Towards a standardised assessment procedure for developmental apraxia of speech

Long-Term Outcomes for Individuals With Childhood Apraxia of Speech

PURPOSE

The study's primary aims were to describe the long-term speech outcomes for adolescents and young adults with a history of childhood apraxia of speech (CAS) and to examine the association of persistent speech sound errors with measures of literacy skills, phonological processing, motor speech production, and parent report of early motor difficulty.

METHOD

Data from a large longitudinal 25-year study were used to explore outcomes for 32 individuals with a history of CAS, ages 12;6 (years;months) to 25 years (M = 17.4, SD = 4.7). Persistent and nonpersistent groups were compared on decoding, phonological processing, multisyllabic word repetition, diadochokinetic rate, and parent report of motor involvement. Parametric (Welch's t tests) and nonparametric tests (Wilcoxon and Fisher exact tests) were used to identify differences between the groups' distributions. Developmental trajectories of speech production were plotted.

RESULTS

Outcomes for individuals with CAS are highly variable, with some demonstrating speech sound errors into adolescence and young adulthood. Speech sound errors were primarily on later developing sounds. Persistence was significantly associated with early motor difficulties. Difficulties with multisyllabic words, phonological processing, and literacy were often present regardless of persistence or nonpersistence of speech errors.

CONCLUSIONS

Children with CAS are at risk for persistent speech sound errors into adulthood. For children showing limited progress with more traditional speech therapy, alternative interventions should be explored. Individuals with persistent speech sound errors are more likely to have a history of early motor deficits. Regardless of persistence, participants with CAS demonstrated ongoing weaknesses in literacy, phonological processing skills, and complex speech production tasks.

Music and musical elements in the treatment of childhood speech sound disorders: A systematic review of the literature

PURPOSE

Music-based interventions are used in the treatment of childhood speech sound disorders (SSDs). Hypotheses on working mechanisms are being developed, focussing on shared neural processes. However, evidence of the effect of treatment with musical elements in SSDs in children is lacking. This study reviews the literature regarding the use of music-based interventions in the treatment of childhood SSDs.

METHOD

A systematic search in six databases was conducted, yielding 199 articles, eight of which met the inclusion criteria. Included articles were reviewed on study characteristics, patient characteristics, interventions, outcomes and methodological quality.

RESULT

This review included four case studies, three single-subject design studies and one cohort study. Seven studies reported positive outcomes on speech production, but outcome measures in the four studies with experimental design were not all aimed at the level of speech (motor) processes. Methodological quality was sufficient in one study.

CONCLUSION

Seven out of eight studies in this review report positive outcomes of music-based interventions in the treatment of SSDs. However, these outcomes are not sufficiently supported by evidence due to insufficient methodological quality. Suggestions for improving methodological quality in future research are presented.

Comorbidity and Severity in Childhood Apraxia of Speech: A Retrospective Chart Review

PURPOSE

The purpose of this study was to investigate comorbidity prevalence and patterns in childhood apraxia of speech (CAS) and their relationship to severity.

METHOD

In this retroactive cross-sectional study, medical records for 375 children with CAS (M age = 4;9 [years;months], SD = 2;9) were examined for comorbid conditions. The total number of comorbid conditions and the number of communication-related comorbidities were regressed on CAS severity as rated by speech-language pathologists during diagnosis. The relationship between CAS severity and the presence of four common comorbid conditions was also examined using ordinal or multinomial regressions.

RESULTS

Overall, 83 children were classified with mild CAS; 35, with moderate CAS; and 257, with severe CAS. Only one child had no comorbidities. The average number of comorbid conditions was 8.4 (SD = 3.4), and the average number of communication-related comorbidities was 5.6 (SD = 2.2). Over 95% of children had comorbid expressive language impairment. Children with comorbid intellectual disability (78.1%), receptive language impairment (72.5%), and nonspeech apraxia (37.3%; including limb, nonspeech oromotor, and oculomotor apraxia) were significantly more likely to have severe CAS than children without these comorbidities. However, children with comorbid autism spectrum disorder (33.6%) were no more likely to have severe CAS than children without autism.

CONCLUSIONS

Comorbidity appears to be the rule, rather than the exception, for children with CAS. Comorbid intellectual disability, receptive language impairment, and nonspeech apraxia confer additional risk for more severe forms of CAS. Findings are limited by being from a convenience sample of participants but inform future models of comorbidity.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22096622.

Use of Automated Kinematic Diadochokinesis Analysis to Identify Potential Indicators of Speech Motor Involvement in Children With Cerebral Palsy

PURPOSE

This study examined multiple variables obtained from an automated measure of lip movement during a diadochokinesis (DDK) task to identify those with potential to detect mild speech motor involvement in school-age children diagnosed with cerebral palsy (CP).

METHOD

Eight children with CP and high speech intelligibility and a matched group of eight children with typical development (TD) completed a DDK task while their lip and jaw movements were recorded. A custom MATLAB algorithm was used to automatically extract 23 kinematic measures of children's lip movements during production of the DDK sequences. Mann-Whitney U tests were used to compare groups on the kinematic measures, and receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of measures that significantly differed between groups.

RESULTS

Five of the 23 kinematic variables differed significantly between the CP and TD groups. These were two measures of overall DDK performance (i.e., duration of the DDK sequence and number of cycles) and three spatial and temporal measures of lip movement. Duration of the DDK sequence and the mean displacement of the lips across cycles had the highest diagnostic accuracy, differentiating CP and TD groups with 88% sensitivity and 88% specificity.

CONCLUSIONS

Automatically derived kinematic measures of DDK sequences differentiated children with CP and high intelligibility from typically developing children. Future research is needed to determine the clinical utility of these measures for detecting speech motor impairment.

