Consonant and syllable structure patterns in childhood apraxia of speech: developmental change in three children

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.

A Pilot Randomized Control Trial of Motor-Based Treatments for Childhood Apraxia of Speech: Rapid Syllable Transition Treatment and Ultrasound Biofeedback

PURPOSE

Both Rapid Syllable Transition Treatment (ReST) and ultrasound biofeedback are effective approaches to treating childhood apraxia of speech (CAS). The purpose of the study was to compare outcomes from these two motor-based treatment approaches for school-age children with CAS.

METHOD

In a single site, single blind randomized control trial, 14 children with CAS ages 6-13 years were randomly assigned to 12 sessions over 6 weeks of either of ultrasound biofeedback treatment (with a speech motor chaining practice structure) or ReST. Treatment was delivered at The University of Sydney by students trained and supervised by certified speech-language pathologists. Transcriptions from blinded assessors were used to compare the two groups on speech sound accuracy (percent phonemes correct) and prosodic severity (lexical stress errors and syllable segregation) in untreated words and sentences at three time points: pretreatment, immediately posttreatment, and 1-month posttreatment (i.e., retention).

RESULTS

Both groups showed significant improvement on treated items indicating a treatment effect. At no time was there a difference between groups. Both groups showed a significant improvement in speech sound accuracy on untreated words and sentences from pre to post and neither group showed an improvement in prosody pre-post. Changes to speech sound accuracy were retained by both groups at 1-month follow-up. Significant improvement in prosodic accuracy was reported at the 1-month follow-up.

CONCLUSIONS

ReST and ultrasound biofeedback were equally effective. Either ReST or ultrasound biofeedback may be viable treatment options for school-age children with CAS.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22114661.

Psychosocial Comorbidities in Adolescents With Histories of Childhood Apraxia of Speech

Purpose Adolescent psychosocial outcomes of individuals with histories of childhood apraxia of speech (CAS) were compared to outcomes of individuals with histories of speech sound disorders (SSD) only and SSD with language impairment (LI). It was hypothesized that individuals with more severe and persistent disorders such as CAS would report poorer psychosocial outcomes. Method Groups were compared using analyses of variance on a psychosocial assessment battery that included measures of hyperactivity and inattention, anxiety, depression, internalizing and externalizing behaviors, thought problems, and social outcomes. Results Results revealed significant group differences on self-report of social problems and parent report of hyperactivity, thought problems, and social problems at adolescence. Compared to the SSD-only group, the CAS group had significantly higher parental ratings of hyperactivity and social problems in adolescence. The CAS and SSD + LI groups did not differ on psychosocial measures, possibly due to the high rate of comorbid LI in the CAS group. The CAS group also had more individuals who scored in the borderline/clinical range on self-report of social problems than the SSD-only group. The CAS group did not differ from the SSD + LI group in the number of participants scoring in the borderline/clinical range on measures. Conclusions Individuals with histories of CAS demonstrate increased rates of social problems and hyperactivity based on parent ratings compared to adolescents with histories of SSD only; however, most do not score within the clinical range. The persistence of speech sound errors combined with self-reported and parent-reported social difficulties suggests that speech-language pathologists should be sensitive to the social and emotional impact of CAS and make appropriate referrals to mental health professionals when warranted.

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.

Simplification of syllable structure in childhood apraxia of speech: a 2-year follow-up French case study

Although Childhood Apraxia of Speech (CAS) has been extensively investigated in the clinical literature, most of the findings regarding impairments in the production of syllable structure, recorded within this population, have been mainly focused on English. The main purpose of this two-year follow-up case study was, therefore, to examine whether syllable complexity may be considered as a robust indicator in CAS and whether it can explain the persistence of errors and, if so, at what age. This was tested in a boy followed up annually from age 5 to 7 who was administered a narrative task. Data analyses used the Phon program to estimate accuracies of different syllabic structures, phones, singleton and cluster consonants. Overall, the findings suggest that this child experienced difficulty producing syllabic structure commensurately with the level of complexity of the target structures. Notably, the presence of syllable planning/sequencing deficit found in French data clearly supports the hypotheses according to which (a) there is a relationship between the level of complexity of syllabic structures and their simplification and (b) the persistence of errors on the most complex syllables remains, becoming a robust indicator for identifying CAS from other speech disorders. Further cross-language investigations on syllable complexity in CAS are needed to design better assessments and to plan efficient intervention.

