Neuroplasticity: Exam 1 Flashcards
CNS pathology
what happens?
- damaged area OR areas connected by damaged path. STOP working normally
- Result depends on what part is damaged
Recovery
what happens?
-
Sparing
- lack of observable deficit
-
Compensation– a way to get better
- accomplish goal in NEW and DIFF way
-
True Recovery–neuroPT’s goal!!!
- gradual return of lost function
- end result==> accomp. goal in same manner as was done prior to CNS injury
What contributes to recovery ?
- Plasticity—reorg. of CNS
-
reversal of Neural Shock
- shock is right after injury
- Denervation hypERsensitivity
- activation redundant systems
Capacity of the CNS to adapt to functional demands and therefore to the system’s capacity to reorganize
Neural Plasticity
Neural Plasticity
Capacity of the CNS to adapt to functional demands and therefore to the system’s capacity to reorganize
Capacity for Neuroplasticity:
2 types
- Functional–Short-term
- Structural–Long-term
Capacity for Neuroplasticity:
Functional (short-term)
changes in efficiency or strength of synaptic connections
*short term because just affects the already existing conections
Capacity for Neuroplasticity:
Structural (Long-term)
changes in organization and numbers of connections among neurons
*long term because changes in the numbers and organization
Plasticity:
2 types
- ReACTIVE Synaptogenesis
- Regenerative Synaptogenesis
Plasticity:
Reactive Synapto.
Think Sprouts!!!
- collateral sprouting
- axons sprout NEW synapses
- sprouts typ. from SAME neural system
Plasticity:
Regenerative Synapto.
*Think Neuron heals!!!
- neural regen.
- occurs when injured axons sprout NEW dendrites
Research on Neuroplasticity
3 conclusions:
- Phys rehab after stroke is a potent modulator of plasticity process
- happens because of DEMAND
- demand leads to angiogenesis and synaptogenesis
- new blood vessels
- new neural connects.
- Int of training shown to INC recovery!!!
Neural Shock
Explain…
- Temp abolition of excitability in areas related to damaged area from:
- dec blood flow
- reduction in metabolism
- Lesion==swelling==dramatic LOSS of function==rapid RETURN of function
Therapeutic implication of Neural Shock
- Goal of early PT:
-
disinhibit system
- STOP inhibition and let system function again
-
disinhibit system
Denervation Hypersensitivity
occurs when neuron loses normal input, results in hypersensitivity of post-synaptic membrane to neurotransmitters
*Injury==rapid LOSS function==function restored because neurons become MORE sensitive
occurs when neuron loses normal input, results in hypersensitivity of post-synaptic membrane to neurotransmitters
*Injury==rapid LOSS function==function restored because neurons become MORE sensitive
Denervation Hypersensitivity
Ischemic Penumbra
- cells bordering ischemic region
- neurons are viable, but NOT functional
- lost connects OR insuff. blood flow
- improved thru tx w/ amphetamines and PT
System Redundancy
- recruitment of previously silent/unused synapses
- suggests presence of synapses that do not normally function due to neuronal competition
- training may lead to unmasking these silent synapses ALONG W/ amphetamines
- facilitates activation
Recruitment of previously silent/unused synapses
System redundancy
*includes neuronal competition
What happens during recovery?
COMBO of processes occurring simultaneously OR sequentially
*NOTE: PT’s must understand these processes!!!
CNS Pharmacologic interventions
*remember goal to DISinhibit system
- prevent scarring
- prevent swelling
- stimulate growth
- Disinhibit inhibited regions
Spontaneous recovery occurs due to _______ when?
Nat. processes AFTER lesion
When is recovery considered spontaneous?
- Much of the recovery in first 3-4 wks after insult are spont.
- normalize edema, circ, and/or neural shock
NOTE: changes after 3-4wks are due to other mech’s
Spontaneous recovery and PT research?
was it the PT intervention OR spont. recovery that was going to happen anyway?
