Lecture 1: Neuroplasticity and Motor control Flashcards
What Is Neuroplasticity?
Adaptive capacity of the central nervous system
• Mechanism by which the brain encodes experience and learns new behaviors
• Mechanism by which the damaged brain relearns lost behavior in response to rehabilitation
How Is Neuroplasticity Measured?
Animal Studies
- Cortical map reorganization
- -intracortical microstimulation
- Morphological markers of plasticity
- -Synaptogenesis
Human Studies
- Cortical excitability and cortical map reorganization
- -Transcranial magnetic stimulation
What Are Exercise-Dependent Plasticity Practice Variables?
1) Use it or lose it (task complexity)
2) Use it and improve it
3) Specificity
4) Repetition Matters
5) Intensity Matters (task difficulty)
6) Salience Matters
7) Age matters
8) Transference
9) Interference
10) Time
Use it or lose it
failure to drive specific brain functions can lead to functional degradation
Use it and improve it*
Training that drives a specific brain function can lead to enhancement of that function
Specificity*
the nature of training experience dictates the nature of the plasticity
Repetition Matters*
induction of plasticity requires sufficient repetition
Intensity Matters
induction of plasticity requires sufficient training intensity
Salience Matters*
The training experience must be sufficiently salient to induce plasticity
Use it or lose it
failure to drive specific brain functions can lead to functional degradation
Transference
plasticity in response to one training experience can enhance the acquisition of similar behaviors
Interference
Plasticity in response to ones experience can interfere with the acquisition of other behaviors
Time
different forms of plasticity occurs at different times during training
Intensity Matters/ task difficulty
induction of plasticity requires sufficient training intensity
Salience Matters*
The training experience must be sufficiently salient to induce plasticity
must matter to the person
Interference
Plasticity in response to one’s experience can interfere with the acquisition of other behaviors
Functional reorganization of the motor cortex is dependent on
Task complexity
• Skill dependent rather than use dependent
• Skill acquisition is more important than movement repetition
• Skill acquisition is more important than strengthening
What induces cortical reorganization, strength training or skill learning
Skill learning
What is TMS
Transcranial Magnetic Stimulation
• Non-invasive method to cause depolarization in neurons of the brain
• Current through the primary coil induces a magnetic field
• TMS applied over Stimulus-response curve motor cortex → contraction of contralateral muscles
• Electrode over muscle in the periphery (biceps) measures motor evoked potentials (MEPs)
Neuroplasticity in the damaged brain
- Spontaneous neural recovery
- Mechanism for spontaneous recovery
- Recovery from diaschisis
Spontaneous neural recovery
plastic response to injury that demonstrate functional restoration independent of rehabilitation experience
Mechanism for spontaneous recovery:
Reversal of acute physiologic changes that occurred from injury
• Lessening of edema
• Reestablishment of pre-morbid neurotransmitter levels
• Reabsorption of blood in cases of hemorrhage
What does diaschisis mean
Diaschisis: the selective disruptive effect of a focal lesion on the operations of areas with which it was structurally and functionally connected; associated with the acute injury events
(idea of penumbra around a stroke)
Windows of ‘Spontaneous Recovery’
~1 year for brain injury
~6 months for CVA
Neuroplasticity and compensation
your neuroanatomy changes to reflect compensatory movements. worsens the repair on affected side because that side is getting lazy.
plasticity of dendrites and synapses was seen in the contralesional motor co
What is Motor Control?
The scientific field of study concerned with:
- How all kinds of movements (genetically defined or learned through practice) are controlled
- How the CNS is organized so that many individual muscles and joints become coordinated
- How sensory information from the environment and/or from the body is used in the control of movement and how such information allows a person to select and plan an action
Movement emerges from:
TIME
•Task
•Individual
•Environment
The individual generates movement to meet the demands of the task being performed within a specific environment.
What do we as therapists manipulate to help pt with movement
The task
What do we as therapists manipulate to help pt with movement
The task
What is an Open Movement Task
task is ever changing and unpredictable i.e. Soccer • Requires constant monitoring of the sensory system to alter the motor plan
What is a Closed Movement Tasks
fixed and relatively predictable environments • Requires less constant sensory monitoring
Movement emerges from :The Environment
Tasks are performed in a wide range of environments.
CNS must take into consideration the environment
What is a Closed Movement Tasks
fixed and relatively predictable environments • Requires less constant sensory monitoring
What are Regulatory features and examples
affects the performance
i.e. the size, shape, and weight of a cup to be picked up and the type of surface on which we walk
What are Non -Regulatory features
affects performance on a small margin
i.e. background noise and the presence of distractions. Shumway-Cook
What systems are apart of motor control
Coordination Perception, Cognition ROM Muscle Tone Sensation Synergy Strength
What is meant by Movement emerges from The Individual:
Motor/Action Systems
• Both the neuromuscular and biomechanical system contribute to functional movement control.
• Strength, balance, coordination, range of motion
• There are a number of joints and muscles that must all be controlled referred as “degrees of freedom problem”
What is the relationship between balance and perception?
Balance is related to strength and holding tone but also using the visual inputs and proprioception.
What is meant by Movement emerges from The Individual:
1) Cognitive System
2) Sensory, Perceptual Systems
Why must the study of motor control include the study of cognitive processes as they relate to perception and action.
There are different ways we process and perceive information
Cognitive system includes
includes: • attention • planning • problem solving • motivation
- All above must be considered as it relates to the patient’s intent or goals (Subjective)
- Study of motor control must include the study of cognitive processes as they relate to perception and action.
Why is sensation and perception are essential to the control of functional movement.
Perception is the integration of sensory impressions into psychologically meaningful information.
• Perception is subject to interpretation
• Sensory/perceptual proprioception critical to the regulation of movement.
What is the ventral stream processing
“What pathway” / Perception pathway
From the striate cortex to the inferior temporal cortex
What is dorsal stream processing
“Where pathway”/ Action
projects form the parietal region and mediates the sensory motor
What is visual agnosia and which pathway would be affected
inability to recognize the size, shape and orientation of visual objects
affects the “what pathway”
