Neuroplasticity and Neurorehabilitation

Neuroplasticity and Neurorehabilitation

• Motor learning/relearning relies on neuroplasticity.
• Neuroplasticity is the central nervous system’s (CNS) ability to change structurally and functionally in reaction to experiences.
• Existing neural connections are strengthened.
• New neural connections form.
• Pruning/focusing of neural connections occurs, leading to skill development and preferential pathways.
• Neuroplasticity can occur across the lifespan.
• It occurs in both normal and damaged brains.
• It's vital to determine which factors can boost neuroplasticity and optimize skill learning for PTs.
• Factors include the following: specific practice parameters, individual traits (cognition, attention, motivation, sleep), brain chemicals, genetics.

Kleim, 2012: Long Term Potentiation (LTP)

• Recording shows Tetanic Stimulation.
• The graph displays change in EPSP Amplitude (mV) over Time (mins).

Parameters of Neural Activity

• Intensity is defined as the number of stimuli per unit time.
• Repetition refers to the total number of stimuli.
• Timing refers to the temporal arrangement of stimuli, which can be synchronous or asynchronous.

Frequency-Dependent Plasticity

• A graph depicts Change in EPSP Amplitude (mV) over Time (mins), comparing 50Hz and 5Hz frequencies.
• 50Hz shows LTP, while 5Hz results in LTD.

Stimulation Repetition's Influence

• A graph shows % EPSP Change over Days, comparing 5 Days and 1 Day of stimulation.
• It shows LTP and Post-LTP effects.

Motor Skill Learning and Reorganization

• Motor skill learning induces motor map reorganization in the brain.
• Digit, Wrist, Digit + Wrist, Digit + Prox, and Wrist + Prox, are shown in red, green, yellow, teal and blue.
• Reorganization changes are shown at Baseline, Training I, Training II, Extinction, and Reacquisition.

Tactile Discrimination Training

• Tactile discrimination training reorganizes somatosensory maps.
• The maps show mRF Distal, mRF Proximal, and Dorsal Hand.

Movements and Coordination

• Movements made together stay together, impacting motor map organization in the brain.
• Maps show Digit, Wrist, Digit+ Wrist, Digit + Prox, and Wrist+ Prox, across Pre-Training and Post-Training stages.

Neuroplasticity and PT Rehabilitation

• Neuroplasticity can occur across the lifespan.
• It occurs in both normal and damaged brains.
• It's vital to determine which factors can boost neuroplasticity and optimize skill learning for PTs.
• Factors include the following: specific practice parameters, individual traits (cognition, attention, motivation, sleep), brain chemicals, genetics.

Experience-Dependent Plasticity Principles

• Use it or lose it: Failure to drive specific brain functions leads to functional decline.
• Use it and improve it: Training specific brain functions enhances them.
• Specificity: Training dictates the nature of neuroplasticity.
• Repetition matters: Plasticity needs repetition.
• Intensity matters: Plasticity needs training intensity.
• Time matters: Plasticity occurs at different times during training.
• Salience matters: Salient training induces plasticity best.
• Age matters: Younger brains respond better to training.
• Transference: Training enhances similar behaviors.
• Interference: Training disrupts other behaviors.

Exercise and Neuroplasticity

• Studies show that exercise helps people with stroke, Parkinson's, and MS
• Exercise has elements, such as neuroplasticity that can improve motor learning and behavioral recovery.

Common Exercise Elements

• Goal-directed motor skill training is an element
• Including: Repetition, Intensity, and a Challenge beyond self-perceived capability,
• Intensive aerobic exercise.

Different Training Experiences

• Skill training results in Synaptogenesis and reorganization of Motor Maps.
• Endurance training leads to Angiogenesis.
• Strength training also results in Synaptogenesis.

Goal-Directed Motor Skill Training

• Common practices for Stroke are Constraint-Induced Movement Therapy (CIMT) and Body Weight Support Treadmill Training (BWSTT).
• For Parkinson's Disease (PD), common elements involve gait and dynamic balance practices, combined with cognitive engagement.
• These cognitive elements promote the use of frontal cortex loops involved in motor learning

Review of Motor Deficits in PD

• Many well-learned motor skills are automatic & unconscious.
• Loss of motor automaticity is the deterioration of basal ganglia function seen in PD.
• Individuals with PD need to become more cognitively engaged through practice and learning via.
• Some are: Instruction & feedback (verbal, proprioceptive) and Cueing (attention) such as Visual, verbal, auditory, rhythmic Other elements are: Dual tasking (attention) and overall motivation.

Impact of Exercise for Treadmill Training

• Increase intensity & challenge by adjusting speed & incline.
• Include verbal feedback &/or cues to draw attention to task and promote cognitive engagement for best outcomes in PD
• Amplitude training includes large amplitude movements of whole body while practicing a skill.
• It incorporates significant amount of verbal feedback & attention strategies.
• Tai Chi uses dynamic postural control via weight shifting to control COG.

Exercises and Coordination (Dance - Tango)

• The need is to coordinate movements with a partner (cognitive engagement).
• Cueing and attention are provided by music & rhythm.

Exercises and Coordination (Boxing)

• Dynamic balance activities occur with multidirectional movements.
• High-speed UE punching motions occur.
• Trunk rotation and anticipatory postural adjustments are needed.

High Intensity Multimodal Exercise Boot Camp

• Combination of aerobic exercise, strengthening and balance;
• 90 minute sessions; 3 days/wk within 8 weeks,
• Including: 30 min mod-high intensity aerobic exercise at 70% - 80% of estimated max HR and 30 min strengthening of major muscle groups of trunk, UEs & LES
• Activities include 15 min balance training, anticipatory PC, reactive PC and dynamic gait involving side stepping, variable speeds, head turns, over obstacles
• Sensory orientation; EO & EC; firm & compliant surfaces.
• Contains 15 min of active rest and stretching.

Aerobic Exercise Effects on Brain Function

• Aerobic exercise appears to "prime" the brain for neuroplasticity.
• Occurs by increasing levels of BDNF, neurotrophic factors and neurotransmitters.
• Promotes overall brain health.

How Exercise Impacts Neuroplasticity

• Aerobic exercise alone won't induce neuroplastic changes for motor learning (LTP & dendritic branching).
• Studies show those with PD, Stroke and MS indicate that aerobic exercise when combined with challenging task practice/experience can have neuroprotective and neurorestorative effects.

Aerobic Exercise and Motor Rehab (Post Stroke)

• Aerobic exercise can prime motor rehabilitation after stroke, improving function.
• Exercise boosts BDNF levels in areas such as the cerebral cortex, hippocampus, cerebellum, and spinal cord.
• Facilitates LTP and dendrite formation in neural circuits.

Disease Modifying Effects of Exercise

• Neuroprotective effects:
  • Exercise increases neurotrophic factors to protect basal ganglia from deterioration/DA depletion.
    • Strenuous exercise can reduce risk for PD.
  • BDNF reduces neuroinflammation & oxidative stress in PD via antioxidant processes.
  • BDNF and GNF mediate neuronal repair and plasticity in MS.
• Neurorestorative effects:
  • It shows exercise effects on neurotransmitters/receptors can restore synapses within the BG for normal motor learning/behavior.
    • May modify the course of PD.
  • Cortical reorganization may result in more normal function in MS.