EARLY INTERVENTION MAY REDUCE THE SEVERITY OF AUTISM
Carolyn Lex
Writer’s comment: I
first became interested in autism the summer after my freshman year of
high school when I was a volunteer teacher’s aide. I was assigned a
class of severely handicapped children, and the student I found most
interesting was an autistic 11-year-old boy. At the time, he did not
speak and was treated as intellectually “slow.” Since then, treatment
advances have enabled this young man to integrate into regular high
school classes with an aide who “facilitates” his communication through
a laptop computer. The best part of writing my paper for English 102
(Writing in the Health Sciences) was contacting the young man’s mother,
whom I had never met, and listening to her story of raising Jason and
his three brothers. It reinforced my observation that first summer that
the disabled are people first, people with whom we have a great deal
more in common than we have differences.
- Carolyn Lex
Instructor’s comment:
Carolyn wrote this paper for English 102: Writing in the Health
Sciences. It is a feature article like you find in the Tuesday “Science
Times” of the New York Times.Notice that she cites her sources
the way that journalists do, naming them in the article as though she
both read their work and talked with them (but, because she is a
student, she also includes a nonjournalistic reference list). It seems
to me that Carolyn has risen to the difficult challenge of addressing
an educated audience of both critical scientists and non-scientists
reading for interest—her article is people-oriented, follows an
enticing and engaging structure, and provides new, clear, fascinating
detail on a significant topic. If I found it in the New York Timesone Tuesday morning, I would keep reading right through breakfast.
- Susan Palo, English Department
Scientists are gaining a new understanding of how the
brains of autistic individuals work. Their discoveries have led many to
believe that early intervention may reduce the severity of the
disorder.
The brain continues to develop after birth. Therefore, early
damage can often be compensated for if another part of the brain takes
over the responsibilities of the damaged area. Because the brain’s
ability to reorganize itself declines rapidly during the first few
years of life, techniques that allow for early detection of autism are
critical. Several such diagnostic methods have recently been proposed.
Most of these are based on the analysis of videotapes of infants later
diagnosed with autism.
Autism is a developmental disorder that affects the functions
of the brain. Individuals with autism most often have serious problems
with social interaction and with communication and imagination, as well
as unusual behavior patterns (rituals, preoccupations, and repetitive
behaviors).
Dr. Philip Teitelbaum and his colleagues at the University of
Florida in Gainesville were able to detect reliable differences in the
movements of autistic infants at 4-6 months of age. The way these
children learn to roll over and later to walk is not the same as the
way of normally developing children. Overall, the movements of autistic
children are less coordinated. For example, when sitting, they
distribute their weight unevenly, causing them to fall over. Results
from his study led Teitelbaum to conclude that “movement disturbances
play an intrinsic part in the phenomenon of autism… and can be used to
diagnose the presence of autism in the first few months of life.”
According to Teitelbaum, most infants learn to turn over
around three months of age. They accomplish this task by rotating their
body in a corkscrew fashion. The pelvis moves first, followed by the
trunk and finally the shoulders and head. This order is reversed around
6 months, when the roll is initiated with the turning of the head.
The autistic babies in the videos did not follow either of
these patterns. Some were completely unable to turn over. The rest,
Teitelbaum describes, “arch themselves sideways by raising the head and
pelvis upward. This narrows the base of the body so that by moving the
upper leg forward that leg can serve as a weight to topple the body
over. All of the segments of the body move en bloc,not in a corkscrew fashion. This results in the child falling over, without any active rotation.”
In terms of walking, according to Teitelbaum, normal children,
learning to walk for the first time, always progress through a series
of stages. The earliest form of walking is called the “waddling walk.”
This name comes from the way the baby waddles from side to side with
each step. The next stage involves a more coordinated movement of the
legs, but the child does not shift its weight until both feet are
planted firmly on the ground. The final stage is characterized by the
synchronization of the moving legs with the transfer of weight.
Teitelbaum’s videotapes revealed that autistic children proceed
more slowly though these stages, occasionally becoming stagnated at a
certain stage. For example, a three-year-old boy was found to still use
the “waddle walk” with his right leg, while his other leg moved in a
more “mature” style. Another five-year-old boy showed age appropriate
movement, but the shift of weight did not occur until both feet were
back on the ground.
At the University of Washington, a second pair of
researchers, Dr. Julie Osterling, and Dr. Geraldine Dawson, also used
videotape analysis to look for distinguishing behaviors of autistic
children. They focused on early social behaviors including pointing,
looking at others, and orienting to name in videos of the children’s
first birthday. Like Teitelbaum, they also found differences between
autistic and normally developing children: “The development of the
children with autism seemed to be arrested in the earlier sensorimotor
stages while the control children continued to progress at a normal
rate.” Most significant was how little time the autistic children spent
looking at others.
To experts, the results of these studies are promising.
Although the sample size in both experiments was small, the detection
techniques used were highly reliable. Evaluators blind to the child’s
diagnosis correctly identified 95% of the autistic children. The
earlier these children are identified, the sooner they can receive
treatment and the more likely it is that their condition will improve.
Parents of autistic children often notice abnormalities in
the behaviors of their children in the first few months of life. One
mother recalls the first time she knew something was wrong with her
son: “I noticed that Jason seemed distant starting when he was about 6
months old, but the doctor assured me that he would grow out of it.”
The clinical diagnosis of autism is currently based on social
interactions that are not observed at such a young age. Because most
children are not diagnosed until they are around 3 years old, treatment
does not start until this time.
