James S. Andrews and Heidi M. Feldman
Children with delayed language are at increased risk for learning disabilities, such as difficulties of reading and writing, which may negatively impact a child’s academic achievement. As adults, individuals with language and speech difficulties may hold lower-skilled jobs and experience more behavior problems and impaired psychosocial adjustment as compared to individuals with normal skills. For these reasons, pediatric clinicians should be skilled at evaluating language development and managing delays and disorders.
DEFINITIONS
Language is the distinctly human ability to use a system of arbitrary symbols to convey meaning among individuals. Receptive language refers to what a child understands, and expressive language refers to what a child produces. While language refers to this system of symbols, speech refers to the usual output of this system in which the medium of exchange is a set of decodable vocal sounds. eTable 86.1 enumerates and defines several elements of language and speech that may be disordered in developmental difficulties.
Atypical development of language and speech is classified as delayed or disordered. Delayed language develops in the typical sequence but at a slower rate. Disordered language deviates from the typical sequence.1Expressive language disorders may involve limited production of vocabulary, misuse of words and their meanings, difficulty expressing ideas, immature grammatical patterns, or altered patterns of conversation. Mixed receptive-expressive language disorders may include, in addition to any of the features above, difficulty in following directions or comprehending words, sentences, or ideas. Speech disorders include problems in the production of speech sounds; disruptions in the flow or rhythm of speech; problems with voice pitch, volume, or quality; and poor intelligibility. Articulation and phonologic disorders limit the child’s ability to articulate, sequence, or organize the sounds of the language. Another speech-sound disorder, childhood apraxia of speech or developmental verbal dyspraxia, is associated with difficulty in planning, programming, and producing speech sounds.3
EPIDEMIOLOGY
The estimated prevalence of delays and disorders of language and speech vary significantly among studies. Between 5% and 8% of children 2 to 4.5 years of age experience combined speech and language delay, and between 2.3% and 19% experience pure language delay.4 By kindergarten, 7.4% of children are estimated to have a language development disorder not related to cognitive impairment or mental retardation.2 Because so many children are affected, many studies have sought to identify the factors associated with increased risk of language or speech delay. Known risk factors include premature birth, male gender, family history of specific language impairment, and lower socioeconomic status.5-7 Boys are up to twice as likely as girls to develop language delay.6 Children whose first-degree relatives have a history of language, speech, or reading delays or disorders have substantially higher rates of language disorders than do children without a positive family history. In contrast, the evidence does not support a relation between birth order, otitis media, or multilingual environment and increased prevalence of language delay.6,8-10
ETIOLOGY AND PATHOGENESIS
Language and speech development represents a highly complex and interactive process, and not surprisingly, the influences are varied and numerous. Thus, the etiology of language and speech delay and disorders is rarely single but rather multifactorial. eTable 86.2 summarizes in broad terms the requirements for typical language and speech development as well as situations in which these requirements may not be sufficiently met. In general, language and speech delay can be due to biologic causes, such as hearing loss or atypical cognition; atypical cognition may be associated with genetic or neurologic disorders or autism. Language and speech delay may also be secondary to environmental causes, such as impoverished linguistic environment.
We know that children generally learn language and speech from their environment. Hearing loss reduces a child’s verbal input, in quantity and/or quality, and also represents one of the commonest causes of language delay. Permanent hearing loss that is severe enough to affect language development and learning occurs in 1 to 6 per 1000 children.1 Children with hearing loss may demonstrate reduced vocabulary, delayed development of syntax, and distortions of speech sounds and prosody patterns.1 Linguistically impoverished households also certainly contribute to increased risk of language delay.
Other biologic etiologies of language and speech delays and disorders include cognitive impairment (mental retardation), autism spectrum disorders, and oral motor dysfunction. Autism spectrum disorder encompasses a broad array of symptoms, including language difficulties. Most but not all children with autism spectrum disorder will have receptive and expressive language delays.14
CLINICAL MANIFESTATIONS
As clinicians, we worry when a child fails to meet the typical milestones for language and speech development. Table 86-1 outlines many of the milestones for receptive and expressive language development along with indicators of clinically significant delay. Given the significant variation in the rate of language development in typically developing children and the high prevalence of transient developmental delays, the great clinical challenge is determining which children require intervention. Indeed, in approximately 35% to 45% of children, language delay at 2 years of age resolves by 3 years of age.15
Different etiologies of language delay manifest differently. Concomitant findings may include physical, neurological, developmental, and behavioral manifestations. Hearing loss may be suspected on the basis of the pattern of the child’s understanding and production or on the basis of anatomical abnormalities of the outer and middle ear. Global developmental delay may be suspected on the basis of other delays in cognitive or motor skills. If such developmental findings persist into school age, the child may meet diagnostic criteria for cognitive impairment (mental retardation).
Autism spectrum disorder may be suspected when language development is not only delayed but also disordered with respect to vocabulary, grammar, or communicative pattern. The child may also demonstrate impaired social interactions and stereotyped behaviors.
Specific language impairment may be suspected when language skills are less advanced than other cognitive abilities. The impairment may affect only expressive language or both receptive and expressive language. In some children, social aspects of communication are affected, making differentiation of these semantic-pragmatic language impairments from autism challenging.
