AUTISM UPDATE
| DIAGNOSIS OF AUTISM SPECTRUM DISORDERS —Laura A. Carpenter, PhD, Assistant Professor of Pediatrics,
Medical University of South Carolina, School of Medicine, Charleston
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| Autism triad: 1) impaired social skills; 2) impaired communication skills (in Asperger’s syndrome, pragmatic language
impairment); 3) stereotyped behaviors, interests, and activities
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| Diagnostic categories: classic autistic disorders, classic Asperger’s syndrome, or pervasive developmental disorder,
not otherwise specified (PDD-NOS); ≈6.5 children in 1000 have autism spectrum disorder (ASD); of those, 2.2
in 1000 have classic autistic disorder, 1 in 1000 Asperger’s syndrome (rare); 3.3 in 1000 have PDD-NOS; PDD and
Asperger’s syndrome not necessarily less severe (although patients with Asperger’s syndrome have normal intelligence
and some gifted, functional impairment in daily living severe)
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| Screening vs diagnosis: screening identifies children at risk for ASD; once identified, patients need full diagnostic
evaluation by professional with specialized training in autism; ≈8% of pediatricians routinely screen for ASDs
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| Diagnostic lag: for later-identified children, first parental concerns arise during second year of life (usually because
child not talking); often, critical period for early intervention missed
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Barriers to Screening and Diagnosis
| Introduction: when concerns expressed by physician, some families not ready to hear them early on
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 | 1) Screening instruments: many health professionals concerned about quality of screening instruments and risk
of alarming families unnecessarily (especially about young children); lack of consensus about screening instruments
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| 2) Screening very young or delayed children: some diagnostic criteria typical behaviors in infants (eg, hand
flapping, lack of pretend play [normal onset occurs after first year of life])
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| 3) Limitations of office visit: time available for assessment; reimbursement; because of limitations, physician’s
observation may conflict with parents’ report
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| 4) Evaluation: parents not sure where to refer child; long waiting lists; diagnostic stability (ie, labeling for life)
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| 5) Efficacy of therapy: no point in making diagnosis if no effective therapy available
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Overcoming Barriers
| Screening instruments: top screens have high specificity but lower sensitivity (many children missed); to address
lack of consensus, new clinical report from American Academy of Pediatrics (AAP) will provide standards for type
of screening at each clinical visit, recommendations for screening, and screening tools; research ongoing to develop
better methods for identifying children at risk
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| Screening very young children: lower limit for age of diagnosis? new research on infant siblings of children
with autism following high-risk population from birth to 9 mo; autism may be difficult to identify during first year
of life—many instruments not designed for children <18 mo of age; (Modified Checklist for Autism in Toddlers
[M-CHAT] normed for children ≥16 mo of age); some diagnostic criteria for autism also typical behaviors for infants
and toddlers (eg, echolalia, jargon, lack of pretend play, repetitive movements, insistence on sameness); when
evaluating older children with significant cognitive delay, consider mental age and motor and self-help skills
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| Office visits: good screening instruments available that parents can complete in 5 to 10 min; if parents’ report does
not match observations by physician, consider having child return for developmental visit in 1 to 2 mo
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| Evaluation: waiting lists long (do not watch and wait); diagnosis at 2 yr of age stable (most children still meet criteria
at 9 yr of age); diagnosis provides—access to therapeutic services; guidance for treatment; prompt for parents
to seek support services
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| Efficacy of therapy: >10 controlled treatment outcome studies (and hundreds of other studies) show positive outcomes
after applied behavior analysis (ABA); early intervention desirable due to early neural plasticity
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Screening Children 12 to 48 mo of Age
| Key indicators at 12 mo of age: failure to—respond to name; look at people; follow pointed finger; point to make
request or show interest; deficits—more significant than excesses
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| Early red flags in social development: no shared smiles or warm joyful expressions by 6 mo of age; no exchange
of sounds by 9 mo of age; no babbling by 12 mo of age; no back-and-forth gestures (eg, pointing, showing,
reaching, waving) by 12 mo of age; no single words by 16 mo of age; no meaningful 2-word phrases by 24 mo of
age; regression—25% to 35% of patients lose skills during second year of life; regression at any age not normal
(refer)
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| When to screen: AAP recommends routine developmental surveillance at 12, 18, and 24 mo of age (if patient fails,
perform autism-specific screening); suspicion based on physician observation; parental concerns—first concerns
arise at 15 to 18 mo of age, but reported to pediatrician several months later; typically, language delay first reported
sign; siblings of children with autism—rate of recurrence only 4.5% to 10%, but 100 times greater than in general
population; in addition, siblings at increased risk for other causes of language delay
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| Screening tools for toddlers
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| Quantitative Checklist for Autism in Toddlers (Q-CHAT): in development; Pervasive Developmental Disorder
Screening Test (PDDST) also useful
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| M-CHAT: 23-item questionnaire (parent circles yes or no); failure on 3 items or on any critical item, indication for
referral; in evaluating failed items, make sure parent understood question; critical items—at 12 mo, children
should take interest in other children, point, imitate parent, respond to name, and demonstrate joint attention;
form available from Developmental and Behavioral Pediatrics Online (dbpeds.org)
