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Overview of Autism

Stephen M. Edelson, Ph.D.

Center for the Study of Autism, Salem, Oregon

 

 

It has been over 50 years since Dr. Leo Kanner, a psychiatrist at

Johns Hopkins University, wrote the first paper applying the

term 'autism' to a group of children who were self-absorbed and who

had severe social, communication, and behavioral problems. This paper

provides a general overview of the complexity of this developmental

disability by summarizing many of the major topics in autism.

 

Prevalence

For many years, the most cited statistic is that autism occurs in 4.5

out of 10,000 live births. This was based on large-scale surveys

conducted in the United States and England. More recently, estimates

on the prevalence of autism have ranged been as high as 1/4% to 1/2%

of the population. These estimates typically include those with

autism, Asperger syndrome, and PDD.

 

Autism is three times more likely to affect males than females. This

gender difference is not unique to autism since many developmental

disabilities have a greater male to female ratio.

 

Major characteristics

Many autistic infants are different from birth. Two common

characteristics they may exhibit include arching their back away from

their caregiver to avoid physical contact and failing to anticipate

being picked up (i.e., becoming limp). As infants, they are often

described as either passive or overly agitated babies. A passive baby

refers to one who is quiet most of the time making little, if any,

demands on his/her parents. An overly agitated baby refers to an

infant who cries a great deal, sometimes non-stop, during his/her

waking hours. During infancy, many begin to rock and/or bang their

head against the crib; but this is not always the case.

 

In the first few years of life, some autistic toddlers reach

developmental milestones, such as talking, crawling, and walking,

much earlier than the average child; whereas others are considerably

delayed. Approximately one-half of autistic children develop normally

until somewhere between 1 1/2 to 3 years of age; then autistic

symptoms begin to emerge. These individuals are often referred to as

having 'regressive' autism. Some people in the field believe that

candida albicans, vaccinations, exposure to a virus, or the onset of

seizures may be responsible for this regression. It is also thought

that some children with 'regressive' autism may have Landau-Kleffner

Syndrome (see next section).

 

During childhood, autistic children may fall behind their same-aged

peers in the areas of communication, social skills, and cognition. In

addition, dysfunctional behaviors may start to appear, such as self-

stimulatory behaviors (i.e., repetitive, non-goal directed behavior,

such as rocking, hand-flapping), self-injury (e.g., hand-biting,

headbanging), sleeping and eating problems, poor eye contact,

insensitivity to pain, hyper-/hypo-activity, and attention deficits.

 

One characteristic which is quite common in autism is the

individual's `insistence on sameness' or 'perseverative' behavior.

Many children become overly insistent on routines; if one is changed,

even slightly, the child may become upset and tantrum. Some common

examples are: drinking and/or eating the same food items at every

meal, wearing certain clothing or insisting that others wear the same

clothes, and going to school using the same route. One possible

reason for `insistence on sameness' may be the person's inability to

understand and cope with novel situations.

 

Autistic individuals sometimes have difficulty with the transition to

puberty. Approximately 25% have seizures for the first time during

puberty which may be due to hormonal changes. In addition, many

behavior problems can become more frequent and more severe during

this period. However, others experience puberty with relative ease.

 

In contrast to 20 years ago when many autistic individuals were

institutionalized, there are now many flexible living arrangements.

Usually, only the most severe individuals live in institutions. In

adulthood, some people with autism live at home with their parents;

some live in residential facilities; some live semi-independently

(such as in a group home); and others live independently. There are

autistic adults who graduate from college and receive graduate

degrees; and some develop adult relationships and may marry. In the

work environment, many autistic adults can be reliable and

conscientious workers. Unfortunately, these individuals may have

difficulty getting a job. Since many of them are socially awkward and

may appear to be 'eccentric' or 'different,' they often have

difficulty with the job interview.

