| Screen
for autism CONTINUED |
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A significant
minority of children with ASD, i.e. 20% of those with the typical
presentation, apparently develop normal communication skills during
the first year of life, and then lose them or "regress"
during the second year. These kids go on to develop like other children
with ASD, but the family is understandably quite anxious about "cause"
in this situation. While a child in the middle of a regression should
be investigated for potentially treatable underlying conditions,
e.g. active or sub-clinical epilepsy or metabolic disease, most
of them have primary, i.e. genetic, ASD. For obvious reasons, it's
these families who've been most suspicious of vaccinations, environmental
toxins, etc. - none of which have shown any evidence suggesting
that they contribute.
 Tim's
case
Tim is a 2-year-old who doesn't talk yet, although he manages
to get many of the things he needs for himself. When he can't
get what he wants, he has impressive tantrums and doesn't appear
to be comforted by his parents' efforts to calm him down - in
fact, he dislikes being held even when not upset, and is quite
irritated by his mother's singing. Tim has begun to "run
the house" because his parents have noted that he requires
things in a particular order so that he can be happy with them.
Indeed, one of the frequent triggers for tantrums is a relatively
minor deviation in routine. Although Tim's grandparents tried
to tell his parents that Tim was "just spoiled," their
physician focused on his developmental deviances and suggested
an assessment for ASD. |
Should we
screen for ASD?
Recent epidemiologic data reveal that although the "core"
syndromes of autistic disorder or Asperger's syndrome have remained
relatively uncommon at a prevalence around 1/1,000, the broader
spectrum of ASD has a prevalence of 6/1,000 (or 1/150), and the
male-to-female ratio is 4:1. While there's no evidence of increasing
incidence, this prevalence makes it likely that every primary care
physician will have several children with ASD in his or her practice.
In the crucial period between a child's immunization at 18 months
and entry into school, it's the GPs who are most likely to encounter
the first symptoms suggesting ASD.
Screening has recently been recommended by
the AAP on every well-child visit and at ages 18 and 24 months.
Many provincial governments in Canada are starting developmental
screening programs. While reliable and valid general developmental
screening instruments, e.g. the Parents' Evaluation of Developmental
Status (PEDS),8 and screens for
early language development are available,9
there aren't any good ASD screening instruments yet. At this time,
the Modified CHecklist for Autism in Toddlers (M-CHAT) is the best
option,10 and is currently in
development. A number of "red flags" to guide surveillance
for ASD have been identified and are outlined in Table
2. Additional information about screening can be found on the
"first signs" website (www.firstsigns.org)
or in the AAP statement.1 Screening
tests for adults are also being developed.
 Patrick's
case
Patrick is a 12-year-old who has always done extremely well
in school, but is now asking to change schools because of bullying.
He started junior high this year, and his parents chose to send
him to a larger school with more academic options, as Patrick
wants to go to university and become a paleontologist. The kid
knows more about dinosaurs than any of his teachers, and will
talk about dinosaurs without interruption for hours unless the
listener is very blunt in telling him to stop (his family members
have learned to do this). Patrick has a new "best friend"
in school this year, but unfortunately this individual has been
setting him up to do inappropriate things such as "moon"
the teacher during class. A counsellor has been helping Patrick
understand that this person is actually a bully. The same counsellor
has suggested that Patrick might have Asperger's syndrome, and
an assessment is being arranged. |
When is further
assessment required?
Whenever you or the family suspect ASD, further assessment is required.
A positive screen is not a diagnosis, and definitive diagnostic
assessment is outlined below. All individuals in whom ASD is considered
a possibility should have their hearing checked and be seen by a
speech-language pathologist in order to connect them with any communication
interventions available. Children in the appropriate age group for
early intervention or education services should be directed to these,
as an intervention worker can both carry out the initial assessment
and begin treatment. The question of whether or not to direct families
to additional resources about ASD is usually moot, as the majority
will already be familiar with the considerable resources of the
internet. Many families also benefit from the personal contact opportunities
available from their local autism society.
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