Communication disorders are among the most common disorders in childhood. To communicate effectively, children must have a mastery of language “that is the ability to understand and express ideas” using words and speech, the manner in which words are spoken. Language disorders include expressive and mixed receptive-expressive language disorder, whereas speech disorders include phonological disorder and stuttering. Language competence spans four domains: phonology, grammar, semantics, and pragmatics. Phonology refers to the ability to produce sounds that constitute words in a given language and the skills to discriminate the various phonemes (sounds that are made by a letter or group of letters in a language). To imitate words, a child must be able to produce the sounds of a word. Grammar designates the organization of words and the rules for placing words in an order that makes sense in that language. Semantics refers to the organization of concepts and the acquisition of words themselves. A child draws from a mental list of words to produce sentences. Children with language impairments exhibit a wide range of difficulties with semantics that include acquiring new words, storage and organization of known words, and word retrieval. Speech and language evaluations that are sufficiently broad to test all of the above skill levels will be more accurate in evaluating a child's remedial needs. Pragmatics has to do with skill in the actual use of language and the rules of conversation, including pausing so that a listener can answer a question and knowing when to change the topic when a break occurs in a conversation. By age 2 years, toddlers may know up to 200 words, and by age 3 years, most children understand the basic rules of language and can converse effectively.
Expressive Language Disorder
Expressive language disorder is diagnosed when a child demonstrates a selective deficit in expressive language development relative to receptive language skills and nonverbal intelligence. Children with expressive language disorder often present verbally as younger than their age. Expressive language disturbance often appears in the absence of comprehension difficulties. Children with expressive language disorder alone have courses and prognoses that differ from children with mixed receptive-expressive language disorder.
The prevalence of expressive language disorder is estimated to be as high as 6 percent in children between the ages of 5 and 11 years of age. Surveys have indicated rates of expressive language as high as 15 percent in children under age 3 years. In school-age children over the age of 11 years, the estimates are lower, ranging from 3 percent to 5 percent. The disorder is two to three times more common in boys than in girls and is most prevalent among children whose relatives have a family history of phonological disorder or other communication disorders.
The specific cause of developmental expressive language disorder is likely to be multifactorial. Subtle cerebral damage and maturational lags in cerebral development have been postulated as underlying causes. Some children with language disorders have difficulty processing information in a time-limited manner. Scant data are available on the specific brain structure of children with language disorder, but limited magnetic resonance imaging (MRI) studies suggest that language disorders are associated with a loss of the normal left-right brain asymmetry in the perisylvian and planum temporale regions. Results of one small MRI study suggested possible inversion of brain asymmetry (right > left). Left-handedness or ambilaterality appears to be associated with expressive language problems. Evidence shows that language disorders occur with higher frequency in certain families. Genetic factors have been suspected to play a role, and several studies of twins show significant concordance for monozygotic twins for developmental language disorders. A recent report described a hypothesis of specific genes at 7q11.23 that appear to be exquisitely sensitive to dosage alterations that can influence human language and visuospatial capabilities. The Williams-Beuren syndrome (WBS) locus at 7q11.23 is susceptible to recurrent chromosomal rearrangements, including the microdeletion that causes WBS. WBS typically presents as a phenotype, including characteristic cardiovascular, cognitive, and behavioral features. It is hypothesized, however, that instead of microdeletions, reciprocal duplications of the WBS could also occur and may be associated with the phenotype of language dysfunction. Some studies have found that some individuals with WBS are at an increased risk of expressive language disorder. Environmental and educational factors are also postulated to contribute to developmental language disorders. Data suggest that prenatal exposure to substances such as alcohol and cocaine, for example, are likely to be associated with both delays in language acquisition, and expressive language ability.
Subtle cerebral damage and maturational lags in cerebral development have been assumed as underlying causes. Slight data are available on the specific brain structure of children with language disorder, but limited magnetic resonance imaging (MRI) studies suggest that language disorders are associated with a loss of the normal left-right brain asymmetry in the perisylvian and planum temporale regions. Results of one small MRI study suggested possible inversion of brain asymmetry (right > left). Left-handedness or ambilaterality appears to be associated with expressive language problems.
Signs and Symptoms
DSM-IV-TR Diagnostic Criteria for Expressive Language Disorder
A. The scores obtained from standardized individually administered measures of expressive language development are substantially below those obtained from standardized measures of both nonverbal intellectual capacity and receptive language development. The disturbance may be manifest clinically by symptoms that include having a markedly limited vocabulary, making errors in tense, or having difficulty recalling words or producing sentences with developmentally appropriate length or complexity.
B. The difficulties with expressive language interfere with academic or occupational achievement or with social communication.
C. Criteria are not met for mixed receptive-expressive language disorder or a pervasive developmental disorder.
D. If mental retardation, a speech-motor or sensory deficit, or environmental deprivation is present, the language difficulties are in excess of those usually associated with these problems.
Children with expressive language disorders may be ostracized by peers because of their poor ability to explain what they are talking about. They may appear vague when telling a story and use many filler words such as stuff and things instead of naming specific objects.
