Autistic Spectrum Disorder Flashcards
When was the last revision from DSM-5 for ASD diagnosis?
2013
When was the last revision from ICD for ASD?
ICD-11 in 2018
What is social/pragmatic communication disorder?
A new diagnostic category introduced in DSM-5 to identify those individuals with persistent deficits in social communication and social interaction in the absence of restricted, repetitive patterns of behaviour, interests and activities
What is ASD?
Autism spectrum disorder has been characterized by qualitative behavioural abnormalities in communication, reciprocal social interaction together with patterns of repetitive, restricted and stereotyped interests and activities. These deficits are pervasive, persistent, usually present in early childhood and likely to lead to impairments in functioning across different settings.
How common is ASD?
The National Institute of Health and Clinical Excellence (NICE) states the diagnosis is queried in approximately 3% of the child population and epidemiological studies suggest prevalence rates of at least 1 in 100.
What is the genetics behind ASD?
It has a complex genetic basis with strong heritability (60% concordance reported in twin studies). Recurrence rates for siblings have been reported between 3 and 10% with up to 18.7% when the broader autism spectrum is considered.
How often is ASD associated with a different medical condition?
In 10–15% of cases ASD is associated with a known medical condition. Consistently recognized genetic conditions include tuberous sclerosis (TS) and fragile X.
What the risk factors for ASD?
- Sibling with ASD
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Parental schizophrenia-like-psychosis or affective disorder
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Maternal sodium valproate use during pregnancy
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Gestational age less than 35 weeks
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Intellectual disability
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Birth defects associated with central nervous system including cerebral palsy
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Down syndrome
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Fragile X
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Tuberous sclerosis
What are the associated medical condtions?
Neurofibromatosis
Phenylketonuria (untreated)
Fetal alcohol syndrome
Smith–Lemli–Opitz syndrome
CHARGE syndrome
Duchenne muscular dystrophy
Congenital rubella
Iron-deficiency anaemia
How often is macrocephaly seen in ASD?
20-30%
What is the significance of macrocephaly in ASD?
Macrocephaly is a recognized feature of ASD in 20–30% of cases though must be interpreted in the context of parental head circumferences. Studies have shown that as a group, head circumference accelerates during the first 2 years of life, with deceleration possibly occurring in later childhood since average head circumference has been reported in adolescence and adulthood. Although there have been conflicting views around the relevance and cause of these changes, they are reported to happen prior to the onset of clinical symptoms and may be a useful clinical indicator. Gene mutations in PTEN (Phosphatase and Tensin Homolog) have been found in children with ASD and macrocephaly with case series reporting a yield of 5% in those with head circumferences greater than 98th percentile.
Why is there a delay in ASD diagnosis until 4-5 years of age?
Due to a combination of factors that include
- variability of assessment pathways
- demand on services
- lack of recognition of subtle difficulties at a young age
- presence of additional diagnoses and inclusion of school age individuals who may only present at an older age when their difficulties may become more overt as they are unable to manage increasingly challenging academic and/or social expectations.
What the earliest feature of ASD?
Difficulties and delay in social interaction are often the earliest features in ASDs
Which feature is highly suggestive of ASD?
Lack of joint attention
What is absence of joint attention?
failure to show interest, share a focus of attention and follow gaze
What are examples of gestures that may be inadequate?
shaking head, nodding, waving, clapping
What is the difference between specific language disorder and ASD?
In contrast to those with specific language disorders, children with ASD often fail to use gestures or mime to compensate. Instead, parents may describe the child either obtaining a required object themselves or taking another person’s hand to the object as if to use them as a ‘tool’.
How is language affected?
Language is often atypical with idiosyncratic use of words or phrases, e.g. nonsense or jargon words, or referral to self as ‘you’ (pronominal reversal). Other features include abnormal delivery of speech (prosody), i.e. unusual pitch, speed, volume or tone. Whatever the language skills present, two-way reciprocal conversational interchanges tend to be difficult, particularly if the topic of conversation is restricted to the narrowed/circumscribed and repetitive interest of the affected individual. An individual with ASD often struggles to engage in social chat and build on conversation about someone else’s hobby or interest.
What is delayed echolalia?
Delayed echolalia is the term applied to copied or directly imitated speech, e.g. from an adult (such as a relative or teacher, television or radio) that is repeated some time after it is originally heard.
How often is regression seen in ASD?
20-30%
When is language regression most often reported?
Regression most commonly affects language, usually at the less than 10 word stage, therefore it is most often reported from 18 to 24 months of age.
What to worry about if there is regression after 3 years?
Autistic regression in children over 3 years or regression in motor domains warrant careful assessment by a paediatrician or paediatric neurologist to consider neurodegenerative conditions, such as Rett syndrome and Landau Kleffner.
How ofetn is LD seen in ASD?
Comorbid learning disability is reported to affect approximately 50% of people with ASD’s
What is the association between ASD and epilepsy?
The risk of epilepsy in ASD is increased compared with the general population and linked to lower IQ and regression, with peaks of incidence occurring at pre-school age and adolescence. Between 18% and 29% of children with ASD are affected and any seizure type can occur.
