Autistic%20disorder Diagnosis

Diagnostic Criteria

• According to DSM-5 criteria, autism spectrum disorder (ASD) is diagnosed as having the characteristic symptoms of:
  • Persistent social communication and interaction deficits that are manifested either previously or currently by the following deficits in:
    • Social-emotional reciprocity that may range for example from abnormal social approach and unsuccessful normal back-and-forth conversation; to decreased sharing of interests, emotions or affect; to inability to initiate or respond to social interactions
    • Nonverbal communicative behaviors that are used for social interaction exemplified by:
      • Verbal and nonverbal communication that are poorly integrated
      • Abnormal eye contact and body language
      • Lack of understanding and use of gestures
      • Absence of facial expressions and nonverbal communication
    • Developing, maintaining and understanding relationships seen as:
      • Difficulty in adjusting behavior that fits various social settings
      • Difficulty in sharing imaginative play or in making friends
      • Lack of interest in other people
    • Severity of the above deficits will be based on impairments on social communication and restricted, repetitive patterns of behavior
  • Restricted, repetitive behaviors, interests or activities demonstrated by ≥2 of the following symptoms observed either previously or currently:
    • Motor movements, use of objects or speech is stereotyped or repetitive, for example, motor stereotypes, echolalia, ordering of toys or flipping objects, idiosyncratic phrases
    • Insists on adherence to routines, sameness, or ritualized patterns of verbal or nonverbal behavior such as showing frustration at small changes, hard to deal with transitions, rigid thinking patterns, rituals in greeting, taking the same route or eating the same food every day
    • Abnormal strength or focus on highly restricted or fixated interests like being deeply preoccupied or attached to unusual objects, having excessively circumscribed or perseverative interests
    • Heightened or diminished response to sensory input or unusual interest in the sensory aspects of the environment such as having apparent indifference to pain or temperature, responding adversely to particular sound or texture, frequent smelling or touching of objects, visual fascination with lights or movement
    • Severity of the above symptoms will be based on impairments on social communication and restricted, repetitive patterns of behavior
  • The above symptoms must be present from early childhood. However, they may not be fully evident until social demands exceed limited capacities or may be masked by learned strategies as the child ages
  • The above symptoms bring about significant impairment in function eg social, occupational or other important areas of functioning
  • The disturbances are not due to intellectual disability or global developmental delay
• Usually, autistic disorder and intellectual disability co-occur and it is diagnosed as comorbid if there is the presence of social communication that is below expected for general developmental level
• ASD diagnosis is given to individuals with well-established DSM-4 diagnosis of autistic disorder, Asperger’s disorder or pervasive developmental disorder that is not otherwise specified. For individuals that do not meet the criteria for ASD but have marked deficits in social communication, they should be evaluated for social communication disorder
• Also according to DSM-5, specify if autistic disorder has:
  • Presence or absence of accompanying intellectual impairment
  • Presence or absence of accompanying language impairment
  • Associated with a known genetic or medical condition or environmental factor
  • Associated with another neurodevelopmental, behavioral or mental disorder
  • Catatonia

Diagnostic Tools

• Should at least have moderate sensitivity and good specificity
• Includes interview with the parents and direct observation of patient

Parental Interviews

• Should be standardized with regard to present concern and history of behavior
• The following diagnostic tools may be used:
  • Gillian Autism Rating Scale
  • Parent Interview for Autism
  • Pervasive Developmental Disorders Screening Test - Stage 3
  • Autism Diagnostic Interview-Revised (ADI-R)
  • Diagnostic Interview for Social and Communication Disorders (DISCO)
  • Developmental, Dimensional and Diagnostic Interview (3di)

Direct Observation

• A structured observation of the social and communication skills of the patient
• The following diagnostic tools may be used:
  • Childhood Autism Rating Scale 2nd edition (CARS-2)
  • Screening Tool for Autism in Two-Year-Olds
  • Autism Diagnostic Observation Schedule 2nd edition (ADOS-2)

