Speech & Language Delays

& Disorders

Reviews: ETIOLOGY ASSESSMENT INTERVENTION

POINTS OF INTEREST

· factors affecting language skills

· utterance length versus MLU

· language therapy: for whom & when?

THE ISSUE Children with language delays and disorders may have limited expressive or receptive language skills, difficulty with the acquisition of grammatical structures, inappropriate social communication skills, difficulty with non-verbal communication skills, or deficient literacy skills (Roseberry-McKibbin & Hegde, 2006). Children with speech delays or disorders may have difficulty with articulation skills and learning phonological rules. While there are many known causes of language learning difficulties, researchers are less certain about the causes of articulation and phonological disorders when there are no obvious medical or health impediments. Both speech and language disorders can be assessed using formal or informal measures. Often clinicians use a combination of the two. Clinicians employ a variety of treatment techniques for both speech and language delays and disorders.

THE REVIEWS Almost 45% of the 66 reviews included in the Catalogue were in the category of Speech and Language Delays and Disorders. Fifteen reviews explored the etiology of speech and/or language disorders. Some of the reviews also described relationships amongst interrelated factors and disorders, and one review described ways in which the development of consonant clusters might be evaluated. Seven reviews focused on assessment and seven focused on intervention.

WHAT THE REVIEWS CONCLUDE The median prevalence of primary speech and language delay is approximately 5.59%, according to a review of studies in the United Kingdom. This review found little evidence to support the notion that prevalence declines over age, after the sharp drop after 2 years of age. There were also no data to suggest that prevalence has increased over the past 30 years. Approximately 60% of children with early expressive delays and about 25% with expressive/receptive difficulties recover fully. It was unclear whether children resolved spontaneously or due to therapeutic interventions. Concern is expressed for the 40% of children with expressive language delays, and 75% of children with expressive/receptive difficulties whose problems do not resolve. No data were presented to describe the prevalence or natural history of children with pragmatic language disorders.

Clinicians are often asked why children have difficulty with speech and/or language. Five reviews addressed this question and found that factors such as a family’s socioeconomic status (affects vocabulary development), children’s psychological stress (word-finding difficulties), children’s verbal working memory, and adoption from settings with low language stimulation, all affect language skills. Phonological disorders have been linked with both implicit (unintentional learning through exposure to the patterns of language) and explicit (learning with attention, or meta-cognitive learning) learning difficulties.

Reading and writing skills have also been linked to children’s language skills. For example, children’s linguistic skills can be used to predict spelling ability, and oral language can predict reading proficiency. Specifically, lower standardized scores on expressive language, phonological awareness, and rapid automatized naming predict lower level reading (decoding) abilities. Lower standardized scores on expressive and receptive language skills predict lower reading comprehension skills. Clinical reviews of the prosody of children’s mutlisyllabic word productions, word finding difficulties, word processing, and normal acquisition of consonant clusters are also included in reviews of etiology. The relationship between specific language impairment and limb motor skills is described.

The seven assessment reviews widely varied in topic. Some provided assessment suggestions for specific populations. For example, one review described the importance of including discourse sampling as an assessment tool for individuals with neurogenic language disorders, while another advocated for the use of maximum phonation tasks such as vowel prolongations and syllable repetitions for identifying motor speech difficulties. Perceptual speech analysis should be a key component in the assessment of children with cleft palate and related disorders. This conclusion was based on independent analysis of speech data by specialized therapists. Goal attainment scaling is an assessment tool that can be used with any number of clients to evaluate treatment progress, compare across treatment goals, and compare across clients with similar goals. Other reviews of assessments advocated for improvements in current practices used by speech-language pathologists. For instance, standardized assessment measures should not be used indiscriminately with children from culturally and linguistically diverse populations. Instead processing-dependent measures such as digit span, working memory, non-word repetition, or dynamic assessment tools, such as test/teach/re-test and task/stimulus variability, should be adopted. Utterance length, rather than mean length of utterance (MLU), is the preferred measure of syntactic development. MLU will identify some, but not all preschoolers with language delays or disorders. Finally, significant semantic deficits can exist in children with language impairment. SLPs need to expand their semantic language assessments beyond vocabulary size by including abilities to learn new words, sort the phonological forms of new words in short term memory, and create or sort elaborate lexical representations.

Three of the seven reviews of intervention techniques considered shared storybook reading. While this technique is generally effective, clinicians should consider children’s orientation and motivation toward shared book reading, the impact of modifying adult-child discourse patterns during interactive book reading, and the impact of social and cultural influences on children’s expectations toward interactions with books (e.g., story book reading is a less-frequently occurring activity in low-income families as compared to middle-income families, and discourse patterns while reading may differ between adults and children depending on cultural background). Embedded-explicit literacy intervention is another therapeutic technique that has produced some positive effects on emergent literacy development where the classroom teacher and the SLP collaborate to implement treatment in the classroom. Concepts and skills that are explicitly targeted include: phonological awareness, print concepts, alphabet knowledge, writing, narrative and literate language. The teacher and the SLP work together to deliver embedded learning opportunities in the classroom. For example, the SLP may take an active role in the classroom for 45 minutes one day and work with the children individually and in small groups reading books and engaging in literacy-rich activities. During the rest of the week, the teacher provides ongoing literacy learning experiences for all children in the classroom.

Two reviews examined the effectiveness of speech and language interventions. They concurred that therapy is generally effective for children with phonological and vocabulary delays or disorders. There was less success in therapy for children with syntactic difficulties, and little evidence for treatment of receptive language difficulties. Longer therapy blocks (> 8 weeks), and the inclusion of normally-developing peers in language therapy sessions were both associated with more effective treatment outcomes. These two reviews acknowledged that there were unfortunate gaps in the evidence base for treatment effectiveness, and that there were many research opportunities.

Finally, two reviews examined language intervention practices. One provided ten principles of grammar facilitation for children with specific langauge impairment such as manipulating discourse so targeted features are more salient, systematically contrasting forms used by the child with more mature forms of adult grammar using sentence recasts, and avoiding telegraphic speech. The other review examined the Fast ForWord computer program for children with language impairment and found there was not enough evidence to support its effectiveness.

Reference
Roseberry-McKibbin, C., & Hedge, M.N. (2006). An Advanced Review of Speech-Language Pathology, 2^nd Edition. Austin, TX.: Pro-Ed., Inc.