Neurodevelopmental Disorders Flashcards
Historical perspective
regarded as subhuman, a menace, object of dread
1870-1890 - objects of pity, burdens of charity, holy innocents
started to be viewed as a threat - eugenics movement
late 50s and 60s - people with ID viewed as able to learn
early medical model
dominated first have of 20th century
these people needed continuous medical care, were institutionalized
deinstitutionalization in 1960s - educational mainstreaming, community based services
intellectual disability DSM-5-TR
three criteria
deficits in intellectual functions - reasoning, problem solving
deficits in adaptive function - failure to meet standards for independence
onset of deficits during developmental period
conceptual domain of functioning
mild severity - difficulties in some academic skills, abstract thinking, functional use of academics skills, concrete approach to solutions
moderate severity - skills lag behind markedly, academic skill remains at elementary level, ongoing assistance needed
severe - attainment of conceptual skills is limited - little understanding
profound severity - conceptual skills involve physical world not symbolic processes
social domain of functioning
mild severity - immature in social interactions, difficulties regulating emotions, gullible
moderate severity - marked differences, much less complex, relationships with family and friends, don’t perceive social cues
severe - single words or phrases, focuses on present, simple speech and gestural communication
profound - may understand some simple instructions, express their own distress through nonsymbolic communication
practical domain of functioning
mild severity - need support with complex daily living tasks, recreational skills resemble those as age mates
moderate severity - can care for personal needs - eating, dressing, hygiene - requires teaching, maladaptive behaviour
severe - support for all daily activities and supervision at all times, maladaptive behaviour including self injury
profound - dependent on others in all aspect of daily physical care, maladaptive behaviour
identity and first person language
identity first - autistic individual, autistic
person first - person with autism
prevalence of intellectual disability
2% of general population
support services know of a substantially smaller portion
WHO - 3%
Canada - 0.78%
diagnostic issues in intellectual disabilities
intellectual functioning determined on basis of psychometric testing and IQ scores
categories based on IQ
mild - 50-55-70
moderate - 35-40-50
severe - 20-25-35
profound - less than 20
borderline - raised prevalence from 3-16%
cut off at 75 +-5
the challenges of assessing IQ
use of IQ tests has been the subject of considerable controversy - tests do not take into account sensory, motor, language deficits
test environment may not be familiar
measuring adaptive behaviour
use psychological assessment
adaptive behaviours
- communication
- daily living or personal living skills
- socialization skills
- motor skills
may also assess activities of daily living, challenging or maladaptive behaviours
interviewing strategies
cautious - families may give biased information - over estimate higher functioning - “cloak of competence”
acquiescence - tendency of those with D.D. to answer affirmatively in interviews - social desirability, language limitations
should use yes-no, forced choice, sometimes open ended
genetic causes of intellectual disability
down syndrome and fragile x - pieces of chromosomes are missing or duplicated - copy number variations
55-70% genetic cause for moderate-severe, 14% of mild
types of genetic inheritance
dominant - tuberous sclerosis, neurofibromatosis
recessive - phenylketonuria, Tay-sachs, galactosemia
x-linked - abnormal gene on X chromosome, generally recessive, so will operate only when it appears on both X chromosomes - Y chromosome cannot override - fragile x syndrome, Lesch-Nyhan syndrome
chromosomal abnormalities
down syndrome
- trisomy 21: 95%
- extra chromosome on pair 21, so 47 total chromosomes
1/700 births, 1/100 after age 40
translocation - part of 21st chromosome breaks off and attaches to another - 4%
mosaicism - uneven cell division, some cells have 45 chromosomes, some have 47
prenatal screening for chromosomal abnormalities
maternal serum screening - blood test 15-20 weeks - detects AFP - increased AFP indicates risk of abnormalitu
non-invasive prenatal testing - available from 9-10 weeks on
nuchal translucency - 10-14 weeks, measuring fluid - more fluid = more risk of abnormality
prenatal screening for chromosomal abnormalities 2
amniocentesis - 11-18 weeks - amniotic fluid withdrawn
chorionic villus sampling - obtains cells from placenta
circulating fetal DNA - tested for conditions, new technique
metabolic disorders - phenylketonuria
inborn error of metabolism
liver enzyme on chromosome 12 inactive - inability to process phenylalanine - can build up in brain and lead to ID
