Autism also called “autism spectrum disorders”, pervasive developmental disorders are a group of various diseases, the most common of which is autism. Although expressed in various ways, they manifest themselves in three main elements: impaired social interactions, impaired verbal and non-verbal communication, and the presence of stereotypical and repetitive behaviors.
Their medical care is based on so-called intervention measures that aim to improve the capacities and autonomy of children and adults with these disorders.
Autism spectrum disorders occur during a child’s development and interfere with their ability to communicate with others. These disorders are also called “pervasive developmental disorders” or “PDD”.
There is an official definition which attempts to summarize all the forms observed because the symptoms of these disorders are very variable from one child to another:
“Pervasive developmental disorders are a group of disorders characterized by a low quality of reciprocal social interactions and modalities of communication, as well as a restricted, stereotypical and repetitive repertoire of interests and activities. These anomalies constitute an invasive characteristic of the subject’s functioning, in all situations”.
This definition highlights several traits common to all forms of autism spectrum disorders:
* The difficulty for people with Alzheimer’s in exchanging and bonding with other people;
* Their tendency to prefer a few particular activities and to repeat them excessively;
* The fact that these disorders are present permanently and prevent the child from developing harmoniously.
Childhood autism (often simply called “autism”) is the most common form of pervasive developmental disorder. His symptoms appear before the age of three and are present all the time. The child tends to isolate himself and to withdraw into himself, his gaze is elusive and he presents marked difficulties in establishing relationships with those around him.
In addition, language acquisition is delayed or even absent, and he finds it difficult to fix his attention in a lasting manner.
Children with autism tend to develop repetitive behaviors (eg, twisting of hands, body movements) and to comply with inflexible rituals. In the majority of cases, mental retardation exists, of varying severity depending on the child.
Childhood disintegrative disorder strongly resembles childhood autism. Very rare, it occurs in children aged three to ten years in whom development has been normal until then. It results in a regression of the child’s achievements in the areas of motor skills (movements), language and social behavior. The child restricts himself to limited activities, isolates himself, becomes hyperactive and ceases to be clean.
To better describe autism spectrum disorders, specialists distinguish between different forms depending on the age at which they appear, their symptoms and the existence of a known genetic cause:
* Childhood autism;
* Asperger’s syndrome;
* Rett syndrome;
* Childhood disintegrative disorder;
* Atypical autism and other pervasive developmental disorders.
The first two forms are the most common and the most characteristic of the disorders usually observed. They can be expressed with varying degrees of severity and their symptoms vary widely from person to person.
ARE AUTISTIC SPECTRUM DISORDERS FREQUENT?
It is estimated that 0.6 to 0.7% of under 20s have pervasive developmental disorders (PDDs) of all forms (0.2% for childhood autism). During the last twenty years, the frequency of pervasive developmental disorders has increased due to the improvement in the detection of these disorders by health professionals and due to the broadening of the diagnostic criteria, in particular for the forms PDD without mental retardation.
Rett syndrome is a genetic disease that mainly affects girls and results in
developmental regression after the first six to eight months of life.
This serious disease is classified as a pervasive developmental disorder but its genetic origin (a mutation in the X chromosome) sets it apart from other autistic disorders. Rather, it is a genetic disease whose symptoms are very similar to those of childhood autism in its severe form.
IS MY CHILD AUTIST?
Parents regularly wonder if the unusual behaviors they observe in their child could be the first signs of a pervasive developmental disorder.
While the spectrum of autistic disorders is broad, three elements should attract attention, especially if they are added to each other: disturbances in social interactions, impairments in verbal and non-verbal communication, and the presence of stereotypical and repetitive behaviors.
Examples of social interaction disorders in PDDs Lack of smile or late smile in response to a smile. Apparent indifference to people. Impassibility in the presence of others. Excessive reaction or indifference to sounds (the child may appear to be deaf). Lack of reaction to the call of his first name. The child does not reach out in anticipation of being carried. Refusal to be comforted, refusal to embrace. Solitary activities
Examples of verbal and non-verbal communication disorders in PDDs Absence or delay of language (or stopping after the start of language acquisition). Inability to communicate, either by speech, by gesture, or by facial expressions. Very limited understanding of language. Difficulty imitating facial expressions or certain gestures, such as pointing, clapping, or greeting. Lack of response to other people’s attempts to communicate. Anomalies in the form or content of language: tendency to repeat what he hears; repetitions of sentences, immediate or delayed. Present but limited utilitarian language (demand for object, food, attention, etc.) and poor use of language for age-appropriate social interactions. Lack of proper intonation of the voice. Difficulty using personal pronouns appropriately (“you” is used instead of “I”)
Examples of stereotypical and repetitive behavior in PDDs Special handling of objects (spinning or aligning them). Excessive attachment to unusual objects. Unusual movements of the body (swaying, rapid flapping of the hands in butterfly wings). Abnormal reactions to objects (staring at an object or light for long periods of time). Intolerance of changing elements of the environment, even insignificant ones, manifested in tears or anger. Insistence on strictly pursuing routine acts.
THE CAUSES OF AUTISM AND OTHER PDDs
Today, pervasive developmental disorders (PDDs) are considered to be primarily due to genetic abnormalities that are thought to change the way the brain is organized during infancy. These mutations would interfere with the establishment of connections between brain cells (neurons). Certain genetic abnormalities have also been found in children with PDD.
Other factors probably play a role: in 10 to 30% of cases, a true twin of a child with PDD does not have this disorder despite having identical genes in both children. However, compared to that of genes, the role of these other factors seems limited.
Other genetic diseases linked to mutations in a single gene are expressed by various disorders including PDD. The most common are Fragile X syndrome and Bourneville tuberous sclerosis.
Some previously suspected risk factors have been denied by studies. Among these factors that do NOT increase the risk of developing PDD:
* Gluten intolerance (celiac disease);
* The psychological characteristics of the parents;
* Vaccination with the MMR vaccine (measles-mumps-rubella);
* The presence of mercury salts in the environment;
* The nature of the links between mother and child.
SCHOOLING OF CHILDREN WITH PDD
For some children with PDD, especially many with Asperger’s syndrome, schooling can take place in the classroom, from kindergarten through high school, sometimes all the way to college.
For others, for example those with severe autism, it is often more suitable to offer an environment specifically adapted to their needs in a medico-social (medico-educational institute) or health (day hospital) establishment, and to organize their education within the framework of the teaching unit of this establishment.
Finally, for many children with PDD, it is possible to go to school:
* Or in a regular class with support from a school assistant.
* Or within a collective education system specifically designed to meet the particular needs of students with PDDs (reduced number of five or six students on average, with significant supervision).
THE EVOLUTION OF AUTISM
Communication and language may improve throughout the life of people with childhood autism, especially non-verbal communication which frequently improves as they move from adolescence to adulthood (in about one person in two). Regarding language, if the child with childhood autism has not developed functional language by the age of five, the likelihood of acquiring it becomes lower and lower with age. About 10% of adults with childhood autism have not developed language.
Disorders in social interactions are the symptom of autistic disorders that most frequently persists throughout life. About 50% of people with childhood autism have severe social interaction problems in adulthood. Expression of emotions improves more in people with childhood autism without mental retardation than in those with mental retardation.
As they move from adolescence to adulthood, a reduction in stereotypical behavior is seen in about one in two people with autism. In 20 to 35% of people, adolescence is accompanied by worsening of the disorder. About one in five people with this form of PDD have severe behavioral problems as adults.