Autism Spectrum Disorders: Early Course and Diagnosis

1
Autism Spectrum Disorders Early Course and
Diagnosis
Rhea Paul, Ph.D., CCC-SLP And Kasia Chawarska,
Ph.D. Yale University School of Medicine Child
Study Center www.autism.fm
2
Overview

• Early diagnosis of ASD conceptual and
  methodological challenges
• First year early signs
• Symptoms of ASD in 2nd and 3rd year
• Stability of clinical diagnosis
• Changes in syndrome expression

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Diagnosis of Autism

• Onset of Autism prior to 36 months
• Average age of diagnosis of autism in children
  under 12 years 4 to 5 years
• Average time elapsed between first parental
  concerns and the diagnosis 2 to 3 years

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Onset of Parental Concerns

• Average 14.7 months (SD6.5)
• Age of first concern
• 0-11m 20
• 12-17m 36
• 18m-24 44
• Primary concerns
• Speech delays
• Social concerns

(Chawarska, Paul, Klin et al., 2007,Journal of
Autism and Developmental Disorders).
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Onset of Autism Overt Manifestations

• Early onset (1st year)
• early manifestations of lack of social
  reciprocity (inborn autistic disturbances of
  affective contact Kanner, 1943)
• Later onset (2nd year)
• Plateau developmental slowdown after a period of
  more or less typical development (Landa et al.,
  2007)
• Regression social withdrawal and loss of words
  20-30 (Eisenberg Kanner, 1955 Dawson et al.,
  2006 Landa et al., 2007)
• Large prospective studies are needed!

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Challenges in Early Diagnosis

• Diagnostic issues
• DSM-IV (1994) few lt36 month olds included in the
  field trial
• Limited sensitivity and specificity of the
  state-of-the-art diagnostic instruments (ADOS-G,
  ADI-R) in children with mental age lt 18 months
• Conceptual issues
• Birth to 36 months period of rapid development
  change
• Symptoms are likely to vary depending on
  chronological and mental age

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Autism in the 1st year of life

• Retrospective studies
• Parental report
• Video diaries analysis
• Prospective studies
• Recurrence risk in younger sibs
• Autism approximately 5-10, higher for the
  spectrum disorder
• High risk for other disorders (learning problems,
  social difficulties, language delays, broader
  autism phenotype, etc.)

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Head Growth Pattern Infants with Autism

• Unusual head growth pattern in infants with
  autism (Courchesne et al., 2001 2003)
• Initial acceleration, followed by deceleration
  after 12 months (Dawson et al., 2007 )
• Unclear etiology
• Unclear relation to autism
• Issues of sensitivity and specificity
• Need for more precise measurement of brain size
  sMRI sibling studies

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Abnormalities in Social Interaction

• Limited social reciprocity (no social smile, few
  bids for attention, little pleasure derived from
  interactions)
• Unusual eye contact
• Limited affective range and facial expressions
  directed at others
• Limited joint attention skills
• Poor observational/imitative learning
• Limited response to name

Chawarska Volkmar (2005). Autism in Infants
and Toddlers. In Handbook of Autism and
Developmental Disorders
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Communication

• Low frequency of communication
• Paucity of conventional gestures (nonverbal
  communication)
• Limited goals of communication (instrumental
  versus declarative)
• Stereotypical/idiosyncratic use of language
  (e.g., echolalia, scripting)
• Use of others body to communicate
  (hand-over-hand gestures)

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Abnormalities in Play and Imagination Development

• Functional play (may be spared but limited)
• Pretend play marked difficulties
• Absent
• Present but repetitive and lacks creativity

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Restricted Interests and Repetitive Behaviors

• Interest in specific visual stimuli (lights,
  spinning objects)
• Seeking sensory input (jumping, rocking,
  spinning)
• Interest in details of objects (e.g., wheels,
  dials)
• Hand and finger mannerisms

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ASD Screeners-Under 3

• M-CHAT
• STAT
• CSBS Screener
• PDDST

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ASD Diagnostic Instruments-Under 3

• ADOS-T
• ADI-R
• CARS
• CSBS

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Best Estimate Clinical Diagnosis

• Limited utility of the existing diagnostic
  measures (DSM-IV, ADI-R, ADOS-G) in infants and
  toddlers with ASD (Chawarska Volkmar, 2005
  Volkmar et al., in press)
• Expert clinical diagnosis constitutes gold
  standard (Klin et al., 2003 Lord Risi, 2000
  Spitzer Williams, 1988 Stone et al., 1999)
• Importance of assessing social communicative
  skills in a context of cognitive and adaptive
  functioning as well as medical hx (Chawarska et
  al., in press Klin et al., 2003 Lord Risi,
  2000 Volkmar, et al., 1994).
• Clinical experience matters (Rutter, 1978 Klin,
  Lang, Cicchetti, Volkmar, 2000).

