Exam 1 Flashcards
Neuroplasticity
neural system continuously remodeled throughout life and after injury by experience and learning in response to activity and behavior
Cell Body Damage
Neurons not replaced
Zone of Ischemia
reversible, insufficient blood supply, natural healing process
Zone of injury
reversible, medication can help tissue, area of edema or swelling next to infarct
Zone of Infarction
Damage is permanent, cell body damaged, axonal damage,
Penumbra (core zone)
area of mild to moderately affected tissue adjacent to the area of ischemia
Ischemic Stroke (tissue plasminogen activator)
stared within 3 hours after ischemic stroke, 50% with no clinical benefits, MCA main challenge
collateral sprouting
4-5 days after injury, replace vacant synaptic fields, do not replace original circuitry
You have been asked to treat a patient in the acute care hospital on Friday. You note that following her ischemic CVA she has very little movement in her Right Upper Extremity. When you come back to work on Monday, you notice great improvement in her UE function. You suspect that she has had natural healing and has responded to medication in which area?
zone of Ischemia
Principle 1:
Use it or Lose it …Neural circuits can degrade without activity, brain area can shift responsibility
Principle 2:
Use it or Improve It….practice of specific tasks can increase areas of the brain that respond during the task
Principle 3:
specificity matters: changes in specific brain areas occur relative to the task is practiced….skilled practiced results in changes in neural connectivity
Principle 4
Repetition Matters
Repetition of new task required to see neural changes
Changes at the neuronal level not observed until significant repetition of new task, even when behavioral improvements observed
Principle 5
Intensity Matters
Need to differentiate between intensity
and repetition
High intensity stimulation = long-term potentiation
Low intensity stimulation = long-term depression
Human Brain Derived Neurotrophic Factor
Responsible for:
axon targeting
neuron growth
maturation of synapses during development
synaptic plasticity
Prevents neuronal cell death after cerebral ischemia
Human Brain Derived Neurotrophic Factor affects what:
Affects neuroplasticity by facilitating long-term potentiation
Strengthening of connections through dendritic growth & remodeling
Secreted in CNS by:
Constitutive pathway
Activity-dependent pathway
Principle 6
Time Matters
Neuroplasticity is a process
Gene expression→synapse formation→motor map reorganization
Earlier rehabilitation post-infarct prevents loss and promotes dendritic growth more so than delayed rehab
Principle 7
Salience Matters
Neural system that mediates saliency
Engaging system is critical for driving experience-dependent plasticity
If task is salient:
attention to task
acetylcholine
Lack of ACH prevented re-organization of motor cortex
Principle 8
Age Matters
Neuroplasticity altered in older brain
Neuroplastic changes can occur but may be slower
Effects may be lessened with history of greater physical and mental activity
Principle 9
Transference
Ability to improve in 1 area may make it easier to improve in similar tasks
Principle 10
Interference
Ability of plasticity within given neural circuitry to impede induction of new or expression of existing plasticity within same circuitry ≠ learning
Motor Learning
A set of internal processes associated with practice or experience leading to RELATIVELY PERMANENT CHANGE in the capability for skilled behavior
Law of Effect
Behaviors that are rewarded will be repeated at the cost of other behaviors while those that produce adverse effect will be less likely to occur
Motor learning Manual guidance
increase Performance
decrease Learning
decrease Retention
Motor learning Observational learning
increase performance, decrease learning, decrease errors
Types of practice: constant
Practice of same task for multiple repetitions
Types of practice: Variable
Training that includes same basic task, but frequent changes so that the performer is constantly confronting novel instances of “to-be-learned” information
Length of practice session: massed
time spent in practice > rest
Length or practice: distributed
– rest periods are scheduled t/o the practice session
Type of task: whole
To allow person to understand movement in its entirety
Type of Task: part
For tasks that have discrete stop & start
Stages of learning: Cognitive
planning, early, what to do
Stages of learning: associative
practice, intermediate, how to do
Stages of learning: autonomous
automatic, final, how to succeed
Optimal Theory of Motor Learning
how the person is doing the movement going to optimize the quality of the movement, make sure the patient is motivated to do the movement, attentional focuse and what is expected for success
Speed/accuracy trade off
the faster you go the there will be a decrease in accuracy
Maximizing learning of skill
Person
Motor learning emerges from a complex system of perception/cognition/action processes
Maximizing learning of skill
ATTENTION Is foundation
Environmental: closed
All variables such as the setting and objects remain the same.
Environmental: constant motion
Objects or support surface are in motion, but do not change over successive attempts.
Environmental: open
Environment changes between trials; support surface is in constant motion
Environmental: variable motion
The environment is stationary, but features within the environment change.
