Autism is a condition that manifests in early childhood and is
characterized by qualitative abnormalities in social interactions,
markedly aberrant communication skills, and restricted repetitive and
stereotyped behaviors.
Most individuals with autism also manifest
mental retardation, typically moderate mental retardation with
intelligence quotients (IQs) of approximately 35-50. Although children
with autism are often difficult to evaluate with intelligence tests,
three fourths of autistic children function in the mentally retarded
range.
Generally, the lower the IQ, the greater the likelihood of
autism. However, the low functioning level hinders assessment for key
characteristics of autism in individuals with profound mental
retardation and IQs below approximately 20. A small portion of those
with autism never develop spoken language. Thus, diagnostic instruments
for autism may give spurious results in children with profound mental
retardation.
This article addresses autism in individuals with
mental retardation. For information concerning individuals with autism
spectrum disorders and related conditions without mental retardation,
please see
Asperger Syndrome and
Pervasive Developmental Disorder.
Seizure
disorders are common in individuals with autism. Movement abnormalities
are a prominent feature in a subset of individuals. Motion anomalies
have been reported at birth in some individuals. Motion analysis may
provide evidence of autism in early infancy before other manifestations
occur.
[1] Although
autistic disorder was initially reported in children of high social
class, subsequent research has established that autistic disorder
equally afflicts all social classes.
The motion anomalies
demonstrated by children with autism are often highly characteristic.
Children with autism who exhibit motion anomalies often stand out as odd
because of the motions. An example of a motion typical in autism occurs
when the child places a hand with fingers separately outstretched
before the eyes and rapidly moves the hand back and forth. A similar
experience results from moving up and down while gazing through the
slats of Venetian blinds. This action is described as self-stimulation
because it produces a visual sensation of movement.
Many of the
motions of children with autism appear to be attempts to provide sensory
input to themselves in a barren environment. Through special education,
children may learn to suppress the movements. The movements may then be
exhibited at times of particular stress or excitement.
Although
the etiology is unknown, hypotheses include genetic abnormalities;
obstetric complications; exposure to toxic agents; and prenatal,
perinatal, and postnatal infections (see Etiology).
[2, 3, 4, 5] Maternal rubella is associated with significantly higher rates of autism and other conditions in children. Additionally,
tuberous sclerosis is associated with autism as a comorbid disorder.
[6] Approximately 10% of children with a pervasive developmental disorder exhibit a known medical condition.
On the other hand, anecdotal reports that autism may be linked with vaccinations for
measles,
mumps, and
rubella have not been confirmed.
[7] Parents should be encouraged to fully immunize their children.
[8]
Effective
treatment of associated behavioral problems includes intensive
behavioral, educational, and psychological components. Interventions
initiated at the time of diagnosis increase the likelihood of a
favorable outcome (see Treatment).
[9] Regular
screening of infants and toddlers for symptoms and signs of autistic
disorder is crucial because it allows for early referral of patients for
further evaluation and treatment.
The initial clinical
descriptions of autism suggested that cold, rejecting parents
("refrigerator mothers") caused autism in offspring; however, careful
study of children with autism and their parents has disproved this
hypothesis. Autism is not caused by a lack of warmth and affection in
parents, nor to any other emotional or psychological deficits in the
parents. Blaming parents for the development of autism in their children
is inappropriate.
Several instruments have been developed to
diagnose autism and other pervasive developmental disorders. To
administer tools for the diagnosis of autism and related conditions in a
reliable and valid manner, extensive training and experience is needed.
Therefore, unless they have wide experience with children with autism
and understand the concepts implicit in the diagnostic criteria and
rating scales, pediatricians and other clinicians are advised to refer
patients with possible autism to experienced clinicians for definitive
diagnostic evaluations.
One goal of this article is to convey
fundamental concepts related to autism and related conditions. Readers
of this article must obtain considerable additional training before they
can reliably and validly apply diagnostic criteria and rating tools.
Although
psychoanalytic approaches to treatment of children with autism were
common in the mid-20th century, these approaches were not found to be
effective and are no longer used. Pharmacotherapy is ineffective in
treating the core deficits of autism but may be effective in treating
associated behavioral problems and comorbid disorders. The possible
benefits from pharmacotherapy must be balanced against the likely
adverse effects on a case-by-case basis.
Resource link : http://emedicine.medscape.com/article/912781-overview
