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What is Autism?
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Revising Medical
Author: Roxanne Dryden-Edwards,
MD
Revising Medical Editor: William
C. Shiel, Jr., MD, FACP, FACR
Autism is a developmental
disorder that is characterized
by impaired development in
communication, social
interaction, and behavior.
Autism is classified as a
Pervasive Developmental Disorder
(PDD), which is part of a broad
spectrum of developmental
disorders affecting young
children and adults––the
Autistic Spectrum Disorders (ASD).
The range of these disorders
varies from severely impaired
individuals with autism to other
individuals who have
abnormalities of social
interaction but normal
intelligence––Asperger's
syndrome. The ways in which
autism is exhibited can differ
greatly. Additionally, autism
can be found in association with
other disorders such as mental
retardation and certain medical
conditions. The degree of autism
can range from mild to severe.
Mildly affected individuals may
appear very close to normal.
Severely afflicted individuals
may have an extreme intellectual
disability and unable to
function in almost any setting.
In the past, autism has been
confused with childhood
schizophrenia or childhood
psychosis, and may have been
misunderstood as schizotypal
personality disorder in some
adults. As additional research
information about autism becomes
available, the scope and
definition of the condition
continues to become more
refined. Much of the past
confusion about the disorder has
been resolved. |
Symptoms of
Autism
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The current Diagnosis and
Statistical Manual of Mental
Disorders–Fourth Edition,
Treatment Revision (DSM–IV–TR)
identifies three features that
are associated with autism:
impairment in social
interaction,
communication, and
behavior.
Impairment in social
interaction
First, patients with autism
fail to develop normal personal
interactions in virtually every
setting. This means that
affected persons fail to form
the normal social contacts that
are such an important part of
human development. This
impairment may be so severe that
it even affects the bonding
between a mother and an infant.
It is important to note that,
contrary to popular belief,
many, if not most, autistic
persons are capable of showing
affection and do demonstrate
affection and do bond with their
mothers or other caregivers.
However, the ways in which
autistic individuals demonstrate
affection and bonding may differ
greatly from the ways in which
others do so. Their limited
socialization may erroneously
lead parents and pediatricians
away from considering the
diagnosis of autism. As the
child develops, interaction with
others continues to be abnormal.
Affected behaviors can include
eye contact, facial expressions,
and body postures. There is
usually an inability to develop
normal peer and sibling
relationships and the child
often seems isolated. There may
be little or no joy or interest
in normal age–appropriate
activities. Affected children or
adults do not seek out peers for
play or other social
interactions. In severe cases,
they may not even be aware of
the presence of other
individuals. |
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Communication
Communication is usually
severely impaired in autistic
persons. What the individual
understands (receptive language)
as well as what is actually
spoken by the individual
(expressive language) is
significantly delayed or
nonexistent. Deficits in
language comprehension include
the inability to understand
simple directions, questions, or
commands. There may be an
absence of dramatic or pretend
play and these children may not
be able to engage in simple
age–appropriate childhood games
such as Simon Says or
Hide–and–Go–Seek. Adults may
continue to engage in playing
with games that are for young
children.
Autistic individuals who do
speak may be unable to initiate
or participate in a two–way
conversation (reciprocal).
Frequently the way in which an
autistic person speaks is
perceived as unusual. Their
speech may seem to lack the
normal emotion and sound flat or
monotonous. The sentences are
often very immature: "want
water" instead of "I want some
water please." Those with autism
often repeat words or phrases
that are spoken to them. For
example, you might say "look at
the airplane!" and the child or
adult may respond "at airplane,"
without any knowledge of what
was said. This repetition is
known as echolalia. Memorization
and recitation of songs,
stories, commercials, or even
entire scripts is not uncommon.
While many feel this is a sign
of intelligence, the autistic
person usually does not appear
to understand any of the content
in his or her speech. For more,
please read the Autism and
Communication article.
Autistic persons often
exhibit a variety of repetitive,
abnormal behaviors. There may
also be a hypersensitivity to
sensory input through vision,
hearing, or touch (tactile). As
a result, there may be an
extreme intolerance to loud
noises or crowds, visual
stimulation, or things that are
felt. Birthday parties and other
celebrations can be disastrous
for some of these individuals.
Tags on clothing may be
perceived as painful. Sticky
fingers, playing with modeling
clay, eating birthday cake or
other foods, or walking barefoot
across the grass can be
unbearable. On the other hand,
there may be an underdeveloped
(hyposensitivity) response to
the same type of stimulation.