Concurrent Predictors of Supplementary Sign Use in School-Aged Children With Childhood Apraxia of Speech

PURPOSE

Manual sign is a common alternative mode of communication taught to children with childhood apraxia of speech (CAS). Gesture use is positively related to later increases in vocabulary and syntactic complexity in typical development, but there is little evidence supporting the use of manual sign for children with CAS. We sought to identify the communicative functions of signs and gestures produced by children with CAS and to identify concurrent factors suggesting which children are more likely to benefit from sign-supported speech intervention.

METHOD

Measures of receptive and expressive language were gathered from 19 children (ages 3.8-11.1 years) with CAS in a school-based sign-supported speech program. Fourteen of the children produced a total of 145 manual signs, which included both gestures and signs from American Sign Language (M = 10.4 per child, SD = 11.6). Manual signs were coded according to whether they conveyed information that was semantically redundant with (complemented) or added information to (supplemented) their speech.

RESULTS

Children produced 107 complementary manual signs (75.4%) and 38 supplemental (24.6%) manual signs. Of the 38 supplemental signs, 24 (63.2%) provided additional information in the presence of unintelligible or no speech and 14 (36.8%) provided additional information in the presence of intelligible speech. Children's expressive language scores significantly predicted and accounted for 38.4% of the variance in the number of supplemental signs that children used.

CONCLUSION

Children with CAS whose oral expressive language was relatively more impaired produced the most supplementary signs, suggesting that children with oral expressive language challenges are more likely to rely on them for communicating words they cannot yet speak.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21217814.

Reading Skills in Children With Suspected Childhood Apraxia of Speech and Children With Reading Disorders: Same or Different?

PURPOSE

The primary aim of this study was to compare decoding and literacy-related skills of children with suspected childhood apraxia of speech (sCAS) to children with reading disorders (RD) and no history of speech sound disorder (RD-no SSD) to determine if the groups differ in decoding and the endophenotypes that contribute to RD. We also explored the association between language impairment (LI) and decoding and literacy-related skills within the participant group with sCAS.

METHOD

Participants were school-age children and adolescents, 8-14 years of age, with a diagnosis of sCAS (n = 13) or RD-no SSD (n = 16). The sCAS and RD-no SSD groups were compared on measures of single-word decoding, oral language, motor-speech skills, phonological processing, and speech-in-noise perception, employing t tests and analysis of covariance. The sCAS + LI and sCAS-only groups were compared on similar measures using t tests.

RESULTS

Compared to the RD-no SSD group, the sCAS group performed significantly worse on measures of phonological processing, multisyllable word repetition, diadochokinetic rate, and speech-in-noise perception. The groups did not differ on measures of single-word decoding, with mean scores for both groups falling below average. All participants with sCAS + LI demonstrated deficits in literacy and literacy-related skills compared to a smaller percentage of the sCAS-only group.

CONCLUSIONS

Children with sCAS and children with RD-no SSD demonstrate similar impairments in literacy. However, the endophenotypes underlying these difficulties can differ between the groups. Deficits in skills needed for literacy may require specifically tailored interventions to address reading difficulties for children with sCAS, especially for those with comorbid LI.

The importance of deep speech phenotyping for neurodevelopmental and genetic disorders: a conceptual review

Background

Speech is the most common modality through which language is communicated, and delayed, disordered, or absent speech production is a hallmark of many neurodevelopmental and genetic disorders. Yet, speech is not often carefully phenotyped in neurodevelopmental disorders. In this paper, we argue that such deep phenotyping, defined as phenotyping that is specific to speech production and not conflated with language or cognitive ability, is vital if we are to understand how genetic variations affect the brain regions that are associated with spoken language.

Speech is distinct from language, though the two are related behaviorally and share neural substrates. We present a brief taxonomy of developmental speech production disorders, with particular emphasis on the motor speech disorders childhood apraxia of speech (a disorder of motor planning) and childhood dysarthria (a set of disorders of motor execution). We review the history of discoveries concerning the KE family, in whom a hereditary form of communication impairment was identified as childhood apraxia of speech and linked to dysfunction in the FOXP2 gene. The story demonstrates how instrumental deep phenotyping of speech production was in this seminal discovery in the genetics of speech and language. There is considerable overlap between the neural substrates associated with speech production and with FOXP2 expression, suggesting that further genes associated with speech dysfunction will also be expressed in similar brain regions. We then show how a biologically accurate computational model of speech production, in combination with detailed information about speech production in children with developmental disorders, can generate testable hypotheses about the nature, genetics, and neurology of speech disorders.

Conclusions

Though speech and language are distinct, specific types of developmental speech disorder are associated with far-reaching effects on verbal communication in children with neurodevelopmental disorders. Therefore, detailed speech phenotyping, in collaboration with experts on pediatric speech development and disorders, can lead us to a new generation of discoveries about how speech development is affected in genetic disorders.

Vowel variability and contrast in Childhood Apraxia of Speech: acoustics and articulation

Phoneme production may be affected by limited speech motor control in Childhood Apraxia of Speech (CAS), with a general instability of acoustic targets across multiple repetitions of speech stimuli. This acoustic and Ultrasound Tongue Imaging (UTI) study shows that increased variability and reduction of contrast in vowel production is found in native Italian speakers with CAS, particularly as far as the height dimension is concerned. The data suggest that vowel production should play a major role in CAS diagnosis and treatment. Moreover, this study shows that a combined acoustic and articulatory approach allows direct observation of lingual dynamics together with an estimation of changes in the acoustic dimension. The two dimensions are shown not to correspond in a straightforward way in the speech of children with CAS, and encourage consideration of articulatory compensation strategies aimed at saving the acoustic identity of vowels.