Lastly, given that language provides a medium for children to express their emotion and understand their experiences, when language does not develop typically, children may also suffer academic, social, and emotional consequences. On average, half of the children referred to speech-language pathologists or to special education classes for learning disabilities have socioemotional problems. Clinicians must remember that not all emotional and behavioral problems are secondary to children’s language difficulties. Emotional and behavioral problems are also associated with conditions that lead to language and speech delay. A large proportion of children with specific language impairment have comorbid psychiatric disorders, such as attention deficit disorder, disruptive behavior disorders, and mood disorders.16
ASSESSMENT AND DIAGNOSIS
Assessment of young children focuses around careful history taking and observation. Gathering information from the child’s caregivers using open-ended questions is a convenient starting point. For example, the clinician may ask, “What does your child understand?” to evaluate receptive language, and “How does your child communicate what he or she wants?” to assess expressive language. After these initial open-ended questions, the clinician may follow up with more specific questions based on the typical milestones. “Red flags” indicating the need to refer for further speech and language evaluation are summarized in Table 86-2.
Table 86-1. Language Milestones and Red Flags
General screening tests can assist in the identification of children with delays.17 If a child is positive on a general screen, then formal inventories, such as the Capute Scales18 and the MacArthur-Bates Communicative Development Inventory (CDI),19 may be helpful to confirm suspicion that a child is delayed. The US Preventive Services Task Force found no evidence that language screening instruments are any more effective than careful clinician observation and parent report in identifying children in need of further evaluation.4
Children with language or speech delays should receive a full audiologic assessment, using the assessment techniques appropriate for the child’s age. Children with normal hearing but with evidence of impairment of cognitive, motor, or social skills should receive a comprehensive developmental assessment, often including an evaluation of the home environment. Psychologists and medical specialists, such as developmental-behavioral pediatricians or neurologists, will usually also evaluate the child and provide a specific diagnosis. Children who are otherwise developing typically may be referred to a speech-language pathologist for verification of the degree and nature of language or speech delay as well as for treatment recommendations. The importance of prompt referral to early intervention services for comprehensive evaluation and, if necessary, treatment cannot be overemphasized. eFigure 86.1 depicts a generalized algorithm for evaluation and management of children presenting with concern for language or speech delay. eTable 86.4 lists several useful online resources for clinicians in evaluating and managing children with speech and language disabilities.
MANAGEMENT
For purposes of management, pediatric clinicians should conceptualize a language or speech disorder as a chronic special health care need. For chronic care to be successful, it must involve a long-term commitment between a motivated, prepared primary care team and a proactive, informed family.21 A medical home should be created that assumes the responsibility of coordinating the medical, educational, and psychosocial needs of the child and family.22
The management plan for children with language and speech difficulties should address three domains: the child, the family, and the child’s environment. Once a child has been diagnosed with a language or speech disorder, management should include referral for early intervention or special education services if the severity of the disorder meets state eligibility criteria, involvement of the appropriate specialists (eg, speech-language pathologists), and advising the family on raising a child with language or speech difficulties. Further guidance is provided in the online text and with appropriate consultation.
Perhaps the most beneficial activity that parents can engage in with their child to promote language development is reading. Lastly, given the association between lower socioeconomic status and delayed language development, the clinician must be particularly vigilant for opportunities to help facilitate language learning in lower income families.
Table 86-2. Indications for Referrals for Speech and Language Delays and Disorders
In many cases, treatment is based on the type and severity of the language or speech disorder. Speech-language pathologists are often the primary treatment providers or consultants to an early intervention or special education team. For a child with delayed development, many treatments focus on optimizing the child’s linguistic environment using the techniques discussed previously. Group therapy, especially involving interaction with typically developing children, is also known to benefit children with language delay. For a child with a speech-sound disorder, the goal of treatment is to help the child systematically learn to produce the sounds correctly. Speech-language pathologists may be helpful in differentiating true stuttering from developmental dysfluency. Treatment for true stuttering can be challenging and often consists of techniques to reduce the frequency and severity of the stuttering events and to help control the negative affective responses to the stuttering.
NATURAL HISTORY AND PROGNOSIS
Treatment interventions for language and speech delays and disorders are effective. In the absence of treatment, the median persistence of language and speech delays and disorders from preschool to school-aged is estimated to be between 50% and 82%.15 Three review articles can be consulted for comprehensive analyses of the various treatments.4,27,28 Briefly summarized, the earlier intervention begins, the greater the chance of improvement. For expressive disorders, particularly phonological and vocabulary difficulties, the response to therapy is greatest. There is mixed evidence supporting the effectiveness of treatment for expressive disorders of syntax. The response to therapy for receptive disorders is generally less well established. Interestingly, some studies have shown no significant difference in outcome when treatment is administered by professionals versus by trained parents, which demonstrates the importance of empowering families to actively participate in their own treatment plan.27
The child’s long-term prognosis depends on the severity of the underlying disorder. Some children, despite the apparent resolution of isolated language and speech delays at 3 or 4 years of age, do experience later difficulties in reading. Children who have language problems affecting grammar, meaning, and conversational skills have a high prevalence of mental health disorders over time. Thus, long-term care within the medical home should include close monitoring of academic, emotional, and behavioral functioning.