This individual may use abnormal
means to experience visual,
auditory, or tactile (touch)
input. This person may head
bang, scratch until blood is
drawn, scream instead of
speaking in a normal tone, or
bring everything into close
visual range. He or she might
also touch an object, image or
other people thoroughly just to
experience the sensory input.
Autistic children and adults
are often tied to routine and
many everyday tasks may be
ritualistic. Something as simple
as a bath may only be
accomplished after the precise
amount of water is in the tub,
the temperature is exact, the
same soap is in its assigned
spot and even the same towel is
in the same place. Any break in
the routine can provoke a severe
reaction in the individual and
place a tremendous strain on the
adult trying to work with them.
There may also be
non–purposeful repetition of
actions or behaviors. Persistent
rocking, teeth grinding, hair or
finger twirling, hand flapping
and walking on tiptoe are not
uncommon. Frequently, there is a
preoccupation with a very
limited interest or a specific
plaything. A child or adult may
continually play with only one
type of toy. The child may line
up all the dolls or cars and the
adult line up their clothes or
toiletries, for example, and
repeatedly and systematically
perform the same action on each
one. Any attempt to disrupt the
person may result in extreme
reactions on the part of the
autistic individual, including
tantrums or direct physical
attack. Objects that spin, open
and close, or perform some other
action can hold an extreme
fascination. If left alone, an
autistic person may sit for
hours turning off and on a light
switch, twirling a spinning toy,
or stacking nesting objects.
Some individuals can also have
an inappropriate bonding to
specific objects and become
hysterical without that piece of
string, paper clip, or wad of
paper. |
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Causes of Autism
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Since autism was first added
to the psychiatric
literature fifty years ago,
there have been numerous
studies and theories about
its cause. Researchers still
have not reached agreement
regarding its specific
causes. First, it must be
recognized that autism is a
set of a wide variety of
symptoms and may have many
causes. This concept is not
unusual in medicine. For
instance, the set of
symptoms that we perceive of
as a "cold" can be caused by
literally hundreds of
different viruses, bacteria,
and even our own immune
system. Autism is,
undoubtedly, a
biologically–based disorder.
In the past, some
researchers had suggested
that autism was the result
of poor attachment skills on
the part of the mother. This
belief has caused a great
deal of unnecessary pain and
guilt on the part of the
parents of autistic
children, when in fact, the
inability of the individual
with autism to interact
appropriately is one of the
key symptoms of this
developmental disorder.
In
support of a biological
theory of autism, several
known neurological disorders
are associated with autistic
features. Autism is one of
the symptoms of these
disorders. These conditions
include tuberous sclerosis
(an inherited disorder), the
fragile X syndrome, cerebral
dysgenesis (abnormal
development of the brain),
Rett syndrome, and some of
the inborn errors of
metabolism (biochemical
defects). Autism, in short,
seems to be the end result
or "final common pathway" of
numerous disorders that
affect brain development. In
general, however, when
clinicians make the
diagnosis of autism, they
are excluding the known
causes of autistic
behaviors. However, as the
knowledge of conditions that
cause autism advances, fewer
and fewer cases will be
thought of as being "pure"
autism and more individuals
will be identified as having
autism due to specific
causes.
There is a strong
association between autism
and seizures. This
association works in two
ways: First, many patients
(20 to 30%) with autism
develop seizures. Second,
patients with seizures,
which are probably due to
other causes, may develop
autistic–like behaviors. One
special and often
misunderstood association
between autism and seizures
is the Landau–Kleffner
Syndrome. This syndrome is
also known as acquired
epileptic aphasia. Some
children with epilepsy
develop a sudden loss of
language skills––especially
receptive language (the
ability to understand). Many
often also develop the
symptoms of autism.
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These children often, but not
always, have a characteristic
pattern of electrical brain
activity seen on EEG
(electroencephalogram) during
deep sleep called electrographic
status epilepticus during sleep
(ESES). The usual age of onset
of language loss or regression
is around four years of age,
which makes the Landau–Kleffner
syndrome distinguishable from
autism on these grounds, in that
autism usually is first
exhibited in younger children.
However, in recent years, some
children (very, very few) who
did not exhibit overt
(observable) seizures were found
to have Landau–Kleffner
syndrome.
The importance of these
findings is that, although rare,
the Landau–Kleffner syndrome can
resolve spontaneously and in
some cases can be treatable with
prednisone, a steroid medication
related to cortisone. This
association between the Landau–Kleffner
syndrome and autism has led many
clinicians and families to
search for the typical EEG
pattern (ESES) in autistic
individuals. This unusual EEG
pattern is seen only in deep
sleep, which usually requires
prolonged recordings of up to 12
hours. Many, many autistic
children and adults will display
some abnormalities on their
sleep EEG, but probably very few
have true Landau–Kleffner
syndrome that will respond to
treatment.
