Autism Spectrum Disorders Flashcards
ASDs are characterized by severe and pervasive impairment in several areas of development:
- Reciprocal social interaction skills
- Communication & language skills
- The presence of stereotyped behavior, interests and activities
Often Associated with:
-Mental Retardation and/or a diverse group of medical conditions (e.g., chromosomal abnormalities, congenital infections, structural abnormalities of the CNS, etc.)
Autism - DSM (#?)
DSM 3 - 1980
In most cases there (is or isn’t) normal devlopment
Is not
Cause of Autism?
- No single cause (multiple causes)
- No biological marker
Current view of autism
some factor(s) act through one or more mechanism to produced a final common pathway of CNS insult that results in the behavioral syndrome of autism
Current Research
- Abnormalities in the genome
- mechanisms underlying the expression of abnormalities during brain development
- Resulting structural and functional abnormalities in the brain
- Behavioral expressions of autism
Autism Gene
- FXR1
- 15q11-13
- 17q11-21
Mirror Neurons
- Found in inferior frontal gyrus and inferior parietal lobule
- Theorized to be important for understanding actions and learning through imitation
- Contributes to theory of mind skills
- fMRI show less activity in the inferior frontal gyrus in autistic children
Amygdala
- “almond”
- important for fear conditioning, memory consolidation, and emotional responses
- suspected to be a concern in autism
- Men and boys with autism have fewer neurons in amygdala
- Either there are fewer neurons or autism is degenerative
Amygdala damage impairs ….
recognition of complex mental states more than it does basic emotions, though both are affected
Basal Ganglia
- Difficulties with dealing with environmental changes
- egosyntonic vs. egodystonic
Right caudate size
- Basal Ganglia
- Right caudate volume is 10% greater in autistic individuals
Oxytocin in Autism
- synthesized in hypothalamus released via posterior pituitary
- some data suggests it has a role in enhancing social behaviors, establishing empathy, and decreasing repetitive behaviors
Fusiform Gyrus
-FG is a general recognition area for things that people enjoy or like
Autistics tend to lack the facial inversion effect
most individuals by 6 months of age are better at recognizing faces when presented right-side up, but autistics never achieve it and thereby recognize faces equally well right-side up or upside down
Activation of fusiform gyrus
- in autistic children when shown mothers but not strangers
- perhaps autistic kids could be trained to learn better face recognition skills
Brain Size
- Initially kids with AS have smaller heads from 1-2 months, but then grow to normal from 6-14 months
- in in grey matter cells
Vaccines
Thought there may have been a connection between MMR and PDD/Autism, but the USIM has confirmed it to be false
Diet
- some kids with PDD will show symptom improvement when gluten (found in wheat products) and casein (found in dairy products) are removed from their diet
- Kids with PPD may have inc opiods in urine, but they do not respond to naltrexone
Autism is a
- spectrum disorder
- Usually related to cognitive skills (roughly ½ – ¾ are MR
- retrospective diagnosis (developmental history is vital)
Greatest Hallmark of Autism is
- inconsistency in development
- spurts then delays (he began to speak then stopped)
Normal Developmental Oddities
- spinning
- toe walking
- odd/rigid food preferences
- # Many autistic symptoms are developmentally “normal”
Two Types of Onset
- Symptoms present in the first year of life (most cases)
- Apparent normal development for the first 12 – 24 months of life prior to the onset of symptoms
Epidemiology
- occurs worldwide
- estimates 1:100
- Delays in diagnosis of at least 1.5 years
- Usually around 3 years of age
- 4:1 gender ratio male to female
Familial pattern
- each subsequent child born into a family with an autistic child has a 8-9% chance of having autism
- Twin studies show 60 –85% concordance for identical twins vs. 10% concordance for fraternal twins
Associated Illnesses/ Comorbidity
- Frequently associated with MR
- Epilepsy
- Developmental Syndromes
- ADHD
- OCD
- Depression and Anxiety