Procedural Learning, Grammar, and Motor Skills in Children With Childhood Apraxia of Speech, Speech Sound Disorder, and Typically Developing Speech

Purpose This case-control study sought to determine if (a) children with childhood apraxia of speech (CAS), other speech sound disorders (SSDs), and typical development would perform differently on a procedural learning assessment and (b) whether grammatical ability would impact group differences. Method Communication, motor, and procedural learning abilities were assessed in 48 children with CAS (n = 13), SSD (n = 20), and typical development (n = 15), between 43 and 97 months of age (M = 66 months, SD = 12 months). Results On average, children with CAS demonstrated grammatical and motor impairments and required an increased number of exposures to the visuospatial sequence to demonstrate procedural learning, compared to peers with SSD or typical development. A subset of children from each group demonstrated an unanticipated procedural learning pattern wherein they evidenced an uptick in reaction time during the second sequenced block. Children with CAS with this pattern still evidenced procedural learning gains by the fifth sequenced block. In contrast, children with SSD and typical development with this pattern showed poor procedural learning outcomes and were characterized by lower scores on language and motor assessments as well. Conclusions This research provides partial support for the procedural learning deficit hypothesis in children with CAS and for a subset of children with SSD as well. Future research should examine the role of a serial reaction time task in identifying children at risk of multisystem communication and motor deficits. Supplemental Material https://doi.org/10.23641/asha.14173532.

Differential Diagnosis of Apraxia of Speech in Children and Adults: A Scoping Review

Purpose Despite having distinct etiologies, acquired apraxia of speech (AOS) and childhood apraxia of speech (CAS) share the same central diagnostic challenge (i.e., isolating markers specific to an impairment in speech motor planning/programming). The purpose of this review was to evaluate and compare the state of the evidence on approaches to differential diagnosis for AOS and CAS and to identify gaps in each literature that could provide directions for future research aimed to improve clinical diagnosis of these disorders. Method We conducted a scoping review of literature published between 1997 and 2019, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. For both AOS and CAS, literature was charted and summarized around four main methodological approaches to diagnosis: speech symptoms, quantitative speech measures, impaired linguistic-motor processes, and neuroimaging. Results Results showed that similar methodological approaches have been used to study differential diagnosis of apraxia of speech in adults and children; however, the specific measures that have received the most research attention differ between AOS and CAS. Several promising candidate markers for AOS and CAS have been identified; however, few studies report metrics that can be used to assess their diagnostic accuracy. Conclusions Over the past two decades, there has been a proliferation of research identifying potential diagnostic markers of AOS and CAS. In order to improve clinical diagnosis of AOS and CAS, there is a need for studies testing the diagnostic accuracy of multiple candidate markers, better control over language impairment comorbidity, more inclusion of speech-disordered control groups, and an increased focus on translational work moving toward clinical implementation of promising measures.

Protocol for Correcting Residual Errors with Spectral, ULtrasound, Traditional Speech therapy Randomized Controlled Trial (C-RESULTS RCT)

Background

Speech sound disorder in childhood poses a barrier to academic and social participation, with potentially lifelong consequences for educational and occupational outcomes. While most speech errors resolve by the late school-age years, between 2 and 5% of speakers exhibit residual speech errors (RSE) that persist through adolescence or even adulthood. Previous findings from small-scale studies suggest that interventions incorporating visual biofeedback can outperform traditional motor-based treatment approaches for children with RSE, but this question has not been investigated in a well-powered randomized controlled trial.

Methods/design

This project, Correcting Residual Errors with Spectral, ULtrasound, Traditional Speech therapy Randomized Controlled Trial (C-RESULTS RCT), aims to treat 110 children in a parallel randomized controlled clinical trial comparing biofeedback and non-biofeedback interventions for RSE affecting the North American English rhotic sound /ɹ/. Eligible children will be American English speakers, aged 9–15 years, who exhibit RSE affecting /ɹ/ but otherwise show typical cognitive-linguistic and hearing abilities. Participants will be randomized, with stratification by site (Syracuse University or Montclair State University) and pre-treatment speech production ability, to receive either a motor-based treatment consistent with current best practices in speech therapy (40% of participants) or treatment incorporating visual biofeedback (60% of participants). Within the biofeedback condition, participants will be assigned in equal numbers to receive biofeedback in the form of a real-time visual display of the acoustic signal of speech or ultrasound imaging of the tongue during speech. The primary outcome measure will assess changes in the acoustics of children’s production of /ɹ/ during treatment, while a secondary outcome measure will use blinded listeners to evaluate changes in the perceived accuracy of /ɹ/ production after the completion of all treatment. These measures will allow the treatment conditions to be compared with respect to both efficacy and efficiency.

Discussion

By conducting the first well-powered randomized controlled trial comparing treatment with and without biofeedback, this study aims to provide high-quality evidence to guide treatment decisions for children with RSE.

Trial registration

ClinicalTrials.gov identifier NCT03737318, November 9, 2018.