While the causes of autism are still unknown, evidence from
recent research supports the hypothesis of prenatal brain damage. The
cause of this damage is unknown, although leading scientists have
suggested an intrauterine virus, chromosomal abnormalities, or
metabolic disorders as possibilities.
Whatever the cause, these experts say, the results appear to
be an incomplete or defective development of the cerebellum and
brainstem. Both of these structures have extensive connections with
other parts of the brain, especially in what is known as the limbic
system.
The limbic system, a group of structures located toward the
inside of the brain, is important for its role in motivation, behavior,
emotion, and arousal, all of which are known to be affected by autism.
According to Dr. Stephen Edelson from the Center for the Study of
Autism, “The correspondence between behaviors seen in autism and what
we know of the limbic system is compelling.” Researchers right now,
however, know very little about the contribution of the limbic system
to autism.
The cerebellum is responsible for the coordination of
movement. An incomplete or defective development could account for the
differences Teitelbaum detected in motor development.
Dr. Eric Courchesne at the University of California at San
Diego has studied the role of the cerebellum in controlling attention.
He suggests that “these attention . . . deficits may in part underlie
the failure of autistic babies to engage in normal joint social
attention and their failure to develop normal social communication
skills.”
The children Courchesne studied at Children’s Hospital in San
Diego were especially impaired in the ability to shift their attention.
A normal infant, Courchesne explains, “shifts his or her focus of
attention to follow the rapidly changing verbal, gestural, postural,
tactile, and facial cues that signal changes in the stream of social
and nonsocial information.” Furthermore, he adds “[They] use behavioral
cues (gestural, postural, and so forth) to direct shifts of attention
in the mother during such joint interchanges.” In contrast, autistic
babies, Courchesne explains, “enter the world unable to smoothly and
selectively shift their mental ‘spotlight’ of attention.”
The cerebellum also modulates the brainstem’s response to
sensory stimulation. It follows that the baby would be unable to
respond appropriately to sensory stimuli. This impairment leads some
autistic infants to avoid all forms of stimulation, while others may
engage in self-stimulatory behaviors such as head banging.
Luckily, early intervention may help alleviate some of these
behaviors. Cindy Hatch-Rasmussen from the Center for the Study of
Autism is experienced with using sensory integration therapy to help
autistic children. Sensory integration takes advantage of the ability
of the infant brain to reorganize itself by forming new connections. If
other parts of the brain can be stimulated to take over the
responsibilities of the damaged structures, these children may be able
to function normally. This therapy focuses on three areas of sensory
stimulation: tactile (touch), vestibular (balance), and proprioceptive
(an awareness of one’s physical self).
Tactile stimulation comes from the sense of touch. Autistic
children can be over or under reactive to touch. According to
Rasmussen, an oversensitivity to touch can lead to “excessive brain
activity, which can neither be turned off nor organized. This type of
over stimulation in the brain can make it difficult for an individual
to organize one’s behaviors and concentrate.”
The vestibular system is comprised of the organs of the inner
ear and is responsible for our perception of motion and our awareness
of our position in space. Hypersensitive children may attempt to avoid
vestibular stimulation and become afraid of things like elevators.
Conversely, hyposensitive children will attempt to stimulate their
vestibular system with actions like spinning and jumping.
Finally, the proprioceptive system is the system of muscles
and joints responsible for the way we hold our bodies (i.e., posture)
and the way we move. Signs of proprioceptive problems, Rasmussen
reports, include “clumsiness, a tendency to fall, a lack of awareness
of body position in space, odd body posturing, minimal crawling when
young, difficulty manipulating small objects (buttons, snaps), eating
in a sloppy manner, and resistance to new motor movement activities.”
Sensory integration therapy is based on the idea that
exposure to a variety of sensory stimuli stimulate the brain to
organize itself in a way that allows this information to be
meaningfully processed. This constitutes a reorganization of the
central nervous system that can compensate for the areas that are
damaged. With Rasmussen’s help, the children receiving sensory
integration therapy are also assisted in “learning to inhibit or
modulate sensory information and in processing a more organized
response to sensory stimuli.” If this sort of therapy is started early
enough, experts believe that it will be effective in decreasing the
severity of the symptoms of autism.
Courchesne, E., J. Townsend, and O. Saitoh. (1996). The brain in infantile autism: Posterior fossa structures are abnormal. Neurology, 2, 84-92.
Edelson, S. (1999). Autism and the limbic system. In Center for the Study of Autism.[Online] Available: http://www.autism.org/limbic.html [1999, March 7]
Hashimoto, T., M. Tayama, K. Murakawa, and T. Yoshimoto. (1995). Development of the brainstem and cerebellum in autistic patients. Journal of Autism and Developmental Disorders,1, 1-18.
Lex, Carolyn. (February 1, 1999). Interview with a mother of an autistic child.
Osterling, J., and G. Dawson. (1994). Early recognition of children with autism: A study of first birthday home videotapes. Journal of Autism and Developmental Disorders,24, 247-258.
Rasmussen, C. (1999). Sensory Integration. In Center for the Study of Autism.[Online]. Available: http://www.autism.org/si.html [1999, March 8]
Teitelbaum, P., O. Teitelbaum, J. Nye, J. Fryman, and R. Maurer. (1968, November 18). Movement analysis in infancy may be useful for early diagnosis of autism. PNAS [Online]. Available: http://www.pnas.org/cgi/content/full/95/23/13982 [1999, March 7].