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| Checklist for Autism in Toddlers (CHAT): questions for parents similar to M-CHAT; office visit observations—
did child make eye contact during appointment? includes interview designed to elicit, eg, looking in response to
pointing, pretend play, pointing
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Screening in Preschool and School-Aged Children
| Social Communication Questionnaire: adapted from Autism Diagnostic Interview-Revised (ADIR); brief yes-
or-no questionnaire for parents; focuses on behaviors seen at 4 to 5 yr of age
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| “Telling” questions: for child—when asked, child should be able to name preferred friend by school age and list
2 activities they like to do together; for parent—what does your child like to do in free time? ask about favorite
toys, and what child does with them; responses of normal children—child enjoys range of age-appropriate activities,
and plays with toys as intended (eg, putting toy cars through imaginary car wash, instead of simply grouping
them by color)
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Screening for Asperger’s Syndrome
| Reasons for delayed parental concern: early behaviors may seem positive—ease of care; ability to focus on
one thing for long period; early reading acquisition; exceptional knowledge in one area; seemingly mature interests;
difficulties may not arise until child enters structured school setting—compliance with classroom routine and
demands required; later, social world more complex
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| Krug Asperger’s Disorder Index (KADI): designed for children 6 to 21 yr of age; 32 items; not associated with
overdiagnosis
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| Childhood Asperger Syndrome Test (CAST): not yet published (initial data encouraging); 37 items; patient age 4
to 11 yr; form available from Autism Research Centre (autismresearchcentre.com)
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ASD Diagnosis
| Pediatrician’s role: children who fail ASD screening tests should be referred for services (immediately) and ASD
diagnostic evaluation; refer children with language delays for audiologic evaluation
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| Comprehensive evaluation: detailed developmental, medical, and behavioral history; physical examination; unstructured
observation of child; structured interaction; cognitive and adaptive measures to determine child’s developmental
status; information from parent and teacher; once diagnosis made—if requested by parents, genetic
testing standard of care; make referrals to other subspecialists as needed
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| Differential diagnosis: social phobia, especially in older children; posttraumatic stress disorder, especially in children
abused or neglected during first 2 yr of life; selective mutism (compare behavior in different settings)
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Gold Standard Diagnostic Tools
| ADIR: long-form parent interview; not many clinicians use it routinely; helpful in complex cases
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| Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV): final word in diagnosis
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| Autism Diagnostic Observation Schedule (ADOS): structured activities that allow evaluator to interact with
child to assess social and communication skills; takes 45 min to administer (longer to score); different modules for
young nonverbal children vs older adolescents or adults; tasks based on developmental level and language
ability—child’s response to bubble play (including interaction with parent and observer); pretend play (eg, birthday
party for action figure or doll) to evaluate creativity and imagination; ability to engage with observer key; older
patients—asked to create story from illustrations; social questions test whether patient has insight into social relationships,
including reasons for problems or difficulties in past; ADOS only one part of comprehensive diagnostic
evaluation
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| ASDs overdiagnosed? quirkiness not disorder; many functional people have symptoms of ASD—unusual interests;
exceptional memory for facts; poor social skills; few friends; adherence to routine; sensory issues (eg, unusual
tactile sensitivity); look for—behaviors that interfere with daily living
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| AUTISM: RECENT RESEARCH— Martin T. Stein, MD, Professor of Pediatrics, University of California, San Diego,
School of Medicine
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| Misconceptions that lead to under-referral to early intervention programs (study by Silverstein et al,
2006)
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| Federally funded early intervention program: allows pediatricians, teachers, parents, and others to refer children
based on suspicion or diagnosis of developmental or behavioral problem; referrals appropriate for suspicion of developmental
delay (DD), known DD condition, or medical conditions associated with high probability of DD
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| Parameters of study: randomized sample of 1600 AAP members (response rate 55%)
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| Results: referrals lower among pediatricians who considered specific diagnosis necessary for referral; delayed
speech (if specific diagnosis deemed necessary for referral, rate 77%; for referral based on suspicion, rate 87%);
global delay or loss of milestones (disparity not statistically significant); parental concern for inappropriate development
less likely to cause referral for pediatricians who found no specific diagnosis compared to those who
did
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| Criteria for early intervention: suspicion of DD in first 3 yr of life or medical condition with high probability of DD
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| Advancing paternal age and autism (study by Reichenberg et al, 2006)
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| Background: most studies conclude that advanced maternal age not associated with autism; studies equivocal about
paternal age
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| Parameters: population-based cohort study of all births in Israel over 6 yr; follow-up at 17 yr of age; all diagnoses
by board-certified child psychiatrists using standardized diagnostic criteria and psychometric tools
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| Findings: at that time, prevalence of ASDs 8.3 per 10,000; diagnoses of ASDs 5.7 times more likely in offspring of
men ≥40 yr of age, compared with fathers <30 yr of age; study controlled for socioeconomic status and maternal
