Comments Regarding the Investigation of Developmental Apraxia of Speech

1998 ◽  
Vol 41 (4) ◽  
pp. 958-960
Author(s):  
Claire M. Waldron
Keyword(s):  
Theoretical Model ◽  
Diagnostic Marker ◽  
Receptive Language ◽  
Speech Disorders ◽  
Written Language ◽  
Adult Onset ◽  
Apraxia Of Speech ◽  
Language Status ◽  
Developmental Apraxia ◽  
Strongly Agree

The conclusions and discussion were based on only 16 children who were identified based on clearly described criteria. Those subjects have widely varying ages, unspecified treatment histories, and varying receptive language status. The authors did not claim that these results are generalizable to a larger population of children, but I fear that their results will be interpreted that way by others. Identifying unusual phrasal stress deficits in 8 of 16 children with suspected DAS should not be construed or implied as evidence for a diagnostic marker for a subtype of DAS. I strongly agree with the authors that longitudinal studies of children with persistent and unusual speech disorders are needed. Studies concerning children's responses to treatment are also needed. Although models of adult onset apraxia (AOS) may provide useful procedures for measuring or describing speech and nonspeech characteristics of DAS, using AOS as a theoretical model or clinical analogy to DAS leads us to ask less relevant questions about children with unusual and persistent speech disorders. Children with suspected DAS are different from adults who have AOS. Children who have never spoken normally or used language normally are different from adults who have acquired a speech disorder after decades of using spoken and written language normally. In order to intervene efficiently and appropriately, we need to know whether and how children with DAS differ from other children, not how they might resemble adults with an acquired disorder.

Metrical Analysis of the Speech of Children With Suspected Developmental Apraxia of Speech

1999 ◽  
Vol 42 (6) ◽  
pp. 1444-1460 ◽  
Author(s):  
Shelley L. Velleman ◽  
Lawrence D. Shriberg
Keyword(s):  
Differential Diagnosis ◽  
Diagnostic Marker ◽  
Lexical Stress ◽  
Apraxia Of Speech ◽  
Speech Delay ◽  
Acoustic Measures ◽  
Metrical Phonology ◽  
Developmental Apraxia ◽  
Metrical Analysis ◽  
Better Than

Previous studies have shown that metrical analysis accounts for syllable omissions in young normally developing children better than prior perspectives. This approach has not yet been applied to children with disorders. Inappropriate sentential stress has been proposed as a diagnostic marker for a subgroup of children with suspected developmental apraxia of speech (SD-DAS), suggesting that the application of metrical perspectives to this population may be appropriate. This report extends the goal of identifying diagnostic markers for SD-DAS using analytic procedures from metrical phonology. The lexical metrical patterns of children with SD-DAS were compared to those of a group of children with speech delay (SD) to verify the applicability of metrical constructs to children with disorders while at the same time seeking lexical stress characteristics that might be useful for differential diagnosis. The lexical stress errors of children in both the SD and SD-DAS disorder groups were found to conform to patterns identified in metrical studies of younger normally developing children, confirming the applicability of this approach to children with disorders. Lexical metrical patterns did not differentiate the groups from each other. However, syllable omissions persisted to much later ages in the SD-DAS subjects, especially those children previously identified as having inappropriate phrasal stress. Further metrical studies of the speech of children with suspected SD-DAS are needed, both at the lexical and the sentential level, using both perceptual and acoustic measures.

scholarly journals A Diagnostic Marker to Discriminate Childhood Apraxia of Speech From Speech Delay: I. Development and Description of the Pause Marker

2017 ◽  
Vol 60 (4) ◽  
Author(s):  
Lawrence D. Shriberg ◽  
Edythe A. Strand ◽  
Marios Fourakis ◽  
Kathy J. Jakielski ◽  
Sheryl D. Hall ◽  
...  
Keyword(s):  
Classification System ◽  
Diagnostic Marker ◽  
Speech Disorders ◽  
Apraxia Of Speech ◽  
Speech Delay ◽  
Childhood Apraxia Of Speech ◽  
Motor Speech ◽  
Motor Speech Disorders ◽  
Cross Classification ◽  
Classification Procedures

Purpose The goal of this article (PM I) is to describe the rationale for and development of the Pause Marker (PM), a single-sign diagnostic marker proposed to discriminate early or persistent childhood apraxia of speech from speech delay. Method The authors describe and prioritize 7 criteria with which to evaluate the research and clinical utility of a diagnostic marker for childhood apraxia of speech, including evaluation of the present proposal. An overview is given of the Speech Disorders Classification System, including extensions completed in the same approximately 3-year period in which the PM was developed. Results The finalized Speech Disorders Classification System includes a nosology and cross-classification procedures for childhood and persistent speech disorders and motor speech disorders (Shriberg, Strand, & Mabie, 2017). A PM is developed that provides procedural and scoring information, and citations to papers and technical reports that include audio exemplars of the PM and reference data used to standardize PM scores are provided. Conclusions The PM described here is an acoustic-aided perceptual sign that quantifies one aspect of speech precision in the linguistic domain of phrasing. This diagnostic marker can be used to discriminate early or persistent childhood apraxia of speech from speech delay.

