Expressive Language Disorder

The essential feature of Expressive Language Disorder is an impairment in expressive language development.

Scores on standardized measures of expressive language development must be below those obtained from standardized measures of both non-verbal intellectual capacity and receptive language development for a diagnosis of Expressive Language Disorder.

When standardized instruments are not available or appropriate, the diagnosis may be based on a thorough functional assessment of the individual's language ability.

The difficulties may occur in communication involving both verbal language and sign language. The language difficulties interfere with academic or occupational achievement or with social communication. The symptoms do not meet criteria for Mixed Receptive-Expressive Language Disorder or a Pervasive Developmental Disorder.

If Mental Retardation, a speech-motor or sensory deficit, or environmental deprivation is present, the language difficulties are considered additional impediments to these other factors/conditions.

The linguistic features of the disorder vary depending on its severity and the age of the child. These features include a limited amount of speech, limited range of vocabulary, difficulty acquiring new words, word-finding or vocabulary errors, shortened sentences, simplified grammatical structures, limited varieties of grammatical structures (e.g., verb forms), limited varieties of sentence types (e.g., imperatives, questions), omissions of critical parts of sentences, use of unusual word order, and slow rate of language development. Nonlinguistic functioning (as measured by performance intelligence tests) and language comprehension skills are usually within normal limits.

Origins

Expressive Language Disorder may be either acquired or developmental. In the acquired type, an impairment in expressive language occurs after a period of normal development as a result of a neurological or other general medical condition (e.g., encephalitis, head trauma, irradiation). In the developmental type, there is an impairment in expressive language that is not associated with a postnatal neurological insult of known origin. Children with this type often begin speaking late and progress more slowly than usual through the various stages of expressive language development.

Prevalence

Prevalence estimates vary with age. In children under 3, language delays are quite common, occurring in 10%–15% of children. By school age, prevalence estimates range from 3% to 7%. The developmental type of Expressive Language Disorder is more common than the acquired type.

Course

The developmental type of Expressive Language Disorder is usually recognized by age 3 years, although milder forms of the disorder may not become apparent until early adolescence, when language ordinarily becomes more complex. The acquired type of Expressive Language Disorder due to brain lesions, head trauma, or stroke may occur at any age, and the onset is sudden. The outcome of the developmental type of Expressive Language Disorder is variable. A majority of children with this disorder improve substantially; in a smaller proportion, difficulties persist into adulthood.

Diagnostic criteria summarized from:

American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders, fourth edition. Washington, DC: American Psychiatric Association.