PTE 743: exam 2

neuroplasticity, genetic anomalies, down syndrome, muscular dystrophy, and standardized assessments

what is neuroplasticity?

the brain’s ability to adapt and change it’s structure and function in response to environmental stimuli

what’s the difference between adaptive and maladaptive neuroplastic changes?

• adaptive: the process of reorganizing and rewiring of the brain’s structure and function in response to experiences, learning, and environmental stimuli

• maladaptive changes: the process of harmful changes of the brain’s structure and function that can occur in response to injury, illness, or prolonged stress

T or F: maladaptive neuroplastic changes can result in learned non-use.

T

is neuroplasticity limited to the formation of synapses?

no, its always changing and adapting

what are the three neuroplastic changes that are important to observe during the first five years of life?

1. sensory pathways (vision and hearing)

2. language

3. higher cognitive functions

of the three neuroplastic changes, which one peaks earliest?

sensory pathways; during 1-6 months

of the three neuroplastic changes, which one peaks second?

language; during 6-9 months

• higher cognitive functions peaks third; during 1-5 years

T or F: the neruoplastic changes (sensory pathways, language, and higher cognitive function) begins in utero.

T

how does a sedentary vs. an active lifestyle impact neuroplasticity?

the skill levels, varying challenges, and intensity of activities within these lifestyles can determine the rate of neruoplasticty formations

• an active lifestyle is best compared to sedentary

what microanatomical structure of an axon shows that neuroplasticity goes beyond neuronal connectivity?

oligodendrocytes (support cells)

LTP (long term pontentiation)

the result of long-term excitation that leads to increased synapses and strength of existing synapses

LTD (long term depression)

the result of lack of excitation leading to pruning and cellular death

T or F: neuroplasticity does not occur during rewarded compensation because its a compensated movement.

F; neuroplasticity occurs all the time and rewarded compensation is a good end goal for some patients

when do destructive physiological processes occur after an injury to a neuron?

immediately following the injury

• the destruction can then extend beyond the initial injured area

at what intensity should a therapist treat a patient following a neuronal injury?

moderate-ish

• don’t want an intensity that is too high because there’s so much changing that it could adversely affect recovery in a negative way

• use caution and help as much as needed to avoid patient frustration or elevated vital signs

transneural degeneration

neuronal death or dysfunction spreads from one neuron to another, either forward (anterograde) or backward (retrograde) from the site of initial damage, often due to disrupted synaptic connections

what are the two types of focal degeneration and describe them?

1. retrograde: the proximal part of an injured axon retracts from the site of injury and fails to regenerate, potentially leading to cell death

2. anterograde: the distal part of an injured axon retracts from the axon cell body (soma)

neurons don’t function in isolation, therefore what happens when one neuron dies?

the death of one neuron can diminish the activity or even cause the death of other connecting neurons

when can you expect neurogenesis to occur in adults?

when exposed to an enriched environment

• mostly near the hippocampus and olfactory bulb

______ ______ appears to be maladaptive and a result of neuronal competition. competition for “real estate” can even occur in areas adjacent to the lesion.

contralateral neuroplasticity

what tools do physicians use to monitor reorganization in the primary motor cortices following a stroke?

imaging and elecrophysiological recordings

how many days post-stroke should a therapist be cautious with intensity?

7 days

T or F: in animals, neuroplasticity decreases in response to voluntary exercise during the first 7 days following insult but increases in response to voluntary exercise during days 7-14.

T

what two movements are the most predictive and easiest to test following a stroke?

1. shoulder abduction

2. finger extension

*test during the first 72 hours post-stroke incident for best predictor of outcomes

what can a patient do to offset neural competition?

by performing challenging tasks

list the 10 principles for practical application.

1. use it or lose it

2. use it or improve it

3. specificity

4. repetition matters

5. intensity matters

6. time matters

7. salience matters

8. age matters

9. transference

10. interference

what problem does degrees of freedom pose on patients?

increase in degrees of freedoms with many direction options for movement, can make it difficult to relearn a task

what are the three stages of learning?