• All children should undergo routine developmental screening during a well-child visit
  • Close surveillance is recommended in children at high risk for autism (eg if presenting with symptoms of autism, with a sibling diagnosed with autistic disorder, with a genetic condition with known autism spectrum disorder risk, history of prematurity or prenatal exposures)
• Identify patients at risk of any developmental problems and among which, patients at risk of autism should be identified
  • Screening should include autism, language delay, learning difficulties, social problems, anxiety or depression
• Developmental screening tools are available for the pediatrician’s use:
  • Ages and Stages Questionnaire
  • Child Development Inventories
  • Parent’s Evaluations of Developmental Status
• Developmental language milestones appropriate for age should be assessed:
  • Babbling by 12 months
  • Appropriate gesture to point and show by 12 months
  • Single words by 16 months
  • Spontaneous 2-word phrases by 24 months
  • Decline of language and social skills at any age
• Milestones inappropriate for the child’s age should warrant further evaluation
• Formal audiologic assessment and lead screening are recommended in children with developmental delays, especially those with social and language delays, and those who remain for a prolonged period of time in the oral-motor stage of play
• Surveillance by healthcare providers is recommended at 18-months old and again at 24-36-months old for checking of signs of autism
• Screening for any abnormal socio-emotional-developmental delay, any odd repetitive behaviors in the developmental screening or failure of joint attention or the use of Checklist for Autism in Toddlers (CHAT) may be considered so that some high functioning autism or Asperger syndrome will not be missed

Evaluation

• Determine presence of other medical conditions associated with autistic disorder
  • Fragile X syndrome
  • Tuberous sclerosis
  • Mitochondrial disorders
  • Soto syndrome
  • Inborn error of metabolism that may require treatment
  • Fetal alcohol syndrome
• Confirm presence of comorbidity that may require treatment such as seizure disorder, intellectual disability, attention-deficit hyperactivity disorder, sleep problems, feeding problems, deficits in motor coordination
• Complete audiologic assessment should be made to obtain hearing status, including middle ear function

• Screening for autism should be done on all patients failing developmental screening tests

Checklist for Autism in Toddlers (CHAT)

• For 18 months-old children
• Highly specific but less sensitive to milder symptoms
• May be used to detect clinical features of autistic disorder in young children but is not intended for ruling out of autism

Early Screening for Autistic Traits (ESAT)

• A screening tool containing 14 questions answerable by yes or no
• Can be used for children 14-15 months
• Includes screening for early signs and symptoms of autistic spectrum disorder (ASD) (eg attention, eye contact)

Infant Toddler Checklist (ITC)

• A 24-item questionnaire which is a component of the Communication and Symbolic Behavior Scales Developmental Profile (CSBS-DP)
• Used to screen for communication delays in children age 6-24 months

Modified Checklist for Autism in Toddlers (M-CHAT)

• A 23-item questionnaire regarding the child’s behavior
• Parent report version of CHAT, as part of surveillance
• Used for children 16-30 months of age; for 18 months old to early identify autism and 24 months-old children for identification of regression among toddlers
• Like CHAT, this is also used to detect clinical features of autistic disorder but is not intended for ruling out of autism
• The revised version of this tool called Modified Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F) contains less questions, simplified scoring, but with improved positive predictive value

Parent’s Observations of Social Interactions (POSI)

• A 7-item caregiver-report screening tool for ASD used in children 16-35 months of age

Screening Tool for Autism in Toddlers and Young Children (STAT)

• Clinician-directed, interactive and observation measure used for screening in children age 24-36 months
• Consists of a 20-minute-long-play-based sessions wherein 12 activities in 4 domains (play, requesting, directing attention and motor imitation) are evaluated

Social Communication Questionnaire (SCQ)

• Formerly known as Autism Screening Questionnaire
• Parent-rated questionnaire
• For children 4 years and older
• Child’s social interaction, communication, language and stereotypic behaviors are evaluated