Factors Influencing Recovery after Brain Damage Flashcards
1
Q
8 common misconceptions about recovery/damage
A
- Recovery from brain dysfunction depends largely on injured person’s efforts
- Someone with severe brain dysfunction can recover completely (apart from some persistent problems with memory)
- Misattributing behaviour (ie. Fatigue, aggression) that results from brain dysfunction to the person’s personality or life stage
- People are more forgiving of behaviour if they have bandage/visible scarring on head
- Emotional problems after brain injury are usually not related to brain dysfunction
- A second brain injury can restore lost memories in those with amnesia
- People with amnesia are totally normal in every other respect
- People with amnesia have no trouble learning new info (ie. They believe amnesia is entirely retrograde -> loss of memory for events prior to injury)
2
Q
Anosognosia
A
- May occur after stroke and hemiplegia (paralysis on one side of the body)
- May involve confabulation (making up a story that fits the current circumstances that are not reflective of reality) or somatoparaphrenia (identifying paralyzed limb as someone else’s; not their own)
- Often goes away after a few days-weeks after stroke
- Linked to various forms of dysfunction
3
Q
Forms of dysfunction linked to anosognosia
A
- Movement disorders
- Contralateral neglect
- Memory disorders
- Dysexecutive syndrome (‘frontal lobe syndrome’): Disinhibition, aggression, impulsiveness, and disruptions in planning and certain types of memory (i.e., working memory)
4
Q
4 studies describing importance of self-awareness in successful recovery
A
- Prigatano & Wong study: your ability to accurately predict your recovery increases likelihood of achieving your recovery goals
- Jehkonen study: those with initial anosognosia had poorer functional outcomes
- Gialanella study: rehabilitation progress not as strong when anosognosia is present
- Cheng & Man study: “Awareness Intervention Program” (AIP); AIP group showed improved self-awareness but was not associated with improved functional outcome
5
Q
effect of age on recovery
A
- In monkeys, removal of primary motor cortex in infancy results in less dramatic impairment than in adulthood
- In humans, brain injury resulting in aphasia before age 1 is associated with best recovery; recovery diminishes as age increases
- Prefrontal lesions before 16 months may be associated with an inability to learn social and moral rules later in life
6
Q
effect of damage on recovery
A
- Direct relationship between size of brain lesion and extent of recovery (Larger lesions -> more functional impairments)
- Patients with bilateral lesions show less recovery than patients with unilateral lesions
- Ex. Bilateral hippocampal lesions -> severe anterograde amnesia; unilateral lesions -> less severe
- Differences due to Chronic vs. Acute Dysfunction
7
Q
effect of damage on recovery: chronic vs. acute dysfunction
A
- Massive slow-growing tumour (chronic) can have little impairment/functional deficit
- On the other hand, sudden stroke with associated damage of comparable size (acute) can result in functional devastation
8
Q
effect of environment on recovery
A
- Environmental factors may affect the amount of functional recovery following brain injury
- Ex. Animal models in enriched environments recover better
- Ex. Monkeys with focal strokes to the motor cortex were re-trained in skilled hand use
9
Q
Secondary Effects
A
- Edema
- Diaschisis
10
Q
Secondary effects: edema
A
- Swelling (edema) after stroke may mask or distort functions in essentially intact regions of the brain
- Dissipation of these effects may account for substantial early recovery (the regions were never broken, they just stop being distorted by edema)
11
Q
Secondary effects: Diaschisis
A
- Brain lesion can cause dysfunction in an area remote to it because of its strong connections with that area
- Thus, recovery can occur because of a spontaneous reduction of diaschisis (metabolic depression in cerebral areas remote to the lesion)
12
Q
Compensatory strategies
A
- Mainstay of rehabilitation of patients with brain dysfunction
- Recovery may not represent true restitution of function, but substitution of a new behaviour
- Patient learns strategies to adopt to his or her new motor, sensory, or cognitive impairments
- Ex. Rats use compensatory strategies to walk across beam
13
Q
Therapy dose
A
More therapy time, more recovery (even when controlling for time post-injury)
14
Q
What is Targeted Temperature Management (TTM)?
A
therapeutic cooling of the human body used for neuroprotection
15
Q
What are the mechanisms of TTM?
A
- One mechanism:
- lowers brain metabolism (glucose and O2 consumption) ->
- lower risk of energy failure (prevents failure of sodium pumps and potassium influex) ->
- decreased risk of cell death
- Another mechanism:
- Decreases pressure by reducing inflammation and cerebral blood volume