Need control vs. experimental groups
What are some influences on recovery?
- age
- lesion characters.
- environment/experience
- amt practice time/training provided
- NEED
- therap. recovery is goal driven!!!
Recovery and age
Initial sparing, BUT deficits may develop as organism matures
Aging effects on deficits
maturational status of area damaged
how “mature” is the damaged area
- If area is functionally mature
- damage is comparable
- if area is not mature
- may be no INITIAL deficit, BUT one might develop as that region matures
Aging effects on deficits other than Maturational status (2)
- Functional status of remaining system
- Size of the lesion AND location
(golf ball size as child vs. adult two diff scenarios!!)
Lesion characteristics
varies by _____ and _____
size AND location
*Bigger + proximal == WORSE
Lesion characteristics
*speed of lesion growth
Consider serial lesion phenomenon
- problem develops slow and thus the body compensates around it
- evidence of plasticity !!!
Experiential factors on recovery
Pre and post-injury experience and environment can influence outcome
How does Training differ from Experience?
refers to specific tasks rather than general activity
*Appropriate practice results in improvement
*perfect practice makes perfect!!!
NEED in terms of recovery
- NEED to use a poorly functioning body part will drive recovery
- IF indiv does not NEED to use that body part—unlikely recovery will occur
Learned non-use or….
no drive to use that side
What has led to the theory of Constrained Induced Mvmt Therapy (CIMT)
*forced to use affected extremity
although the initial loss of function is neural cause….
MANY pts continue to NOT USE involved side
this is what has led to CIMT…
What is Motor Control?
using motor memory and current sensory input to coordinate effective and efficient mvmts and govern posture
using motor memory and current sensory input to coordinate effective and efficient mvmts and govern posture
Motor learning
Perception-Action cycle
Note: where strength is in this…
see pic
What is Motor Control?
ability to regulate or direct the mech’s essential to mvmt
ability to regulate or direct the mech’s essential to mvmt
Motor Control
Theories of Motor Control (6)
Remember…motor control is ability to regulate or direct the mech’s essential to mvmt
- Reflex
- Hierarchial
- Motor Programming
- Systems
- Dynamical Action
- Ecological
Theories of Motor Control
Reflex
- Reflexes==building blocks of complex behavior
- aka theres a reflex for everything
-
work tog. for common purpose
- chaning
- stim–resp–resp
Limits of Reflex Theory
Does NOT explain what?
- mvmt in ABSENCE of stimuli
- fast mvmts
- Mult. resp’s to SAME stim
- production of novel mvmts
theories of motor control
Hierarchial
*basically…Higher lvls control Lower lvls
- Control is top down
- Higher lvls exert control on Lower lvls
Limits of Hierarachial reflex approach
Does NOT explain
- Dominance of reflex behavior in adults
- balance and righting
- swallowing
- bottom up control
Hierarchial Approach and Signe Brunnstrom
used reflex/hierarchial theory to describe abnorm mvmt following a motor cortex lesion
Theories for motor control
Motor Programming
includes what?
- mvmt controlled by centralized program
-
activated externally
- stimulus
-
centrally
- volunt/involunt
-
activated externally
- EX: locomotion spinal cats
- Central Pattern Generators (CPGs)
In regards to Motor Programming theories of Motor control…
Explain Central pattern generator
- area contains data for stereotyped mvmt
- neuronal circuit—stereotyped and hardwired
- body wt supported gait/TM training
EX. Cat experiment==> front legs getting back legs to work on TM after SC cut
Limits of Motor programming theory
Does NOT explain
- MSK and environmental variation in motor task performance
Theories of motor control:
Systems theory
- systems work cooperatively to achieve mvmt
- HIGHER lvls activate LOWER lvls
- LOWER lvls activate synergies
Limits of Systems theory
Does NOT…
emphasize interaction of individual and environment
Motor control theories
Dynamical Action
- mvmt control evolves into preferred patterns of mvmt
-
ex. throwing a ball
- “here is HOW you do it”
-
***Attractor sites
- certain patterns you always follow to achieve mvmt
- stable steady state of motor control system that leads to behavior according to preferred coordination states
-
ex. throwing a ball
Limits of Dynamic Action
does NOT explain..