Facilitating Acquistion
effortful practice –> varied learning styles –> active engagement w/task
Recovery of Function
Refers to reacquisition of movement skills lost through injury
Reorganization of both perception and action systems in relation to specific tasks and environments
Person uses Task Solutions
Learning a Motor Skill
Complex process that reflects spatial, temporal and hierarchical organization of the CNS that contributes to organized and purposeful motor behavior
Single Nucelotide Polymorphism
BDNF Gene Val66met
1 of many genetic variants that could potentially affect aerobic exercise effects on brain & post stroke rehabilitation
Polymorphism individuals with it have:
Decreased cognition (object recognition) when engaged in 4 weeks of aerobic exercise
increase intensity
Individuals without polymorphism
Greater motor map plasticity
Greater retention on motor learning task
Novel motor skill vs simple repetition of familiar task
May be dependent on fact that CNS has been impaired
Factors that Influence Cognition
Side effect of medication
Depression
Sleep deprivation
Depression in Stroke
affect: Cognitive Function
Basic Principles of Exercise Prescription: overload
Increased effort above normal
See increase in strength, flexibility & aerobic capacity
Results in fatigue & temporary decrease in capacity
Basic Principles of Exercise Prescription: Adaptation
Capacity of exercise (strength, flexibility & aerobic capacity) increases to level greater than original value due to adaptation
Basic Principles of Exercise Prescription: progression
Exercise stimulus MUST INCREASE over time to elicit continued improvements
Basic Principles of Exercise Prescription: specificity
Adaptations induced by training are SPECIFIC to the stress
Weight Acceptance
Transfer weight from one leg to another
Most difficult task of gait
Weight Acceptance Goals:
forward progression
stability
shock absorption
Single Limb Support
Maintain stability on one leg while the body advances over it
Single Limb Support Goal
Stability
Forward progression
Swing Limb Advancement
unload the leg and advance it forward
Swing Limb Advancement
Goals
foot clearance
limb advancement
The Functional Tasks of Gait
Weight Acceptance
Single Limb Support
Swing Limb Advancement
The three tasks must be accomplished while:
during gait training:
changing direction and elevation
performing other tasks
encountering changes in ground surfaces
avoiding obstacles
withstanding perturbations
minimizing energy expenditure
Gait speed:
Common units: meters/sec, meters/min
Ranges of speed:
Adult males: 1.36 m/sec
Adult females: 1.32 m/sec
Gait cadence:
Ranges of cadence
adult males: 111 steps/minute
adult females: 121 steps/minute
Cadence is not a good measure of gait quality by itself
See: normal cadence with decrease step length & decrease speed
Gait Step length and stride length
ranges of stride length
adult males: 1.48 meters
adult females: 1.32 meters
a stride length = two consecutive step lengths
step lengths can be unequal, but stride lengths are always equal
Gait foot angle:
normally 7 degrees, increases base of support
Gait trunk rotation
Pelvis rotates 5 degrees one direction
Trunk rotates 5 degrees other direction
Gait Arm Swing
Normal
24 degrees extension
6 degrees flexion
Restrict arm motion increases energy cost
Dynamic Stability what muscles are required:
Hip extensors (LR) Hip abductors (LR, TSt) Knee extensors (LR) Ankle plantarflexors (MST, TSt)
Muscle Activity – Initial Contact
Ankle
Anterior tibialis isometric contracts
Knee
Quads and Hamstrings isometric
Hip
Glut max and adductor magnus isometric
Muscle Activity – Loading Response
Ankle
Anterior tibialis eccentric
Knee
Quadriceps eccentrically –peak activity
Hip
Extensors, adductors, abductors stabilize
Muscle Activity – Mid Stance
Ankle
Soleus and gastroc control forward progression of tibia
Knee
Quadriceps for stability
Hip
Abductors only
Muscle Activity – Terminal Stance
Ankle
Gastroc/Soleus peak activity
Control tibia forward movement
Knee
No quad activity
Possible Hamstring activity
Hip
TFL
Muscle Activity – Pre Swing
Ankle
Gastroc/soleus
Knee
Minimal knee flexor activity
Hip
Adductor longus and Rectus Femoris
Muscle Activity – Initial Swing
Ankle
Tibialis anterior concentric
Extensor hallucis and digitorum longus peak activity
Knee
Biceps femoris concentric- peak activity
Hip
Iliacus, gracilis and sartorius peak activity
Muscle Activity – Mid Swing
Ankle
Tibialis anterior
Knee
Hamstrings eccentric in late part
Hip
Hamstrings late in phase
Muscle Activity – Terminal Swing
Ankle
Tibialis anterior
Knee
Hamstrings peak in activity eccentrically
Quadriceps start contracting
Hip
Hamstrings peak in activity eccentrically
Hip musculature begin to activate to prepare for IC
Gait deviations can cause
increased energy expenditure
abnormal stresses on muscles, joints, etc.
safety risk
Four major categories of problems:
Impaired Motor Control
Abnormal ROM (↑ or ↓)
Decreased Sensation/Perception
Pain
also due to: balance disorder, impaired cognition