Developmental Apraxia of Speech

1997 ◽  
Vol 40 (2) ◽  
pp. 313-337 ◽  
Author(s):  
Lawrence D. Shriberg ◽  
Dorothy M. Aram ◽  
Joan Kwiatkowski
Keyword(s):  
Diagnostic Marker ◽  
Unknown Origin ◽  
Conversational Speech ◽  
Apraxia Of Speech ◽  
Speech Delay ◽  
Motor Speech ◽  
Motor Speech Disorder ◽  
Developmental Apraxia ◽  
Working Hypotheses ◽  
Prior Stress

Two prior studies in this series (Shriberg, Aram, & Kwiatkowski, 1997a, 1997b) address the premise that children with developmental apraxia of speech (DAS) can be differentiated from children with speech delay (SD) on the basis of one or more reliable differences in their speech. The first study compared segmental and prosody-voice profiles of a group of 14 children with suspected DAS to profiles of 73 children with SD. Results suggest that the only linguistic domain that differentiates some children with suspected DAS from those with SD is inappropriate stress. The second study cross-validated these findings, using retrospective data from a sample of 20 children with suspected DAS evaluated in a university phonology clinic over a 10-year period. The present study is of particular interest because it cross-validates the prior stress findings, using conversational speech samples from 19 children with suspected DAS provided by five DAS researchers at geographically diverse diagnostic facilities in North America. Summed across the three studies, 52% of 48 eligible samples from 53 children with suspected DAS had inappropriate stress, compared to 10% of 71 eligible samples from 73 age-matched children with speech delay of unknown origin. Discussion first focuses on the implications of stress findings for theories of the origin and nature of DAS. Perspectives in psycholinguistics, neurolinguistics, and developmental biolinguistics lead to five working hypotheses pending validation in ongoing studies: (a) inappropriate stress is a diagnostic marker for at least one subtype of DAS, (b) the psycholinguistic loci of inappropriate stress in this subtype of DAS are in phonological representational processes, (c) the proximal origin of this subtype of DAS is a neurogenically specific deficit, (d) the distal origin of this form of DAS is an inherited genetic polymorphism, and (e) significant differences between acquired apraxia of speech in adults and findings for this subtype of DAS call into question the inference that it is an apractic, motor speech disorder. Concluding discussion considers implications of these findings for research in DAS and for clinical practice.

Alternative Research Perspectives

1998 ◽  
Vol 41 (4) ◽  
pp. 960-963
Author(s):  
Lawrence D. Shriberg ◽  
Dorothy M. Aram ◽  
Joan Kwiatkowski
Keyword(s):  
Unknown Origin ◽  
Receptive Language ◽  
Speech Disorders ◽  
Adult Onset ◽  
Need For Treatment ◽  
Research Perspectives ◽  
Explanatory Account ◽  
Adults And Children ◽  
Alternative Research ◽  
Internal And External Validity

Waldron begins the final section of her letter with the claim that the data for all but 16 of the 48 children with suspected DAS should be discounted, noting that even the 16 subjects "have widely varying ages, unspecified treatment histories, and varying receptive language status." Waldron evidently views the data for the 16 children provided by the five collaborating researchers (Study 3: A–E) as valid, but not the data obtained from the samples provided by the second author (Aram & Horowitz, 1993, as cited in Shriberg et al., 1997b) or the samples provided by local clinicians (Study 2). As reviewed at the outset of the present discussion, we take a different position on both criteria for suspected DAS and on the value of subject diversity for the questions posed. What is most relevant from a scientific perspective is that even if our findings were restricted to the 16 children whom Waldron accepts as valid subjects, we submit that they would sufficiently motivate our interpretations and conclusions. The issue here appears to be a difference in perspective on the role and responsibilities of researchers. Waldron is concerned that, notwithstanding the caveats we include about threats to internal and external validity of our findings, some readers might act inappropriately in the clinic based on their interpretation of our findings. We report that inappropriate stress occurred in approximately 50% of the children with suspected DAS (whether totaling 16 or 48 children), compared to 10% of the 71 eligible children with speech delay of unknown origin. In our view, our fundamental task as researchers is to provide a clear report of our science. In turn, if sufficiently stimulating to the scientific community, the report may motivate others to attempt to replicate and explicate our findings. Finally, we respect Waldron's interest in learning how children with DAS differ from other children, but we disagree with her conclusion that studies comparing DAS with adult onset apraxia (AOS) "leads us to ask less relevant questions about children with unusual and persistent speech disorders." Perhaps the source of our difference is in alternative perceptions of how to reach the end goal of helping children, possibly including prevention. Waldron stresses the need for treatment-relevant research, noting, "In order to intervene efficiently and appropriately, we need to know whether and how children with DAS differ from other children, not how they might resemble adults with an acquired disorder." We, too, are interested in treatment, but specifically as it follows from a well-developed explanatory account of the origin and nature of the disorder (see discussion, Shriberg et al., 1997c, pp. 332–333). A possible route toward such an account is to explore the relevance of neuroscience data in adult onset speech disorders, an approach that has been productive for studying dysarthria in adults and children. As reviewed in the first and third papers, our interest in how the speech of children with suspected DAS might resemble the speech of adults with acquired apraxia addresses the hypothesis of common deficits in underlying neurolinguistic or psycholinguistic processes. A report from such a study is in preparation.