 

Subgroups and Related Disorders

There is no adjective which can be used to describe every type of

person with autism because there are many forms of this disorder. For

example, some individuals are anti-social, some are asocial, and

others are social. Some are aggressive toward themselves and/or

aggressive toward others. Approximately half have little or no

language, some repeat (or echo) words and/or phrases, and others may

have normal language skills. Since there are no physiological tests

at this time to determine whether a person has autism, the diagnosis

of autism is given when an individual displays a number of

characteristic behaviors.

 

In the last five years, research has shown that many people who

engage in autistic behaviors have related but distinct disorders.

These include: Asperger Syndrome, Fragile X Syndrome, Landau-Kleffner

Syndrome, Rett Syndrome, and Williams Syndrome. Asperger Syndrome is

characterized by concrete and literal thinking, obsession with

certain topics, excellent memories, and being 'eccentric.' These

individuals are considered high-functioning and are capable of

holding a job and of living independently.

 

Fragile X Syndrome is a form of mental retardation in which the long

arm on the X chromosome is constricted. Approximately 15% of people

with Fragile X Syndrome exhibit autistic behaviors. These behaviors

include: delay in speech/language, hyperactivity, poor eye contact,

and hand-flapping. The majority of these individuals function at a

mild to moderate level. As they grow older, their unique physical

facial features may become more prominent (e.g., elongated face and

ears), and they may develop heart problems.

 

People with Landau-Kleffner Syndrome also exhibit many autistic

behaviors, such as social withdrawal, insistence on sameness, and

language problems. These individuals are often thought of as

having 'regressive' autism because they appear to be normal until

sometime between ages 3 and 7. They often have good language skills

in early childhood but gradually lose their ability to talk. They

also have abnormal brain wave patterns which can be diagnosed by

analyzing their EEG pattern during an extended sleep period.

 

Rett Syndrome is a degenerative disorder which affects mostly females

and usually develops between 1/2 to 1 1/2 years of age. Some of their

characteristic behaviors include: loss of speech, repetitive hand-

wringing, body rocking, and social withdrawal. Those individuals

suffering from this disorder may be severely to profoundly mentally

retarded.

 

Williams Syndrome is characterized by several autistic behaviors

including: developmental and language delays, sound sensitivity,

attention deficits, and social problems. In contrast to many autistic

individuals, those with Williams Syndrome are quite sociable and have

heart problems.

 

Causes

Although there is no known unique cause of autism, there is growing

evidence that autism can be caused by a variety of problems. There is

some indication of a genetic influence in autism. For example, there

is a greater likelihood that two monozygotic twins (i.e., identical

twins) will have autism than two dizygotic twins (i.e., fraternal

twins). In the case of monozygotic twins, there is a 100% overlap in

genes; whereas in dizygotic twins, there is a 50% overlap in genes,

the same overlap as in non-twin siblings. Currently, a great deal of

research has focused on locating the 'autism gene;' however, many

researchers speculate that three to five genes will likely be

associated with autism. There is also evidence that the genetic link

to autism may be a weakened or compromised immune system. Other

research has shown that depression and/or dyslexia are quite common

in one or both sides of the family when autism is present.

 

There is also evidence that a virus can cause autism. There is an

increased risk in having an autistic child after exposure to rubella

during the first trimester of the pregnancy. Cytolomegalo virus has

also been associated with autism. Additionally, there is also a

growing concern that viruses associated with vaccinations, such as

the measles component of the MMR vaccine and the pertussis component

of the DPT shot, may cause autism.

 

There is growing concern that toxins and pollution in the environment

can also lead to autism. There is a high prevalence of autism in the

small town of Leomenster, Massachusetts, where a factory

manufacturing sunglasses was once located. Interestingly, the highest

proportion of autism cases were found in the homes down-wind from the

factory smokestacks. Recently, a large proportion of autistic

children were identified in Brick Township, New Jersey. Several

agencies are now attempting to uncover the reason(s) for the high

proportion of autism in this community.

 

Physical abnormalities

Researchers have located several brain abnormalities in individuals

with autism; however, the reasons for these abnormalities is not

known nor is the influence they have on behavior. These abnormalities

can be classified into two types--dysfunctions in the neural

structure of the brain and abnormal biochemistry of the brain. It

will be important for future researchers to examine the relationship

between these two types of abnormalities.