The essential feature of expressive language disorder is marked impairment in the development of age-appropriate expressive language, which results in the use of verbal or sign language markedly below the expected level in view of a child's nonverbal intellectual capacity. Language understanding (decoding) skills remain relatively intact. When severe, the disorder becomes recognizable by about the age of 18 months, when a child fails to utter spontaneously or even echo single words or sounds. Even simple words, such as Mama and Dada, are absent from the child's active vocabulary, and the child points or uses gestures to indicate desires. The child seems to want to communicate, maintains eye contact, relates well to the mother, and enjoys games such as pat-a-cake and peek-a-boo. The child's vocabulary is severely limited. At 18 months, the child may be limited to pointing to common objects when they are named.
When a child with expressive language disorder begins to speak, the language impairment gradually becomes apparent. Articulation is often immature; numerous articulation errors occur but are inconsistent, particularly with such sounds as th, r, s, z, y, and l, which are either omitted or are substituted for other sounds.
By the age of 4 years, most children with expressive language disorder can speak in short phrases, but may have difficulty retaining new words. After beginning to speak, they acquire language more slowly than do most children. Their use of various grammatical structures is also markedly below the age-expected level, and their developmental milestones may be slightly delayed. Emotional problems involving poor self-image, frustration, and depression may develop in school-age children.
Course and Prognosis
The prognosis for expressive language disorder is related to the severity of the disorder. Studies of late talkers concur that 50 to 80 percent of these children master language skills that are within the expected level during the preschool years. Most children who begin to talk later than average but catch up during preschool years, are not at high risk to develop further language or learning disorders. Outcome of expressive language disorder is influenced by other comorbid disorders. If children do not develop mood disorders or disruptive behavior problems, the prognosis is better. The rapidity and extent of recovery depend on the severity of the disorder, the child's motivation to participate in therapy, and the timely institution of speech and other therapeutic interventions. The presence or absence of other factors such as moderate to severe hearing loss, mild mental retardation, and severe emotional problem also affects the prognosis for recovery. As many as 50 percent of children with mild expressive language disorder recover spontaneously without any sign of language impairment, but children with severe expressive language disorder may later display features of mild to moderate language impairment.
Recent literature has shown that children who demonstrate poor comprehension, poor articulation, or poor academic performance tend to continue to have problems in these areas at follow-up 7 years later. An association is also seen between particular language impairment profiles and persistent mood and behavior problems. Children who have poor comprehension associated with expressive difficulties seem to be the most socially isolated and impaired with respect to peer relationships.
Expressive language level and many nonverbal and communication skills are strongly related in children with language impairment. Expressive language may be seen as an index of general development or as a marker of social and other communication skills. Especially in preschool age groups, expressive language appears to be related to social and nonverbal communication skills as much as it is simply a measure of knowledge of words.
Controversy exists among experts whether intervention for young children with expressive language difficulties should be initiated as soon as it is noted, or whether waiting until age 4 or 5 years is the optimal time to begin treatment. Treatment for expressive language disorder is still generally not initiated unless it persists after the preschool years. Various techniques have been used to help a child improve use of such parts of speech as pronouns, correct tenses, and question forms. Direct interventions use a speech and language pathologist who works directly with the child. Mediated interventions, in which a speech and language professional teaches a child's teacher or parent how to promote therapeutic language techniques, have also been efficacious. Language therapy is often aimed at using words to improve communication strategies and social interactions as well. Such therapy consists of behaviorally reinforced exercises and practice with phonemes (sound units), vocabulary, and sentence construction. The goal is to increase the number of phrases by using block-building methods and conventional speech therapies.
Psychotherapy may be useful for children whose language impairment has affected their self-esteem, insofar as it can be used as a positive model for more effective communication and broadening social skills. Supportive parental counseling may be indicated in some cases. Parents may need help to reduce intrafamilial tensions arising from difficulties in rearing language-disordered children and to increase their awareness and understanding of the disorder.
More research is needed to establish whether early intervention for preschoolers with language deficits has long-term benefits and to develop comprehensive treatment programs that may address the direct language interventions along with interventions for common comorbid communication and learning disorders.
Mixed Receptive-Expressive Language Disorder
Children with mixed receptive-expressive learning disorders exhibit impaired skills in the expression and reception (understanding and comprehension) of spoken language. The expressive difficulties in these children may be similar to those of children with only expressive language disorder, which is characterized by limited vocabulary, use of simplistic sentences, and short sentence usage. Children with receptive language difficulties may be experiencing additional deficits in basic auditory processing skills, such as discriminating between sounds, rapid sound changes, association of sounds and symbols, and the memory of sound sequences. These deficits may lead to a whole host of communication barriers for a child, including a lack of understanding of questions or directives from others, or inability to follow the conversations of peers or family members. Recognition of the disorder in children with mixed expressive-receptive language disorders may be delayed because of early misattribution of their communication by teachers and parents as a behavioral problem rather than a deficit in understanding.
Mixed receptive-expressive language disorder is believed to occur in about 5 percent of preschoolers and to persist in approximately 3 percent of school-age children. It is less common than expressive language disorder alone. Mixed receptive-expressive language disorder is believed to be at least twice as prevalent in boys as in girls.