Reading Outcomes for Individuals With Histories of Suspected Childhood Apraxia of Speech

Purpose The primary aims of this study were to examine the speech-language correlates of decoding difficulties in children with histories of suspected childhood apraxia of speech (sCAS) and to identify predictors of low-proficiency reading levels. Method Participants were school-age children and adolescents, 7-18 years of age, diagnosed with sCAS (n = 40) or speech sound disorder but no sCAS (SSD-no sCAS; n = 119). The sCAS and SSD-no sCAS reading groups were compared on measures of performance IQ, oral language, phonological awareness, rapid automatic naming, diadochokinetic rates, single word articulation, and multisyllable and nonsense word repetition. Logistic regression analyses were employed to identify predictors of low-proficiency reading in the sCAS and SSD-no sCAS groups. Results Sixty-five percent of the participants with sCAS compared to 24% of those with SSD-no sCAS were classified as low-proficiency readers based on nonsense and single word decoding. Analysis failed to reveal significant differences in reading, oral language, or phonological awareness between low-proficiency readers with sCAS and low-proficiency readers with SSD-no sCAS. Oral language and phonological awareness skills were the best predictors of reading level for all participants, followed by performance on multisyllabic word repetition and diadochokinetic rate. Conclusions The language and phonological awareness deficits of children with sCAS are related to their risks for reading failure. To a lesser degree, motor speech deficits and speech sound production also increase risks for reading difficulties. The findings justify early intervention for this subset of children.

Vowel Duration Discrimination of Children With Childhood Apraxia of Speech: A Preliminary Study

Purpose The ability of 5- and 6-year-old male children (23 participants) between the chronological ages of 5;0 and 6;11 (years;months) with childhood apraxia of speech (CAS; n = 9) and with typical development (TD; n = 14) to detect differences in vowel duration of syllable pairs is explored. We asked whether the children with CAS show different patterns of performance on the vowel duration difference experimental task than those of their similarly aged peers with TD. Method A male adult audio-recorded the syllable /bɑ/. The /ɑ/ was digitally lengthened and shortened, while maintaining uniform fundamental frequency and amplitude of the vowel and duration of the consonant /b/ at 42 ms. Vowel lengths increased in 40-ms increments, ranging from 208 to 488 ms. Eight pairs of syllables, 1 with equal length and 7 with differing vowel lengths, were randomly presented to the children 10 times in blocks of 16 pairs via a computer application. Results Numerous complementary analyses indicated patterns of performance differed for children with CAS compared to the children with TD. The children with CAS were notably less accurate in their duration discrimination and evidenced greater variability in their performances across duration difference conditions than their peers with TD, signifying they were generally challenged to discriminate the vowel duration differences. Conclusion These results suggest that CAS, which is more generally considered a motor speech disorder, may have a perceptual component of CAS related to vowel duration discrimination. Further research directions and clinical implications are discussed. Supplemental Material https://doi.org/10.23641/asha.8411876.

Protocol for the Connected Speech Transcription of Children with Speech Disorders: An Example from Childhood Apraxia of Speech

OBJECTIVE

While it is known that connected speech has different features to single-word speech, there are currently few recommendations regarding connected speech transcription. This research therefore aimed to develop a clinically feasible protocol for connected speech transcription. The protocol was then used to assist with description of the connected speech of children with childhood apraxia of speech (CAS), as little is known about their connected speech characteristics.

PARTICIPANTS AND METHODS

Following a literature review, the Connected Speech Transcription Protocol (CoST-P) was iteratively developed and trialled. The CoST-P was then used to transcribe 50 connected utterances produced by 12 children (aged 6-13 years) with CAS. The characteristics of participants' connected speech were analysed to capture independent and relational analyses.

RESULTS

The CoST-P was developed, trialled, and determined to have adequate reliability and fidelity. The frequency of inter-word segregation (mean = 29) was higher than intra-word segregation (mean = 4). Juncture accuracy was correlated with intelligibility metrics such as percentage of consonants correct.

CONCLUSION

Connected speech transcription is challenging. The CoST-P may be a useful resource for speech-language pathologists and clinical researchers. Use of the CoST-P assisted in displaying CAS speech characteristics unique to connected speech (e.g., inter-word segregation and juncture).

Comorbid morphological disorder apparent in some children aged 4-5 years with childhood apraxia of speech: findings from standardised testing

There is continuing debate about the origins of productive morphological errors in children with speech sound disorders. This is the case for children with theorised phonetic and motor disorders, such as children with childhood apraxia of speech (CAS, e.g., Ekelman & Aram, 1983; McNeill & Gillon, 2013 ). The morphological skills of children with CAS remain relatively unexplored in pre-schoolers. We investigated English morphology in a retrospective, cross-sectional design of 26 children aged 4-5 years who completed the Clinical Evaluation of Language Fundamentals-Preschool (2nd edition; Wiig, Secord & Semel, 2006). The research aims were to determine: (1) the language profile of the children, (2) the accuracy of each morpheme type produced, and (3) how many of those morphological errors are explained by speech errors (clusters, late developing phonemes, central vowels or weak syllable stress)? The results indicate the group of children with CAS had poorer expressive language skills than receptive skills and 48% demonstrated difficulties with morphology in word structure and recalling sentences subtests. The children had poor accuracy and inconsistent production of a range of morphemes and despite many errors due to the speech characteristics of the stimuli on the CELF-P2, motor speech concerns could not explain all the child's morphological errors. The results suggest morphological difficulties are co-morbid to CAS and when this occurs, treatment for morphosyntax is indicated. There are also significant clinical implications in the assessment of morphosyntax for children with CAS which are discussed.

