In this post, I link to and excerpt from PedsCases‘ Autism Spectrum Disorder, by Lauren Robinson Dec 21, 2014.
All that follows is from the above resource.
This episode defines the core features of Autism Spectrum Disorder (ASD), provides an approach to screening and diagnosis, and discusses initial management strategies. This episode was written by Lauren Robinson, Dr. Lyn Sonnenberg, and Dr. Debra Andrews. Lauren is a senior medical student at the University of Alberta. Dr. Sonnenberg is the program director and Dr. Andrews is the divisional director for developmental pediatrics at the University of Alberta.
Related Content:
- Case: Speech Delay in 2 year old male
- Case: A “very happy” 12 month old male
- Podcast: Developmental Assessment
What follows are excerpts from the script.
The Centre for Disease Control and Prevention’s latest numbers
indicate the prevalence of autism is 1 in 68 children, with boys affected about 4-5 times more frequently than girls. The reported increase in prevalence of autism since the 1980’s is
controversial. Is there more autism or are we just better at recognizing it? There are no clear answers.How we screen for autism. First, it is important to note that a positive screen does not equal a diagnosis of autism, because
autism shares symptoms with other developmental disorders. A positive screen is only the first step.In Canada, screening for any developmental condition, including autism, starts with developmental surveillance. This should take place universally at all well-child visits,
and may include taking a history using developmental milestones or using a standardized developmental screening tool, such as the Ages and Stages questionnaire (the ASQ), the Parents’ Evaluations of Developmental Status (PEDS) or, in Ontario, the Nipissing District Developmental Screen. The Canadian Paediatric Society has recommended that all children have an extended well child visit at 18 months of age and that health care providers use a standardized screener at that time.Lauren: So what features in the developmental history would make me more worried about autism?
Dr. Sonnenberg: Simply put, failure to meet milestones in the social and communication domains. There also are some red-flags you should try to remember, which would make you want to further investigate. Do you remember what some of these are?
Lauren: Yes. No big smiles or joyful expressions by 6 months, the absence of sharing sounds, smiles or other facial expressions by 9 months, and the lack of pointing, showing, and waving by 12 months old. In terms of communication, no words by 16 months and no two word meaningful phrases by 2 years is abnormal.
Dr. Sonnenberg: That’s right. It’s also important that when there is any delay, it is interpreted in the context of the child’s development as a whole. For example, in a two year-old who meets the milestones of a one year-old in all developmental domains would be less specifically concerning for autism as their social-interaction capabilities are aligned with their developmental age. Of course, further work-up of global
developmental delay would certainly be indicated in this child.Lauren: Is there anything else I should be asking on history?
Dr. Sonnenberg: As for any pediatric history, it is important to start broadly and ask the caregivers if they have any concerns, developmental or otherwise. Inquiring about a family history of autism or other genetic disorders is key, as autism has high heritability. In addition, asking about feeding and a general review of systems is important, as feeding issues can be associated with autism, and development can be affected by many chronic medical conditions.
Dr. Sonnenberg: In many children, no. Sometimes head circumference may be increased, especially in comparison to body proportions, in the toddler years, particularly if it started out in the normal range. There is also a subgroup of children with Autism who have medical syndromes, such as fragile X, which may have findings on physical exam. Eye contact and hand flapping can also be noted, so a thorough physical exam is important, looking especially for dysmorphology and minor anomalies.
*Fragile X Syndrome
Updated: Jul 23, 2020 from emedicine.medscape.com:Fragile X syndrome, also termed Martin-Bell syndrome or marker X syndrome, is the most common cause of inherited mental retardation, intellectual disability, and autism and is the second most common cause of genetically associated mental deficiencies, after trisomy 21. Conservative estimates are that fragile X syndrome affects approximately 1 in 2500-4000 males and 1 in 7000-8000 females.
The criterion standard diagnostic test for fragile X syndrome involves molecular genetic techniques that detect the FMR1 gene. [1]
Lauren: Let’s say during developmental surveillance this 18 month-old boy had not been pointing to objects to get his parents’ attention, and spent hours everyday sitting spinning the wheels of his favorite toy car. In terms of language, he was able to say three words. He seemed to be aligned with his peers in terms of motor development, but never seemed very interested in the other toddlers at daycare. His physical exam was normal.
Dr. Sonnenberg: Now you are suspicious of Autism. In this case, it would be appropriate to move onto the second level of screening. Indications for secondary screening are:
parental concern, having a sibling with autism, and having social or communication delays during developmental surveillance. Secondary screening involves using an autism- specific screening tool, such as the Modified Checklist for Autism in Toddlers Revised with Follow-up ( or the M-CHAT-R/F)*. It’s a questionnaire administered by a health practitioner to parents for children age 16-30 months.*Modified Checklist for Autism in Toddlers Revised with Follow-up (M-CHAT-R/F)
Instructions for Use
The M-CHAT-R can be administered and scored as part of a well-child care visit, and also can be used by specialists or other professionals to assess risk for ASD. The primary goal of the M-CHAT-R is to maximize sensitivity, meaning to detect as many cases of ASD as possible. Therefore, there is a high false positive rate, meaning that not all children who score at risk will be diagnosed with ASD. To
address this, we have developed the Follow-Up questions (M-CHAT-R/F). Users should be aware that even with the Follow-Up, a significant number of the children who screen positive on the M-CHAT-R will not be diagnosed with ASD; however, these children are at high risk for other developmental disorders or delays, and therefore, evaluation is warranted for any child who screens positive. The M-CHAT-R can be scored in less than two minutes. Scoring instructions can be downloaded from
http://www.mchatscreen.com. Associated documents will be available for download as well.Lauren: Okay, so say I decide to use the M-CHAT R/F, and I score it and it‘s positive. What should I do next?
Dr. Sonnenberg: After a positive screen, the next step is referral to a multidisciplinary team for diagnostic assessment. The team varies depending on local resources but usually includes a physician, (usually a developmental pediatrician, child psychiatrist, or pediatric neurologist), psychologist, speech language pathologist, nurse, social worker, and/or occupational therapist. These are all individuals with expertise in the diagnosis of autism and other forms of developmental delay.
Lauren: So it sounds like investigations are highly dependent on history and physical exam, and it is important not to send these children for tons of tests without reason.
Dr. Sonnenberg: Exactly! Although the cause of autism is not known, most cases seem to be polygenetic. Very rarely is there ever one gene, metabolic abnormality, brain lesion, or environmental influence leading to autism.
Lauren: That makes sense. So once children see the multidisciplinary team, how is the diagnosis made?
Dr. Sonnenberg: It is likely that the team will use several tools, such as the Autism Diagnostic Inventory Revised (or ADI-R) for the autism history and the Autism Diagnostic Observation Schedule (or ADOS) for a standardized, semi-structured observation of the child assessing socialization, communication, and play skills. The diagnostician will use the results from these tools, the results of the assessments of other multi-disciplinary team members, and their own clinical judgment in accordance with the Diagnostic Statistic Manual of Mental Disorders, Fifth Edition.
Lauren: So once we have a diagnosis, what are the treatments available?
Dr. Sonnenberg: Early, intensive educational and behavioral therapy has been associated with improved language and social skills. To get a sense what is meant by“intensive”, most interventions are than 25 hours per week.
Lauren: That’s a lot of intervention! Aren’t there any medications that help with autism?