Language disorders most likely have multiple determinants, including genetic factors, developmental brain abnormalities, environmental influences, neurodevelopmental immaturity, and auditory processing features in the brain. As with expressive language disorder alone, evidence is found of familial aggregation of mixed receptive-expressive language disorder. Genetic contribution to this disorder is implicated by twin studies, but no mode of genetic transmission has been proved. Some studies of children with various speech and language disorders have also shown cognitive deficits, particularly slower processing of tasks involving naming objects, as well as fine motor tasks. Slower myelinization of neural pathways has been hypothesized to account for the slow processing found in children with developmental language disorders. Several studies suggest an underlying impairment of auditory discrimination, because most children with the disorder are more responsive to environmental sounds than to speech sounds.
Due to slower myelinisation of neural pathways, it has been hypothesized to account for the slow processing found in children with developmental language disorders. In some cases, bilateral EEG abnormalities are seen. Also, an impairment of auditory discrimination suggests the children’s responsiveness to environmental sounds than to speech sounds. They have a partial hearing defect for true tones, an increased threshold of auditory arousal, and an inability to localize sound sources.
Signs and Symptoms
DSM-IV-TR Diagnostic Criteria for Mixed Receptive-Expressive Language Disorder
The scores obtained from a battery of standardized individually administered measures of both receptive and expressive language development are substantially below those obtained from standardized measures of nonverbal intellectual capacity. Symptoms include those for expressive language disorder as well as difficulty understanding words, sentences, or specific types of words, such as spatial terms.
The difficulties with receptive and expressive language significantly interfere with academic or occupational achievement or with social communication.
Criteria are not met for a pervasive developmental disorder.
If mental retardation, a speech-motor or sensory deficit, or environmental deprivation is present, the language difficulties are in excess of those usually associated with these problems.
The essential clinical feature of the disorder is significant impairment in both language comprehension and language expression. In the mixed disorder, the expressive impairments are similar to those of expressive language disorder, but can be more severe. The clinical features of the receptive component of the disorder typically appear before the age of 4 years. Severe forms are apparent by the age of 2 years; mild forms may not become evident until age 7 (second grade) or older, when language becomes complex. Children with mixed receptive-expressive language disorder show markedly delayed and below-normal ability to comprehend (decode) verbal or sign language, although they have age-appropriate nonverbal intellectual capacity. In most cases of receptive dysfunction, verbal or sign expression (encoding) of language is also impaired. The clinical features of mixed receptive-expressive language disorder in children between the ages of 18 and 24 months result from a child's failure to utter a single phoneme spontaneously or to mimic another person's words.
Many children with mixed receptive-expressive language disorder have auditory sensory difficulties or cannot process visual symbols, such as explaining the meaning of a picture. They have deficits in integrating both auditory and visual symbols for example, recognizing the basic common attributes of a toy truck and a toy passenger car. Whereas at 18 months, a child with expressive language disorder only can comprehend simple commands and can point to familiar household objects when told to do so, a child of the same age with mixed receptive-expressive language disorder cannot either point to common objects or obey simple commands. A child with mixed receptive-expressive language disorder usually appears to be deaf, but the child can hear. He or she responds normally to nonlanguage sounds from the environment, but not to spoken language. If the child later starts to speak, the speech contains numerous articulation errors, such as omissions, distortions, and substitutions of phonemes. Language acquisition is much slower for children with mixed receptive-expressive language disorder than for children without this disorder.
Children with mixed receptive-expressive language disorder have difficulty recalling early visual and auditory memories and recognizing and reproducing symbols in proper sequence. In some cases, bilateral EEG abnormalities are seen. Some children with mixed receptive-expressive language disorder have a partial hearing defect for true tones, an increased threshold of auditory arousal, and an inability to localize sound sources. Seizure disorders and reading disorder are more common among the relatives of children with mixed receptive-expressive language disorder than they are in the general population.
Most children with mixed receptive-expressive language disorder are impaired socially and in terms of nonverbal communication. This impairment causes a variety of additional difficulties and often results in poor self-esteem and feelings of inferiority that, in turn, can further prevent the child from succeeding in the usual developmental tasks.
Course and Prognosis
The overall prognosis for mixed receptive-expressive language disorder is less favorable than that for expressive language disorder alone. When the mixed disorder is identified in a young child, it is usually severe, and the short-term prognosis is poor. Language develops at a rapid rate in early childhood, and young children with the disorder may appear to be falling behind. In view of the likelihood of comorbid learning disorders and other mental disorders, the prognosis is guarded. Young children with severe mixed receptive-expressive language disorder are likely to have learning disorders in the future. In children with mild versions, mixed disorder may not be identified for several years, and the disruption in everyday life may be less overwhelming than that in severe forms of the disorder. Over the long run, some children with mixed receptive-expressive language disorder achieve close to normal language functions. The prognosis for children who have mixed receptive-expressive language disorder varies widely and depends on the nature and severity of the damage.
