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Autism, New Goal is Finding it Soon Enough to Fight it
by Anahad O'Connor, New York Times, December 14, 2004
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Sitting in a
small evaluation room at the University of Washington,
apprehension written on her face, Christa Zamora turned her eyes
toward her son Connor and contemplated his future.
A talkative and animated 2-year-old, Connor appears normal, Ms.
Zamora said, but it is too soon to be certain. Doctors diagnosed
autism in her older son, Cameron, just before he turned 3. And
with Connor, who is also at risk for developing the devastating
neurological disorder, which runs in families, she has decided
to be proactive, enrolling him in an early diagnosis study for
children as young as 16 months.
"I'm very concerned," said Ms. Zamora, who is also worried about
her third child, a boy due in February. "Connor seems to be past
the danger zone. But Cameron repeats himself a lot, and
sometimes I see Connor doing the very same things."
Across the country, thousands of toddlers like Connor are
joining studies that could signal new hope for a baffling
childhood disorder.
For years, autism was rarely noticed before the age of 2, its
symptoms overlooked by busy parents or so subtle that
pediatricians missed them. According to federal figures, only a
third of the 6-year-olds who were receiving treatment for autism
in 2002 had been identified by age 4.
But in the last two years much has changed. Propelled by an
explosion of public awareness and growing evidence that early
treatment with behavioral therapy can improve a child's chances,
scientists have set out to diagnose the disorder as early as
possible, and slowly, more children with autism are being
identified before they turn 2.
Already, the average age of diagnosis in Britain has tumbled
from roughly 43 months to 38 months or younger in only a few
years, a pattern experts see emerging in the United States. And
studies now under way could sharply alter the landscape of early
detection by allowing physicians to routinely screen children
before age 2, perhaps even in infancy.
"Part of it is that parents are more interested, and that
pediatricians are getting a lot more sophisticated at detecting
it," said Dr. Fred Volkmar, a professor of child psychiatry at
Yale. "As these things have come together, there's no question
we're seeing a lot more parents who are coming forward around
the country with younger and younger children."
Autism isolates, robbing those afflicted of their ability to
communicate or to grasp even basic social cues. Human faces,
awash in meaning to most people, are inscrutable to people with
autism; many cannot look another person in the eye. But
behavioral therapy is one bridge to the outside world, and while
experts say it can make a difference at any age, almost all
agree that it has the largest effect on a child's language,
social development and I.Q. when started before children turn 4.
"Intervention should start before the age of 3, and certainly by
the age of 4," said Dr. Deborah Fein, a professor of psychology
at the University of Connecticut. "After a certain point, you
can still teach an autistic child certain things, ameliorate
destructive behaviors, but you're not really going to change the
developmental pathway that they're on."
The goal now, experts say, is to augment screening techniques so
cases no longer elude them as the window for intervention
narrows.
At the University of Washington and elsewhere, researchers are
experimenting with a routine test that can flag children by 18
months, the earliest point for reliably identifying the
disorder, many experts contend. It is also early enough for
therapists to intervene.
At the same time, other researchers see promise in more
sophisticated diagnostic tools - devices that can measure brain
and behavioral responses to the sound of a mother's voice, or
genetic or biological markers that can be detected in infancy.
"The goal is to be able to identify these kids at birth," said
Dr. Geraldine Dawson, director of the University of Washington's
autism center. "Until fairly recently, we hadn't really defined
the very early symptoms of autism. But in the last several
years, research has identified the behaviors you can see in a
child as young as 12 months."
Dr. Dawson and others hope to accelerate their progress by
focusing on high-risk groups. About one person in 200 in the
general population suffers from autism spectrum disorder,
compared with roughly one person in 20 who has an autistic older
brother or sister.
As a result, researchers are increasingly focusing on the
families of autistic children, recruiting younger siblings who
can be followed from birth to pinpoint when normal development
veers off course.
Such studies could help scientists learn, among other things,
why roughly a quarter of children with the disorder descend into
autism seemingly overnight, quickly spiraling from talkative to
mute, outgoing to aloof. In the past, when diagnoses were made
after age 4 or 5, scientists were forced to rely on grainy home
videos of first birthdays for early clues. Now, they are seeing
autism unfold before their eyes.
"We're hoping that if we follow enough kids, we can watch that
progression," said Dr. Catherine Lord, director of the autism
and communication disorders program at the University of
Michigan.
