Title: Ray Kent Symposium Differentiating Motor Planning
1Ray Kent Symposium Differentiating Motor
Planning Phonologic Impairment in Severe
Speech Disorders
- Edy Strand
- Department of Neurology
- Associate Professor, Mayo College of Medicine
2Purpose - Scope
- Task
- Speak on the topic of differentiating motor
planning phonologic impairment in severe speech
sound disorders in children
3In 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
4Purposes 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
6Phonology
- 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.
7Childhood 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.
9Dysarthria
- 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.
11Dysarthria 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
12What 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
13What 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
14What 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
16Diagnostic 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.
17Diagnostic 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.
18Diagnostic 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)
19Diagnostic 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
20Speech 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
21Speech 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
22Markers 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
23ASHA 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.
25Many 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
261. 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?
28Co-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
29For 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
322 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
343. 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
354. 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
36a) 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.
39b) 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
40Assessment of Motor Systems
- Examination of Neuromuscular Condition
- Structural functional Exam
- Motor Speech Examination
- Examination of Physiological subsystems
41Motor 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
42Motor 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
43MSE 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
44Motor 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
45Motor 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
46Standardized 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
47DEMSS
- 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
48DEMSS
- 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
49DEMSS
- 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
50Subjects
- 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
51Procedure
- 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
52Procedure
- 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.
53Hierarchical 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.
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55DEMSS
- 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
56Interpretation 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
57Interpretation 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
58Determining 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
59Determining 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.
60In 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.
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