A comprehensive speech and language evaluation is recommended for children with mixed receptive-expressive language disorder, before embarking on a speech and language remediation program. Preschoolers with mixed receptive-expressive language disorder optimally receive interventions designed to promote social communication and literacy as well as oral language. For children at the kindergarten level, optimal intervention includes direct teaching of key prereading skills as well as social skills training. An important early goal of interventions for young children with mixed receptive-expressive language disorder is the achievement of rudimentary reading skills in that these skills are protective against the academic and psychosocial ramifications of falling behind early on in reading. Some language therapists favor a low-stimuli setting, in which children are given individual linguistic instruction. Others recommend that speech and language instruction be integrated into a varied setting with several children who are taught several language structures simultaneously. Often, a child with mixed receptive-expressive language disorder will benefit from a small, special-educational setting that allows more individualized learning.
Psychotherapy may be helpful for children with mixed receptive-expressive language disorder who have associated emotional and behavioral problems. Particular attention should be paid to evaluating the child's self-image and social skills. Family counseling in which parents and children can develop more effective, less frustrating means of communicating may be beneficial.
Children with phonological disorder are unable to produce speech sounds correctly because of omissions of sounds, distortions of sounds, or atypical pronunciation. Typical speech disturbances in this disorder include omitting the last sounds of the word (e.g., saying mou for mouse or drin for drink), or substituting one sound for another (saying bwu instead of blue or tup for cup). Distortions in sounds can occur when children allow too much air to escape from the side of their mouths while saying sounds like sh or producing sounds like s or z with their tongue protruded. Speech sound errors can also occur in patterns because a child has an interrupted air flow instead of a steady airflow preventing the entire word to be pronounced (e.g., pat for pass or bacuum for vacuum). Children with a phonological disorder can be mistaken for younger children because of their difficulties in producing speech sounds correctly. The diagnosis of a phonological disorder is made by comparing the skills of a given child with the expected skill level of others of the same age. The disorder results in errors in whole words because of incorrect pronunciation of consonants, substitution of one sound for another, omission of entire phonemes, and, in some cases, dysarthria (slurred speech because of incoordination of speech muscles) or dyspraxia (difficulty planning and executing speech). Speech sound development is believed to be based on both linguistic and motor development that must be integrated to produce sounds.
Surveys indicate that the prevalence of phonological disorder is at least 3 percent in preschoolers, 2 percent in children 6 to 7 years of age, and 0.5 percent in 17-year-old adolescents. Approximately 7 to 8 percent of 5-year-old children in one large community sample had speech sound production problems of developmental, structural, or neurological origins. Another study found that up to 7. percent of children between the ages of 7 and 11 years had phonological disorders. Of those, 2.5 percent had speech delay (deletion and substitution errors past the age of 4 years) and 5 percent had residual articulation errors beyond the age of 8 years. Developmental phonological disorders occur much more frequently than disorders with known structural or neurological origin. The disorder is approximately 5 two to three times more common in boys than in girls. It is also more common among first-degree relatives of patients with the disorder than in the general population. According to DSM-IV-TR, the prevalence falls to 0.5 percent by mid to late adolescence.
The likely causes of phonological disturbance include multiple variables perinatal problems, genetic factors, auditory processing problems, hearing impairment, and structural abnormalities related to speech. A developmental lag or maturational delay in the neurological process underlying speech has been postulated in some cases. The likelihood of a subtle brain abnormality is supported by the observation that children with phonological disorder are also more likely to manifest soft neurological signs as well as additional disorders, including receptive and expressive language difficulties and a higher-than-expected rate of reading disorder. Genetic factors are implicated by data from twin studies that show concordance rates for monozygotic twins that are higher than chance.
Articulation disorders caused by structural or mechanical problems are rare. Phonological disorders caused by neurological impairment can be divided into dysarthria and apraxia or dyspraxia. Dysarthria results from an impairment in the neural mechanisms regulating the muscular control of speech. This can occur in congenital conditions, such as cerebral palsy, muscular dystrophy, or head injury or because of infectious processes. Apraxia or dyspraxia is characterized by difficulty in the execution of speech even when no obvious paralysis or weakness of the muscles used in speech exists.
Environmental factors may play a role in developmental phonological disorder, but constitutional factors seem to make the most significant contribution. The high proportion of phonological disorder in certain families implies a genetic component in the development of this disorder. Poor motor coordination, laterality, and handedness are not associated with phonological disorder.
A developmental lag or maturational delay in the neurological process underlying speech has been postulated as well as the likelihood of a subtle brain abnormality. It is supported by the observation that children with phonological disorder are also more likely to manifest soft neurological signs as well as additional disorders, including receptive and expressive language difficulties and a higher-than-expected rate of reading disorder. Phonological disorders caused by neurological impairment can be divided into dysarthria and apraxia or dyspraxia. Dysarthria results from an impairment in the neural mechanisms regulating the muscular control of speech. Apraxia or dyspraxia is characterized by difficulty in the execution of speech even when no obvious paralysis or weakness of the muscles used in speech exists.
Signs and Symptoms
DSM-IV-TR Diagnostic Criteria for Phonological Disorder
Failure to use developmentally expected speech sounds that are appropriate for age and dialect (e.g., errors in sound production, use, representation, or organization such as, but not limited to, substitutions of one sound for another [use of /t/ for target /k/ sound] or omissions of sounds such as final consonants).
The difficulties in speech sound production interfere with academic or occupational achievement or with social communication.
If mental retardation, a speech-motor or sensory deficit, or environmental deprivation is present, the speech difficulties are in excess of those usually associated with these problems.
