Chapter 25 - Recovery, Plasticity, and Rehab Flashcards
What is recovery of function
process where the brain regains lost abilities after injury, but can range from complete restoration to partial improvement
What is compensation
finding new ways to perform tasks, rather than restoring the lost function itself
Who decides if recovery has occurred
patient, physician, spouse, employer, WEC, insurance?
depends on who is the right person to ask
ex. family thought injured patient showed great recovery and Kolb’s disagreed
When does recovery occur
common view = over by 6-12 months (wrong)
not a specific timeline!
can occur for a long time after
What does the portrait case tell us
15 year old that had right hemisphere stroke. (due to rib breaking) had some motor recovery but remained severely impaired in left hand
23 years later started swimming and began to feel movement in his left hand
What are the levels of analysis in plasticity
- behaviour
- neural imaging
- cortical maps (invasive and noninvasive)
- physiology (LPT)
- synaptic organization
- mitotic activity
- molecular structure
cortical maps
can see in monkeys the digit and wrist movement during tasks
specific experiences produce specific changes
physiological level
stimulation of neuron and get responses.
now blast the cell, now records a new average response
result in changes to dendritic and more synapses
mitotic activity
exercise increases generation of new neurons and increased blood flow
What are the 10 principles of brain plasticity
- common to all NSs: plasticity is a universal trait
- can be analyzed at multiple levels
- 2 general types of plasticity = experience expectant (during development) and experience-dependent (brain changes that are already present) both change from experience
- even similar behaviours can lead to different plastic changes and different regions
- experience-dependent changes interact = past experiences like stress can influence future experiences
- varies with age - younger brains are more flexible
- time-dependent - some changes are permanent and others are short lived
- linked to experience’s relevance
- intensity and frequency influence - more intense and frequent experiences lead to greater/faster brain changes
- maladaptive - can have negative effects
experience expectant vs experience dependent plasticity
expectant = something that changes due to experience that you were predicting/expecting
dependent = changes that occur due to experience, but were not expecting (ex. taking a neuro class when you were born)
What is metaplasticity
refers to the flexibility of synaptic plasticity and the brains ability to change how it adapts and learns based on past experiences
What is maladaptive plasticity
when brain changes lead to negative outcomes
due to drug use, motor disorders, hyperconnectivity, conditions
What is the key structural changes is where
at the synapse
What is learned nonuse
people learn to not use where they had an injury
ex. have a stroke and can’t use left hand, so learn how to live without using it (negative outcome because can’t recover if don’t use it)
What are 3 early postinjury treatments
- tPA to unblock vessels in ischemic stroke (a block)
- neuroprotectants (drug reduces body temperature in rats, we are too big for it to work,) protect neurons from damage after injury, reduce secondary damage, minimize further harm
- thrombectomy (procedure to remove a blood clot from the brain, restoring blood flow)
What factors influence recovery of function
age (young), handedness (left-handed = less lateralized), sex (female), intelligence (higher intelligence), personality, small lesion
more connections
what assumptions regarding cortical organization are challenged by the concept of recovery
brain functions are not rigidly fixed to specific locations
cortical maps can remap after injury
What mechanisms might be responsible for recovery
neuroplasticity - form new connections and reorganize existing ones
cortical reorganization - undamaged areas take over
neurogenesis - new neurons generated
compensatory mechanisms
What evidence is there that recovery (compensation) occurs
neuroimaging studies = show other areas take over
animal models = research shows animals form new connections and areas of the brain compensate
rehabilitation
neuroplasticity
genetic and pharmacological evidence - boost neurotrophic factors and reduce inflammation to promote recovery
what types of therapies might prove beneficial
electrical stimulation (vagus nerve stimulation), cognitive rehabilitation (targeted exercises), tactile stimulation (massage), growth factors and stem cells, pharmacological therapies (drugs), physiotherapy, musical and behaviour therapies
what physiological events are associated with brain damage
cellular injury and death
excitotoxicity - excessive release of glutamate to overstimulate neurons that damage cells
inflammation - worsening damage
oxidative stress - injury causes production of reactive oxygen species
what does the nudo experiment show
cortical plasticity, of motor function recovery after brain injury after monkeys experienced sensorimotor cortex lesion
cortex reorganized and adjacent areas took over motor functions, rehabilitation significantly increased cortical reorganization from repetitive motor training that underwent practice with impaired limbs, can recover motor abilities through plasticity
how does age relate to recovery
younger individuals recovery better due to higher neuroplasticity and cell regeneration
older brain = reduced plasticity and cognitive reserve
