Down Syndrome - Pt 1 Flashcards
what is the pathology behind down syndrome
extra 21st chromosome
- trisomy 21
what are the 3 mechanisms leading to the extra 21st chromosome seen in down syndrome
- NON-DISJUNCTION: failure of 21st chromosome to separate (95% of cases)
- TRANSLOCATION: long arm of #21 attached to another chromosome
- MOSAICISM: some but not all cells have defect
- ie some cells display the trisomy 21 and some don’t
what was Down the first to describe down syndrome as
relative to clinical presentation
what is the significance of someone with down syndrome d/t a mosaicism mechanism
these individuals might not present with all the clinical features of down syndrome seen in other mechanisms
what inc the risk of a child being born with down syndrome
inc maternal age
why has the survival rate inc from 50% in the 90s to 95% in the 2000s (2)
early detection & prenatal dx
- EI and healthcare
greater normalization in society
- better health, higher autonomy, community integration and dec institutionalization
what are prenatal diagnostic methods to screen for down syndrome (4)
amniocentesis
chorionic villus sampling (CVS)
ultrasound
percutaneous umbilical cord sampling
how is CVS sampling utilized as a diagnostic method for down syndrome
contains lots of rapidly dividing fetal cells
- do a chromosome analysis
when can a CVS sampling be taken
early (~8wks)
how is ultrasound utilized as a diagnostic tool
look for thickening of nuchal cord
screen for CHD and heart defects
- down syndrome pop has inc risk of CHD
what is another name for percutaneous umbilical cord sampling and what is a consideration of its usage
cordocentesis
very risky
what two diagnostic test which dec risk of fetal death
amnio
CVS
what is a diagnostic toll used after birth
screen for distinctive features
- then do a chromosomal analysis
what is a consideration of the presentation of down syndrome
despite everyone having similar features, everyone can have a different unique presentation bc of unique genetic makeup
what role gene therapy play in the medical management of people with down syndrome
growing research
- able to correct DS cells in vitro
ethical questions as to whether they should just because we now can
what are the 2 main categories of clinical presentation
- phenotype (observable traits)
- systems
what are phenotype characteristics of people with down syndrome (5)
- short neck, excess skin
- flattened face and nose
- small head, ears, mouth
- upward slanting eyes
- brushfield spots
why do you see excess skin at the back of pts with down syndrome’s necks
thickened nuchal fold
what are brushfield spots
white spots on colored part of eye
describe how patients with down syndrome usually present with their eye shape
upward slanting
- often skin fold comes out from upper eyelid and covers inner corner of eye
what are general growth/maturation phenotypes
small stature
not all segments equally grow/mature
how is growth/maturation assessed in pts with DS
specific growth charts for people with DS
what are specific characteristics of the growth and maturation of someone w DS (5)
- relatively short legs, but not trunk
- hands and feet - short/stubby
- underdeveloped middle phalanx of 5th finger
- crease in middle of palm
- deep groove in between 1st and 2nd toe
describe skeletal maturity characteristics of someone w DS
slower rate than those w/o DS
- esp in early childhood
- speeds up to be only mildly slower with age
what are 3 likely reasons for an inc incidence of obesity in DS
could be genetic
reduced activity (motor ability, motivation)
family
what are systems that can have impairments in DS (8)
hearing
leukemia
thyroid
obstructive sleep apnea
cardiac
GI
MSK
CNS
how is hearing impaired in DS
high prevalence of ear infections and conductive loss
- inc w aging (significantly more than people w ID and not DS)
recommendations for hearing loss in DS
ABR (auditory brainstem response) starting at 6mo
what phenotype can impact hearing
shape of face impacts hearing
what thyroid dysfunction is seen in DS
underactive (hypothyroidism)
when and how is the obstructive sleep apnea seen in DS managed
referral for sleep tests starting at 4yo
what type of congenital heart defects can be seen in DS
atrial-septal
ventriculo-septal
how can congenital heart defects in DS manifest if not noted right away
early fatigue
poor color
what GI dysfunction are pts w DS most at risk for
esophageal or duodenal atresia
what 3 GI congenital abnormalities can be seen in DS
most common upper esophagus not connected to lower/stomach
esophagus connected to trachea (aka tracheal esophageal
esophageal narrowing
what are early signs of a congenital abnormality of the GI system
early and massive vomiting d/t blockage
what is the treatment for a GI disorder
surgery
what are 4 common msk dysfunctions seen in DS
hypoplasia
ligamentous laxity
C-spine abnormalities
- osseous changes
- atlantoaxial instability
SC compression
where is hypoplasia in DS primarily seen and what is it influenced by
pelvic and hip dysplasia
- risk of subluxation
influenced by: collagen defect & low tone
why is hip dysplasia so common and how can this link to another phenotype
not developed enough
- similar to why face is so flat
- hip is similarly flat
where and why do we see ligamentous laxity in DS
varied locations
d/t collagen defects
what are 3 osseous changes can happen at the c-spine in DS
atlanto-occipital (changes in joint shape)
C1 hypoplasia
anomolies of C-vertebral bodies
why can you see atlanto-axial instability in DS and what is a consideration for this
d/t lax transverse ligament
many are asymptomatic if have it
what are yellow/red flags depending on the situation (9)
neck pain
spasms of neck ms
vertigo
changes in gait
drop attacks
torticollis
weakness
inc tone/clonus
sensory changes (stocking/glove)
what happens if the transverse ligament is too lax
with flexion the atlantoaxial sublux so odontoid process impinges the SC
what is anticipatory guidance to provide to family/coaches ab AAI (2)
- maintain C-spine in neutral position during any procedure (ie surgical, radiographic, etc.)
