Autistic Disorder Diagnosis

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					       Autism:
Screening & Diagnosis
      Morning Report
      January 4, 2005
                    Definition
Autism is a complex neurodevelopmental disorder
The behavioral manifestations that define autism
include deficits in (1) social interaction, (2)
communication (verbal and nonverbal) and (3) restricted,
repetitive patterns of behavior
   “Autistic Spectrum Disorders” (ASDs) describes the wide
   range of these behavioral patterns seen in affected patients
Cognitive ability is not part of the diagnostic criteria, but
is an important prognostic indicator
          Genetics of Autism
A genetic basis for autism is supported by a 60%
concordance rate for autism and 70% for ASD among
monozygotic twins
High recurrence rates among siblings of children with
ASD
  risk increases from 0.2% up to 10-20% w/ a subsequent child
  (~50-fold increase)
Several chromosomal defects have been implicated
  Most consistent findings have been on chromosomes 7q, 2q,
  and 15q
         Scope of the Problem
1 in 1000 children w/autism; 1 in 500 w/ an ASD

Boys > Girls (4:1)

Average age of diagnosis is about 6 yrs
  Most parents recognized something was wrong by 18 months

Results from a large (n=1300) recent parent survey indicated:
   Less than 10% are diagnosed at the initial presentation
   Only 40% of patients referred to another professional were
   given a formal diagnosis
   Over 30% of parents report no help was offered after formal
   diagnosis (education, therapy, referrals)
   Only 10% of parents reported that a professional explained
   their child’s problem to them
“Pervasive Developmental Disorders”

The behavioral manifestations of autism can be
seen in other individuals w/ social
communication disorders
DSM-IV criteria classify children under the
terminology pervasive developmental disorders and
include 5 subgroups within this category
PDD subgroups: Autistic disorder, Asperger
syndrome, PDD-NOS, Childhood
Disintegrative Disorder, and Rett Syndrome
      Autism: Clinical Features
Impairment of joint attention (ability to use eye
contact/pointing to share experiences with others) and pretend
play are present in almost all children w/ autism
Limited eye contact
Aloofness
Loss of awareness or intermittent awareness of environment
Non-verbal to advanced speech (but lacks communicative
intent)- imitation of songs, rhymes, TV advertisements is
common
Severe MR to advanced intellectual functioning
   Islands of abilities in certain areas of functioning (puzzles, art, music,
   reading, computer or mathematical calculations)
Stereotypic behaviors- hand flapping, finger flicking, compulsive
sniffing
            Joint Attention
Joint attention should be fully developed by 18
months of age
  At 9mo, children should follow a point when a
  caregiver points and says, “Look at the ___”
  At 1yr, children should demonstrate
  “protoimperative pointing”
  At ~15-18 months, children demonstrate
  “protodeclarative pointing”
      Screening & Diagnosis
Clinically identifying children with Autism
involves 2 levels of investigation
  1.) Routine developmental screening to identify
  those at risk for atypical development and specific
  screening for autism for those identified at risk
  specifically for autism
  2.) Diagnosis and Evaluation of Autism which
  involves more in-depth investigation of already
  identified children and differentiates autism from
  other developmental disorders

                          Filipek PA, et al. Neurology 2000;55- 468
Routine Developmental Screening
25% of children in any primary care office demonstrate
developmental issues
The AAP recommends continual developmental
screening at every well-child visit (until school-age)
Sensitive and specific screening tools include Ages and
Stages Questionnaire, The BRIGANCE Screens, Child
Development Inventories
  The Denver-II has been found to be insensitive and lacks
  specificity and is not recommended for development screening
Several studies have shown that parental concerns
about speech & language development and behavior
were highly sensitive and specific
                               Filipek PA, et al. Neurology 2000;55- 468
                    Red Flags
No babbling by 12 months
No gestures by 12 months (i.e. pointing, waving
“bye-bye”)
No single words by 16 months
No two-word spontaneous phrases (not
echolalia) by 24 months
Loss of any language or social skills at any age

 Failure to meet these milestones is associated with a high
           probability of a developmental disability
  Siblings of Autistic Children
Siblings of autistic children deserve careful
monitoring given the high rate of recurrence

Siblings should be closely monitored for
abnormal social, communication and play skills

Screening should also be performed for
language delays, learning difficulties, social
problems, anxiety and depressive symptoms
Autism-Specific Screening Tools
AAP recommends screening specifically for Autism when children
fail routine developmental screening or when parents have concerns

