Week 3 - Asd In Early Life

Front 1

ASD as a cluster of neurodevelopmental disorders:

Back 1

- Represents a deviance from the normal developmental course; a different way of developing, not just a delay in the pace of normal development

- Highly heterogeneous; probably a cluster of conditions with different causes and siliar behavioural representation

- No definitive genetic/biological test

Front 2

Assessment:

Back 2

Procedure of gathering information about a person's skills and weaknesses

- Thorough assessments are needed for accurate diagnosis and need to be able to indicate a treatment/management plan

Front 3

Diagnosis:

Back 3

Deciding that a particular classification fits that person's presentation

- Can be difficult because symptoms vary considerably in different people and symptoms are expressed differently at different chronological/mental ages

Front 4

Who is involved in an assessment and diagnosis?

Back 4

Multidisciplinary team with ASD expertise:

- Medical practitioner: Paediatrician, Psychiatrist.- Allied health workers: Speech Pathologist & Psychologist.

- Others may include: Occupational Therapist, Social Workers & Educators.

Front 5

How are assessments conducted?

Back 5

- Specialist team/clinic (sent to an ASD clinic at the Royal Children's Hospital)

- Oversight by medical practitioner with referral to allied health workers.

Front 6

What tools are used during an assessment?

Back 6

- Standardised assessments (different tests) & other forms of information gathering (informal observation at school).

- Combined with clinical judgement – toward a DSM-5 Diagnostic Classification.

Front 7

Steps to and through an ASD diagnosis:

Back 7

1. Concerns raised

2. Referral for assessment/monitoring

3. Diagnosis given

4. Intervention/Support accessed

These steps may overlap, go back and forth, or be out of order

Front 8

"Concerns Raised"

Back 8

Either:

- The parent becomes concerned.

- Someone else raises concerns to parent (relative; friend; child minder)

- Concerns identified through standard community screening: - Maternal & Child Health (MCH) nurse or similar

- Triggers referral to GP; Paediatrician; Speech Therapist; Specialist service

Front 9

Community Based Screening for ASD - Level 1

Back 9

Screening tools to ‘flag’ potential early ASD:

- Targets all children during standard wellness checks, there is often low specificity in tests

Checklist for Autism in Toddlers (CHAT; Baron-Cohen et al., 1992; 1996):

̶ Administered at 18-months: Excellent specificity (98%); poor sensitivity (38%).

Modified-CHAT (Robins et al., 2001):

̶ Administered at 24 months: Identifies many children who do not have ASD.

Early Screening of Autistic Traits Questionnaire (ESAT; Swinkelset al., 2006):

̶ Well-baby clinic at 14 months: again, low sensitivity

Front 10

Community Based Screening for ASD - Level 2

Back 10

- For those flagged 'at risk' on the basis of level 1 screening

- Referred for level 2 screen (cheap&quick) and diagnostic assessment (expensive&lengthy)

- Aims to specifically identify children with ASD vs. other developmental difficulties.

- Social Communication Questionnaire (SCQ; Rutter et al., 2003)

- Parent questionnaire. Childhood Autism Rating Scales (CARS; Schopleret al., 1988)

Front 11

Developmental Surveillance

Back 11

- There are multiple time points where children are able to be assessed

- This is a level 1 tool with a different procedure

Front 12

There are multiple opportunities/ages to 'catch' children showing early signs for Developmental Surveillance:

Back 12

--> 12 months

--> 18 months

--> 24 months

--> 36 months

Front 13

Specificity

Back 13

Proportion of children without ASD, correctly identified as such (how specific the test is - ability to rule out non-ASD)

Front 14

Sensitivity

Back 14

Proportion of children with ASD, correctly identified as such (how sensitive the test is at correctly detecting children with ASD)

Front 15

Positive Predictive Value (PPV)

Back 15

Test "accuracy" - case ascertainment rate

Front 16

Negative Predictive Value (NPV)

Back 16

Correctly identifying that a child is "not at risk"

Front 17

Social Attention and Communication Study

Back 17

- 241 MCH Nurses were trained

- Surveillance on 20,770 children in Melbourne

- Those at risk were referred

- Then followed up every 6 months until they were 24 months old

- Total children showing ASD: 89/110

Positive Predictive Value: 81%

Estimated Sensitivity: 83.4%

Estimated Specificity: 99.9%

Front 18

From the Social Attention and Communication study, what was the estimated prevalence of ASD?