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.

Looking to the Future: Speech, Language, and Academic Outcomes in an Adolescent with Childhood Apraxia of Speech

OBJECTIVE

The clinical course of childhood apraxia of speech (CAS) is poorly understood. Of the few longitudinal studies in the field, only one has examined adolescent outcomes in speech, language, and literacy. This study is the first to report long-term speech, language, and academic outcomes in an adolescent, Liam, with CAS.

METHODS

Speech, language, literacy, and academic outcome data were collected, including 3 research-based assessments. Overall, data were available at 17 time points from 3;10 to 15 years.

RESULTS

Liam had moderate-to-severe expressive language impairment and poor reading, writing, and spelling up to 10 years. His numeracy was at or above the national average from 8 to 14 years. He made gains in preadolescence, with average expressive language at 11 years and above average reading and writing at 14 years. Nonword reading, reading comprehension, and spelling remained areas of weakness. Receptive language impairment was evident at 13 years, which was an unexpected finding.

CONCLUSION

Findings from single cases can be hypothesis generating but require verification in larger cohorts. This case shows that at least some children with CAS may gain ground in adolescence, relative to same age peers, in expressive language and academic areas such as reading and writing.

Tutorial: Assessment and Analysis of Polysyllables in Young Children

Purpose

Polysyllables, words of 3 or more syllables, represent almost 30% of words used in American English. The purpose of this tutorial is to support speech-language pathologists' (SLPs') assessment and analysis of polysyllables, extending the focus of published assessment tools that focus on sampling and analyzing children's segmental accuracy and/or the presence of phonological error patterns.

Method

This tutorial will guide SLPs through a review of 53 research papers that have explored the use of polysyllables in assessment, including the sampling and analysis procedures used in different research studies. The tutorial will also introduce two new tools to analyze and interpret polysyllable speech samples: the Word-Level Analysis of Polysyllables (WAP; Masso, 2016b) and the Framework of Polysyllable Maturity (Framework; Masso, 2016a).

Results

Connected speech and single-word sampling tasks were used across the 53 studies to elicit polysyllables, and a number of analysis methods were reported, including measures of segmental accuracy and measures of structural and suprasegmental accuracy. The WAP and the Framework extend SLPs' depth of analysis of polysyllables.

Conclusion

SLPs need a range of clinical tools to support the assessment and analysis of polysyllables. A case study comparing different speech analysis methods demonstrates the clinical value in utilizing the WAP and the Framework to interpret children's polysyllable productions in addition to traditional methods of speech sampling and analysis.

Interventions for childhood apraxia of speech

BACKGROUND

Childhood apraxia of speech (CAS) affects a child's ability to produce sounds and syllables precisely and consistently, and to produce words and sentences with accuracy and correct speech rhythm. It is a rare condition, affecting only 0.1% of the general population. Consensus has been reached that three core features have diagnostic validity: (1) inconsistent error production on both consonants and vowels across repeated productions of syllables or words; (2) lengthened and impaired coarticulatory transitions between sounds and syllables; and (3) inappropriate prosody (ASHA 2007). A deficit in motor programming or planning is thought to underlie the condition. This means that children know what they would like to say but there is a breakdown in the ability to programme or plan the fine and rapid movements required to accurately produce speech. Children with CAS may also have impairments in one or more of the following areas: non-speech oral motor function, dysarthria, language, phonological production impairment, phonemic awareness or metalinguistic skills and literacy, or combinations of these. High-quality evidence from randomised controlled trials (RCTs) is lacking on interventions for CAS.

OBJECTIVES

To assess the efficacy of interventions targeting speech and language in children and adolescents with CAS as delivered by speech and language pathologists/therapists.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, eight other databases and seven trial registers up to April 2017. We searched the reference lists of included reports and requested information on unpublished trials from authors of published studies and other experts as well as information groups in the areas of speech and language therapy/pathology and linguistics.

SELECTION CRITERIA

RCTs and quasi-RCTs of children aged 3 to 16 years with CAS diagnosed by a speech and language pathologist/therapist, grouped by treatment types.

DATA COLLECTION AND ANALYSIS

Two review authors (FL, AM) independently assessed titles and abstracts identified from the searches and obtained full-text reports of all potentially relevant articles and assessed these for eligibility. The same two authors extracted data and conducted the 'Risk of bias' and GRADE assessments. One review author (EM) tabulated findings from excluded observational studies (Table 1).