Faint Signs Often Missed
In some cases, researchers are already reporting breakthroughs.
Last month, Dr. Ami Klin, an associate professor of child
psychology and psychiatry at Yale, published one of the most
comprehensive case reports of a toddler with autism. The child,
called Helen by Dr. Klin in the article to protect her identity,
was 15 months old when autism was diagnosed. At 12 months, her
language skills deteriorated and she began withdrawing. By the
time she reached the clinic, she had almost no interest in other
people. Her brother, two years older, is also autistic.
"Historically, children wouldn't reach a specialized center like
ours until a much later stage," Dr. Klin said.
Experts say that while more and more children like Helen are
coming to their attention, for now, they are the exception. It
is too soon, many agree, for most children that young to be
spotted by anyone other than a specialist or an alert parent who
has already raised an autistic child.
At that age, the range of social behaviors is limited, and most
tests were developed for older children, intended to see if a
child was engaging in age-appropriate activities like playing
peek-a-boo or showing interest in other children. The signs of
autism may be too faint to show up in such tests, or simply not
yet present.
"One big problem is that some kids just don't have all the
features by 2 or 3," Dr. Volkmar said.
Chances Slip Away
Another problem, even with older children, is that pediatricians
rarely use the tests, which can take time to administer, to
screen their young patients. Instead, one study by the American
Academy of Pediatrics found, most physicians prefer to "eyeball"
children, a notoriously unreliable method that probably allows
many cases to go unnoticed.
Other doctors sidestep the issue altogether. Parents who express
concerns about their toddlers are often told to wait a few
months, "to see if the child grows out of it." Rather than make
the fateful decision to refer a child to a specialist for a
diagnosis, some experts say, pediatricians sometimes suggest
instead that the children are late talkers, or only slightly
behind.
"I think a lot of doctors, if they aren't completely sure about
what they are seeing, are afraid to say so," said Dr. Isabelle
Rapin, a professor of child neurology at the Children's Hospital
at Montefiore in the Bronx. "So they tell the parent 'you're
overworried,' or they come up with all sorts of excuses because
they don't want to give a parent the news that their child might
be autistic."
But delaying a diagnosis, and as a result early treatment, can
have lifelong consequences. A child referred to a specialist can
end up on a waiting list for months in some parts of the United
States. When the diagnosis finally comes, another year could go
by while the child waits on a second list for treatment.
"The journey is easily over two years from the first step
to getting treatment," Dr. Dawson said.
All the while, chances to slow the progression of the disorder
slip away. To encourage parents and physicians to act quickly
when a child's development is stagnating, experts at the Centers
for Disease Control and Prevention, working with other groups,
have begun a public awareness campaign, called "Learn the Signs.
Act Early."
It is designed to educate parents and health care professionals
about the major milestones, from imitating facial expressions to
finger-pointing and telling stories, that a child needs to
achieve at various developmental points between 3 months and 5
years.
Casting a Wide Net
And who better to spot autism than parents? Subtle changes in
behavior may be more obvious to a mother or father who sees a
child daily than to a pediatrician who has 50 other patients.
So experts want parents to play a larger role. They have taken a
widely used screening tool, the Checklist for Autism in
Toddlers, or the CHAT, and replaced a section that pediatricians
complete with a series of yes-or-no questions for parents. It
can be filled out in just a few minutes, ideally at home or in a
waiting room before a child's checkup. It is available online at
firstsigns.org.
Unlike its earlier version, which is extremely precise, the new
M-CHAT casts a wide net. In England, studies of thousands of
children showed that the CHAT, although it accurately identified
many cases of autism, was so specific that it failed to detect a
majority of cases. The M-CHAT, with looser boundaries and
greater sensitivity, is intended to flag even subtle cases.
Experts say that it will probably produce more false positives -
flagging children who are not actually autistic - but that they
prefer to err on the side of caution.
Dr. Fein, of Connecticut, is leading a large study to help
validate the M-CHAT's usefulness. In the last five years, about
4,000 New England toddlers, ages 18 months to 24 months, have
been screened with the test during normal visits to their
pediatricians. At the age of 4, they are evaluated once more to
determine whether the M-CHAT is accurate. So far, Dr. Fein said,
autism has been diagnosed in about 200 cases, and the test is
holding up.
"Most of the kids stay with their diagnosis," she said. "If we
didn't think they were autistic at 2, then they aren't autistic
at 4."