Back 18

1 in 119 children (~1%)

Front 19

Autism Diagnostic Observation Schedule (ADOS) (Lord et al., 2000-2013)

Back 19

• Focus of observation is on key diagnostic features.

- Social motivation and communication skills.

- Restricted, repetitive and stereotyped behaviours & interests.

• Assessor does specific things and observes child’s response.

- Various aspects of behaviour scored.

- Key items transferred to ‘diagnostic algorithm’.

- Cut-off scores facilitate interpretation

Front 20

Autism Diagnostic Interview - Revised (ADI-R) (Lord et al., 1994)

Back 20

- Semi-structured interview assessment with parent/caregiver reports

> Social motivation and communication skills. > Restricted, repetitive and stereotyped behaviours & interests.

> Allows checking of ‘onset’ criterion and regression.

- Interviewer scores various aspects of parent/caregiver response

Front 21

Mullen Scales of Early Learning (1995)

Back 21

Tests:

• Visuo-Spatial Skills

• Motor Skills: Gross Motor & Fine Motor

• Language Skills: Receptive (comprehension) & Expressive (production)

Front 22

What is the atypical profile common in ASD?

Back 22

They have visuo-spatial strengths and language weaknesses (especially receptive language)

- There is an atypical profile of different strengths and weaknesses in cognitive skills

- What we see in autism is often a strange profile where some skills are abnormally good and otherskills are abnormally poor for that particular person's age

- Performance is normally in a straight line on average, across the different domains

Front 23

If it is not ASD then it could be (and not to be confused with):

Back 23

- Acquired brain injury

- Speech/language impairment (SLI); Attention-deficit/hyperactivity disorder (ADHD); Obsessive compulsive disorder (OCD); Psychopathy; Schizophrenia.

Front 24

What occurs after an ASD diagnosis?

Back 24

- Intervention

- Management

- Support

Front 25

What percentage of parents reported suspecting a problem with then child at <12 months?

Back 25

~ 50%

The interval between first concerns and seeking professional help M = 6 months

Front 26

What was the average time between parental first concerns & ASD diagnosis?

Back 26

2 - 4 years

Diagnosis is usually between 3 & 5 years (Bent, Dissanayake & Barbaro, 2015), with the average age of diagnosis being 4.1 years

Front 27

What are the four broad methods for identifying the early signs of ASD?

Back 27

1. Retrospective parent report

2. Retrospective analysis of home video footage

3. Prospective high-risk sibling studies.

4. Prospective community-based screening/surveillance studies

Front 28

What is the definition of retrospective?

Back 28

Looking back in time

Front 29

What is the definition of prospective?

Back 29

Looking forward in time

Front 30

Method 1: Retrospective Parent Report

Back 30

Done through an interview or questionnaire

- Problems may be present < 3 years

- Problems may always be there or may have a regressive onset

- Parent-report can be subject to recall/response biases

- Behaviours of interest may be too subtle to notice

Front 31

Method 2: Retrospective Home Video Studies

Back 31

Objective observation of natural behaviour in real life contexts through using technology (video cameras)

This allows to show for any irregular behaviours/ symptoms of ASD

Front 32

Method 3: Prospective High-Risk Sibling Studies

Back 32

- There is a ~1% population prevalence

- But there is high heritability ~20% sibling recurrence

- Recruit participants in toddler-hood; infancy; (pre-natally!?)

- Track over early developmental period and assess for ASD

Front 33

Method 4: Prospective Identification in the Community

Back 33

• Large sample sizes required: e.g. if 1% population prevalence & you want 100 children with ASD, need to screen at least 10,000 children – and only if your test has Tim (Godber)’s “perfect d”... ;)

• Can only ‘catch’ children as early as the screening tool ‘works’.

• Long follow-up time required.

Front 34

When does ASD first appear?

Back 34

Three different modes of onset:

1. Innate: Born with it and presents right away.

2. Plateau: Starts fine but rate of development slows (still acquiring new skills but not as quickly)

3. Regression: Starts fine with sudden skills loss (child ‘becomes’ autistic)

Front 35

Canalisation:

Back 35

Restored ‘normative’ development in many high-risk siblings

Front 36

What are "simplex" and "multiplex" families?

Back 36

“Multiplex” refers to families in which multiple individuals are affected by a specific disease, while “simplex” refers to families in which only a single individual has a specific disease.