Neuroplasticity & Cognitive Rehabilitation Flashcards
What is neuroplasticity?
the brains capacity to change following experience (“experience-dependent change”)
What is neuropathic pain?
caused by lesion/disease of somatosensory nervous system
messed up pain wiring → nerves are sending pain signals for no good reason
What are the 3 mechanisms of neural plasticity?
- Functional Plasticity
- Structural Plasticity
- Neurogenesis
What is functional plasticity?
- strengthening/weakening synapses
- modified gene expression & protein synthesis
- increased/decreased connectivity b/w distant brain areas
- reorganization of firing patterns within brain areas
What is structural plasticiy?
- changes in dendritic spine density & morphology
- axonal sprouting
- up- or down-regulation of synaptic pruning
What is neurogenesis?
birth of new neurons
What is evidence of the age-dependent nature of plasticity?
- children born w/ cataracts (obstruct vision) can reorganize to favour other eye, not case for adults (less plasticity)
- children born blind visual cortex assumes non-visual functions, adults visual cortex fire on own w/o sensory input
What are 3 examples of the plasticity of cortical maps?
- reading braille increases sensory representation of reading finger
- focal dystonia: disorder involving involuntary muscle movements & postures of an overused body part
- phantom limb phenomenon related to cortical map reorganizatino
What are 2 interventions that target neuroplasticity?
- Psychedelics & anti-depresssants - make brain more sensitive to environmental experience (good & bad)
- rTMS - acts upon BDNF, same as traditional ECT - highly effective & fast-acting for severe depression (carries stigma)
What is central sensitization?
plastic change in pain processing in the central nervous system
ie. new spontaneous activity in spinal cord (if myelin is damaged)
ie. increased excitability & receptive field size of CNS neurons when touch & pain signals are “unbalanced”
ie. damaged inhibitory circuits in brainstem & spinal cord - normal pain inhibition processes are lost
What are the 3 manifestations of central sensitization?
- allodynia: pain in response to usually non-painful stimuli
- primary hyperalgesia: already painful sensations become more painful
- secondary hyperalgesia: hyperalgesia in areas outside of the original injury
What is cognitive rehabilitation therapy?
treatments aimed to improve cognitive functioning through the combined action of compensation, plasticity, and recovery
(particularly for TBI & stroke)
What are some potential areas of application of cognitive rehabilitation therapy?
- attention deficits after TBI/stroke
- visual scanning for neglect after right-hemisphere stroke
- compensatory strategies for mild memory deficitss
- language deficits after left-hemisphere stroke
- social-communication deficits after TBI
- metacognitive strategy training for deficits in executive functioning
How does cognitive rehabilitation therapy relate to the idea of plasticity?
- training affected behaviours (targeting recovery & plasticity)
- offering external support (targeting compensation)
What are 2 obstacles to developing evidence-based therapies for recovery of function after cerebral injury?
- no clear definition of recovery (ie. return of function vs partial improvement - research/treatment goals unclear)
- translating animal research to humans is difficult (ie. rats don’t completely translate to human)
What are 3 general principles of plasticity in the normal brain? With example for each.
- The brain changes in response to many types of experiences (sensorimotor training, drugs, hormones, stress all lead to brain changes)
- Different types of neuronal changes happen independently (changes in dendritic length don’t always match changes in spine density)
- Different brain regions show different plasticity rules (Prefrontal cortex responds differently to experiences compared to sensory or motor regions)