Children with phonological disorder are delayed in, or incapable of, producing speech sounds that are expected for their age, intelligence, and dialect. The sounds are often substitutions for example, the use of t instead of k and omissions, such as leaving off the final consonants of words. Phonological disorder can be recognized in early childhood. In severe cases, the disorder is first recognized at about 3 years of age. In less severe cases, the disorder may not be apparent until the age of 6 years. A child's articulation is judged disordered when it is significantly behind that of most children at the same age level, intellectual level, and educational level.
In very mild cases, a single speech sound (i.e., phoneme) may be affected. When a single phoneme is affected, it is usually one that is acquired late in normal language acquisition. The speech sounds most frequently misarticulated are also those acquired late in the developmental sequence, including r, sh, th, f, z, l, and ch. In severe cases and in young children, sounds such as b, m, t, d, n, and h may be mispronounced. One or many speech sounds may be affected, but vowel sounds are not among them.
Children with phonological disorder cannot articulate certain phonemes correctly and may distort, substitute, or even omit the affected phonemes. With omissions, the phonemes are absent entirely for example, bu for blue, ca for car, or whaa? for what's that? With substitutions, difficult phonemes are replaced with incorrect ones for example, wabbit for rabbit, fum for thumb, or whath dat? for what's that? With distortions, the correct phoneme is approximated but is articulated incorrectly. Rarely, additions (usually of the vowel uh) occur for example, puhretty for pretty, what's uh that uh? for what's that?
Omissions are thought to be the most serious type of misarticulation, with substitutions the next most serious, and distortions the least serious type. Omissions, which are most frequent in the speech of young children, usually occur at the ends of words or in clusters of consonants (ka for car, scisso for scissors). Distortions, which are found mainly in the speech of older children, result in a sound that is not part of the speaker's dialect. Distortions may be the last type of misarticulation remaining in the speech of children whose articulation problems have mostly remitted. The most common types of distortions are the lateral slip in which a child pronounces s sounds with the airstream going across the tongue, producing a whistling effect and the palatal or lisp in which the s sound, formed with the tongue too close to the palate, produces a ssh sound effect.
The misarticulations of children with phonological disorder are often inconsistent and random. A phoneme may be pronounced correctly one time and incorrectly another time. Misarticulations are most common at the ends of words, in long and syntactically complex sentences, and during rapid speech.
Omissions, distortions, and substitutions also occur normally in the speech of young children learning to talk. But, whereas young, normally speaking children soon replace these misarticulations, children with phonological disorder do not. Even as children with phonological disorder grow and finally acquire the correct phoneme, they may use it only in newly acquired words and may not correct the words learned earlier that they have been mispronouncing for some time.
Most children eventually outgrow phonological disorder, usually by the third grade. After the fourth grade, however, spontaneous recovery is unlikely, and so it is important to try to remediate the disorder before the development of complications. Often, beginning kindergarten or school precipitates the improvement when recovery from phonological disorder is spontaneous. Speech therapy is clearly indicated for children who have not shown spontaneous improvement by the third or fourth grade. Speech therapy should be initiated at an early age for children whose articulation is significantly unintelligible and who are clearly troubled by their inability to speak clearly.
Children with phonological disorder may have various concomitant social, emotional, and behavioral problems, particularly when comorbid expressive language problems are present. Children with expressive language disorder and severe articulation impairment and those whose disorder is chronic and nonremitting are the ones most likely to suffer from psychiatric problems.
Course and Prognosis
Spontaneous remission of symptoms is common in children whose misarticulations involve only a few phonemes. Children who persist in exhibiting articulation problems after the age of 5 years may be experiencing a myriad of other speech and language impairments, so that a comprehensive evaluation may be indicated at this time. Children over the age of 5 with articulation problems are at higher risk for auditory perceptual problems. Spontaneous recovery is rare after the age of 8 years.
Treatment is typically recommended for children with moderate to severe developmental phonological disorders. Two main approaches have been used successfully to improve phonological difficulties. The first one, the phonological approach, is usually chosen for children with extensive patterns of multiple speech sound errors that may include final consonant deletion, or consonant cluster reduction. Exercises in this approach to treatment focus on guided practice of specific sounds, such as final consonants, and when that skill is mastered, practice is extended to use in meaningful words and sentences. The other approach, the traditional approach is utilized for children who produce substitution or distortion errors in just a few sounds. In this approach, the child practices the production of the problem sound while the clinician provides immediate feedback and cues concerning the correct placement of the tongue and mouth for improved articulation. Children who have errors in articulation because of an abnormal swallowing resulting in tongue thrust and lisps are treated with exercises that improve swallowing patterns and, in turn, improve speech. Speech therapy is typically provided by a speech-language pathologist, yet parents can be taught to provide adjunctive help by practicing techniques used in the treatment. Early intervention can be helpful because, for many children with mild articulation difficulties, even several months of intervention may be helpful in early elementary school. In general, when a child's articulation and intelligibility is noticeably different than peers by the age of 8 years of age, speech deficits often lead to problems with peers, learning, and self-image, especially when the disorder is so severe that many consonants are misarticulated, and when errors involve omissions and substitutions of phonemes, rather than distortions.