MAIN RESULTS

This review includes only one RCT, funded by the Australian Research Council; the University of Sydney International Development Fund; Douglas and Lola Douglas Scholarship on Child and Adolescent Health; Nadia Verrall Memorial Scholarship; and a James Kentley Memorial Fellowship. This study recruited 26 children aged 4 to 12 years, with mild to moderate CAS of unknown cause, and compared two interventions: the Nuffield Dyspraxia Programme-3 (NDP-3); and the Rapid Syllable Transitions Treatment (ReST). Children were allocated randomly to one of the two treatments. Treatments were delivered intensively in one-hour sessions, four days a week for three weeks, in a university clinic in Australia. Speech pathology students delivered the treatments in the English language. Outcomes were assessed before therapy, immediately after therapy, at one month and four months post-therapy. Our review looked at one-month post-therapy outcomes only.We judged all core outcome domains to be low risk of bias. We downgraded the quality of the evidence by one level to moderate due to imprecision, given that only one RCT was identified. Both the NDP-3 and ReST therapies demonstrated improvement at one month post-treatment. A number of cases in each cohort had recommenced usual treatment by their speech and language pathologist between one month and four months post-treatment (NDP-3: 9/13 participants; ReST: 9/13 participants). Hence, maintenance of treatment effects to four months post-treatment could not be analysed without significant potential bias, and thus this time point was not included for further analysis in this review.There is limited evidence that, when delivered intensively, both the NDP-3 and ReST may effect improvement in word accuracy in 4- to 12-year-old children with CAS, measured by the accuracy of production on treated and non-treated words, speech production consistency and the accuracy of connected speech. The study did not measure functional communication.

AUTHORS' CONCLUSIONS

There is limited evidence that, when delivered intensively, both the NDP-3 and ReST may effect improvement in word accuracy in 4- to 12-year-old children with CAS, measured by the accuracy of production on treated and non-treated words, speech production consistency and the accuracy of connected speech. The study did not measure functional communication. No formal analyses were conducted to compare NDP-3 and ReST by the original study authors, hence one treatment cannot be reliably advocated over the other. We are also unable to say whether either treatment is better than no treatment or treatment as usual. No evidence currently exists to support the effectiveness of other treatments for children aged 4 to 12 years with idiopathic CAS without other comorbid neurodevelopmental disorders. Further RCTs replicating this study would strengthen the evidence base. Similarly, further RCTs are needed of other interventions, in other age ranges and populations with CAS and with co-occurring disorders.

A Randomized Controlled Trial for Children With Childhood Apraxia of Speech Comparing Rapid Syllable Transition Treatment and the Nuffield Dyspraxia Programme-Third Edition

PURPOSE

This randomized controlled trial compared the experimental Rapid Syllable Transition (ReST) treatment to the Nuffield Dyspraxia Programme-Third Edition (NDP3; Williams & Stephens, 2004), used widely in clinical practice in Australia and the United Kingdom. Both programs aim to improve speech motor planning/programming for children with apraxia of speech (CAS), but they differ in types of stimuli used, level of stimulus complexity at initiation of treatment, and the principles of motor learning that they apply.

METHOD

Treatment was delivered to 26 children with mild to severe CAS aged 4-12 years through trained and supervised speech-language pathology students in 1-hr sessions, 4 days a week for 3 weeks at a university clinic. Articulation and prosodic accuracy were assessed at pretreatment, 1 week, 1 month, and 4 months posttreatment using blinded independent assessors to compare treatment, maintenance, and generalization effects.

RESULTS

The ReST and NDP3 treatments demonstrated large treatment effects. ReST maintained treatment gains from 1-week to 4-months posttreatment more effectively than the NDP3. Significant generalization to untreated stimuli was observed for both ReST and NDP3.

CONCLUSIONS

ReST and NDP3 have strong evidence of treatment and generalization gains in children with CAS when delivered intensively. Overall, ReST has greater external evidence from multiple sources but both treatments have support for clinical use.

Volubility, consonant, and syllable characteristics in infants and toddlers later diagnosed with childhood apraxia of speech: A pilot study

PURPOSE

This pilot study explored the volubility, consonant singleton acquisition, and syllable structure development between infants and toddlers (birth-24 months) with typical speech sound production (TYP) and those later diagnosed with childhood apraxia of speech (CAS).

