Autism spectrum disorders are characterized by persistent deficits in social interaction and social communication as well as restricted, repetitive and inflexible patterns of behavior and interests.
The disorder manifests during the developmental period, typically already at early childhood, but the symptoms may not become fully manifest until social demands exceed the limited capacity.
The symptoms are so severe that they cause impairment in important areas of life.
An autistic child should be referred for further examinations with the aim of beginning rehabilitation as early as possible to ensure optimal results.
Autism spectrum
Autism, atypical autism, Rett's syndrome, disintegrative disorder, Asperger's syndrome and pervasive developmental disorder not otherwise specified (PDD-NOS) are included in the ICD-10 diagnoses for autism spectrum disorders.
The DSM-5 classification (published in 2013) contains autism spectrum disorder as an umbrella diagnosis, which is coded in more detail using information on developmental disability and language difficulties.
WHO published in 2018 the ICD-11, which no longer uses autism or Asperger syndrome as a diagnosis. Instead, the diagnosis is autism spectrum disorder, further specified in a similar manner as in DSM-5.
Translation and implementation of ICD-11 in different countries may take a long time.
The diagnosis usually becomes more specific during follow-up, particularly in the youngest children.
Epidemiology
The prevalence of the whole autism spectrum has previously been estimated to be about 1%, but in the United States the prevalence is estimated to be as high as 1:54 in boys and 1:252 in girls: i.e. clearly more common among boys.
Background
Autism is biological in origin. There is no known specific causal factor.
In a small proportion of patients, the cause of the brain dysfunction is known (e.g. known chromosomal abnormality, fragile-X syndrome or some other known syndrome, prematurity and related problems).
Heredity plays an important role in the appearance of autism.
In a family with one autistic child, if no reason explaining the autism is found, the risk of autism in any following siblings is increased.
New individual gene mutations explaining the symptoms have been found in the genomes of autistic people. However, these are rare. Mutations often affect the functioning of synapses. So-called copy number variations (CNV) are found in the genome of about 10-20% of people. They may be new or may be inherited from one of the parents. Their significance as an aetiological factor has to be individually assessed. In the background, there may also be a multi-hit model, meaning that several concomitant gene mutations are needed to produce the disease.
Common genetic abnormalities have been found with conditions such as schizophrenia and mental retardation.
Autism
Symptoms
Symptoms of autism vary individually, and the condition prevails throughout life, even if its forms change with age.
The disorder begins at an early age, generally before the age of 3 years.
In about one third of autistic children there is retardation in the development of speech and language around the age of 1.5-2 years (reduced eye contact, words that the child had already learned may be left out of use).
The growth rate of the head circumference is accelerated in about 30% of patients in early preschool age but levels down later.
There is deviance in reciprocal social interaction.
The use of eye contact, facial expressions and gestures is limited.
The child keeps to him- or herself in the company of others.
Shared attention is minimal or lacking (the child does not adjust his/her gaze to follow pointing, e.g. to an object or person).
The child has difficulty putting him-/herself into another person's position.
The child lacks the skill to imitate.
There is underdevelopment in communication and speech.
There is no babbling, gesticulation or spoken language, or the spoken language is deviant (e.g. consisting of mechanically repeated stock phrases).
Interactive dialogue skills are deficient.
The ability to function is significantly limited and objects of interest are narrowly focused.
Stereotypic movements of the body or hands
Persistent interest in parts of objects
Play based on imagination and roles deficient
Significant anxiety triggered by small changes in the environment
Other common symptoms
Fears, sleeping and eating disorders
Fits of rage, aggression or self-destructiveness
The level of intellectual ability varies. Approximately half of autistic children have intellectual disability. The level of linguistic ability is usually clearly lower than that of non-linguistic abilities.
Diagnosis
Diagnosis is based on typical abnormalities in behaviour.
A careful clinical examination including structured observation (such as the Autism Diagnostic Observation Schedule, ADOS), interviews and assessments (multidisciplinary cooperation) is important for diagnosis.
In autism spectrum disorders, associated/parallel diagnoses are common in practice. These include, for example, attention deficit disorder (ADD/ADHD), various degrees of learning difficulties, epilepsy and psychiatric disorders. Simultaneous diagnosis of ADHD and autism spectrum disorder has become more common. Associated diagnoses are essential considering e.g. the possibilities of pharmacotherapy.