Children with persistent articulation problems are likely to be teased or ostracized by peers and may become isolated and demoralized. Therefore, it is important to give support to children with phonological disorders and, whenever possible, to support prosocial activities and social interactions with peers. Parental counseling and monitoring of child peer relationships and school behavior can help minimize the social impairment with speech and language disorder.
Stuttering is a condition in which the normal flow of speech is disrupted by involuntary speech motor events. Stuttering can include a variety of specific disruptions of fluency, including sound or syllable repetitions, sound prolongations, dysrhythmic phonations, and complete blocking or unusual pauses between sounds and syllables of words. In severe cases, the stuttering may be accompanied by accessory or secondary attempts to compensate such as respiratory, abnormal voice phonations, or tongue clicks. Associated behaviors, such as eye blinks, facial grimacing, head jerks, and abnormal body movements, may be observed before or during the disrupted speech. The disorder usually originates in childhood.
Controversy is found among speech and language experts as to whether stuttering should be considered an independent entity or part of a broader speech and language disorder. Some question whether stuttering should be considered a psychiatric condition at all. Many children who stutter do endure significant psychological distress, and stuttering does cause impairment in everyday life for many children with this condition.
Surveys conducted mainly in the United States and Europe indicate the prevalence of stuttering is about 1 percent in the general population. Stuttering tends to be most common in young children and has often resolved spontaneously by the time the child is older. The typical age of onset is 2 to 7 years of age with a peak at age 5 years. Estimates are that up to 3 to 4 percent of individuals may have stuttered at some time in their lives. Approximately 80 percent of young children who stutter are likely to have a spontaneous remission over time. According to DSM-IV-TR, it dips to 0.8 percent by adolescence. Stuttering affects about three to four males for every female. The disorder is significantly more common among family members of affected children than in the general population. According to DSM-IV-TR, for male persons who stutter, 20 percent of their male children and 10 percent of their female children will also stutter.
Converging evidence indicates that cause of stuttering is multifactorial, including genetic, neurophysiological, and psychological factors that predispose a child to have poor speech fluency. Although research evidence does not indicate that anxiety or conflicts cause stuttering or that persons who stutter have more psychiatric disturbances than those with other forms of speech and language disorders, stuttering can be exacerbated by certain stressful situations.
Other theories about the cause of stuttering include organic models and learning models. Organic models include those that focus on incomplete lateralization or abnormal cerebral dominance. Several studies using EEG found that stuttering males had right-hemispheric alpha suppression across stimulus words and tasks; nonstutterers had left-hemispheric suppression. Some studies of stutterers have noted an overrepresentation of left-handedness and ambidexterity. Twin studies and striking gender differences in stuttering indicate that stuttering has some genetic basis.
Learning theories about the cause of stuttering include the semantogenic theory, in which stuttering is basically a learned response to normative early childhood dysfluencies. Another learning model focuses on classic conditioning, in which the stuttering becomes conditioned to environmental factors. In the cybernetic model, speech is viewed as a process that depends on appropriate feedback for regulation; stuttering is hypothesized to occur because of a breakdown in the feedback loop. The observations that stuttering is reduced by white noise and that delayed auditory feedback produces stuttering in normal speakers lend support to the feedback theory.
The motor functioning of some children who stutter appears to be delayed or slightly abnormal. The observation of difficulties in speech planning exhibited by some children who stutter suggests that higher-level cognitive dysfunction may contribute to stuttering. Although children who stutter do not routinely exhibit other speech and language disorders, family members of these children often exhibit an increased incidence of a variety of speech and language disorders. Stuttering is most likely to be caused by a set of interacting variables that include both genetic and environmental factors.
Organic models focus on incomplete lateralization or abnormal cerebral dominance. Such studies suggest that the right and left hemispheres play distinct opposing roles in the generation of stuttering symptoms: activation of regions in the left hemisphere appears to be related to the production of stuttered speech, while activation of regions in the right hemisphere may represent a compensatory process associated with the attenuation of stuttering symptoms.
The existing data suggest that there is a genetic component to developmental stuttering and that spontaneous recovery and chronicity are influenced by genetic factors. Family, twin and segregation studies all have indicated that stuttering has a large genetic component to its cause. An interaction between genetic and environmental factors is probably involved. Tourette's disorder, attention-deficit hyperactivity disorder, DS, oppositional defiant and conduct disorder, and other behaviours associated with Tourette's disorder appear to be polygenic due in part to 3 dopaminergic genes (dopamine D2 receptor, dopamine β-hydoxylase and dopamine transporter).17 A Mendelian mode of genetic transmission has not been found in DS. As for adult male stutters 9% of their daughters and 22% of their sons will stutter; for adult female stutters the risks are 17% and 36% respectively.
Developmental stuttering is increasingly considered to be a speech disorder resulting from a central neuromotor dysfunction that disorganizes the exact timing needed to generate fluent speech. This has led to increased interest in using drug therapy for PDS refractory to speech therapy. Early controlled trials of haloperidol8 showed that the drug was effective in treating DS, particularly the secondary behaviours, but most patients discontinued treatment because of side effects. Haloperidol, which is a fairly specific D2 receptor antagonist, is also effective in treating motor tics and Tourette's disorder. These conditions, like DS, begin in childhood, are more common in boys than in girls, have a fluctuating course and worsen under stress. In addition, some of the secondary behaviours seen in DS are reminiscent of tics. These clinical observations and single-administration experiments with haloperidol led to the hypothesis that D2 receptor antagonists may be important in the treatment of DS.