METHOD

A retrospective longitudinal between- and within-subjects research design was utilized (TYP N=2; CAS N=4). Vocalizations from participants were analyzed between birth-24 months from home videotapes, volunteered by the children's parents, according to type (nonresonant vs. resonant), volubility, place and manner of consonant singletons, and syllable shape (V, CV, VC, CVC, VCV, CVCV, VCVC, and "Other").

RESULTS

Volubility between groups was not significant but statistically significant differences were found in the number of: resonant and non-resonant productions; different consonant singletons; different place features; different manner classes; and proportional use of fricative, glottal, and voiceless phones. Infants and toddlers in the CAS group also demonstrated difficulty with CVCs, had limited syllable shapes, and possible regression of vowel syllable structure.

CONCLUSIONS

Data corroborate parent reports that infants and toddlers later diagnosed with CAS present differently than do those with typical speech sound skills. Additional study with infants and toddlers later diagnosed with non-CAS speech sound disorder is needed.

LEARNING OUTCOMES

Readers will: (1) describe current perspectives on volubility of infants and toddlers later diagnosed with CAS; (2) describe current perspectives of the consonant singleton and syllable shape inventories of infants and toddlers later diagnosed with CAS; and (3) discuss the potential differences between the speech sound development of infants and toddlers later diagnosed with CAS and those with typical speech sound skill.

A systematic review of treatment outcomes for children with childhood apraxia of speech

PURPOSE

To present a systematic review of single-case experimental treatment studies for childhood apraxia of speech (CAS).

METHOD

A search of 9 databases was used to find peer-reviewed treatment articles from 1970 to 2012 of all levels of evidence with published communication outcomes for children with CAS. Improvement rate differences (IRDs) were calculated for articles with replicated (n > 1), statistically compared treatment and generalization evidence.

RESULTS

Forty-two articles representing Phase I and II single-case experimental designs (SCEDs; n = 23) or case series or description studies ( n = 19) were analyzed. Six articles showed high CAS diagnosis confidence. Of the 13 approaches within the 23 SCED articles, treatments were primarily for speech motor skills ( n = 6), linguistic skills ( n = 5), or augmentative and alternative communication ( n = 2). Most participants responded positively to treatment, but only 7 of 13 approaches in SCED studies reported maintenance and/or generalization of treatment effects. Three approaches had preponderant evidence (Smith, 1981). IRD effect sizes were calculated for Integral Stimulation/Dynamic Temporal and Tactile Cueing, Rapid Syllable Transition Treatment, and Integrated Phonological Awareness Intervention.

CONCLUSIONS

At least 3 treatments have sufficient evidence for Phase III trials and interim clinical practice. In the future, efficacy needs to be established via maintenance and generalization measures.

Mismatch negativity responses in children with a diagnosis of childhood apraxia of speech (CAS)

PURPOSE

To evaluate whether a hypothesis suggesting that apraxia of speech results from phonological overspecification could be relevant for childhood apraxia of speech (CAS).

METHOD

High-density EEG was recorded from 5 children with CAS and 5 matched controls, ages 5-8 years, with and without CAS, as they listened to randomized sequences of CV syllables in two oddball paradigms: phonemic (/ba/, /pa/) and allophonic (/pa/, /p(h)a/).

RESULTS

In the phonemic contrast condition, mismatch negativity (MMN) responses to oddball sounds were observed for the typically developing (comparison) group but not the CAS group, although a component similar to an immature mismatch response was apparent. The allophonic contrast did not elicit MMN responses in the comparison group, but in the CAS group, an MMN-like response was observed.

CONCLUSION

The authors propose that these preliminary findings are consistent with a view of CAS as a disorder that not only affects motor planning but also has a phonological component.

On the context-dependent nature of the contribution of the ventral premotor cortex to speech perception