1. cognitive stage: learner focuses on understanding the whole task and what to do. requires a high level of attention

2. associative stage: focus on the quality of movement and reducing external cues. allows period of assessment and learning to rely on intrinsic proprioceptive feedback

3. autonomous stage: movements are smooth and consistent. learner can focus on adding nuance and strategizing for enhanced performance in varied settings

which learning stage is the best time to include dual tasking and/or adding challenges to task?

autonomous stage

which stage focuses the most on trial and error (“getting a feel for it”)?

associative stage

which stage requires a lot of demonstration, feedback, and attention from therapist?

cognitive stage

what are the two types of feedback?

1. intrinsic

2. extrinsic

what are the aspects of extrinsic feedback?

• knowledge of results

• knowledge of performance

• concurrent, terminal, constant, and variable feedback

constant and variable feedback comes in the forms of summed, faded, bandwidth, and delayed feedback. describe these four.

• summed: feedback given after a set amount of time

• faded: extrinsic feedback given frequently in beginning but decreases as patient improves

• bandwidth: therapist allows 10% error before providing feedback while degrees of freedom are being monitored

• delayed: feedback given after task completion to allow for internalization and intrinsics

list a few examples of types of practices.

• massed: rest time is much less than practice time

• distributed: rest time is longer than practice time

• blocked: practice organized around one task

• serial: predictable order of tasks

• random: unpredicable order of tasks

describe the difference between a closed environment and an open environment.

• closed: free of distractions and predictable

• open: the opposite lol

what are the five neuromuscular facilitation techniques?

1. resistance: facilitates both intrafusal and extrafusal muscle contractions and enhances kinesthetic awareness

2. quick stretch to agonist: facilitates both intrafusal and extrafusal muscle contractions

3. tapping/repeated quick stretch over tendon or muscle belly: facilitates both intrafusal and extrafusal muscle contractions

4. prolonged stretch applied at max available lengthened range: inhibits or dampens muscle contraction and tone

5. joint approximation (compression of joint surfaces): facilitates postural extensors and stabilizing responses

neurodevelopment treatment

based on an ongoing analysis of sensorimotor function and carefully planned interventions designed to improve patient’s function (via using therapeutic handling techniques)

what is the main focus for utilizing neurodevelopmental treatment?

directing the patients to achieve more efficient and effective postural control and movement patterns with abnormal movements being restricted (aka no compensatory interventions)

T or F: postural control is viewed as the foundation for all skilled learning.

T

why might a therapist choose to use sensory stimulation techniques when working with (TBI, stroke, etc.) patients?

to improve:

• alertness, attention, and arousal

• sensory discrimination

• initiation of movements

neuromuscular electrical stimulation

a modality used to stimulate contraction in very weak muscles

• reeducate muscles, improves ROM, reduces spasticity, decreases edema, and manage disuse atrophy

what improvements are evident in stroke patients following neuromuscular electrical stimulation?

• reduce flexor tone and posturing of hand

• improve functional grasp

• reduce shoulder subluxation

compensatory intervention strategies

focus on the early resumption of function by using the less-involved body segments

• or the modification of the task and environment to facilitate relearning of skill, ease of movement, and optimal performance

what are the two key concepts to compensatory intervention strategies?

1. substitution

2. adaptation

when would compensation be necessary for improving function?

may be the only realistic approach possible when recovery is limited and the patient has severe impairments and functional losses with little or no expectation for additional recovery

how many pairs of chromosomes does a healthy individual have?

23

• 22 pairs are autosomes

• 1 pair determines sex

what are genes?

the fundamental units of heredity, segments of DNA that contain the instructions for building specific proteins, ultimately determining traits and characteristics passed down from parents to offspring

list the four nucleotide bases that make up a DNA strand.

