Week 8-Autism Spectrum Disorder Flashcards
ASD affects
1 in 100
ASD is how mnay more time prevalent in males?
4 times
2 core symptoms of ASD
- persistent deficits in social communication
- restricted and fixated interests
behav symptoms with ASD
anxiety, hyperactivity, agitation, impulsivity and sometimes aggresion
functional symptoms of ASD
sensory hypersensitivity,seizures and GI disorders
ASD includes…
aspergers, austistic disorder, PDD-NOS
the phenotypes of ASD
Why is ASD very hard to diagnose?
its very heterogeneous
can diagnose via DSM5 or ICD10
the neuroimaging biomarkers of ASD
Volumetric analysis( regional,cortical volume) fpor thickness and SA. this is because there is widespread reduction in white matter volume
connectivity via fibre tract measurement
functional markers via fMRI,eye tracking
Plasma biomarkers for ASD
abnromal levels of BDNF in blood ASD patients( can be increased or decreased)
decreased nighttime production of melatonin
altered components of metabolic(creatine kinase, lactate dehydrogenase) and inflamm(IL-1b, IL-4) pathways
what causes easly brian enlargemnt in ASD kids below 5
thought to be because of increase in synapses/glial cells/dendrites and neural connectivity because of synpase pruning defects,increased cortical thickness and folding in the partietal lobe,decreased GABA R expression in the superior frontal and parietal cortices, abnormal columnar structure in the neocortex, hypometabolism in the frontal regions
The neuropath of ASD
Early brain enalrgement in ASD children
increased brain volume disappears aorung 6-8 to abnormal slowness in growth
abnormaliteis (smaller neurons and reduced volume that are more densley packed) in limbic structures in older indivs including hippocampus,amygdala,cingulate cortex
cerebellar abnormalities of decreased volume,reduced number,size of pyrkinje cells
Where we should look for strutcural chnages in the brian should be guided by…
the 3 main symptoms
how does the minicolumn/column strutcure differ between ASD and non disordered childers?
in ASD the minicolumns in layers 3-5 are more closely packed than non disordered children
is ASH heritable?
YES highly, ~90%
List some ASD suseptitbility genes
SHANK2 and 3(scaffold proteins), adhension moelcules like Cadhgerins, GABA receptor subunits, voltage gated Ca+ subunits, regulators of chromatic remodelling MSCP2, CHD8, proteins involved in synapse formation neurexins and neuroligins
Have SNPs been found for asd?
yes but ecah is only low risk
The main genetic hypotheiss of ASD is that…
many variants of small effect contirbute ot the tipping of the person over the asd threshold
ASD risk factors
maternal infection/immune dysfucntion
endocrine fatcors like maternal stress
obstretric factors like low birthweight,preterm,c-section,uterine bleeds
environmental factors like illicit drugs, maternal exposure to prescription med, heavy metals like mercury, pollution/enviornemntal toxins, cigarette smoke
Theories of ASD
Impeded plasticity
Excitation inhibition dysregulation
theory of mind
impeded plasticity is..
Excitation and Inhibititon Dysregulation
imbalance of glutaminergic and GABAergic synapses
ASD patients are susceptible to dev of epileptic seizures
theory of mind
the capacity to understand subjective mental states including subjective mental states including thought and desired is known as ToM
ToM develops early in children without liabilities byt is delayed in children with ASD
Oxytocin in pregnancy and ASD
potential oxytoxin treatment?
intranasal oxytocin has been trialed as a therpay
oxytocin as a sociability hormone is ASD kids
plays a role in social behaviour
Discrete trial trianing
naturalistic interventions
Learning experience:an alternative program
Early strat denver model
Skill based model
3 main thing pahrmocological treatments of ASD trear
antipsychotics for aggression/irritability
antidepressants for hyperactivity/inattention/receptive behavior and impulsivity
these treat symptoms not cause