 

With respect to brain structure, Drs. Bauman and Kemper examined post-

mortem brains of several autistic individuals and have located two

areas in the limbic system which are underdeveloped--the amygdala and

the hippocampus. These two areas are responsible for emotions,

aggression, sensory input, and learning. These researchers also found

a deficiency of Purkinje cells in the cerebellum. Using Magnetic

Resonance Imaging, Dr. Courchesne has found two areas in the

cerebellum, vermal lobules VI and VII, which are significantly

smaller than normal in autistic individuals. Interestingly, there are

a some autistic individuals whose vermal lobules VI and VII are

larger than normal. One or both of these areas of the cerebellum are

believed to be responsible for attention.

 

With respect to biochemistry, many autistic individuals have elevated

levels of serotonin in their blood and cerebral spinal fluid, whereas

others have relatively low levels of serotonin. It should be

mentioned that other disorders, such as Down Syndrome, attention

deficit/hyperactivity disorder, and unipolar depression are also

associated with abnormal levels of serotonin. There is also evidence

that some autistic individuals have elevated levels of beta-

endorphins, an endogenous opiate-like substance in the body. It is

felt that those individuals who have an increased pain tolerance may

likely be due to elevated levels of beta-endorphins.

 

A dysfunctional immune system has also been associated with autism.

It is thought that a viral infection or an environmental toxin may be

responsible for damaging the immune system. As mentioned above, there

is also evidence of a genetic association to a compromised immune

system. Researchers have found that many autistic individuals have a

decreased number of helper t-cells which help the immune system fight

infection.

 

There is growing evidence that the gut or intestinal tract of autism

children is impaired. Researchers have documented yeast overgrowths

(candida albicans), low levels of phenyl sulfur transferase, and

measles virus in their intestinal tract.

 

Sensory impairments

Many autistic individuals seem to have an impairment in one or more

of their senses. This impairment can involve the auditory, visual,

tactile, taste, vestibular, olfactory (smell), and proprioceptive

senses. These senses may be hypersensitive, hyposensitive, or may

result in the person experiencing interference such as in the case of

tinnitus, (a persistent ringing or buzzing in the ears). As a result,

it may be difficult for individuals with autism to process incoming

sensory information properly.

 

Sensory impairments may also make it difficult for the individual to

withstand normal stimulation. For example, some autistic individuals

are tactilely defensive and avoid all forms of body contact. Others,

in contrast, have little or no tactile or pain sensitivity.

Furthermore, some people with autism seem to 'crave' deep pressure.

Another example of sensory abnormalities is hypersensitive hearing.

Approximately 40% of autistic individuals experience discomfort when

exposed to certain sounds or frequencies. These individuals often

cover their ears and/or tantrum after hearing sounds such as a baby's

cry or the sound of a motor. In contrast, some parents suspect their

children of being deaf because they appear unresponsive to sounds.

 

Cognition

" Theory of mind " refers to one's inability to realize that other

people have their own unique point of view about the world. Many

autistic individuals do not realize that others may have different

thoughts, plans, and perspectives than their own. For example, a

child may be asked to show a photograph of an animal to another

child. Rather than turning the picture around to face the other

child, the autistic child may, instead, show the back of the

photograph. In this example, the autistic child can view the picture

but does not realize that the other child has a different perspective

or point of view.

 

About 10% of autistic individuals have savant skills. This refers to

an ability which is considered remarkable by most standards. These

skills are often spatial in nature, such as special talents in music

and art. Another common savant skill is mathematical ability in which

some autistic individuals can multiply large numbers in their head

within a short period of time; others can determine the day of the

week when given a specific date in history or memorize complete

airline schedules.

 

Many autistic individuals also have a narrow or focused attention

span; this has been termed 'stimulus overselectivity.' Basically,

their attention is focused on only one, often irrelevant, aspect of

an object. For example, they may focus on the color of a utensil, and

ignore other aspects such as the shape. In this case, it may be

difficult for a child to discriminate between a fork and a spoon if

he/she attends only to the color. Since attention is the first stage

in processing information, failure to attend to the relevant aspects

of an object or person may limit one's ability to learn about objects

and people in one's environment.

