Mr. Phinoj K Abraham (MOTh)
Assistant Professor,
SRM College of Occupational Therapy
(plastos) - ‚capable of being molded’

Neuroplasticity:
‘the ability of the CNS to remodel itself’

Neuroplasticity is how...
Neuroplasticity
Historical Background
Two Current Concepts
Importance in Rehabilitation
Role of Occupational Therapist
Rel...
Until 1970 : brain structure is relatively immutable in
adulthood.
In the 1960s,
Paul Bach-y-Rita - electrically stimulate...
A tragic stroke that left his 68 year old father paralyzed
inspired Bach-y-Rita to study brain rehabilitation
His brother ...
David Hubel and Torsten Wiesel:
Study with kittens
The experiment involved sewing one eye shut and
recording the cortical ...
Jenkins & Merzenich (1987) removed monkey’s 1 Peripheral
Nerve , later found that adjacent neurons had started to
respond ...
(Ramachandran V 1992).
“if someone were to lose their right
hand in an accident, they may then have

the feelings of a pha...
Enhancement of existing
connections

Formation of new
connections

Very active research area; concepts areare continully b...
Type
1.

Mechanism

Enhancement of existing connections
A. Synapse development
B. Synapse strengthening

2.

Duration

Phy...
1. Enhancement of existing connections

Increased use of a synapse in existing
pathways e.g. learning a new task
Or altern...
Increased
afferent input

+
+
+

New synapses
evolve leading to
increased
excitation
Ragert et al., 2004
Effectiveness of a synapse can be increased for at least 3
durations:
1. Seconds and minutes

(short-term memory)

2. Hour...
Two point discrimination threshold in
pianists index finger

Ragert et al., 2004
R

L

Comparison of musicians to non-musi...
2) Formation of new connections
Unmasking of pre-existing pathways
Sprouting of new pathways
Possible reasons why some synapses could
be ‘silent’
Inhibited by dominant pathways
Too little transmitter
Too few recepto...
Parallel pathway; neurons
with a comparable role

Dominant pathway

Subservient pathway

+

+
Lesion to
dominant
pathway

Subservient pathway is
unmasked

+
Activity is
continued
despite
lesion

+
Cell body

Axon

Sprouting occurs
following damage or
denervation to the
nervous system and
is the growth of new
axons fro...
INJURY
Following
denervation, neurotro
phic factors or nerve
growth factors are
released, they are
polypeptides capable
of...
The release of
nerve growth
factors
stimulates
neurites or new
axons to sprout
and look for
the source of
the NGF

INJURY
...
Injury results in
cell death

Cell is re-innervated
from alternative
stimulus

Sprouting may be a means of recovery; it ma...
1. Strengthen and develop
normal synapses
OT’st need to

2. Guide axonal sprouting
3. Facilitate unmasking of
alternative ...
Provide positive sensory input
i.e. “appropriate handling”
Facilitate “functional”
movement
Provide treatment at
“optimum”...
NEGATIVE
PLASTICITY
Disuse/ unskilled
Noisy. nonspecific

POSITIVE PLASTICITY

Modulation

Not challenging

Outcome

Negat...
Mirror Therapy for patients with stroke & Amputation
Ramachandran, Rogers-Ramachandran & Cobb 1995

Hypothesis
Every time ...
Mirror Box
To retrain the brain, and thereby
eliminate the learned paralysis
The patient places the good limb into

one si...
Ex.
“Examining the Neuroscience Evidence for SensoryDriven Neuroplasticity: Implications for SensoryBased Occupational The...
Neuroplasticity is the focus of a growing body of
research with significant implications for neuro-

rehabilitation.
Neuro...
Bibliography
Neurological Rehabilitation – Umphred Darcy 4th edition
Physiological basis of Rehabilitation

Journals
Mirro...
Introduction to Neuroplasticity & its application in neuro rehabilitation
Introduction to Neuroplasticity & its application in neuro rehabilitation
Introduction to Neuroplasticity & its application in neuro rehabilitation
Upcoming SlideShare
Loading in …5
×