special diet for prevention - earlier start the better
metabolic disorders - other
congenital hypothyroidism - treated through hormone thyroxine
hyperammonemia - deficiency in enzyme that transforms ammonia
gauchers disease and hurlers disease = deficient enzymes
maternal infections
rubella - during first three months of pregnancy can lead to ID, visual defects, deafness, heart disease
HIV
developmental delays or disabilities occur in 75-90% of children with HIV who do not receive treatment
transmitted through delivery, breast milk
poor growth, delayed growth and development, cognitive delays, memory problems
fetal alcohol spectrum disorder - facial abnormalities
short eye openings, elongated flattened area between nose and mouth, thin upper lip, flattened cheeks and nasal bridge
fetal alcohol spectrum disorder - prevalence
1-3/1000 live births
2-3% of elementary school children
globally - 8/1000 children, 1/13 women who consume alcohol during pregnancy give birth to a child with FASD
fetal alcohol spectrum disorder - deficits
in cognitive and executive functioning that last a lifetime
behavioural challenges, impulse control, ADHD, social difficulties
binge drinking particularly significant impact
secondary disabilities - poor judgement, inappropriate sexual behaviour, drug problems, delinquency into adulthood
other drugs
anticonvulsant ditalin, chemotherapy, hormone therapy - teratogenic effects - facial anomalies, malformed limbs, risk of later cancer
thalidomide and congenital limb deficiency
birth related causes
extreme prematurity, lack of oxygen, prolonged or complicated labour - visual deficits, cerebral palsy, speech and learning difficulties
psychosocial disadvantage
poverty, nutrition, large family size, lack of structure - contributing factors
if given little opportunity to practice cognitive skills - may not develop as rapidly
more likely to come from disadvantaged families - poverty is a major risk factor
prevention and early intervention programs
can significantly improve outcomes
encouragement of curiosity, organizational assistance, positive reinforcement, skill rehearsal
down syndrome physical features
short stature, epicanthic fold over skin over inner corner, wide and flat nose bridge, stubby hands and fingers, large protruding tongue, poor muscle tone
down syndrome health issues
congenital heart disease, gastrointestinal abnormalities, congenital cataracts
risk for developing alzheimers - half of adults over 50 have dementia symptoms, dementia associated with mortality in 70% of this group
down syndrome intellectual impairment
intellectual impairment ranges from mild to severe - most is mild-moderate
difficulties in expressive language
delayed nonverbal cognitive development, deficits in verbal abilities and auditory short term memory
down syndrome treatment
early intervention and education - contributes to adaptive functioning
antibiotics to reduce infections
fragile x syndrome
weakened or fragile site on X chromosome
FMR-1 gene larger
more than 200 repeats of cytosine and guanine instead of 6-50
fragile x and intellectual disability
after down syndrome, most common hereditary cause
males - weaknesses in sequential processing of information in a particular order
females - 1/3 experience mild intellectual disability - attention, short term memory, planning, problem solving, math
fragile x prevalence
approx 1/200 females affected
1/700-1/1000 males
fragile x facial features
high forehead, elongated face, large jaw, underdeveloped earls, enlarged testes in males
characteristics less pronounced in carrier females
fragile x expressive language
males
jocular, staccato, perseverative, sing songy speech
problems with communication and socialization
15-50% males meet criteria for autism
family well being and neurodevelopmental disorders
families of those with disabilities experience more stress
use coping strategies like positive reframing or reappraisal of experiences
deinstitutionalization and community integration or inclusion
changing views led to thousands with disabilities and the provision of community based services
evaluating quality of life
three components
- being in physical, physiological, and spiritual domains
- belonging in physical, social, community environments
- becoming, focusing on strategies to achieve hopes and goals
challenging behaviours and dual diagnosis
diagnostic overshadowing - perceiving mood changes or maladaptive behaviours to be solely a function of the developmental disorder might cause real psychiatric disorders to be missed
3-4x risk of developing schizophrenia, bipolar, anxiety
dual diagnosis
co-occurrence of serious behavioural or psychiatric disorders in people with intellectual disabilities
40%
many are taking medication, CBT is helpful
offending behaviour and dignity of risk
dignity of risk - right of individuals to choose to take some risk in engaging in life experiences and the consequences associated with that risk
offenders with ID - 15-30%