On the other hand, about 15 to 20 percent of the children
labeled autistic at 2 no longer meet the definition by the time
they turn 4. That could mean that they were false positives, Dr.
Fein said, or simply that catching them early made a difference.
"One possibility is that they got good, effective intervention
and recovered, which I think is what's really going on," she
said. "I see a lot of kids at 2 who are clearly autistic and
then at 4 they are doing terrific. These are kids who have
recovered enough so that no one would ever know that they were
on the autistic spectrum."
Such outcomes, Dr. Fein said, are rare but not impossible. Many
more children who begin behavioral therapies will make more
modest gains, improving just enough to grasp a few rules of
social interaction, or building a small vocabulary. Still others
will remain severely disabled, beyond the reach of any therapy.
Dr. Eric Fombonne at McGill University in Montreal, for one,
says that some children cannot completely overcome autism.
He points to studies suggesting that children who show marked
improvement after behavioral intervention are those labeled
P.D.D.-N.O.S., or pervasive developmental disorder not otherwise
specified, because they exhibit only some autistic symptoms.
Those who meet the stricter definition of autism often show less
impressive results.
"Some children, at base line, have more severe difficulties and
won't always make the expected gains," said Dr. Fombonne, a
professor of child and adolescent psychiatry.
The extent of behavioral therapy's potential remains an open
question, and evidence suggests that it varies enormously from
one child to the next. Yet even those who believe it has only
limited effect on some children seem to agree, nonetheless, that
it is most helpful when started early.
"What we do know is if you start it after a certain age, the
outcome is going to be more negative," said Dr. Fombonne. "It
makes sense that that would be the case."
In the coming years, some advocates hope, every child will be
screened for autism by his or her second birthday, with the
M-CHAT or a similar checklist. But casually observing a small
child's behavior only reveals so much, and researchers say they
will need more diagnostic tools if they are to detect faint
glimmers of the disorder in infants.
A Mother's Melody
Dr. Patricia Kuhl and colleagues at the University of Washington
think they have one answer. They have found that small children
are naturally lured by the melody of a mother's speech - the
stretched pronunciation of vowels that produces sounds like "ah"
and "oo."
When exposed to this baby talk, or "motherese," normally
developing children display a distinct pattern of brain activity
that can be measured with electrodes, while autistic children
show little interest and fail to produce the expected neural
response. Autistic subjects, on average, prefer to listen to a
computer generated warble instead.
The findings suggest that autistic brains may be wired
differently from birth, leading to delays in language and other
hallmarks of the disorder.
"The beauty from a practical aspect is that these simple
measures can be used extremely early in life," Dr. Kuhl said.
Perhaps the simplest autism screening tool, one that many
consider the holy grail of early detection research, is a
genetic test. It is not clear to what extent environmental
influences - infections and childhood vaccines, for example
- play a role in the onset of the disorder, but experts are
certain that heredity is a major factor. Studies of identical
twins, for example, suggest that if one twin has autism then the
other has more than a 60 percent chance of being autistic as
well.
After years of searching, they have homed in on several regions
of different chromosomes that may lie behind autism, and earlier
this year a team at the Mount Sinai School of Medicine in New
York pinpointed at least one gene that contributes to the
disorder. A simple genetic test, however, is more elusive than
it seems. Experts suspect that more than 20 genes could be
involved, each underlying a different aspect of autism. Dr.
Dawson, in her studies of high-risk siblings, is finding that
even children who inherit just a few of these genes, like Connor
Zamora in Seattle, may periodically display repetitive movements
or other quirky behaviors without actually crossing the
threshold into full-blown autism. About 10 to 15 percent of
siblings may have this milder variant, Dr. Dawson said.
"It's a new concept for parents to understand," she said. "They
could have a young child who doesn't have enough symptoms to
have autism, but has some mild aspects like language delay or
social awkwardness that they might need help with."
Experts say that for all the promise it might hold, a screening
technique that can consistently detect children younger than 18
months, not to mention in infancy, is probably years away. To
the extent that that is even possible, scientists say they would
then have to grapple with a much larger problem: providing
treatment to an explosion of small children when services are
already stretched thin.
"We're going to have more and more children under 3 getting
diagnosed," said Dr. Volkmar. "But sadly, it looks like we're
going to have fewer and fewer services for them."
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