 

Interventions

Over the years, families have tried various types of traditional and

non-traditional treatments to reduce autistic behaviors and to

increase appropriate behaviors. Although some individuals are given

medications to improve general well-being, there is no primary drug

which has been shown to be consistently effective in treating

symptoms of autism. The most widely prescribed medication for

autistic children is Ritalin, (a stimulant used to treat Attention

Deficit/Hyperactivity Disorder). However, there are no double-blind

controlled studies to demonstrate its effectiveness for those with

autism.

 

The two treatments which have received the most empirical support are

Applied Behavior Analysis (ABA; behavior modification) and the use of

vitamin B6 with magnesium supplements. Behavior modification involves

a variety of strategies, (e.g., positive reinforcement, time-out), to

increase appropriate behaviors, such as communication and social

behavior, and to decrease inappropriate behaviors, such as self-

stimulatory and self-injurious behavior.

 

Vitamin B6 taken with magnesium has been shown to increase general

well-being, awareness, and attention in approximately 45% of autistic

children. There are also a number of recent reports about the

benefits of another nutritional supplement, Di-methylglycine (DMG).

DMG also seems to help the person's general well-being, and there are

many anecdotal reports of it enhancing communication skills.

 

Some people with autism have excessive amounts of a type of yeast

called 'candida albicans' in their intestinal tract. It is thought

that high levels of candida albicans may be a contributing factor to

many of their behavioral problems. One scenario is that when a child

develops a middle ear infection, the antibiotics that help fight the

infection may destroy microbes that regulate the amount of yeast in

the intestinal tract. As a result, the yeast grows rapidly and

releases toxins in the blood; and these toxins may influence the

functioning of the brain. Excessive candida albicans can be treated

with rather mild medications such as Nystatin.

 

Food intolerances and food sensitivities are beginning to receive

much attention as possible contributors to autistic behaviors. Many

families have observed rather dramatic changes after removing certain

food items from their children's diet. Researchers have recently

detected the presence of abnormal peptides in the urine of autistic

individuals. It is thought that these peptides may be due to the

body's inability to breakdown certain proteins into amino acids;

these proteins are gluten (e.g., wheat, barley, oats) and casein

(found in human and cow's milk). Many parents have removed these

substances from their children's diets and have, in many cases,

observed dramatic, positive changes in health and behavior.

 

As mentioned earlier, many autistic individuals have sensory

impairments. Sensory integration techniques are often used to treat

dysfunctional tactile, vestibular, and proprioceptive senses. Some of

the techniques involve swinging a child on a swing in various ways to

help normalize the vestibular sense and rubbing different textures on

the skin to normalize the tactile sense. In addition, an autistic

woman, Dr. Temple Grandin, developed a hug machine which provides the

individuals with deep pressure which appears to have a calming effect

on the person.

 

Many autistic individuals are also sensitive to sounds in their

environment. They may hear sounds beyond the normal range and/or

certain sounds may be perceived as painful. Auditory integration

training, (listening to processed music for ten hours), is an

intervention which is often used to reduce these sensitivities.

Visual training is another sensory intervention designed to normalize

one's vision. There are several different methods of visual training.

One popular program, developed by Dr. Melvin Kaplan, involves wearing

ambient (prism) lenses and performing movement exercises which appear

to reorganize and normalize the visual system.

 

Conclusion

Autism is a very complex disorder; and the needs of these individuals

vary greatly. After 50 years of research, traditional and

contemporary approaches are enabling us to understand and treat these

individuals. It is also important to mention that parents and

professionals are beginning to realize that the symptoms of autism

are treatable--there are many interventions that can make a

significant difference.

 

The logo for the national parent support group, the Autism Society of

America, is a picture of a child embedded in a puzzle. Most of the

pieces of the puzzle are on the table, but we are still trying to

figure out how they fit together. We must also keep in mind that

these pieces may fit several different puzzles.

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