Childhood Apraxia of Speech is a sound dysfunction that typically affects children, resulting in inconsistent and imprecise movements when producing speech. It is caused by impaired planning and programming of spatiotemporal movement sequences and can result in errors in speech sound production and prosody. CAS may be associated with known neurological impairment, complex neurobehavioral disorders, or as an idiopathic neurogenic speech sound disorder. ASHA prefers the term CAS over other terms, such as “developmental apraxia of speech” and “developmental verbal dyspraxia,” as they may refer to idiopathic presentations. It is probable that the features of CAS will continue beyond the developmental phase. The DSM-5 uses the term verbal dyspraxia to describe this disorder and includes it under the Speech Sound Disorders category, with associated features of supporting diagnosis.
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Childhood apraxia of speech (CAS) incidence refers to new cases identified in a specific time period, while prevalence refers to people living with the condition. Prevalence estimates of CAS are not reliable due to inconsistent diagnostic guidelines and a lack of validated diagnostic tools. CAS occurs in 1 to 2 children per 1,000, with a higher prevalence in males and a likelihood of concomitant language, reading, and/or spelling disorders. CAS characteristics have greater prevalence in various syndromes such as galactosemia, fragile X syndrome, and velocardiofacial syndrome. Children with autism spectrum disorder do not have a higher prevalence of CAS, despite a higher prevalence of speech delay and errors.
No validated diagnostic features differentiate Childhood Apraxia of Speech (CAS) from other childhood speech sound disorders. However, three features have gained some consensus among researchers, including inconsistent errors on consonants and vowels, disrupted coarticulatory and lengthened transitions between sounds and syllables, and inappropriate prosody. Other characteristics reported in children diagnosed with CAS include articulatory groping, consonant distortions, slower than typical rate of speech, and more. Co-occurring language and literacy problems and nonspeech sensory and motor problems can also be present in children with CAS.
CAS can be congenital or acquired during speech development and occur in various neurobehavioral disorders and conditions. The neurological deficits underlying CAS are not the same as those that underlie dysarthria. Genetic bases for CAS have been investigated, and studies suggest that deficits in the FOXP2 may have an adverse impact on the growth of neural circuits responsible for organizing and carrying out speech movements. The association between the FOXP2 gene and apraxia of speech remains supported by recent research findings.
Role of Speech Therapists
Speech Therapists are crucial in screening, assessing, diagnosing, and treating individuals with CAS. Their roles include clinical/educational services, prevention and advocacy, and education, administration, and research. Appropriate roles for Speech Therapists include providing prevention information, educating other professionals, screening individuals, conducting assessments, diagnosing the presence of CAS, making decisions about management and eligibility for services, developing treatment plans, counseling individuals and families, consulting and collaborating with others, remaining informed of research, and advocating for appropriate services.
Therapists treating CAS must have expertise in diagnosing childhood motor speech disorders, knowledge of motor learning theory, and experience with intervention techniques, such as AAC and assistive technology. As indicated in the Code of Ethics, Speech Therapists who serve this population should be specifically educated and appropriately trained to do so.
Screening for childhood apraxia of speech (CAS) involves an initial assessment by a speech therapist to identify children who need further speech and language assessment. A comprehensive assessment is then conducted, taking into account the International Classification of Functioning, Disability, and Health framework of the World Health Organization. This involves using standardized and nonstandardized measures and activities to assess impairments in speech sound production, communication, and learning and identify any co-morbid conditions or barriers to communication. Speech therapists select culturally and linguistically sensitive assessments and perform a comprehensive oral mechanism examination to differentiate CAS from other speech sound disorders.
Tasks may include nonspeech articulatory postures, single and sequential speech production at different levels and sequential and alternating movement repetitions. Dynamic assessment procedures can help diagnose CAS, determine its severity and prognosis, and identify the amount of cueing necessary to facilitate performance. Assessment results may lead to a diagnosis or provisional diagnosis of CAS, a description of the characteristics and severity of the disorder, and the identification of the risk factors that might contribute to the disorder.