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Stability of Best Estimate Diagnosis

• Short term stability (2nd year to 4 years) (Cox
  et al., 1999 Chawarska et al., 2007)
• Very good for ASD diagnosis (80-90)
• Changes expected within spectrum due to shifts in
  number of symptoms and intensity
• Long term stability (2 to 4 to 9 years) (Lord et
  al., 2006)
• High stability of best estimate ASD diagnosis
  (90)
• Shift from PDD-NOS to Autism Dx 20
• Shift from Autism to PDD-NOS 10

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Stability of the Best Estimate Diagnosis
Chawarska, K. (2007) Talk presented at the
Society for Research in Child Development
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Verbal and Nonverbal Functioning

• Mullen Scales of Early Learning (Mullen, 1995)
• NONVERBAL SCALES
• Visual Reception (VR) object permanence, visual
  discrimination perceptual categorization
• Fine Motor (FM) visual-motor coordination
• VERBAL SCALES
• Receptive Language (RL) understanding of
  nonverbal and verbal communication
• Expressive Language (EL) use of gestures and
  language to communicate

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Stability of Syndrome Expression

• Clinical diagnosis of Autism Spectrum Disorder is
  relatively stable in early childhood (see also
  Lord, 1995 2006 Cox et al., 1999 Charman et
  al., 2006 Chawarska, et al., 2007 Chawarska,
  2007)
• Amongst infants presenting with Autism and severe
  impairments in cognition approximately 30 is
  likely to make very significant gains in all key
  domains of functioning (see also Sutera et al.,
  2007)
• Infants who present with milder symptoms are
  likely retain the diagnosis by the age of 3 to 4
  years but worsening of symptoms is less likely

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Change in Socialization Symptoms from 2 to 4
years

• In the 2nd year
• Profound impairments in motivation and ability to
  engage in reciprocal interactions with others
• In the 4th year
• Improvement in responsivity to attentional cues
  (response to name and verbal and nonverbal bids
  for attention)
• Limited improvement in spontaneous initiation of
  social interactions
• Chawarska et al., 2007, JCPP

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Change in Communication Symptoms from 2 to 4
years

• In the 2nd year
• Profound delays in expressive and receptive
  language in a majority of cases
• Failure to use eye contact, affect, and gestures
  to compensate for lack of language
• In the 4th year
• improvement in responsivitiy to language and
  increased range of vocalizations and
  verbalizations
• increase in frequency of communication
• emergence of echolalia and stereotyped language
• limited spontaneous use of language gestures
  for com.

Chawarska et al., 2007, JCPP
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Change in Stereotyped and Repetitive Behaviors
Domain from 2nd to 4th year

• In the 2nd year
• Unusual interests in sensory dimensions of
  objects light, texture, details
• Some repetitive behaviors (lining up, grouping)
• Very few motor mannerisms
• Self-injurious behaviors extremely rare
• In the 4th year
• Repetitive behaviors might intensify, more
  frequent motor mannerisms, but overall limited
  increase
• Chawarska et al., 2007, JCPP

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Changes in Cognitive Functioning in Autism from
2nd to 4th year

• In the 2nd year
• Verbal skills 30 in average to below-average
  range
• Nonverbal skills 75 in average to below-average
  range
• In the 4th year
• 50 in average to below-average range
• High individual variability in the rate of
  progress
• Verbal skills 50 either maintained average
  standard scores of improved, 50 retained low
  scores or declined
• Nonverbal skills 45 maintained average-below
  average scores, 25 maintained low scores, 30
  declined

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Conclusions

• Symptoms of social dysfunction are apparent in a
  majority of cases by 24 months often earlier
• Stability of the Autism Spectrum diagnosis is
  high
• Young children with ASD differ widely in syndrome
  expression and levels of functioning
• Young children with ASD show highly variable rate
  of progress reflected in changes of diagnostic
  classification, IQ, and verbal ability

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Evaluating Children with ASDUnder 3

• Developmental Assessment (e.g., Mullen)
• Vineland Adaptive Behavior Scales
• CSBS-video example

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Video Examples

• HL