Every autistic child needs an individual rehabilitation programme; such programmes are most successful if the families, day-care personnel and therapists collaborate.
Purposeful and effective rehabilitation can benefit the child's development as well as the quality of life of both the child and his/her family.
Autistic children often need a personal assistant during day care and at school in order to make intensive rehabilitation and education possible.
Rehabilitation may also include individual or group therapy (e.g. speech/communication therapy, occupational therapy or music therapy; in the therapy, cooperation with the persons close to the child is essential to make it possible to use the acquired skills in different situations and environments)Social Skills Groups for Autism Spectrum Disorders (ASD).
It is essential for the family to commit itself to rehabilitation.
Having an autistic child in the family consumes a lot of the family's resources because the child needs constant guidance and supervision. It is important to support the family members in their coping. Peer support and parent guidance/training benefit both parents and autistic children.
Medication may sometimes be necessary.
There is quite a lot of research data available on the use of risperidoneRisperidone for Autism Spectrum Disorder in the treatment of autism spectrum disorders. Medication can be used to treat severe restlessness, irritability and aggressive behaviour, for example.
For example stimulants can be tried for ADHD symptoms, although adverse effects are more common than in non-autistic people.
Melatonin is often used for problems with falling asleep, most commonly at a dosage of 1.5-3 mg whenever necessary.
Other autism spectrum disorders
As the classification of diseases changes, these diagnoses are included in the diagnosis autism spectrum disorder, with the exception of Rett's syndrome which is its own clinical syndrome. The genetic abnormality behind it has already been known for a long time.
Asperger's syndrome
Became known as a separate diagnosis in the 1990s. The criteria are largely the same as for autism.
Distinctly more common in boys than in girls (4-5:1) and may be more difficult to recognize in girls.
The clearest difference compared to autism is that intellectual and linguistic development usually progress normally even if the child has difficulties in social interaction.
Problems with social interaction usually culminate in groups of children of the same age. The child's own view dominates, and he/she does not wish or know how to act with children of his/her age, or does so only on his/her own conditions.
Natural use of eye contact is often difficult.
In communication, the child may use few facial expressions or gestures. Use of standard language or original expressions is common. "Reading between the lines" is difficult.
Mannerisms, such as waving one's hands, particularly when excited, are common.
Objects of special interest are often very intensive and/or narrowly focused. In girls, objects of interest may be "more ordinary", yet intensive.
The ability profile of many patients is irregular. The patient may be good at memorizing, but difficulties in more extensive understanding and productive expression of his/her thoughts may complicate school work, as do the challenges associated with social interaction.
Early recognition of problems is important to prevent accumulation of problems in managing the difficulties of everyday life or social problems and to support independence and later work placement by suitable guidance and rehabilitation.
PDD-NOS, pervasive developmental disorder, not otherwise specified, is a diagnosis often used when the criteria for diseases such as autism are not all fulfilled. Yet the symptoms may be difficult and the need for rehabilitation the same as in patients with autism.
Disintegrative disorder (Heller's disease)
Rare
An extensive developmental disorder, in which a child whose development up to about the age of 3-5 years has been normal or almost normal rapidly becomes retarded, loses nearly all communication skills and shows symptoms that resemble autism, often also restlessness.
Progressive brain diseases and epileptic syndromes must be excluded.
Rett's syndrome
A syndrome with severe symptoms occurring in girls. Caused by a mutation of the MeCP2 gene on the X chromosome. The mutation is found in more than 90% of the patients.
On symptom debut (at the age of about 12 to 18 months) autistic features and irritability may be central. The growth rate of the head circumference is usually retarded early, and the patient may be slow to learn to walk.
Other symptoms typical for the syndrome, such as unsteady motion, retardation of appropriate use of hands, intensive hand mannerisms, breathing symptoms and epilepsy appear later.
References
Autism and Developmental Disabilities Monitoring Network Surveillance Year 2008 Principal Investigators., Centers for Disease Control and Prevention.. Prevalence of autism spectrum disorders--Autism and Developmental Disabilities Monitoring Network, 14 sites, United States, 2008. MMWR Surveill Summ 2012;61(3):1-19. [PubMed]
de la Torre-Ubieta L, Won H, Stein JL et al. Advancing the understanding of autism disease mechanisms through genetics. Nat Med 2016;22(4):345-61. [PubMed]