scholarly journals A Diagnostic Marker to Discriminate Childhood Apraxia of Speech From Speech Delay: II. Validity Studies of the Pause Marker

2017 ◽  
Vol 60 (4) ◽  
Author(s):  
Lawrence D. Shriberg ◽  
Edythe A. Strand ◽  
Marios Fourakis ◽  
Kathy J. Jakielski ◽  
Sheryl D. Hall ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Mayo Clinic ◽  
Diagnostic Marker ◽  
Adult Onset ◽  
Apraxia Of Speech ◽  
Speech Delay ◽  
Likelihood Ratios ◽  
Childhood Apraxia Of Speech ◽  
Acoustic Measures ◽  
Validity Studies

Purpose The purpose of this 2nd article in this supplement is to report validity support findings for the Pause Marker (PM), a proposed single-sign diagnostic marker of childhood apraxia of speech (CAS). Method PM scores and additional perceptual and acoustic measures were obtained from 296 participants in cohorts with idiopathic and neurogenetic CAS, adult-onset apraxia of speech and primary progressive apraxia of speech, and idiopathic speech delay. Results Adjusted for questionable specificity disagreements with a pediatric Mayo Clinic diagnostic standard, the estimated sensitivity and specificity, respectively, of the PM were 86.8% and 100% for the CAS cohort, yielding positive and negative likelihood ratios of 56.45 (95% confidence interval [CI]: [1.15, 2763.31]) and 0.13 (95% CI [0.06, 0.30]). Specificity of the PM for 4 cohorts totaling 205 participants with speech delay was 98.5%. Conclusion These findings are interpreted as providing support for the PM as a near-conclusive diagnostic marker of CAS.

The Labeling Problem in Aphasia

1986 ◽  
Vol 51 (2) ◽  
pp. 176-180 ◽  
Author(s):  
Audrey L. Holland ◽  
Davida Fromm ◽  
Carol S. Swindell
Keyword(s):  
Speech Disorders ◽  
Case Description ◽  
Test Results ◽  
Apraxia Of Speech ◽  
Poor Agreement ◽  
Motor Speech ◽  
Motor Speech Disorders ◽  
Communication Difficulties ◽  
Token Test ◽  
Primary Problem

Twenty-five "experts" on neurogenic motor speech disorders participated in a tutorial exercise. Each was given information on M, a patient who had communication difficulties as the result of stroke, and asked to complete a questionnaire about his problem. The information included a detailed case description, an audiotape of M's speech obtained at 4, 9, 13, and 17 days post-stroke, and test results from the Western Aphasia Battery, the Token Test, and a battery for apraxia of speech. The experts were in excellent agreement on M's primary problem, although it was called by seven different names. The experts were in poor agreement on his secondary problem(s), e.g., the presence and type of aphasia and dysarthria. The results suggest that labeling is difficult, even for "experts." Furthermore, the practicing clinician needs to be sensitive to the likelihood of more than one coexisting problem.

Part II

2000 ◽  
Vol 31 (2) ◽  
pp. 173-175 ◽  
Author(s):  
Penelope K. Hall
Keyword(s):  
Apraxia Of Speech ◽  
Speech Characteristics ◽  
Current Thinking ◽  
Developmental Apraxia ◽  
Previous Letter

In a previous letter to the parent(s) of children with developmental apraxia of speech (DAS), the speech characteristics often exhibited as part of the disorder were described. In this second letter, the issues involved in current thinking about the nature of the disorder are explored. Also shared is information concerning what is thought to be known about the causes of the disorder. An appendix of publications exploring these issues appears at the end of the letter.

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