experience dependent neuroplasticity Flashcards
What are principles of neuroplasticity?
- use it or lose it
- use it and improve it
- specificity
- repetition
- intensity
- salience/meaningfulness
- time since onset: 1st year after TBI/3mo-1yr post stroke
- age: younger=more
- transference
- interference
Ways to grade functional tasks for LE (gait)
- speed
- load
- assistance
- intensity
- error
- UE support/assistive devices
- cardiovasc. factors
- accuracy
ways to grade functional tasks for UE
- position of patient
- objects (position/weight/size)
- adaptive devices
- time constraints
- unilateral vs bilateral
- accuracy
studies with _____ during locomotor training facilitated walking ability
enhanced errors
ex. split belt treadmill (running belts at diff speeds, forwards/backwards)
variability is ____ for learning
good! more like real life
when is there too much variability in practice? When our patient exhibits signs of…
learned helplessness
demoralization
decreased motivation to not fail
what happens when we sleep?
plasticity
(downsizing of dendrites/spines of unnecessary inputs)
-facilitates storage, consolidation of earlier day’s learning
depression results in
smaller hippocampus
neuronal loss
decreased neurogenesis
deficits in concentration/memory
what happens during increased stress
mild stress enhances learning/memory but chronic stress causes NEURONAL LOSS IN HIPPOCAMPUS
-deficits in concentration/memory
regular exercise in mid/late life decreases risk of
dementia!
CARDIORESPIRATORY/AEROBIC EXERCISE
aerobic exercise causes
- better cognition
- better neurogenesis
- more dendritic spine density
- more angiogenesis
- more long term potentiation
_% of people are able to walk post stroke
80% (doesn’t include quality of walking)
_% independently walked at 6 months IF
1.
2.
98% independ. walk at 6 months IF
1. indep sitting balance in first 3 days
AND
2. LE strength of at least 1/5 hip flexors, knee extensors, ankle DFs in first 3 days
27% walked if criteria unmet at ___ days post stroke
27% walked if criteria unmet in 3 days
___% walked if criteria unmet at 9 days post stroke
10% walked if criteria unmet at 9 days
what 2 measures accurately predicted who will be homebound 92% of the time?
- BERG BALANCE SCALE
- FIM-LOCOMOTOR
upon admission to inpatient rehab facility, if BBS was less than ___ and FIM-L ____, then
20x more likely to achieve household ambulation by dc.
BBS below 20
FIM-L 1-2
what is a predictor of UE functional recovery post stroke?
AROM of shoulder and mid finger predicted 71% of variance in UE function at 3 months
What were the results of AVERT study?
no significant diff in deaths, falls, adverse events BUT
better with time in PT, time to first mobilization,
*DECREASED COST OF CARE AT 3 MONTHS
*BETTER MODIFIED RANKIN SCALE AT 3, 12 MONTHS
*ABILITY TO WALK UNASSISTED AT 3, 6 MONTHS
gait speed for unlimited household ambulation
0.27 m/sec
gait speed for limited community ambulation
0.58 m/sec
unlimited community ambulation gait speed
0.8 m/sec
gait speed needed to cross commercial street
2 m/sec
community ambulation for adults without stroke
1.2 m/sec
Von Schroeder et al. reported that normal 64 y/o were able to ambulate with a speed of _____ while chronic stroke survivors of similar age walked at ____
normal: 1.07 m/sec
chronic stroke survivors of similar age walked at 0.8 m/sec
what is the 6th vital sign?
gait speed
0.8 m/sec
What are essential neuroanatomy for walking?
SPGs (spinal cord pattern generators)
mm and peripheral nerves
3. ventrolateral and ventromedial spinal cord pathways
4. medullary reticular formation
5. mesencephalic locomotor region
6. subthalamic locomotor region
what are spinal cord CPGs?
Intrinsic circuits located in the ventral and intermediate gray matter that produces and repeats a functional behavior
For walking, it switches between flexors and extensors
(extensors more peripheral)
properties of CPGs
- They are involved in intra- and inter- limb coordination (involving many joints).
- They can react appropriately to sensory inputs.
- They can recover.
- They can learn.
medial medullary reticular formation
Final integrative center for locomotion before the cord
“Driving” center for locomotion in all animals
Decision to walk is made here.
Source of pathway that descends in V-L cord to provide the tonic drive to CPG in spinal cord
Involved in inter-limb coordination via feedback loops that detect symmetry or asymmetry of limb movement
Why PT’s can influence gait at the level of the Medial Medullary Reticular Formation:
However, in supported treadmill training, limbs can be moved symmetrically, so that feedback goes into the reticular system and the medial medullary RF can begin to develop a better “driver” for the CPG’s.
Gait speed is important, since it will control level of feedback provided to cerebellum via stretch-sensitive muscle receptors.
mesencephalic locomotor region
When this region of midbrain is stimulated with E-stim (in cats) locomotion is initiated with the speed of movement consistent with the intensity of the E-stim.
Thus, this area may help modulate speed of walking.
May be involved in exploratory locomotion
Responsible for spontaneous goal-directed locomotion
subthalamic locomotor region
important but not essential neuroanatomy
Sensation
Dorsolateral spinal cord pathways
Pontomedullary locomotor strip
Cerebellum (vermal)
Red nucleus
Lateral vestibular nuclei
Substantia nigra
Globus pallidus, internal segment
Nucleus accumbens
Limbic cortex
where can you identify motivation to walk?
hippocampus! fear can shut down system
important neuroanatomy interact with essential regions to control locomotion indirectly by:
Timing of swing versus stance phases of gait
Detection of sensory gains during walking (especially if sensations are atypical)
Coordination of walking
Motivation to walk*
accessory regions involved in walking
- motor cerebral cortex
- pyramidal tracts
what is the cerebral cortex involved in?
May influence initiation, timing, the transition from stance to swing, and the precise positioning of the foot
However, cortex may interfere with walking if attention is required for a task
what are 3 key sensory inputs for CPG
- Stretch of hip flexors* – resets the CPG
- Unweighting of triceps surae – gives leg “permission” to take a step
- Weight bearing to facilitate extensor tone in stance limb (muscle receptors in triceps surae, pressure receptors in foot, and joint receptors)
Hip extension during ______(Key phase of gait) triggers swing of the limb via activation of the velocity and amplitude dependent muscle spindles.
Mid-stance to Heel off
key spinal cord segments involved in “stretch of hip flexors”
L2, 3, 4
*if hip is kept from extending, then walking STOPS
For therapeutic benefit, therefore, PT should stretch the_____during key phase of gait and let the leg swing through.
iliopsoas during midstance to heel off
Avoid working on ______, if walking is the goal
static position control
(COM is outside the base of support 80% of the time when walking normally)
learned non-use…
Can occur with overuse of other UE and compensations
May start with decreased sensation and/or motor abilities initially post-stroke
forced use: constraint induced movement therapy
- ability to extend wrist 10-20 degrees (from any position) and slightly extend 2 fingers AT LEAST
- ability to understand and follow directions!
*other criteria (raise arm 45 deg, extend elbow 20 deg with shoulder flexed to 90, stand 2 min, B&B, extend/abduct thumb 10 degrees, medically stable, highly motivated)
CIMT: Adherence-Enhancing Behavioral Strategies (Transfer Package)
Behavioral contract
Home diary
Home skill assignment
Daily administration of Motor Activity Log
Home practice
EXCITE trial results
CIMT stroke survivors!
wolf motor function test, motor activity log, SIS (all improved!
*improvements kept up at 12 and 24 months
*total of 70 participants