age (advancing maternal age not associated with autism after adjusting for paternal age)
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| Possible mechanisms of association: spontaneous mutation or imprinting process where paternal genes expressed
and maternal genes silenced by DNA methylation
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| Study limitations: absence of subgroup classification in autistic spectrum; subgroup of mentally retarded individuals
not identified for comparison; atypical social phenotypes and pragmatic language delays of parents not described;
no information about prenatal or environmental exposures
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| Comment: limitations aside, study suggests that paternal age >40 yr risk factor for autistic child
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| Developmental screening in pediatric practice (new AAP policy statement, 2006)
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| Background: only 23% of pediatricians routinely use standardized instrument for neurodevelopmental testing during
well-child visits; many studies show that without standardized instrument, sensitivity and specificity of assessment
in first 3 yr of life not high
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| Recommendations: perform developmental surveillance as part of all well-child visits, particularly during first 3 yr
of life; surveillance defined as—flexible, longitudinal, and continuous assessment of developmental milestones;
eliciting and attending to parents’ concerns about child’s development; maintaining developmental history in
chart; making accurate and informed observations; identifying presence of risk and protective factors; documenting
process and findings; timing—new policy suggests that pediatricians use standardized developmental
screening test (at 9, 18, and 30 mo of age); rationale—to ensure early recognition and referral of young children
with developmental delays in more accurate way
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| Specific tests: meet psychometric criteria in 4 areas; 1) general development (Denver II, Ages and Stages Questionnaire),
2) language and cognitive development (Early Language Milestone Scale), 3) motor development, and 4)
autism screening (M-CHAT)
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| More about timing: 9 mo of age—ideal time to look at gross and fine motor skills, particularly pincer grasp (complex
visual, spatial, perceptual, and fine motor function; probably single best task to evaluate integrity of central
nervous system); early social skills (eg, separation); 18 mo of age—early language development and emerging
social skills; able to screen for ASDs with accuracy; M-CHAT has reasonably high sensitivity and specificity;
most recommend M-CHAT in each 18- and/or 24-mo visit; 30 mo of age—at 24 mo, up to 20% of normal children
late talkers (>50% at 30 mo)
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| Caution: standardized screening tests not substitute for open-ended questions and careful listening to parents and children
at each clinical encounter; interview and observations tell much; do not rely on standardized screening tests alone
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Suggested Reading
Caronna EB et al: Revisiting parental concerns in the age of autism spectrum disorders: the need to help parents in
the face of uncertainty. Arch Pediatr Adolesc Med 161:406, 2007; Carpenter LA, Macias MM: Screening and
diagnosis of autism spectrum disorders. JSC Med Assoc 102:271, 2006; Charles JM: Autism spectrum disorders:
an introduction and review of prevalence data. JSC Med Assoc 102:267, 2006; Council on Children With Disabilities:
Identifying infants and young children with developmental disorders in the medical home: an algorithm for
developmental surveillance and screening. Pediatrics 118:405, 2006; De Ocampo AC, Jacobs JM: Medical management
of autism. JSC Med Assoc 102:274, 2006; Deer B: Autism research: What makes an expert? BMJ 334:666,
2007; Kelly A et al: The role of pediatricians who care for children with autism. Arch Pediatr Adolesc Med
161:416, 2007; Reichenberg A et al: Advancing paternal age and autism. Arch Gen Psychiatry 63:1026, 2006;
Silverstein M et al: Pediatrician practices regarding referral to early intervention services: is an established diagnosis
important? Ambul Pediatr 6:105, 2006; Stein MT et al: When Asperger’s syndrome and a nonverbal learning
disability look alike. J Dev Behav Pediatr 25:190, 2004.
Resources
Developmental and Behavioral Pediatrics Online (dbpeds.org): M-CHAT form and parent handouts
Autism Research Centre (autismresearchcentre.com): CAST form
American Academy of Pediatrics (aap.org): publications on autism and recent policy statement on developmental
surveillance
Centers for Disease Control and Prevention (cdc.gov/actearly): early intervention information
Autism Society of America (autism-society.org): parent information and support
Educational Objectives
| The goal of this program is to improve the diagnosis and management of autism. After hearing and assimilating this
program, the clinician will be better able to:
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| 1. Overcome barriers to screening for autistic spectrum disorders.
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| 2. Describe early red flags for developmental delay associated with autism.
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| 3. Compare the features of various screening instruments.
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| 4. Recognize the role of advanced paternal age as a risk factor for autism.
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| 5. Describe current recommendations for developmental surveillance from the American Academy of Pediatrics.
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Faculty Disclosure
In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty members to disclose
relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any
identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary
business or commercial interest. For this program, the following has been disclosed: Dr. Stein has been a
consultant to, and received an educational grant from, Eli Lilly.
Acknowledgements
Dr. Carpenter was recorded at the 6th Annual Pediatric Neuroscience Update and 2nd Annual Autism Symposium,
held March 23-24, 2007, in Kiawah Island, SC, and sponsored by the Medical University of South Carolina. Dr. Stein
was recorded at Clinical Pediatrics, held February 15-18, 2007, in Palm Springs, CA, and sponsored by the American
Academy of Pediatrics California Chapter 2. The Audio-Digest Foundation thanks the speakers and the sponsors for
their cooperation in the production of this program.
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