1. guanine

2. cytosine

3. adenine

4. thymine

what are the three possible origins of genetic anomalies?

1. chromosomal disorder

2. single gene disorder: coding error

3. multifacet disorder: a combination of chromosomal and single gene disorder

quiz questions (q): describe an autosomal recessive genetic disorder.

defect is not found on the sex chromosomes; the individual must inherit the defect from both parents to manifest the disease

an error in ______ division leads to a genetic anomaly.

meiotic

• either during first or second round of divisions

• leads to individual having either 22 or 24 pairs

monosomy

a genetic condition where an individual is missing one chromosome from a pair

• results in having only 45 chromosomes instead of 46

what is the most common anomaly resulting from monosomy?

turner’s syndrome

• occurs in females who only have one X chromie; results in absence of ovaries, skeletal deformities, and memory, cognition, and visual-spatial issues all leading to developmental delays

trisomy

a genetic disorder where an individual has an extra copy of a specific chromosome resulting in 3 chromosomes to one pair

down syndrome and klinefelter’s syndrome are both common trisomy anomalies. what are their chromosomal associations?

• down syndrome= chromosome 21

• klinefelter’s syndrome= chromsome 23

translocation

a chromosome abnormality where a segment of one chromosome breaks off and attaches to another chromosome, or where two chromosomes exchange segments

deletion

a type of mutation where a segment of DNA, ranging from a single nucleotide to an entire chromosome, is lost or removed during DNA replication, leading to a change in the genetic code

cri du chat syndrome is the most common anomaly resulting from deletion. describe the syndrome’s presentation within an affected individual.

results from a deletion of chromie #5; high pitch, cat-like cry, small head (microcephaly), expressive language disability, hypotonic, hyperactive, may have intellectual disabilities

micro-deletion

a chromosomal deletion too small to be seen under a microscope, involving the loss of genetic material and potentially causing health problems or syndromes

angelman syndrome and prader-willis syndrome both result from a mico-deletion error. what is the main difference between the two?

• angelman syndrome: maternal copy of the specific chromosome is missing or damaged

• prader-willis syndrome: paternal copy of the specific chromosome is missing or damaged

what does an individual with angleman syndrome present like?

ataxic gait, learning disabilities, short attention span, smiling and laughing often, history of seizure disorders, may have intellectual disabilities

what does an individual with prader-willis syndrome present like?

short, hypotonic, hyperactive, cognitive issues, deficit with knowing when full (leads to obesity), ADD and OCD, may have link to autism and may have an intellectual disability

single gene disorders

caused by mutations in a single gene, leading to inherited conditions that can be dominant or recessive and autosomal or sex-linked

list an example of a dominant and a recessive single gene disorder.

dominant: huntington’s disease

recessive: muscular dystrophy

T or F: osteogensis imprefecta is a single gene disorder that can either stem from a dominant or recessive gene.

T

what neuropathology findings might appear in an individual with down syndrome?

decrease brain mass, small A-P diameter, shallower sulci, delay or lack of myelination formation, seizure disorders

what are the three main deficits seen with down syndrome?

1. sensory deficits

2. cognitive deficits

3. cardiopulmonary deficits

what is the most common sensory deficit possible in an individual with downs?

conductive hearing loss due to damaged ossicle bones

an individual with downs may also have vision issues. what are the most common deficits?

• myopia: nearsightedness

• strabismus: eyes do not align properly and point in different directions

• nystagmus

what is the main cognitive deficit possible in an individual with downs?

language delay; uses gestures and sign language

T or F: individuals with downs are mentally impaired therefore they cannot hold jobs.

F; they are very sociable and reasonably capable, but will take a while to learn a task

what is the main caridopulmonary defect possibly in an indiviual with downs?

atrioventricular canal defect: a congenital heart defect where the center of the heart doesn't form correctly, leading to holes between the heart's chambers and potentially affecting the valves

T or F: atrioventricular canal defect can lead to issues with the heart’s canal and valves (bicuspid and tricuspid).