It must also be noted that
prednisone, in the very high
doses used to treat Landau–Kleffner
syndrome, almost invariably
produces side effects, which may
include weight gain, high blood
pressure, diabetes, growth
failure, stomach ulcers,
irritability, destruction of the
hip joint, and susceptibility to
infectious disease (suppressed
immune system). While most of
these side effects are
reversible, some of the
complications of high dose
prednisone therapy can be
irreversible and even fatal.
Other treatments ranging from
common anticonvulsant therapy to
surgery have been proposed and
are being tried for Landau–Kleffner
syndrome. It is difficult to
evaluate the true effects of any
treatment for Landau–Kleffner
syndrome due to the high rate of
spontaneous resolution of
symptoms (remission). |
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Is Autism Genetic?
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Because many different disorders
can result in autism, this
question is complex. Certainly,
disorders such as the fragile X
syndrome and tuberous sclerosis,
which are both associated with
autism, are inherited. There are
many families with more than one
autistic child where the autism
is not clearly due to another
cause. Recent studies have found
that the gene for at least one
kind of familial autism may be
on chromosome 13. In some
families, autism seems to be
passed from generation to
generation. In other families,
autism is not found in prior
generations, but affects
multiple siblings (brothers or
sisters). The results of this
research makes it likely that at
least one "autism gene" will be
found soon.
However, the majority of
individuals with autism do NOT
have a strong family history,
which supports the premise that
environmental or a combination
of environmental and genetic
factors contribute to the
development of autism. In this
context, environmental is meant
to indicate any non–genetic
factor, including infections,
toxins, nutrition, or others.
How is autism diagnosed?
The essential features of autism
are the significantly impaired
or abnormal development of
communication and social
interaction and the abnormally
restricted repertoire of
behaviors, activities, and
interests. This disturbance in
normal development must manifest
itself prior to age three. While
many parents report normal
development in the first year of
the child, there is actually
limited opportunity to observe
this, as the child is usually
not brought to the attention of
a practitioner until several
years later in many cases. If
there is a period of normal
development, it cannot extend
past age three. |
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Any person with a delay or
regression (loss) of language or
an abnormality of social
interaction beginning prior to
the age of three may be
suspected of being autistic. The
medical evaluation begins with a
thorough medical history and
physical examination. This
examination should be performed
by a practitioner not only
familiar with autism, but with
other disorders that may appear
similar to or mimic the symptoms
of autism. The practitioner
should have particular expertise
in the neurological examination
of impaired individuals, as
subtle findings may lead the
examiner down a particular
diagnostic path. For example,
the presence of mild weakness or
increased reflexes on one side
of the body will lead the
examiner to conclude that a
structural abnormality in the
brain is present and that an MRI
examination of the brain is
appropriate.
The history and
physical examination will point
the examiner to specific
diagnostic testing to evaluate
for other conditions associated
with autism or developmental
delay. Any child who has a
language delay should have his
or her hearing formally
evaluated. It is not sufficient
to simply determine whether or
not a person being examined is
able to hear. In order for
normal language development to
proceed, the individual must
have sufficient hearing
capabilities at low volumes in
the high frequency range.
Therefore, even if the person
turns his or her head to a clap
or shout, he or she may still
have enough of a hearing deficit
to inhibit language development.
There are two types of
hearing tests; behavioral
audiometry and brainstem
auditory evoked responses
(BAER). Behavioral audiometry is
performed by a skilled clinical
audiologist. The person being
examined is placed in a room and
his or her responses to
different tones are observed.
For the BAER, the individual is
sedated and earphones are placed
over the ears. Tones of
different volumes and
frequencies are played and the
electrical response of the brain
is monitored. If the he or she
is capable, behavioral
audiometry is the preferred
method primarily because
sedation is not required.
Depending upon specific features
of the examination and history,
the practitioner may want to
obtain blood and urine samples
for specialized testing to
evaluate for some of the inborn
errors of metabolism and to
obtain DNA for chromosomal
studies and fragile X testing. |
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If the neurological examination
is normal, there is may be no
need for a brain CT ("CAT scan")
or MRI scan. However, if the
neurological examination is
suggestive of a structural brain
lesion, then a neuroimaging
study, preferably an MRI, should
be performed. Newer imaging
procedures such as SPECT or PET
scans are used primarily as
research tools and have no place
in the initial evaluation of the
autistic individual. In very
specialized instances, such as
the autistic person with
difficult–to–control seizures,
such tests may be useful.