Positron emission tomography (PET) studies using 6-fluorodopa (6-FDOPA) as a marker of presynaptic dopaminergic activity showed significantly higher 6-FDOPA uptake in patients with moderate to severe DS than in nonstuttering control subjects in the medial prefrontal cortex, deep orbital cortex, insular cortex, extended amygdala, auditory cortex and caudate tail. Elevated 6-FDOPA uptake in ventral limbic cortical and subcortical regions is compatible with the hypothesis that stuttering is associated with an overactive presynaptic dopamine system in regions of the brain that modulate verbalization.
The development of the new (atypical) neuroleptic medications has resurrected interest in using D2 receptor antagonists to treat DS. The atypical neuroleptics differ from the typical ones in their profile of interaction with receptors. Human PET studies have shown that the serotonin type 2 (5-HT2) receptor occupancy by atypical neuroleptics exceeds the D2 receptor occupancy, and this correlates clinically with a low incidence of extrapyramidal side effects. Risperidone, an atypical neuroleptic with a high D2 receptor occupancy and a high 5-HT2 occupancy20 has been tried in patients with Tourette's disorder21 and chronic tics22 with encouraging results.
A role for serotonin systems in DS has also been proposed.23 Serotonin-specific reuptake inhibitors (SSRIs) such as fluoxetine and clomipramine are known to be effective in the treatment of obsessive-compulsive symptoms. Patients with DS seem to display obsessive-compulsive symptoms at a rate similar to that seen in Tourette's disorder.24 A double-blind, placebo-controlled study of fluoxetine in Tourette's disorder showed a statistically significant reduction in obsessive-compulsive symptoms but no effect on tics.25 The fact that SSRIs occasionally cause akathisia and parkinsonism[26, 27] seems to indicate a certain effect of serotonin on dopamine metabolism. Both neuroleptics and SSRIs can cause nonstuttering people with presumably normal dopaminergic function to stutter, while they can decrease dysfluency in known stutterers.12 The effects of SSRIs on brain dopamine systems are probably more limited when compared with those of neuroleptic medications.
Thus, the hypothesis that antidopaminergic drugs may be effective in the treatment of DS seems to be supported by the similarity of tic-like symptoms seen in DS with the tics seen in Tourette's disorder, past treatment experience with haloperidol in the latter and in DS, recent studies with atypical neuroleptics in Tourette's disorder and neuroimaging studies of presynaptic dopaminergic activity in people with DS. The data supporting a role for serotonin systems in DS are more restricted.
Signs and Symptoms
DSM-IV-TR Diagnostic Criteria for Stuttering
Disturbance in the normal fluency and time patterning of speech (inappropriate for the individual's age), characterized by frequent occurrences of one or more of the following:
sound and syllable repetitions
broken words (e.g., pauses within a word)
audible or silent blocking (filled or unfilled pauses in speech)
circumlocutions (word substitutions to avoid problematic words)
words produced with an excess of physical tension
monosyllabic whole-word repetitions (e.g., -I-I-I see him)
The disturbance in fluency interferes with academic or occupational achievement or with social communication.
If a speech-motor or sensory deficit is present, the speech difficulties are in excess of those usually associated with these problems.
Stuttering usually appears between the ages of 18 months and 9 years, with two sharp peaks of onset between the ages of 2 to 3.5 years and 5 to 7 years. Some, but not all, stutterers have other speech and language problems, such as phonological disorder and expressive language disorder. Stuttering does not begin suddenly; it typically develops over weeks or months with a repetition of initial consonants, whole words that are usually the first words of a phrase, or long words. As the disorder progresses, the repetitions become more frequent, with consistent stuttering on the most important words or phrases. Even after it develops, stuttering may be absent during oral readings, singing, and talking to pets or inanimate objects.
Four gradually evolving phases in the development of stuttering have been identified:
Phase 1 occurs during the preschool period. Initially, the difficulty tends to be episodic and appears for weeks or months between long interludes of normal speech. A high percentage of recovery from these periods of stuttering occurs. During this phase, children stutter most often when excited or upset, when they seem to have a great deal to say, and under other conditions of communicative pressure.
Phase 2 usually occurs in the elementary school years. The disorder is chronic, with few if any intervals of normal speech. Affected children become aware of their speech difficulties and regard themselves as stutterers. In phase 2, the stuttering occurs mainly with the major parts of speech nouns, verbs, adjectives, and adverbs.
Phase 3 usually appears after the age of 8 years and up to adulthood, most often in late childhood and early adolescence. During phase 3, stuttering comes and goes largely in response to specific situations, such as reciting in class, speaking to strangers, making purchases in stores, and using the telephone. Some words and sounds are regarded as more difficult than others.
Phase 4 typically appears in late adolescence and adulthood.
Stutterers show a vivid, fearful anticipation of stuttering. They fear words, sounds, and situations. Word substitutions and circumlocutions are common. Stutterers avoid situations requiring speech and show other evidence of fear and embarrassment.