T

q: T or F: atrioventricular canal defect is the most severe and physically limiting congenital heart defect.

T

T or F: individuals with downs experience the greatest risk of exploitation

T

• poor social intelligence prevents accurate interpretation of others' intentions and increases possible exposure to evil intentions.

list the musculoskeletal issues associated with downs.

• atlanto-axial and atlanto-occipital instability

• scoliosis

• hip instability

• SCFE

• patellar instability

• severe flatfeet (pes planus)

T or F: individuals with downs are hypertonic and hypomobile.

F; hypotonic and hypermobile

why would a therapist want to emphasize cardiovascular fitness in older children and adults with downs?

they’re hypotonicity makes moving more difficult so they live a sedentary lifestyle. they burn more calories when moving so focus on movement to aid in muscle tone, weight balance, and strength

what are some treatment options for treating infants and toddlers with downs?

• tummy time prior to 11 wks old

• sensory rich environments

• orthotics at on-set of walking

• treadmill training

what three areas of the brain are undeveloped in those with downs, making motor learning very specific and important?

1. frontal lobe

2. temporal lobe

3. cerebellum

T or F: auditory feedback is good when teaching those with downs.

F: need visual feedback via modeling/demonstrations

____ _____ practice is most important when teaching those with downs.

task-specific

• allows to teach specific goals to an individual within a specific environment

what are some treatment options for treating children and adolescents with downs?

• resistance training, core strengthening, and balance training

• hippotherpay (with horses not actual hippos)

• whole-body vibration

• orthotics

• cardiovascular training

why might a therapist prefer using whole-body vibration when treating a patient with downs?

it stimulates muscle tone (musculoskeletal) and requires the patient’s body to make microadjustments to maintain balance

muscular dystrophy

a heterogeneous group of inherited disorders characterized by progressive weakness and degeneration of skeletal muscles

what are the five most commonly diagnosed forms of muscular dystrophy?

1. Duchenne MD

2. Becker MD

3. Myotonic MD

4. Limb-girdle MD

5. Congential MD

damage to the _____ found in muscle fibers leads to the loss of the muscle’s integrity.

proteins (of the sarcomeres)

which protein is missing with duchenne MD?

dystrophin

• it provides mechanical stability to the sarcolemma —→ when missing, the sarcolemma becomes fragile

although duchenne MD causes muscular degeneration, what is the most common reason for death in young adulthood?

heart failure or respiratory issues

what age are children with duchenne’s usually diagnosed?

symptoms are noted around 3-5 years of age

• onset 1-4 years

what are the functional timelines for an individual with duchenne’s?

• difficulty with functions by 6-8 years of age

• transitions from ambulation to wheelchair mobility around 10-16 years of age

T or F: all muscles are affected by MD.

F; eye muscles and muscles of mastication are excluded from degeneration

proximal weakness is initially noted with progression to distal musculature in MD cases. why?

proximal muscles usually require the greatest stability with the normal forces required of muscles —> degenerate faster

T or F: respiratory and cardiac muscles are considered proximal musculature in MD cases.

T

• other examples: neck, hip, interscapular, and abdominal musculature

what are examples of secondary impairments found with MD?

• excessive lordosis

• decrease PROM and contractures

• scoliosis

• pulmonary compromise

• gastrointestinal system

• cardiac issues

which muscles experience contractures first in an individual with MD?

gastrocnemii

• followed by the hamstrings and IT bands

why might an individual with MD develop excessive lordosis of the spine?

to allow passive alignment of the shoulders over the pelvis

an individual with MD develops _______ of the knee to allow passive alignment of the hip over the ankle.

hyperextension

what causes pseudo-hypertrophy of the musculature in MD cases?

fibrotic changes to muscle (fibrosis)