The
evaluation of autistic persons
by speech pathologists will
provide not only detailed
information as to the nature of
the language deficits incurred
by the autistic individual, but
will also be the first step in
formulating a specific treatment
plan with respect to language.
Occupational assessment may be
particularly helpful in
determining the day–to–day
strengths and vulnerabilities of
the individual with autism (for
example, sensitivity to clothing
and food texture) and assist
those who care for the person in
promoting his or her strengths
and compensating for their
challenges. |
How is autism
treated?
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Misinformation about autism is
very common. Claims of a cure
for autism are constantly
presented to families of
autistic individuals. There are
various treatment models found
within both the educational and
clinical settings. Yet, there is
only one treatment approach that
has prevailed over time and is
effective for all persons,
autistic or not. That treatment
model is an educational program
that is suitable to a student's
developmental level of
performance. For adults, that
treatment model refers to a
vocational program that is
suitable to the individual's
developmental level of
functioning.
Under the
Individuals with Disabilities
Educational Act (IDEA) Act of
1990, students with a handicap
are guaranteed an "appropriate
education" in the Least
Restrictive Environment (LRE),
which is generally considered to
be as normal an educational
setting as possible. As a result
of this legislation, autistic
children have generally been
placed in a mainstreamed
classroom and pulled out for
whatever supplementary services
were needed. Depending on the
child's needs, he or she could
be placed up to 100% of the
school day in a mainstreamed or
a special education setting or
any combination of the two.
There is an increasing trend,
however, among the advocates for
autistic children, to segregate
these children into small,
highly structured and controlled
academic settings that are
almost free from auditory and
visual stimulation. All
instruction is broken down into
manageable segments. Information
is presented in tiny units and
the child's response is
immediately sought. A classic
stimulus–response approach is
used to maximize learning. Each
unit of information is mastered
before another is presented. A
fundamental behavior such as
putting hands on the tabletop,
for example, must be mastered
before the child is required to
perform any other tasks, or
before more information is
presented. The long–term effects
of this type of treatment as
well as the ability of the child
to transfer this to a broader
context continue to be
evaluated. |
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Autistic individuals must be
taught how to communicate and
interact with others. This is
not a simple task, and it
involves the entire family as
well as other professionals.
Parents of an autistic child or
adult must continually educate
themselves about new treatments
and keep an open mind. Some
treatments may be appropriate
for some individuals but not for
others. Many treatments have yet
to be scientifically proven.
Treatment decisions should
always be made individually
after a thorough assessment and
based on what is suitable for
that child and his or her
family. It is important to
remember, despite some recent
denials, that autism is
virtually a lifelong condition.
Treatment will change as the
individual develops. Families
must beware of treatment
programs that give false hope of
a cure. Acceptance of the
condition in a family member is
a very critical, foundational
component of any treatment
program and is understandably
quite difficult.
Several medications have been
tried or are under current
scrutiny for the treatment of
autism. No medication has
consistently proven to be of
benefit in closely controlled
clinical trials. In the past, a
piece on a television news show
prompted a great deal of
interest in the hormone secretin
as a treatment for autism. An
autistic child with chronic
gastrointestinal complaints
showed dramatic improvement
following some routine testing
performed by a
gastroenterologist during which
a small dose of secretin was
administered. The family and
their physicians felt that the
secretin may have resulted in
the improvement in the symptoms
of autism. Many physicians began
prescribing secretin, which can
be costly for their autistic
patients. However, studies
published appear to completely
refute the claim that secretin
treatment benefits autistic
patients. This example
underscores the importance of
good clinical trials in
determining whether a drug will
help patients with autism.
Autism At A Glance
- Autism is characterized
by impaired development in
social interaction,
communication, and behavior.
- The degree of autism
varies from mild to severe.
- Severely afflicted
patients can appear to have
a profound intellectual
disability.
- The cause of autism is
unknown.
- The optimal treatment of
autism involves an
educational or vocational
program that is suited to
the developmental level of
the child or adult,
respectively.
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For More
Information
The Autism Society of America
7910 Woodmont Ave. Suite 650
Bethesda, MD 20814
301–657–0881 or
–800–3AUTISM fax: 301–657–0869
URL:
http://www.autism–society.org/
National Society For Children
and Adults With Autism
1234 Massachusetts Avenue N.W.,
Suite 1017
Washington, DC 20005
(202) 783–0125
or
contact
444Advocate.com |
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