Checklist for Autism in Toddlers (CHAT)- 18mo
Modified Checklist for Autism in Toddlers
(M-CHAT)- 16-30mo
Social Communication Questionnaire (SCQ) (formerly the
Autism Screening Questionnaire)- older pts 4-6yrs
Pervasive Developmental Disorders Screening Test-II (PDDST-
II/Stage I)- 12-24mo
Australian Scale for Asperger’s Syndrome (ASAS)- school age

                               Filipek PA, et al. Neurology 2000;55- 468
 Checklist for Autism in Toddlers
                           (CHAT)
Screening tool administered at 18 months
Involves parent and physician observation
14 items that measure imitation, pretend play, and joint attention
   9 items are by parent report; 5 require physician observation
Five items are considered critical for screening positive: pretend
play, protodeclarative pointing, following a point, pretending,
and producing a point
   Failing any two items is considered positive and requires rescreening
High specificity (98%); Low sensitivity (38%) for identifying
ASD at 18 months


                                     Filipek PA, et al. Neurology 2000;55- 468
 Modified Checklist for Autism in
      Toddlers (M-CHAT)
Screening tool administered at 16-30mo
Goals are to improve sensitivity and make it more
practical for the office setting
Includes 23 questions, including the 5 critical items
from CHAT but eliminates the observation section
This tool is still being validated. Current data shows a
sensitivity of 85-95% and specificity of 93%
M-CHAT is available w/out charge through
www.firstsigns.org
                          Filipek PA, et al. Neurology 2000;55- 468
Laboratory Investigations for Developmental
           Delay and/or Autism
Formal audiologic evaluation
   All children w/ developmental delays, (especially language
   and social) require a formal hearing evaluation
   Evaluation should include behavioral audiometry,
   tympanometry, and an electrophysiologic procedure like ABR
Lead Screening
   should be performed in any child with pica or living in a
   high-risk environment (CDC recommends every child w/ DD
   undergoes lead screening)



                                    Filipek PA, et al. Neurology 2000;55- 468
                     Referrals
If ASD is suspected, refer patient for a comprehensive
team evaluation and early intervention services sooner
rather than later!
Do not delay referral to EI pending confirmation of diagnosis
IDEA Amendments of 1997 mandate immediate
referral for a free and appropriate public education for
children w/ disabilities from the age of 3 and EI
services for infants and toddlers 0-3yrs.
Identifying children w/ autism and initiating intensive
intervention during the preschool years results in
improved outcomes for most young children with
autism!
 Pitfalls of Screening Methods

Current methods of screening for autism may
not identify:
  Children w/ milder variants of the disorder
  Children without MR or language delay, such as
  verbal children with high functioning autism and
  Asperger’s
  Older children, adolescents and young adults
                        Diagnosis
Definitive diagnosis is based on DSM-IV criteria and
standardized ASD-specific evaluation tools
   DSM-IV Criteria were developed for children 3 yrs and older

Diagnosis also involves searching for etiologic disorders
associated with ASD (involves comprehensive history and physical exam)

Standardized assessment tools for ASD include:
   The Childhood Autism Rating Scale (CARS)
   Autism Diagnostic Interview-Revised (ADI-R)
   Autism Diagnostic Observation Schedule (ADOS)

 *These are intended for use by experienced clinicians and most
 appropriate as part of a comprehensive evaluation within a
 specialty clinic
       Co-morbidities of Autism
Mental retardation (~70%)

Mood, anxiety, obsessive-compulsive disorders

Seizures (7-14% in childhood; 35% in adulthood)
    Presence of MR and a family hx of seizures both increase likelihood of
    seizures

Associated genetic syndromes
    Tuberous Sclerosis (incidence of autism secondary to TS increases if seizures are
    present)
    Fragile X Syndrome
    Angelman Syndrome
    Landau-Kleffner Syndrome (acquired epileptic aphasia)- difficult to differentiate
    from regressive autism
    History & Physical Exam
Family History
  Family members w/ social deficits, manic-depression, OCD, language d/o or
  seizures
Growth Parameters (esp. head circumference)
  Macrocephaly present in 25% of ASD patients; often presents in early to mid-
  childhood
Dysmorphic features (chromosomal anomaly)
  Large ears, long face (Fragile X), broad mouth w/ persistent smile (Angelman)
Skin (neurocutaneous syndromes- esp. tuberous sclerosis)
  Examination w/ a Wood’s lamp is indicated in all pts with suspected ASD
  hypopigmented ash leaf spots
  Facial angiofibromas
Neurologic
  Mental status, cranial nerves, tone, reflexes, gait abnormalities may suggest an
  intracranial process
  Observe for stereotypies commonly present in autistic children
                Exam Tips
Observe the child during the visit
  Eye contact, pointing, pretend play w/ simple toys,
  unusual behavior (spinning, hand-flapping), looks to
  see what you point at etc…
Reduce anxiety during the exam if ASD is
suspected
  Speak softly, avoid persistent eye contact, let parents
  undress and prepare the child, use deep pressure
  (rather than light touch) during exam due to tactile
  sensitivity
Assessment of Specific Deficits
Communication, Speech and Language assessment by a
speech pathologist
  Expressive language function ranges from complete mutism to verbal
  fluency (usually w/ errors in semantics and/or pragmatics)