What is the nature of the interface between speech perception and production, where auditory and motor representations converge? One set of explanations suggests that during perception, the motor circuits involved in producing a perceived action are in some way enacting the action without actually causing movement (covert simulation) or sending along the motor information to be used to predict its sensory consequences (i.e., efference copy). Other accounts either reject entirely the involvement of motor representations in perception, or explain their role as being more supportive than integral, and not employing the identical circuits used in production. Using fMRI, we investigated whether there are brain regions that are conjointly active for both speech perception and production, and whether these regions are sensitive to articulatory (syllabic) complexity during both processes, which is predicted by a covert simulation account. A group of healthy young adults (1) observed a female speaker produce a set of familiar words (perception), and (2) observed and then repeated the words (production). There were two types of words, varying in articulatory complexity, as measured by the presence or absence of consonant clusters. The simple words contained no consonant cluster (e.g. "palace"), while the complex words contained one to three consonant clusters (e.g. "planet"). Results indicate that the left ventral premotor cortex (PMv) was significantly active during speech perception and speech production but that activation in this region was scaled to articulatory complexity only during speech production, revealing an incompletely specified efferent motor signal during speech perception. The right planum temporal (PT) was also active during speech perception and speech production, and activation in this region was scaled to articulatory complexity during both production and perception. These findings are discussed in the context of current theories of speech perception, with particular attention to accounts that include an explanatory role for mirror neurons.

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.

SPEEDY babies: A putative new behavioral syndrome of unbalanced motor-speech development

Even though difficulties in motor development in children with speech and language disorders are widely known, hardly any attention is paid to the association between atypically rapidly occurring unassisted walking and delayed speech development. The four children described here presented with a developmental behavioral triad: 1) atypically speedy motor development, 2) impaired expressive speech, and 3) tongue carriage dysfunction resulting in related misarticulations. Those characteristics might be phenotypically or genetically clustered. These children didn't have impaired cognition, neurological or mental disease, defective sense organs, craniofacial dysmorphology or susceptibility to upper respiratory infections, particularly recurrent otitis media. Attention should be paid on discordant and unbalanced achievement of developmental milestones. Present children are termed SPEEDY babies, where SPEEDY refers to rapid independent walking, SPEE and DY to dyspractic or dysfunctional speech development and lingual dysfunction resulting in linguoalveolar misarticulations. SPEEDY babies require health care that recognizes and respects their motor skills and supports their needs for motor activities and on the other hand include treatment for impaired speech. The parents may need advice and support with these children.

Intervention for childhood apraxia of speech

BACKGROUND

The diagnostic criteria for Childhood Apraxia of Speech (CAS), and the underlying cause(s) for this disorder, remain heavily debated. Some agreement exists that children with CAS may have impairments in one or more of the following domains: non-speech oral motor function, motor speech function, speech sounds and structures (i.e., syllable and word shapes), prosody, language, phonemic awareness / metalinguistic skills, and literacy . Recently consensus has been reached that only three features across these domains have diagnostic validity: (1) inconsistent error production on both consonants and vowels across repeated productions of syllables or words, (2) lengthened and impaired coarticulatory transitions between sounds and syllables, and (3) inappropriate prosody (ASHA 2007). Perhaps due to the ongoing deliberation over aetiology and diagnosis, little evidence on intervention for CAS is published.

OBJECTIVES

To assess the efficacy of intervention delivered by Speech and Language Pathologists(s)/Speech and Language Therapists targeting CAS in children and adolescents.

SEARCH STRATEGY

The following databases were searched: CENTRAL (Issue 4, 2006), MEDLINE (1966 to 01/2007), CINAHL (1982 to 12/2006), EMBASE (1980 to 01/2007), ERIC (1965 to 01/2007), Linguistics Abstracts Online (1985 to 01/2007), PsycINFO (1872 to 01/2007). Reference lists of articles thus identified were examined.

SELECTION CRITERIA

The review considered randomised controlled trials (RCTs) and quasi-randomised studies of children aged 3 to 16 years with CAS, grouped by treatment types (e.g., perceptual and instrumentally-based biofeedback treatment techniques).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed titles and abstracts identified from the searches and obtained full text versions of all potentially relevant articles. Articles were assessed for design and risk of bias. In addition to outcome data, a range of variables about participant group and outcomes were documented.

MAIN RESULTS

Of 825 titles and abstracts searched, only 31 abstracts appeared to meet inclusion criteria. The remaining 794 papers were excluded predominantly on the basis of not including participants with CAS (e.g., focused on other developmental speech disorders or adult acquired apraxia of speech), or for not being intervention studies (i.e. being diagnostic or descriptive). All 31 full text articles obtained were excluded following evaluation as they did not meet inclusion criteria on design. . Thus no studies are included in this review.

AUTHORS' CONCLUSIONS

The review demonstrates a critical lack of well controlled treatment studies addressing treatment efficacy for CAS, making it impossible for conclusions to be drawn about which interventions are most effective for treating CAS in children or adolescents.