Changes in movement transitions across a practice period in childhood apraxia of speech

This study examined changes in speech motor control across a movement transition between sounds within a motor learning task in children with apraxia of speech (CAS) and typical development (TD). It was investigated whether oral articulator movement was refined with practice and whether practice gains generalized to words not included in the practice session. A total of 16 children (ages 5-6) with CAS (n = 8) and TD (n = 8) participated in this study. Novel and real word tokens were produced at three time points. Kinematic data was collected using facial motion tracking at each time point. Children completed a practice session following baseline data collection session that integrated motor learning principles. Three tokens were included in the practice session and the remaining stimuli assessed carryover of practice gains. Kinematic data was then collected immediately following practice and 3 days later. Kinematic analyses were conducted on the movement gesture for the first syllable of each word. Narrow transcription analyses examined speech production accuracy. Children in the CAS group displayed increased consonant and vowel accuracy only for the practised tokens. Adjustments to spatial control and movement variability were observed in the CAS group, though only for practised words. Children in the TD group altered spatial and temporal domains of movement and variability across both practised and non-practised tokens. Interestingly, the CAS group displayed a pattern of increased displacement along with decreased variability, which was not observed in the TD group. The degree to which these findings reflect facilitative or maladaptive changes are discussed. Results are also interpreted in relation to vowel properties, novel/real word status and variable practice of novel and real words.

Variable Practice to Enhance Speech Learning in Ultrasound Biofeedback Treatment for Childhood Apraxia of Speech: A Single Case Experimental Study

PURPOSE

The purpose of this study was to evaluate the role of practice variability, through prosodic variation during speech sound training, in biofeedback treatment for children with childhood apraxia of speech. It was hypothesized that variable practice would facilitate speech sound learning.

METHOD

Six children ages 8-16 years with persisting speech sound errors due to childhood apraxia of speech participated in a single-subject experimental design. For each participant, 2 speech sound targets were treated with ultrasound visual feedback training: one with prosodic variation (i.e., practicing sound targets in words and phrases spoken fast, slow, loud, as a question, command, and declarative), and one without prosodic variation. Each target was treated for half of the 1-hr session for 14 treatment sessions.

RESULTS

As measured by standardized effect sizes, all participants showed greater change on generalization probes for sound targets treated under the prosodic variation condition with mean effect sizes (d2) of 14.5 for targets treated with prosodic variation and 8.3 for targets treated without prosodic variation. The average increase in generalization scores was 38% in the prosodic variation condition compared to 31% without.

CONCLUSIONS

Ultrasound visual feedback may facilitate speech sound learning and learning may be enhanced by treating speech sounds with explicit prosodic variation.

SUPPLEMENTAL MATERIALS

https://doi.org/10.23641/asha.5150119.

Speech Inconsistency in Children With Childhood Apraxia of Speech, Language Impairment, and Speech Delay: Depends on the Stimuli

PURPOSE

The current research sought to determine (a) if speech inconsistency is a core feature of childhood apraxia of speech (CAS) or if it is driven by comorbid language impairment that affects a large subset of children with CAS and (b) if speech inconsistency is a sensitive and specific diagnostic marker that can differentiate between CAS and speech delay.

METHOD

Participants included 48 children ranging between 4;7 to 17;8 (years;months) with CAS (n = 10), CAS + language impairment (n = 10), speech delay (n = 10), language impairment (n = 9), or typical development (n = 9). Speech inconsistency was assessed at phonemic and token-to-token levels using a variety of stimuli.

RESULTS

Children with CAS and CAS + language impairment performed equivalently on all inconsistency assessments. Children with language impairment evidenced high levels of speech inconsistency on the phrase "buy Bobby a puppy." Token-to-token inconsistency of monosyllabic words and the phrase "buy Bobby a puppy" was sensitive and specific in differentiating children with CAS and speech delay, whereas inconsistency calculated on other stimuli (e.g., multisyllabic words) was less efficacious in differentiating between these disorders.

CONCLUSIONS

Speech inconsistency is a core feature of CAS and is efficacious in differentiating between children with CAS and speech delay; however, sensitivity and specificity are stimuli dependent.

Neuroanatomical correlates of childhood apraxia of speech: A connectomic approach

Childhood apraxia of speech (CAS) is a paediatric speech sound disorder in which precision and consistency of speech movements are impaired. Most children with idiopathic CAS have normal structural brain MRI. We hypothesize that children with CAS have altered structural connectivity in speech/language networks compared to controls and that these altered connections are related to functional speech/language measures.

Whole brain probabilistic tractography, using constrained spherical deconvolution, was performed for connectome generation in 17 children with CAS and 10 age-matched controls. Fractional anisotropy (FA) was used as a measure of connectivity and the connections with altered FA between CAS and controls were identified. Further, the relationship between altered FA and speech/language scores was determined.

Three intra-hemispheric/interhemispheric subnetworks showed reduction of FA in CAS compared to controls, including left inferior (opercular part) and superior (dorsolateral, medial and orbital part) frontal gyrus, left superior and middle temporal gyrus and left post-central gyrus (subnetwork 1); right supplementary motor area, left middle and inferior (orbital part) frontal gyrus, left precuneus and cuneus, right superior occipital gyrus and right cerebellum (subnetwork 2); right angular gyrus, right superior temporal gyrus and right inferior occipital gyrus (subnetwork 3). Reduced FA of some connections correlated with diadochokinesis, oromotor skills, expressive grammar and poor lexical production in CAS.

These findings provide evidence of structural connectivity anomalies in children with CAS across specific brain regions involved in speech/language function. We propose altered connectivity as a possible epiphenomenon of complex pathogenic mechanisms in CAS which need further investigation.

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Connectivity anomalies are present in children with Childhood Apraxia of Speech.

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Connectivity anomalies include brain regions involved in speech/language function.

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Altered connectivity correlates with a measure of speech/language dysfunction.

Speech Sound Disorders: What's Motor Got To Do With It?