Stutterers may have associated clinical features: vivid, fearful anticipation of stuttering, with avoidance of particular words, sounds, or situations in which stuttering is anticipated; and eye blinks, tics, and tremors of the lips or jaw. Frustration, anxiety, and depression are common among those with chronic stuttering.
Course and Prognosis
The course of stuttering is usually long term, with some periods of partial remission lasting for weeks or months and exacerbations occurring most frequently when a stutterer is under pressure to communicate. Of all children who stutter, mostly those with mild cases, 50 to 80 percent recover spontaneously. School-age children who stutter chronically may have impaired peer relationships as a result of testing and social ostracism. The children may face academic difficulties if they avoid speaking in class. Later major complications include an affected person's limitations in occupational choice and advancement.
Two distinct forms of intervention have been used in the treatment of stuttering. Direct speech therapy typically targets modification of the stuttering response to fluent-sounding speech by systematic steps and rules of speech mechanics that the person can practice. Another form of therapy for stuttering targets diminishing tension and anxiety during speech. These treatments utilize breathing exercises and relaxation techniques, to help children slow the rate of speaking and modulate speech volume. Until the end of the 19th century, the most common treatments for stuttering were distraction, suggestion, and relaxation. Recent approaches using distraction include teaching stutterers to talk in time to rhythmic movements of the arm, hand, or fingers. Stutterers are also advised to speak slowly in a sing-song or monotone manner. These approaches, however, remove stuttering only temporarily. Suggestion techniques, such as hypnosis, also stop stuttering but, again, only temporarily. Relaxation techniques are based on the premise that it is nearly impossible to be relaxed and stutter in the usual manner at the same time. Current interventions for stuttering use individualized combinations of behavioral distraction, relaxation techniques, and directed speech modification.
Stutterers who have poor self-image, comorbid anxiety disorders or depressive disorders are likely to require additional treatments. Most modern treatments of stuttering include components that target stuttering as, in part, a learned behavior that can be modified through behavioral techniques regardless of the complexity of how they emerged. These approaches work directly with the speech difficulty to minimize stuttering responses, to modify or decrease the severity of stuttering by eliminating the secondary symptoms, and to encourage stutterers to speak, even when stuttering, in a relatively easy and effortless fashion that aims to eliminate fear and blocks.
One example of this approach is the self-therapy proposed by the Speech Foundation of America. Self-therapy is based on the premise that stuttering is not a symptom, but a behavior that can be modified. Stutterers are told that they can learn to control their difficulty partly by modifying their feelings about stuttering and attitudes toward it and partly by modifying the deviant behaviors associated with their stuttering blocks. The approach includes desensitizing; reducing the emotional reaction to, and fears of, stuttering; and substituting positive action to control the moment of stuttering.
Recently developed therapies focus on restructuring fluency. The entire speech production pattern is reshaped, with emphasis on a variety of target behaviors, including rate reduction, easy or gentle onset of voicing, and smooth transitions between sounds, syllables, and words. The approaches have met with substantial success in establishing perceptually fluent speech in adults, but fluency maintenance over long periods and relapses remain problems for all involved in adult-stuttering treatment.
Communication Disorder not Otherwise Specified
Disorders that do not meet the diagnostic criteria for any specific communication disorder fall into the category of communication disorder not otherwise specified. An example is voice disorder, in which the patient has an abnormality in pitch, loudness, quality, tone, or resonance. To be coded as a disorder, the voice abnormality must be sufficiently severe to impair academic achievement or social communication (Table 41-8). Operationally, speech production can be broken down into five interacting subsystems, including respiration (airflow from the lungs), phonation (sound generation in the larynx), resonance (shaping of the sound quality in the pharynx and nasal cavity), articulation (modulation of the sound stream into consonant and vowel sounds with the tongue, jaw, and lips), and suprasegmentalia (speech rhythm, loudness, and intonation). Altogether, these systems work together to convey information and, as importantly, voice quality conveys information about the speaker's emotional, psychological, and physical status. Thus, voice abnormalities can cover a broad area of communication as well as indicate many different types of abnormalities.
Cluttering is not listed as a disorder in DSM-IV-TR, but it is an associated speech abnormality in which the disturbed rate and rhythm of speech impair intelligibility. Speech is erratic and dysrhythmic and consists of rapid, jerky spurts that are inconsistent with normal phrasing patterns. The disorder usually occurs in children between 2 and 8 years of age; in two thirds of cases, the patient recovers spontaneously by early adolescence. Cluttering is associated with learning disorders and other communication disorders.
Because the patient and the family had refused a psychiatric evaluation, the exact causes of the postmutational falsetto could not be determined. Research shows, however, that psychopathology is not higher in persons with cleft lip and palate than in the normal population. The postmutational falsetto was probably an independent condition that was mistakenly assumed to be caused by the cleft lip and palate by the patient, as well as by professionals involved with his care.
DSM-IV-TR Diagnostic Criteria for Communication Disorder Not Otherwise Specified
This category is for disorders in communication that do not meet criteria for any specific communication disorder; for example, a voice disorder (i.e., an abnormality of vocal pitch, loudness, quality, tone, or resonance).