Cognitive and Adaptive Behavioral assessment
  Vineland Adaptive Behavior Scale
  Classic pattern of autism is performace IQ > verbal IQ

Gross and Fine Motor and Sensorimotor assessment by a
occupational and/or physical therapist
  Evaluation of praxias, hypotonia, sensory processing abilities, unusual
  stereotyped mannerisms

                                        Filipek PA, et al. Neurology 2000;55- 468
Laboratory Investigations Indicated
          for Diagnosis
Genetic Testing
    Chromosomes and DNA analysis for FraX are indicated in the presence
    of MR, family hx of MR or FraX, or if dysmorphic features are present
Metabolic Testing
    Amino and organic acid and mitochondrial metabolism testing is
    indicated only w/ lethargy, cyclic vomiting, MR, dysmorphic features, early
    seizures or if NBS was not done
EEG (sleep-deprived w/ sampling during slow wave sleep)
    Indicated only w/ clinical or sub-clinical seizures, history of regression at
    any age
Neuroimaging
    No clinical evidence to support the role of routine neuroimaging, even in
    the presence of megalencephaly

                                           Filipek PA, et al. Neurology 2000;55- 468
        Management (in brief)
Multidisciplinary approach
   A recent review of programs for children w/ ASD
   demonstrated that the best programs were those that
      Initiate therapy as early as possible
      Individualize services for children and families
      Use systematic and structured teaching styles
      Involve families
Specific Strategies: behavioral and social skills training,
parent training and education, habilitative therapies
(OT w/ sensory integration/PT/Speech)
Family Support should not be undermined
   Education, providing info. about local and national resources,
   community organizations, Respite care

                 AAP. Committee on Children w/ Disabilities. Pediatrics. 2001;107:e85
       Medical Management
No pharmacologic cure for ASD
Medications can be helpful to minimize core
symptoms, prevent harmful behaviors
  Risperidone- may improve social relatedness and improve
  hostility, aggression, irritability
  SSRIs- if coexisting depression, anxiety or OCD symptoms
  are present
When considering medical intervention, it is
recommended that the family targets one or two
behaviors that are most troublesome
              AAP. Committee on Children w/ Disabilities. Pediatrics. 2001;107:e85
            Alternative Therapies
Nutritional supplements
   High-dose pyridoxine and magnesium
   Ascorbic acid
   Dimethylglycine
Elimination Diets (food allergy/increased GI permeability theory)
   Gluten
   Milk
Immune Globulin Therapy (defective immune system theory-abnormal T, B,
NK cell, complement)
Secretin
Chelation Therapy- (environmental neurotoxin exposure theory-especially
mercury)
Auditory Integration Training (AIT)- (defective auditory perception theory)
Facilitated Communication (FC)

  The Academy recommends against the use of these therapies


                    AAP. Committee on Children w/ Disabilities. Pediatrics. 2001;107:e85
Dispelling Myths: Vaccines and Autism
Vaccines, especially MMR and thimerosal containing vaccines,
have been postulated as a cause for the increased prevalence of
ASD
A critical review of the literature was completed and published in
Pediatrics, 2004;114 which concluded the previous studies linking
ASD w/ vaccines were of poor quality and had significant design
flaws
The Immunization Safety Review Committee and IOM have
since rejected a causal relationship between MMR and
Thimerosal-containing vaccines and development of autism
Nonetheless, in 2001, thimerosal was removed from all vaccines
in the childhood immunization schedule in the U.S (except some
influenza vaccines)
 Recommended Internet Sites
www.autism-society.org – information for families and
physicians on diagnosis, education, treatment options
www.firstsigns.org – outlines normal milestones and
red flags, information on screening tools
www.DBPeds.org – official web site of the AAP
section on Developmental and Behavioral Pediatrics;
family and physician info; tutorials on developmental
screening
http://156.40.88.3/publications/pubs/autism/facts/in
dex.htm - fact sheets developed by the NICHD
www.cdc.gov/nip/vacsafe/concerns/autism/default.ht
m - information on autism and vaccines

				
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