autism spectrum disorder
persistent deficits in social communication across multiple contexts - reciprocity, nonverbal, relationships
restricted, repetitive behaviour - motor movements, insistent on sameness, fixated interests, odd reaction to sensory input
symptoms present in early developmental period, impairment in functioning, not explained by something else
severity levels in autism
level 1 - requiring support
level 2 - requiring substantial support
level 3 - requiring very substantial support
autism prevalence
canadian estimates 1-3/1000
united states 1/68
higher estimates may reflect changes in diagnostic criteria
3-4x more often in males with high IQs - no difference in low IQs
social interaction
social difficulties and responses to the environment
without expressive language do not use nonverbal signals
infants show little interest in face and eye contact
verbal and nonverbal communication
mute or minimally verbal, often do not communicate meaningfully, abnormal tone
echolalia - repeat phrases or words back to someone
pronoun reversal - refer to selves in third person
behaviour and interests
hand flapping, rocking, repetitive movements - cope with environment
spinning or tapping objects in repetitive and nonfunctional way
autism and intelligence
44% function in average range of intelligence
savants - exceptional ability in math, music, art, memory
assessment of autism
multidisciplinary team - psychologist, psychiatrist, speech and language specialist, occupational therapist, teacher
ADI-R - structured 90 min interview
ADOS-2 - standardized observational measure with different activities
autism etiology
genetic factors play a dominant role
25% cases have genetic cause in form of copy number variation
camouflaging and autism
masking
modify or hide behaviour to conform to what be be considered socially acceptable
learned scripts
associated with higher depression and anxiety, missed diagnoses - girls
medications and autism
none specifically for autism
antidepressants for perseverative behaviour
antipsychotics for hyperactivity, impulsivity, irritability, aggression
used to regulate neurotransmitters
behavioural interventions for autism
focus on cognitive, communication, behavioural challenges
develop self help skills, language, social interaction, academics, reducing maladaptive behaviour
positive and proactive interventions
reductions in behaviours in 80-90% of cases
applied behavioural analysis and early intensive behavioural intervention
75-95% developed useful speech by age 5
many speaking out about trauma endured in these programs - pressure to conform
naturalistic developmental behavioural interventions
therapeutic processes, use natural contingencies, teach developmentally appropriate skills
learning disorders historical perspective
1887 - dyslexia term coined from impaired word
congenital wordblindness
belief that those with dyslexia perceived letters backwards - its a core deficit in phonological processing
learning disorder diagnostic criteria
disruption to normal pattern of explicit learning of academic skills
at least one of
inaccurate or slow reading, hard to understand what is read, difficulties with spelling, difficulties with written expression, difficulties mastering number sense, number facts, problems with mathematical reasoning
controversy in learning disorder diagnosis
no universal agreement
DSM5 generally unhelpful - no info on how learning is impaired, no indicators for remediation
learning disorder with reading impairment
dyslexia
trouble discerning if words rhyme, unable to count syllables, syllable stress, may struggle to delete individual speech sounds
learning disorder with impairment in maths
dyscalculia
inability to process numerical quantities, judgements about quantity and reasoning
core deficits in working memory
low math performance may reflect factors like anxiety about performance or math avoidance
learning disorder with impairment in written expression
dysgraphia
impairments in mechanical act of writing - associated with visual motor skills
or in composing text - associated with deficits in processing speed, working memory, executive functioning
learning disorder prevalence
persistent and continue over the lifespan
specific learning disorders 9/7%
reading disorders 5-17% school aged - most common - 80%
maths 6-7%
more boys than girls in reading disorders
learning disorder etiology
dyslexia - familial and hereditary
50-60% heritability for reading
50-67% heritability for math
relationship between learning disorders and mental health
high likelihood of co-occurring mental health disorders and behavioural difficulties - 2-3x
ADHD and ASD and LD
75% students with LD have lower social competence than comparisons
learning disorder interventions
phonemic awareness, phonics, vocabulary development, reading fluency, reading comprehension strategies
reading strategies taught to at risk children
non responders likely to be diagnosed with LD