-
importance of NS in motor control
- presumption that NS has an unimportant role
theories of motor control
Ecological
- motor control enables us to cope w/ environment
- perception is an important component
- CONSIDERS environmental factors
Limits of Ecological theory
Does NOT:
- emphasize function of NS
Motor control theories
Current theory
- Mvmt is a result of dynamic interplay of:
- perception
- cognition
- action systems
Movement emerges from interaction of 3 things:
- Individual
- Task
- Environment
Components W/in the Individual are: 3
- Perception
- Cognition
- Action
Importance of Action
Motor control is studied in relation to_______
Action
*study of one area may provide insight as to the control of other mvmts
what systems control action?
Perception is the integration of _________ into psychologically meaningful info
Sensory impressions
*Essential
3 types of Perception
- Visual
- Kinesthesia
- Vestibular
*Info about body, environment
why is Cognition essential?
Movement is PURPOSE DRIVEN!!
Processes of Cognition
Attention
Motivation
Emo. aspects
Mvmt emerges from 3 things
- Individual
- Task
- Environment
Diff components of movement
in relation to Task
- manipulation
2. mobility
3. stability
Task Constraints have impact on what?
Control of mvmt
Task constraints following CNS damage….
pt must redevelop what?
Redevlop mvmt patterns
Task constraints:
task grouping
- bed mobility
- transfers
- ADLs
Task Analysis
Discrete vs. Continuous
-
Discrete
- has beginning/end
-
Continuous
- ongoing
Task analysis
Stability vs Mobility
-
Stability
- holding
-
Mobility
- moving
task analysis
manipulation continuum
- Is there manipulation or none at all?
- ex. picking up pen
- are you writing w/ it?
- ex. picking up pen
Task analysis
Attention continuum
- focus to the activity
- how MUCH attn to the task are you giving?
Task analysis
Open vs. Closed
-
Open
-
NO control
- ex. “Catch the ball”
- you know NOTHING about the ball, you just want to catch it
- ex. “Catch the ball”
-
NO control
-
Closed
-
person has control over the variables of the activity
- “Throw me the ball”
- you throw the ball so you control the act.
- “Throw me the ball”
-
person has control over the variables of the activity
Gentile’s Taxonomy of Mvmt Tasks
Categorizes functional mvmt based on what?
Goals of task
Gentile’s Taxonomy of mvmt tasks incorporates THREE areas:
what are they?
- body stability OR mobility
- manipulation
- environmental context
*NO formal application proposed*
Gentile’s Taxonomy
See pics
Considering the Environment
Regulatory features
-
shapes the mvmt
- ex. size, shape, wt of cup to be lifted, walking surf, texture
Considering the Environment
Non-regulatory features
- MAY affect performance, BUT the mvmt need not conform to these features
- ex. background noise and distraction
- aka DOES NOT COMMAND A RESPONSE
Feat’s of the environment can do what to performance?
support OR hinder it
- EX’s
- walking in well-lit environment==easier vs. walking in low light or dark==harder
- Easier to balance while sitting on firm surf vs. soft or mobile one
Analyzing Mvmt
We are looking @ the analysis of 3 things
- analysis of Action lvl
- analysis of Mvmt lvl
- analysis of Neuromotor lvl
Analyzing Mvmt
@ the Action lvl
examines what?
- Examines behavioral outcome
- Did you execute the task?
Analyzing mvmt
@ the Mvmt lvl
analyzes what?
- analyzes mvmt strategy used
- HOW did you do task?
Analyzing mvmt
@ Neuromotor lvl
examines what?
- Examining subsystems involved
- What mm’s are acting and HOW?