Introduction to Neuroplasticity & its application in neuro rehabilitation

6,272 views

Published on

Introduction to Neuroplasticity & its application in neuro rehabilitation. This presentation is aimed at beginners in occupational therapy profession

Published in: Education, Health & Medicine
0 Comments
24 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
6,272
On SlideShare
0
From Embeds
0
Number of Embeds
12
Actions
Shares
0
Downloads
470
Comments
0
Likes
24
Embeds 0
No embeds

No notes for slide
  • Going back to Jerzy Konorski, student of Pavlov, operant conditioningChallenge of neuroplasticity
  • Introduction to Neuroplasticity & its application in neuro rehabilitation

    1. 1. Mr. Phinoj K Abraham (MOTh) Assistant Professor, SRM College of Occupational Therapy
    2. 2. (plastos) - ‚capable of being molded’ Neuroplasticity: ‘the ability of the CNS to remodel itself’ Neuroplasticity is how we adapt to changing conditions, learn new facts, and develop new skills. It is constantly occurring; the brain is always changing (Mark Hallet 2005)
    3. 3. Neuroplasticity Historical Background Two Current Concepts Importance in Rehabilitation Role of Occupational Therapist Related Research
    4. 4. Until 1970 : brain structure is relatively immutable in adulthood. In the 1960s, Paul Bach-y-Rita - electrically stimulated chair with 400 vibrating stimulators for congenitally blind. He Concluded, “We see with our brains, not with our eyes.” Doidge, Norman (2007)
    5. 5. A tragic stroke that left his 68 year old father paralyzed inspired Bach-y-Rita to study brain rehabilitation His brother – a physician- rehabilitated him and he recovered well He believed that ‘Under conditions of interest, such as that of competition, the resulting movement may be much more efficiently carried out than in the dull, routine training in the laboratory’ (Franz, 1921, pg.93)
    6. 6. David Hubel and Torsten Wiesel: Study with kittens The experiment involved sewing one eye shut and recording the cortical brain maps the portion of the kitten’s brain associated with the shut eye was not idle, as expected. Instead, it processed visual information from the open eye. “… as though the brain didn’t want to waste any ‘cortical real estate’ and had found a way to rewire itself.”
    7. 7. Jenkins & Merzenich (1987) removed monkey’s 1 Peripheral Nerve , later found that adjacent neurons had started to respond to the palm.
    8. 8. (Ramachandran V 1992). “if someone were to lose their right hand in an accident, they may then have the feelings of a phantom limb because the areas in the somatosensory cortex that are near to the ones of the hand (the arm and face) will take over (or "remap") this cortical region that no longer has input”
    9. 9. Enhancement of existing connections Formation of new connections Very active research area; concepts areare continully being updated A very active research area; concepts continually being updated
    10. 10. Type 1. Mechanism Enhancement of existing connections A. Synapse development B. Synapse strengthening 2. Duration Physiological Biochemical ms-1 to hours hours to days Formation of new connections A. Unmasking B. Sprouting Physiological Structural minutes to days days to months
    11. 11. 1. Enhancement of existing connections Increased use of a synapse in existing pathways e.g. learning a new task Or alternative pathways following damage Opposite: dendrite atrophy
    12. 12. Increased afferent input + + + New synapses evolve leading to increased excitation
    13. 13. Ragert et al., 2004
    14. 14. Effectiveness of a synapse can be increased for at least 3 durations: 1. Seconds and minutes (short-term memory) 2. Hours and days (intermediate-term memory) 3. Months and years (long-term memory) Such changes can take place at three cellular locations: 1. Presynaptic terminal 2. Postsynaptic membrane 3. Postsynaptic nucleus Kidd et al., 1992