Speech sound disorders (SSDs) are commonly viewed as involving impaired articulation and/or phonological skills. Speech language pathologists working with individuals with (SSDs) assess the articulation of speech sounds and the coordination of articulatory structures with other components of the speech mechanism, including the phonatory, respiratory, and resonatory subsystems. The sound system of the language and the rules that govern how phonemes are combined are equally critical for clinicians to explore. While the terms “articulation” and “phonology” provide clinicians with a framework for classification, children who are broadly identified with (SSDs) may also display characteristics of a motor speech impairment, which can obscure the decision making process with respect to both diagnosis and treatment. One such motor speech disorder is childhood apraxia of speech (CAS). The focus of this paper is to discuss motor speech deficits in children and to review research that aims to distinguish motor speech patterns in children with (SSDs) with and without CAS. We will also address the relationship between emerging speech motor and linguistic skills.

Differential diagnosis of children with suspected childhood apraxia of speech

PURPOSE

The gold standard for diagnosing childhood apraxia of speech (CAS) is expert judgment of perceptual features. The aim of this study was to identify a set of objective measures that differentiate CAS from other speech disorders.

METHOD

Seventy-two children (4-12 years of age) diagnosed with suspected CAS by community speech-language pathologists were screened. Forty-seven participants underwent diagnostic assessment including presence or absence of perceptual CAS features. Twenty-eight children met two sets of diagnostic criteria for CAS (American Speech-Language-Hearing Association, 2007b; Shriberg, Potter, & Strand, 2009); another 4 met the CAS criteria with comorbidity. Fifteen were categorized as non-CAS with phonological impairment, submucous cleft, or dysarthria. Following this, 24 different measures from the diagnostic assessment were rated by blinded raters. Multivariate discriminant function analysis was used to identify the combination of measures that best predicted expert diagnoses.

RESULTS

The discriminant function analysis model, including syllable segregation, lexical stress matches, percentage phonemes correct from a polysyllabic picture-naming task, and articulatory accuracy on repetition of /pətəkə/, reached 91% diagnostic accuracy against expert diagnosis.

CONCLUSIONS

Polysyllabic production accuracy and an oral motor examination that includes diadochokinesis may be sufficient to reliably identify CAS and rule out structural abnormality or dysarthria. Testing with a larger unselected sample is required.

Auditory-motor interactions in pediatric motor speech disorders: neurocomputational modeling of disordered development

BACKGROUND/PURPOSE

Differentiating the symptom complex due to phonological-level disorders, speech delay and pediatric motor speech disorders is a controversial issue in the field of pediatric speech and language pathology. The present study investigated the developmental interaction between neurological deficits in auditory and motor processes using computational modeling with the DIVA model.

METHOD

In a series of computer simulations, we investigated the effect of a motor processing deficit alone (MPD), and the effect of a motor processing deficit in combination with an auditory processing deficit (MPD+APD) on the trajectory and endpoint of speech motor development in the DIVA model.

RESULTS

Simulation results showed that a motor programming deficit predominantly leads to deterioration on the phonological level (phonemic mappings) when auditory self-monitoring is intact, and on the systemic level (systemic mapping) if auditory self-monitoring is impaired.

CONCLUSIONS

These findings suggest a close relation between quality of auditory self-monitoring and the involvement of phonological vs. motor processes in children with pediatric motor speech disorders. It is suggested that MPD+APD might be involved in typically apraxic speech output disorders and MPD in pediatric motor speech disorders that also have a phonological component. Possibilities to verify these hypotheses using empirical data collected from human subjects are discussed.

LEARNING OUTCOMES

The reader will be able to: (1) identify the difficulties in studying disordered speech motor development; (2) describe the differences in speech motor characteristics between SSD and subtype CAS; (3) describe the different types of learning that occur in the sensory-motor system during babbling and early speech acquisition; (4) identify the neural control subsystems involved in speech production; (5) describe the potential role of auditory self-monitoring in developmental speech disorders.

Associations among measures of sequential processing in motor and linguistics tasks in adults with and without a family history of childhood apraxia of speech: a replication study

The purpose of this study was to address the hypothesis that childhood apraxia of speech (CAS) is influenced by an underlying deficit in sequential processing that is also expressed in other modalities. In a sample of 21 adults from five multigenerational families, 11 with histories of various familial speech sound disorders, 3 biologically related adults from a family with familial CAS showed motor sequencing deficits in an alternating motor speech task. Compared with the other adults, these three participants showed deficits in tasks requiring high loads of sequential processing, including nonword imitation, nonword reading and spelling. Qualitative error analyses in real word and nonword imitations revealed group differences in phoneme sequencing errors. Motor sequencing ability was correlated with phoneme sequencing errors during real word and nonword imitation, reading and spelling. Correlations were characterized by extremely high scores in one family and extremely low scores in another. Results are consistent with a central deficit in sequential processing in CAS of familial origin.

Intra-word inconsistency in apraxic Hebrew-speaking children

Intra-word inconsistency in a child is perceived as an indicator of speech impairment. Because the speech of typically developing children is highly variable, the extent and nature of the inconsistency must be defined when used as a diagnostic marker of speech impairment (McLeod, S., & Hewett, S. R. (2008). Variability in the production of words containing consonant clusters by typical 2- and 3-year-old children. Folia Phoniatrica et Logopaedica, 60(4), 163-172). In this paper, we study inconsistency with reference to the prosodic hierarchy (McCarthy, J. J., & Prince, A. S. (1996). Prosodic morphology 1986. Amherst, MA: University of Massachusetts. Retrieved April 15, 2010, from http://ruccs.rutgers.edu/pub/papers/pm86all.pdf), suggesting a new way to describe this phenomenon in childhood apraxia of speech (CAS). The prosodic hierarchy has been used in recent years to demonstrate the phonological development of typical and atypical populations. Sixteen children diagnosed with CAS (average age 3;11) participated in the study. The data, collected from each child in the course of eight weekly meetings, are drawn from naming single words. The results indicate that inconsistency is dominant for two prosodic levels, the segmental and the syllabic, while the prosodic word level was largely preserved.