Diagnosing Childhood Apraxia of Speech (CAS) in children under three years of age is difficult due to several factors, such as the lack of a single validated list of diagnostic features, the presence of developmental disabilities, and co-morbid conditions. It is preferable to diagnose the condition provisionally using phrases such as “CAS cannot be ruled out,” “speech movement planning issues appear likely,” or “CAS suspected.”Several instruments have been proposed to assess speech motor planning and programming skills, but the rigor of their psychometric characteristics has been questioned.
Differential diagnosis of CAS from speech delay, other speech sound disorders, dysarthria, and dysfluency is necessary. Treatment response is important in distinguishing CAS from other disorders. It is essential to consider a child’s complete language system, including dialectal variants and dual or second language acquisition, to differentiate features of CAS from differences in language acquisition.
The primary objective of treating children with Childhood Apraxia of Speech (CAS) is to enhance their communication and language skills by improving their speech production and clarity or by using Augmentative and Alternative Communication (AAC) methods such as gestures, manual signs, voice output devices, and communication boards. Treatment is intensive and individualized and takes place in naturalistic environments, involving as many important people in the child’s life as possible.
Treatment approaches may focus on improving speech production through motor programming, linguistic approaches, or a combination of both. Rhythmic approaches using intonation patterns may also be used to improve functional speech production. AAC methods may also be used to enhance verbal speech production and stimulate the development of language skills.
Treatment options for Childhood Apraxia of Speech (CAS) focus on movement patterns rather than sound patterns. Sensory cueing, visual cueing, verbal/auditory cueing, and tactile facilitation are commonly used techniques to teach movement sequences for speech. Treatment options depend on factors such as the disorder’s severity and the child’s communication needs. Multiple approaches may be appropriate, and the presence of apraxia in other systems may also be considered in treatment planning.
Motor programming approaches
Motor programming approaches are used to treat Childhood Apraxia of Speech (CAS) and are based on motor planning principles. These approaches involve the frequent and intensive practice of speech targets, focusing on accurate speech movement and including external sensory input for speech production. Motor programming approaches consider the practice conditions and provide appropriate performance feedback.
Linguistic approaches to treating CAS focus on speech and functional communication’s linguistic and phonological components. They complement motoric approaches, target speech sounds, and groups of sounds with similar error patterns. The Cycles approach targets phonological pattern errors in children with highly unintelligible speech. In contrast, Integrated Phonological Awareness is designed to enhance phonological awareness, letter-sound knowledge, and speech production in young children who have speech and language impairments.
Prosodic facilitation treatment uses intonation patterns to improve speech production. Augmentative and Alternative Communication (AAC) involves supplementing or replacing natural speech or writing with aided or unaided symbols. When working with bilingual or multilingual populations, SLPs should consider targeting errors present in both languages and selecting stimulus targets that affect both languages to facilitate the cross-linguistic transfer of skills. It’s important to choose goals and targets based on the unique characteristics and word structures of each language and monitor progress in both languages. SLPs should modify goals and approaches as needed. Children may seem to favor speaking in one language, but this doesn’t necessarily indicate a preference for communication in that language.
CAS is a motor speech dysfunction that affects the consistency and precision of movements underlying speech. It is caused by impaired planning and programming of spatiotemporal movement sequences and can result in errors in speech sound production and prosody. CAS may be associated with known neurological impairment, complex neurobehavioral disorders, or as an idiopathic neurogenic speech sound disorder. Although prevalence estimates of CAS are unreliable due to inconsistent diagnostic guidelines, the incidence of this condition is estimated to be 1 to 2 children per 1,000. With a higher prevalence in males and a likelihood of co-occurring language, reading, and/or spelling disorders. No validated diagnostic features differentiate CAS from other childhood speech sound disorders. Still, three features have gained some consensus among researchers. Treatment goals for CAS aim to improve speech production, prosody, and communicative effectiveness. Speech therapists play a crucial role in screening, assessing, diagnosing, and treating individuals with CAS. They must possess specialized knowledge in motor learning theory and experience with appropriate intervention techniques, including augmentative and alternative communication (AAC) and assistive technology.