Neural Reorganization

Question 1

Types of reorganization

Answer 1

Adaptive: assists recovery of function

Maladaptive: prevents recovery of function

Question 2

Where does reorganization occur

Answer 2

Multiple levels!

Spinal reflexes, CPGs, Propriospinal pathways, Cerebellum and Cortex

Question 3

Recovery relies on

Answer 3

Recovery is limited but relies on

Synaptic reorganization
Axonal sprouting
Neurogenesis

Question 4

What is associated with neuro genesis

Answer 4

If BrdU and NeuN are present that indicates the CNS is attempting to form new neurons
(Same side of lesion)

Question 5

Clinical manifestations of reflex changes after SCI

Answer 5

increased tone
Hyperreflexia
Clonus

Question 6

How does the H-Reflex change after and SCI (in regards to gait)

Answer 6

H reflex normally raises with stance and decreases with swing
After an SCI the H flex cannot be modulated and stays hyperactive

Question 7

Can the reflex be trained?

Answer 7

Potentially!
Operant conditioning did help with regulation but its unclear in what patient would benefit from this training

Question 8

What were the results of the operant conditioning

Answer 8

Helps reduce voluntary movement deficits associated with UMN symptoms
Can improve outcomes

Question 9

Do CPGs show plasticity

Answer 9

In the spinal cat studies there was improved recovery after a complete spinal section severance suggesting plasticity occurred in the spinal CPGs

Question 10

Takeaways from spinal cat study

Answer 10

SC is a flexible integration center capable of adapting and shaping its motor circuits in order to optimize function with available inputs

Locomotor training has a powerful effect on spinal plasticity and acts on spinal circuits by reestablishing kinematic parameters approaching the normal state

Question 11

What is needed for CPG reorganization

Answer 11

Sensory feedback:
Hip flexor stretch
Hip extensor tension-weight-bearing (loading)

Repetitive application of sensory feedback in the context of the task

Question 12

Cortical plasticity after and SCI

Answer 12

Motor cortex attempts to reorganize soon after the SCI and continues for months

There are recover attempts to reconnect but eventually there is a “take over” from the remaining intact body parts leaving less “real estate” in the cortex

Question 13

Cortical reorganization after an SCI depends on

Answer 13

Age of injury (> reorganization if SCI is early)
Time since injury (> time, > time for reorganization)
Level of injury
Extent of injury
Therapy

Question 14

Implications for therapy

Answer 14

Spasticity
Weakness
Motor dyscoordination
Weight bearing, balance and propulsion issues