- Other
Phenotype: Social Interaction
- Younger children may have little or no interest in establishing friendships
- Older individuals may have an interest in friendship but lack an understanding of social conventions and how to interact
- Often an individual’s awareness of others is markedly impaired, demonstrating no concept of the needs & interests of others
Phenotype: Communication
- pitch, intonation, rate, rhythm, or stress may be abnormal
- Grammatical structure is often immature, stereotyped
- Disturbance in pragmatic/social use of language is evidenced by an inability to integrate words with gestures or understand humor and non-literal speech/irony/implied meanings
Phenotype: Behavior
- Insistence on sameness”
- A markedly restricted range of interests
- Preoccupation with parts of objects
Assessment of the Autistic Child
- motor skills
- communication
- social skills + emotions
- cognitive ability
- behavioral assessment
- family assessment
Current “Gold Standards” of Evaluation
- ADOS (Autism Diagnostic Observation System - done with child)
- ADI (Autism Diagnostic Interview - done with parent)
Medical Assessment of the Autistic Child
- take a history and physical
- growth milestones (head cirum)
Lab Assessment
- Cytogenetic/Molecular Screening
- ASO Titer and DNAse
- Metabolic Screening (urine)
CHAT
involves a 5-item checklist for PCPs and a 9-item checklist for parents
American Academy of Neurology Warning Signs
- No babbling by 12 months.
- No gesturing, pointing, or waving goodbye by 12 months.
- No single words by 16 months.
- No two words spoken together spontaneously by 24 months (not echolalic)
- Any loss of previously acquired language or social skills at any time.
Prognosis
- Depends on functioning
- Low functioning (IQ 70, VIQ 70)
Some children with autism show improvement in adolescence which is related to good adult outcome:
- dec in activity level
- behavior becomes managable
- self-help skills improve
- communication develops
- iq remains stable
- become more social
A large percentage (10 – 25%?) of children will develop
seizures
Anxiety and depression
most commonly co-occurring psychiatric disorders in adults with autism
Factors related to outcome
- IQ at age 5/6
- Communication skills be age 5
- Early educational intervention
DSM-IV PDD Diagnoses
Four Diagnoses
- Autistic Disorder
- Asperger’s Disorder
- Childhood Disintegrative Disorder
- Pervasive Developmental Disorder Not Otherwise Specified (NOS)
Three domains of symptoms DSM3
- Social Interaction
- Communication
- Behavior, interests, and activity
DSM5
Persistent deficits in social communication & interaction across multiple contexts as manifested by (currently or by history):
- Social/emotional reciprocity
- non-verbal communcation
- developing, maintaining, and understanding
- doesn’t do well with change
Symptoms must (DSM5)
- be present in the early developmental period
- cause significant impairment
- you can use DSM 4 in place of DSM 5 criteria
DSM-5 dimensional approach
- level 3 - very substantial support
- level 2 - requiring substantial support
- level 1 - requiring support
Asperger’s v HFA
Because Asperger’s could not be reliably distinguished from PDD, it’s been removed from DSM-5
Deficit in using language in social situations
Alternative Diagnostic Concepts for Asperger’s
- Schizoid Personality Disorder
- Nonverbal Learning Disorder
- Developmental Learning Disability of Right Hemisphere
- Semantic-Pragmatic Disorder
Asperger’s SyndromeDSM-IV Diagnostic Criteria
2 or 3 symptoms from these domains:
- Social Interaction
- Behaviors, Interests and Activities
Communication in Asperger’s
- Limited inflection and abnormalities in rate and volume of speech are commonly seen
- Speech is often tangential and circumstantial, resulting in a one-sided conversation
- maredly verbose
Motor function in Asperger’s
- slower in development
- clumsier/awkward
Social Skills in Asperger’s
- want friends and intimate relationships
- approach others in eccentric ways
Non-Verbal Learning Disorders
- Asperger’s is often associated with NVLD, but the converse is not necessarily true
- Proficiency in most rote verbal skills
- Proficiency in some simple motor and psychomotor skills