Identifying residual speech sound disorders in bilingual children: a Japanese-english case study

PURPOSE

To describe (a) the assessment of residual speech sound disorders (SSDs) in bilinguals by distinguishing speech patterns associated with second language acquisition from patterns associated with misarticulations and (b) how assessment of domains such as speech motor control and phonological awareness can provide a more complete understanding of SSDs in bilinguals.

METHOD

A review of Japanese phonology is provided to offer a context for understanding the transfer of Japanese to English productions. A case study of an 11-year-old is presented, demonstrating parallel speech assessments in English and Japanese. Speech motor and phonological awareness tasks were conducted in both languages.

RESULTS

Several patterns were observed in the participant's English that could be plausibly explained by the influence of Japanese phonology. However, errors indicating a residual SSD were observed in both Japanese and English. A speech motor assessment suggested possible speech motor control problems, and phonological awareness was judged to be within the typical range of performance in both languages.

CONCLUSION

Understanding the phonological characteristics of the native language can help clinicians recognize speech patterns in the second language associated with transfer. Once these differences are understood, patterns associated with a residual SSD can be identified. Supplementing a relational speech analysis with measures of speech motor control and phonological awareness can provide a more comprehensive understanding of a client's strengths and needs.

Phonetic variability in residual speech sound disorders: Exploration of subtypes

PURPOSE: To explore whether subgroups of children with residual speech sound disorders (R-SSDs) can be identified through multiple measures of token-to-token phonetic variability. METHOD: Children with R-SSDs were recorded during a rapid multisyllabic picture naming task and an oral diadochokinetic task. Transcription-based and acoustic measures of token-to-token variability were derived. Articulation accuracy and general indices of language skills were also measured. RESULTS: Low correlations were observed between transcription-based and acoustic measures of phonetic variability, and among the acoustic measures themselves. Children who were the most variable on one measure were not necessarily highly variable on other measures. Transcription-based measures of variability were associated with language skills. CONCLUSIONS: Measures of phonetic variability did not identify children in the sample as consistently high or low. Data do not support the notion that clear subgroups based on phonetic variability can be reliably identified in children with R-SSDs. The link between highly variable phonetic output (quantified by transcription-based measures) and lower language skills requires further exploration.

A multigenerational family study of oral and hand motor sequencing ability provides evidence for a familial speech sound disorder subtype

PURPOSE: To evaluate phenotypic expressions of speech sound disorder (SSD) in multigenerational families with evidence of familial forms of SSD. METHOD: Members of five multigenerational families (N = 36) produced rapid sequences of monosyllables and disyllables and tapped computer keys with repetitive and alternating movements. RESULTS: Measures of repetitive and alternating motor speed were correlated within and between the two motor systems. Repetitive and alternating motor speeds increased in children and decreased in adults as a function of age. In two families with children who had severe speech deficits consistent with disrupted praxis, slowed alternating, but not repetitive, oral movements characterized most of the affected children and adults with a history of SSD, and slowed alternating hand movements were seen in some of the biologically related participants as well. CONCLUSION: Results are consistent with a familial motor-based SSD subtype with incomplete penetrance, motivating new clinical questions about motor-based intervention not only in the oral but also the limb system.

The relationship between articulatory control and improved phonemic accuracy in childhood apraxia of speech: a longitudinal case study

Jaw movement patterns were examined longitudinally in a 3-year-old male with childhood apraxia of speech (CAS) and compared with a typically developing control group. The child with CAS was followed for 8 months, until he began accurately and consistently producing the bilabial phonemes /p/, /b/, and /m/. A movement tracking system was used to study jaw duration, displacement, velocity, and stability. A transcription analysis determined the percentage of phoneme errors and consistency. Results showed phoneme-specific changes which included increases in jaw velocity and stability over time, as well as decreases in duration. Kinematic parameters became more similar to patterns seen in the controls during final sessions where tokens were produced most accurately and consistently. Closing velocity and stability, however, were the only measures to fall within a 95% confidence interval established for the controls across all three target phonemes. These findings suggest that motor processes may differ between children with CAS and their typically developing peers.

A longitudinal case study of the effects of an integrated phonological awareness program for identical twin boys with childhood apraxia of speech (CAS)

This study is an examination of the longitudinal effects of an integrated phonological awareness approach for identical twin boys with childhood apraxia of speech (CAS). Genetic and environmental factors in the boys' responses to the intervention were also examined. Theo and Jamie (aged 4;5) each participated in 18 hours of intervention prior to school entry and were re-assessed at age 4;9, 5;3, and 5;9 respectively. Their speech, expressive morpho-syntactic, phonological awareness, reading, and spelling development were evaluated over their first year of schooling. Theo and Jamie experienced continued growth in speech and phonological awareness skills following participation in the intervention. They exhibited age-appropriate reading and spelling development during their first year of formal literacy instruction. They had persistent deficits in expressive morpho-syntactic skills despite speech production gains over the study. The results pointed to the benefit of integrating speech and phonological awareness goals within a preventative framework to ensure successful early literacy development for children with CAS. Findings suggested that language difficulties in children with CAS should be targeted during intervention as they do not resolve as the children's speech production difficulties minimize.