- myelopathic s/sx education
what are 5 s/sx of myelopathy seen in AAI
- significant neck pain, radicular pain
- weakness
- spasticity or change in tone, hyperreflexia
- gait difficulties
- change in bowel or bladder function
what is a consideration of imaging for individuals with AAI
plain radiographs don’t predict risk of SCI compression well
- refer for MRI
what is POC for a child w asymptomatic AAI
routine films? no
refer for MRI
- if (+) findings, then monitor
POC for symptomatic AAI ?
immobilize spine
urgent medical assessment in ED needed
- neurosurg consult/imaging
what are sports participation considerations for children with down syndrome
contact sports - inc risk for SCI
- ie football, soccer, gymnastics
no trampolines unless >6yo (all children! even TD) and professionally supervised
what are 3 sports participation screening questions for children with down syndrome
- signs of progressive myopathy?
- poor head/neck motor control (ie pull-to-sit test)
- does neck flexion result in chin resting on chest?
what are 5 CNS clinical presentations of down syndrome
- hypoplastic brain (dec size)
- dec # synapses
- premature aging in brain
- inc comorbidity of Autism
- mild to mod ID
what 3 brain areas are esp dec in size in down syndrome and what are the impacts of this
cerebellum - m. learning/ms tone
frontal lobes - exec function
temporal lobes & hippocampus - episodic memory
how are synapses impacted in down syndrome (3)
dec synaptic density
dendritic spines
neurogenesis
describe the premature aging in the brain seen in down syndrome
early onset of Alzheimer’s type dementia (40-60yo)
not clearly understood
what is a common comorbidity of down syndrome
autism
how does intellectual disability present in down syndrome
mild to mod ID
pattern different than other ID syndromes
- relatively high social intelligence
- impaired explicit memory
when do intellectual disability characteristics present
before age 18
if someone is over the age of 18 and has a traumatic event resulting in characteristics of intellectual disability, how is this labelled
not as an intellectual disability
labelled as post TBI or encephalopathy or whatever caused the onset of sx
what are characteristics of an ID
- significantly below avg IQ score
- limitations in ability to function in areas of daily life (ie communication, self-care, social situations, school activities)
- present <18yo
what is a consideration when evaluating a child with an intellectual disabilitly
what were the circumstances the child was raised
- was it an enriching environment
what is the diagnostic process for someone with an ID
careful IQ and adaptive skill testing
- validity (culture, linguist)
- consider motor, behavior, sensory, communication
what are 6 learning issues of ID that have implications for PT
- capable of learning but… fewer things
- benefit from inc repetition to learn
- slower response times
- poorer ability to generalize skill
- poorer ability to maintain skills not practiced
- more limited repertoire of responses
what are 5 BSF impairments of down syndrome (5)
- hypotonia (varying degrees)
- hypermobile (all joints)
- reaction time (slow)
- dec strength/postural control early in development (& beyond depending on severity)
- dec fitness - unless actively & regularly engaged
what determines reaction time
RT = (stimulus identification) + (response selection) + (response programming)
what does hypotonia and hypermobility impairments contribute to
dec proprioception, movement qualities, and voluntary ms control
what are 4 activity limitations of down syndrome
language
oral motor/feeding
balance
gross motor (delayed)
how does the activity limitation of language present in down syndrome
varied abilities
- some nonverbal
- some completely verbal w motor delay
how does the activity limitation of oral motor/feeding present in down syndrome
hypoplasia of oral cavity - mouth is smaller
- tongue protrudes as result
taught how to retract tongue back into cavity to help w feeding, language, and social
what are 4 factors which impair the activity limitation of balance in down syndrome
- delayed central processing
- impaired sensory organization for balance
- delayed postural control development
- ms activation
in general what is the cause of issues with balance in down syndrome? what isnt?
d/t central issues
not bc of laxity or low tone
while delayed, how does gross motor activity limitations present in down syndrome
rate is slower, but similar sequence to TD
- rate of skill improvement faster w younger children, slows w age
what is the gross motor function measure (GMFM)
standardized tool ages 5mo-16yo
measures changes in early gross motor skills and function over time or w intervention in children w CP/down syndrome
what was the GMFM originally developed for
CP
- valid/reliable for down syndrome
what early gross motor skills does the GMFM look at (7)
lying and rolling
sitting
crawling and kneeling
standing
walking
running
jumping
what are the PT implications of a child at max on GMFM
shifting focus to more physical fitness
- dec PT frequency
- encourage HEP to maintain
what are PT implications of a child not at predicted GMFM level for age
opportunity to reassess
what are 4 problems which arise with age
thyroid abnormalities
MSK disorders
mental illness / depression
inc rate of falls
how do thyroid abnormalities present with agin
hypofunction
- at early or later years
what MSK disorders present with aging (3)
mid-cervical arthritis (high rate)
progressive hip instability (THR)
osteoporosis (high risk, younger age)
- long bone & compression fx of vertebral bodies
what are factors for osteoporosis to present with aging (3)
lower physical activity levels
early menopause in women
dec strength
what is the significance of inc rate of falls with aging
inc rate at a younger age in adulthood
- greater risk for injury from those falls
what is a consideration when looking at measurements/stats of adults with an ID
still not an assessment tool for ID
- have to compare to adults w/o ID