    15. 15. Two point discrimination threshold in pianists index finger Ragert et al., 2004 R L Comparison of musicians to non-musicians Findings were long-lasting piano practising resulted in lower spatial discrimination thresholds in the index finger of piano players in comparison to non-musicians. This decrease in threshold was related to the number of hours practised per day (>3 hours), not to the number of years they had been playing
    16. 16. 2) Formation of new connections Unmasking of pre-existing pathways Sprouting of new pathways
    17. 17. Possible reasons why some synapses could be ‘silent’ Inhibited by dominant pathways Too little transmitter Too few receptors Don’t fire with other inputs
    18. 18. Parallel pathway; neurons with a comparable role Dominant pathway Subservient pathway + +
    19. 19. Lesion to dominant pathway Subservient pathway is unmasked + Activity is continued despite lesion +
    20. 20. Cell body Axon Sprouting occurs following damage or denervation to the nervous system and is the growth of new axons from cell bodies forming new pathways
    21. 21. INJURY Following denervation, neurotro phic factors or nerve growth factors are released, they are polypeptides capable of promoting neuronal survival. lesion Nerve Growth Factor (NGF)
    22. 22. The release of nerve growth factors stimulates neurites or new axons to sprout and look for the source of the NGF INJURY Neurite induced to sprout by NGF lesion NGF
    23. 23. Injury results in cell death Cell is re-innervated from alternative stimulus Sprouting may be a means of recovery; it may also produce unwanted effects For example spinal cord injury patients may experience strange sensations.
    24. 24. 1. Strengthen and develop normal synapses OT’st need to 2. Guide axonal sprouting 3. Facilitate unmasking of alternative or previously subservient pathways
    25. 25. Provide positive sensory input i.e. “appropriate handling” Facilitate “functional” movement Provide treatment at “optimum” time Education
    26. 26. NEGATIVE PLASTICITY Disuse/ unskilled Noisy. nonspecific POSITIVE PLASTICITY Modulation Not challenging Outcome Negative behaviors Novel & Challenging Positive behaviors Stimulation Quality of sensory input Intensive, skilled Appropriate / specific
    27. 27. Mirror Therapy for patients with stroke & Amputation Ramachandran, Rogers-Ramachandran & Cobb 1995 Hypothesis Every time the patient attempted to move the paralyzed limb, they received sensory feedback (through vision and proprioception) that the limb did not move. This feedback stamped itself into the brain circuit (Hebbian Learning) So even when the limb was no longer present, the brain had learned that the limb (and subsequent phantom) was paralyzed. Often a phantom limb is painful because it is felt to be stuck in an uncomfortable or unnatural position, and the patient feels they cannot move it.
    28. 28. Mirror Box To retrain the brain, and thereby eliminate the learned paralysis The patient places the good limb into one side, and the stump into the other It appears as if the phantom limb is also moving to unclench it from potentially painful positions. (Ramachandran, Rogers-Ramachandran & Cobb 1995)
    29. 29. Ex. “Examining the Neuroscience Evidence for SensoryDriven Neuroplasticity: Implications for SensoryBased Occupational Therapy for Children and Adolescents” Shelly J. Lane and Roseann C. Schaaf American Journal of Occupational Therapy May/June 2010 vol. 64 no. 3 375-390
    30. 30. Neuroplasticity is the focus of a growing body of research with significant implications for neuro- rehabilitation. Neuroplasticity - while not a concept unique to OT - holds tremendous application for neurorehabilitation provided by OTs.
    31. 31. Bibliography Neurological Rehabilitation – Umphred Darcy 4th edition Physiological basis of Rehabilitation Journals Mirror therapy improves hand function in subacute stroke: a randomized controlled trial. Arch Phys Med Rehabil. 2008 Mar;89(3):393-8. Guest Editorial - Neuroplasticity and rehabilitation assesssed from www.rehab.research.va.gov/jour/05/42/4/pdf/hallet.pdf retrieved on 303-12 Net References http://en.wikipedia.org/wiki/Neuroplasticity retrieved on 3-03-12 http://en.wikipedia.org/wiki/Mirror_box retrieved on 3-03-12 http://en.wikipedia.org/wiki/Hebbian_learning retrieved on 3-03-12

    ×