What is expressive alalia?

Among the many disorders of speech functions in children there is such a form of language development disorder as expressive alalia (from Greek lalia - speech).

This disorder manifests itself in the fact that children who understand speech have difficulties with active oral expressions and expressions (in Latin - expressio), i.e. In a persistent violation of mastering the system of linguistic units of spoken speech.

Epidemiology

According to epidemiological surveys conducted in North America and Western Europe, 5-7% of preschool children (up to 5-6 years old) have varying degrees of speech development disorders.

Causes of the expressive alalia

In the course of many years of interdisciplinary research and in the process of streamlining the terminology used in the field of pediatric speech disorders, international experts have concluded that motor or expressive alalia can be diagnosed in a child when his or her vocabulary and ability to produce complex sentences and memorize words are below the generally accepted age level, and yet these speech problems are not related to delayed general development, anatomical features of the speech apparatus, autism, or disabilities.

The main causes of this pathology lie in the underdevelopment and/or intrauterine damage to the speech areas (centers) of the brain. That is, in the disorder of the functions of Broca's area or zone, a part of the cerebral cortex that plays a primary role in speech function and the formation of algorithms for using the grammatical and syntactic systems of language. [1]

More details in the publication - Disorder of speech and language development in a child

Risk factors

In identifying the most likely risk factors for expressive alalia, experts note the possibility of a combination of factors, including:

• teratogenic effects of chemicals and drugs used during pregnancy on the fetus;
• brain injury and intracerebral hemorrhage during a difficult or complicated delivery;
• cerebral inflammatory processes of bacterial or viral etiology; [2]
• intrauterine and/or neonatal metabolic disorders;
• of genetic predisposition.

Pathogenesis

Broca's area responsible for speech motor skills includes Brodmann's cytoarchitectonic fields (areas) 44 and 45 (pars opercularis and pars triangularis) in both hemispheres of the brain. In right-handed (dextral) dominant left hemispheres, Broca's area is located in the inferior frontal gyrus (inferior gyri frontalis) of the left hemisphere, just in front of the facial part of the motor cortex (cortex motorius) and just above the sylvian sulcus (sulcus lateralis). [3]

According to experts, motor alalia is more often detected in senestrals, i.e. Left-handed children with a dominant right hemisphere of the brain, while the left hemisphere is responsible for language and speech in right-handed children. And the pathogenesis of abnormalities in the development of speech function in children may be due to an imbalance in the development and disruption of the spatial organization of speech structures in the left and right hemispheres - with lateralization of speech function in the right hemisphere and its increased activity. [4] It is also possible that the conduction of impulses along the neuronal tract (arc-shaped bundle) that connects Broca's area with other brain regions, including Wernicke's area, may be impaired.

Wernicke's area is located next to Broca's area, in the upper part of the posterior temporal lobe (lobus temporalis); it is considered the center of speech perception and understanding. Motor or expressive and impressive alalia (or sensory) is possible, and in the second case it is Wernicke's area that is affected. And when both zones are affected, motor-sensory alalia is detected. [5], [6]

Mechanisms of expressive alalia are also discussed in the articles:

• Expressive speech disorder (general underdevelopment of speech) in children
• Specific disorders of speech articulation (dyslalia) in children

Symptoms of the expressive alalia

Parents should keep in mind: the first signs of delayed speech development in a child are manifested by the absence by two months of humming (and other sounds, except for screaming), which is considered the initial stage of preverbal development of infants.

Common symptoms of expressive alalia include the absence of babbling by 12 months of age and the absence of simple words by 18 months of age.

A speech development disorder should be suspected if:

• By age two, the child is not speaking or using at least 25 words);
• by the age of two and a half years does not pronounce two-word phrases (noun+verb);
• By age three, does not use at least 200 words and is unable to speak in short sentences;
• Has difficulty pronouncing previously learned words as well as putting words together into sentences.

A child with motor alalia, in addition to an insufficient stock of words (compared to other children of the same age), lacks fluency, may have articulation defects, disorders of the syllabic structure of language and agrammatism. In addition, children with this disorder often have signs of psycho-organic syndrome of varying degrees of severity, which are manifested by decreased efficiency in combination with defects in intellectual development, attention deficit disorder, motor disinhibition. [7]

Complications and consequences

Speech development disorders in early childhood can have complications and consequences regarding schooling and everyday social interactions in adulthood. [8]

However, according to the American Academy of Family Physicians, up to 75% of two- to three-year-old children with motor-type alalia have normal speech skills by the time they enter school. [9]

Diagnostics of the expressive alalia

Specialists recognize that diagnosis, that is, formal assessment of expressive alalia has many difficulties.

It is necessary to timely refer to a pediatric neurologist and conduct a study of the neuropsychiatric sphere of the child, as well as a study of cognitive functions.

Instrumental diagnostics may be performed: CT or MRI of the brain, electroencephalography (EEG).

Differential diagnosis

It is necessary to exclude orofacial myofunctional disorders with articulation disorders, bulbar dysarthria in cerebral palsy, receptive speech disorders in autism, psychogenic mutism, mental development disorders, which requires differential diagnosis.

Treatment of the expressive alalia

At the heart of treating a child's language development disorder is working with the child by an experienced speech therapist, and if necessary, a child psychologist or psychiatrist.

And methods of overcoming this disorder are chosen by speech therapists individually, but necessarily aimed at the development of so-called phonemic hearing and perception of words, their syllabic structure, understanding of the lexical and grammatical structure of speech, etc. [10]

Prevention

There are no specific measures to prevent language development disorder, but risk factors for its development can be avoided.

Forecast

The prognosis of expressive alalia depends on the timeliness of diagnosis, the degree of speech impairment and competent speech therapy correction. [11], [12]

Also read:

• How do you teach a child to talk?
• Child's speech development: how to help him?