assessment Data
  • Often very difficult
  • Interaction of language and speech in acquisition
  • Coexisting disorders
  • Complicated syndromes
  • Seeing the child at only one point in time

57
Interpretation of Assessment Data
  • But we have tools to help
  • Theoretical perspectives regarding the
    co-emergence of language and movement in speech
    acquisition
  • Knowledge base
  • Neuromotor and structural development
  • Cognitive and language development
  • Phonological development
  • Previous work and current practices in
    nosology/classification

58
Determining Differential Diagnosis
  • Clinical Decision Making
  • We use those tools in interpreting assessment
    data to confirm or disprove our clinical
    hypotheses regarding the nature of the
    communicative disorder
  • We consider the response patterns and behavioral
    markers (spontaneous elicited from the child)
    and compare them with those associated with the
    different classifications or labels of speech
    disorder type

59
Determining Differential Diagnosis
  • One must also consider the relative contribution
    of linguistic (phonologic) and motor impairment
    and how that impacts the childs speech
    acquisition
  • One can then plan the focus of treatment, as well
    as treatment methods according to that relative
    contribution.

60
In Conclusion
  • Differential Diagnosis is much more than
    assigning a label
  • The clinicians challenge is to use a broad
    knowledge base with best standards of clinical
    practice to guide clinical decisions and
    determine the relative contribution of linguistic
    and motor impairment

61
  • Luckily, Dr. Kent has helped us by greatly added
    to the knowledge base
  • He has provided a great deal of insight and
    perspective in this endeavor.

62
  • Thank you, Ray!

63
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