Vowel patterns in developmental apraxia of speech: three longitudinal case studies

Vowel inventories and error patterns for three children with suspected developmental apraxia of speech (DAS) were analysed over a 3-year period using phonetic transcriptions of connected speech samples. The children demonstrated complete English vowel inventories except for rhotics. However, accuracy of vowel targets in connected speech did not normalize during this period. No consistent patterns of vowel errors were found. There was no decrease in vowel accuracy with increased utterance length or syllable complexity. Findings indicate persistence of vowel inaccuracy in the presence of a relatively complete vowel inventory. This longitudinal data can help to build consensus on use of vowels as a potential clinical marker for differential diagnosis of DAS.

School-Age Follow-Up of Children With Childhood Apraxia of Speech

Purpose: The primary aim of this study was to examine differences in speech/language and written language skills between children with suspected childhood apraxia of speech (CAS) and children with other speech-sound disorders at school age.

Method: Ten children (7 males and 3 females) who were clinically diagnosed with CAS (CAS group) were followed from the preschool years (ages 4–6) to school age (ages 8–10) and were compared with children with isolated speech-sound disorders (S group; n =15) and combined speech-sound and language disorders (SL group; n =14). Assessments included measures of articulation, diadochokinetic rates, language, reading, and spelling.

Results: At follow-up, 8 of the children with CAS demonstrated improvement in articulation scores, but all 10 continued to have difficulties in syllable sequencing, nonsense word repetition, and language abilities. The children also exhibited comorbid disorders of reading and spelling. Group comparisons revealed that the CAS group was similar to the SL group, but not the S group during the preschool years. By school age, however, the SL group made more positive changes in language skills than the CAS group.

Clinical Implications: These findings suggest that the phenotype for CAS changes with age. Language disorders persist in these children despite partial resolution of articulation problems. Children with CAS are also at risk for reading and spelling problems.

Family pedigrees of children with suspected childhood apraxia of speech

Forty-two children (29 boys and 13 girls), ages 3-10 years, were referred from the caseloads of clinical speech-language pathologists for suspected childhood apraxia of speech (CAS). According to results from tests of speech and oral motor skills, 22 children met criteria for CAS, including a severely limited consonant and vowel repertoire, difficulty sequencing syllables, and inconsistent and unusual errors. Family pedigrees for these children were constructed through parent interviews and direct testing of nuclear family members. Familial aggregation for speech-sound and language disorders was demonstrated with 86% reporting at least one nuclear family member affected. Based on parent report, 13 of the 22 children (59%) had at least one affected parent. However, CAS was evident in only two siblings of probands with CAS and two probands with other speech-sound disorders. Based on testing, overall affection rates of speech-sound/language disorders were higher in families of children with CAS than in families of children with other speech-sound disorders. Mothers of children with CAS demonstrated a higher affection rate than mothers of children with other speech-sound disorders. A sex-related threshold model of transmission was also supported with brothers more often affected than sisters for male probands only. If our inclusionary criteria for CAS are valid, these findings support a general verbal trait deficit hypothesis.

LEARNING OUTCOMES

(1) As a result of this activity, the participant will understand potential familial risk factors for CAS; (2) will differentiate aggregation for speech-sound and language disorders in families with CAS from families of children who have other speech-sound disorders; (3) will distinguish how familial aggregation differs in families of boys and girls with CAS; (4) will determine how children with CAS differ in severity from those with other speech-sound disorders.

Diagnostic criteria of developmental apraxia of speech used by clinical speech-language pathologists

The diagnostic criteria used to identify developmental apraxia of speech (DAS) have been at the center of controversy for decades. Despite the difficulty in determining the characteristics that differentiate DAS from other speech acquisition disorders, many children are identified with this disorder. The current report presents the criteria used by 75 speech-language pathologists to establish a diagnosis of DAS. Although 50 different characteristics were identified, 6 of these characteristics accounted for 51.5% of the responses. These characteristics included inconsistent productions, general oral-motor difficulties, groping, inability to imitate sounds, increasing difficulty with increased utterance length, and poor sequencing of sounds. These results are consistent with the general ambiguity of the diagnostic criteria of DAS and suggest that no single deficit is used among clinicians.

The integrity of the syllable in developmental apraxia of speech

Three children with developmental apraxia of speech (DAS) identified the number of syllables in words, judged intrasyllabic sound positions, and constructed syllable shapes within monosyllabic frames. Results suggest that DAS children demonstrate an apparent breakdown in the ability to perceive "syllableness" and to access and compare syllable representations with regard to position and structure. Based on these findings, DAS is viewed as a disorder characterized by an impoverished phonological representation system.

LEARNING OUTCOMES

On the basis of this article, the reader will be able to (1) describe the deficits in syllabic perception demonstrated by some participants with DAS; (2) examine the utility of metalinguistic tasks in the differential diagnosis of DAS; and (3) evaluate the findings with respect to competing theoretical perspectives on DAS.

Research on speech motor control and its disorders: a review and prospective

This paper reviews issues in speech motor control and a class of communication disorders known as motor speech disorders. Speech motor control refers to the systems and strategies that regulate the production of speech, including the planning and preparation of movements (sometimes called motor programming) and the execution of movement plans to result in muscle contractions and structural displacements. Traditionally, speech motor control is distinguished from phonologic operations, but in some recent phonologic theories, there is a deliberate blurring of the boundaries between phonologic representation and motor functions. Moreover, there is continuing discussion in the literature as to whether a given motor speech disorder (especially apraxia of speech and stuttering) should be understood at the phonologic level, the motoric level, or both of these. The motor speech disorders considered here include: the dysarthrias, apraxia of speech, developmental apraxia of speech, developmental stuttering, acquired (neurogenic and psychogenic) stuttering, and cluttering.