L&M Chapter 3 Flashcards

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0
Q

What does blood do in brain?

A

Remove toxic waste products in neural tissue

Oxygen and glucose supply

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1
Q

What is a stroke?

A
Cerebrovascular accident (CVA)
Clinical signs of focal disturbance of cerebral function with prob vascular origin
> 24 hour period
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2
Q

What are the two types of stroke?

A

Hemorrhagic (bleeding from vessel) - 20%

Occlusive (blockage of vessel) - 80%

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3
Q

What are two types of haemorrhagic stroke?

A

Subarachnoid (50%)

Intracerebral (50%)

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4
Q

Describe intracerebral stroke

A

Blood escapes into surrounding tissue, destroys it

Localised

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5
Q

What percentage of haemorrhagic strokes are subarachnoid?

A

Approx 50%

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6
Q

What percentage of strokes are occlusive?

A

Approx 80% all strokes

Much lower mortality rate than haemorrhagic

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7
Q

What are two main types of occlusive stroke?

A
  1. Cerebral Thrombosis - narrowing of vessel, caused by build up of plaque (aatherosclerosis)
  2. Cerebral Embolism - plaque comes from elsewhere in body, gets stuck in narrower vessels in brain.
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8
Q

What impacts on size of infarction (in occlusive stroke)

A
  • location of occlusion, and extent of collateral circulation
  • how big blood vessel is
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9
Q

Describe memory function after ischaemic strokes?

A
  • severe amnesic results if happens in anterior choroidal arteries (MTLs) or posterior cerebral arteries (thalamus)
  • less severe if happens in anterior cerebral arteries (medial frontal lobes, mammillary bodies, fornix, anterior Cingulate cortex) or middle cerebral arteries (lateral frontal and temporal lobes)
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10
Q

What is effect of stroke size on outcome?

A

Localised - less effect

Generalised - much greater cognitive disfunction

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11
Q

What is recovery period after stroke

A

Most significant repaid 0-3 months (daily - weekly improvement)
Continued improvement 3-6 months (monthly improvement)
Rare improvement after 12 months

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12
Q

What is vascular dementia?

A

Second most common dementia, after AD

Caused by multiple strokes, lesions over time

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13
Q

What are some symptoms of frontal lobe stroke?

A
Inappropriate comments, confabulation 
Lack of anxiety or concern about state
Lack of planning or organisation
Impaired unassociated word pairings, same level as associated
Verbal recall improved with recognition
Less loss of visual memory
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14
Q

Describe impairment of memory in stroke

A

Can occur in isolation due to lesioning of structures in primary memory structures
Can occur in conjunction with impairment of other domains, and may be less significant than other dysfunctions

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15
Q

What are three types of head injury?

A

Penetrating (causes localised deficit dependent on location)
Crushing (most damage to base of brain)
Closed head injury (by far most common)

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16
Q

What causes damage in CHI?

A
  • movement of soft cerebral tissue against hard bony skull

- Stretching of brain from its stem

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17
Q

Describe diffuse axonal injury in CHI

A
  • stretching and shearing of cortical fibres (stretched from ‘anchor’ in brain stem)
  • widespread damage
  • reticular formation (at base of brain - responsible for attentiveness and arousal - hence common loss of consciousness)
  • arteries and veins may be torn
  • coup and contracoup injuries
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18
Q

What are coup injuries in CHI?

A

Contusions (haemorrhagic lesions) that occur at point of impact where brain hits skull

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19
Q

What are contre-coup injuries in CHI?

A

Contusions (haemorrhagic lesions) that occur on crests of gyri of cerebral cortex, usually on outside of cortex (can be sub cortical). Opp side to impact.

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20
Q

Where are most common surface contusions (CHI)?

A

Frontal and temporal lobes, adjacent to sphenoidal ridge

21
Q

What are regions of brain where contusions can happen (CHI)

A

Frontal and temporal lobes (most common)
Medial surface of hemispheres
Upper surface of corpus collosum (caused by diff in tissue density)

22
Q

What are secondary complications in CHI?

A

Intracranial hematoma and brain swelling (require imm surgery)
Damage to brain due to hypoxia (body sends more blood to supply osygen, inc pressure) or ischaemia
Longer term: post traumatic epilepsy, hydrocephalus

23
Q

Describe post traumatic amnesia in CHI

A
  • period of time after accident where patient can’t learn new info
  • due to diffuse axonal injury (impairment to attentiveness) NOT to damage to primary memory structures (Atkinson shiffrin model)
24
Q

Describe behaviour and cognition after mod - severe CHI

A
  • socially inappropriate, selfish, irritable (childlike) - frontal lobe
  • changes in mood, elevated or depressed - amygdala
  • attention difficulties and fatigue - diffuse axonal cortical problems
  • lack of problem solving insight, initiative, abstraction (frontal lobe)
25
Q

Memory deficits in mod-severe CHI

A

Retrograde memory (weeks leading up to event) - temporal lobe damage, impacting consolidation of recently encoded memory
Can shrink
Anterograde impairment (can’t learn new info). Significant generalised encoding. Can’t encode arbitrarily related info (MTL), or semantically meaninful info (lateral anterior system)
Bilateral (damage to verbal and non-verbal)
Delayed recall impairment (impaired retrieval), little benefit from recognition (could also indicate frontal lobe damage; due to lack of encoding, hard to tell)
Achrogenesis (can’t put time to event) - frontal lobe
Confabulation (frontal lobe)

26
Q

What are mechanisms of recovery from CHI?

A

Neural recovery (in neurons that are damaged not destroyed)
Reorganization - regeneration
- Plasticity

27
Q

Recovery aides for CHI?

A

Rest
Not working
Behavioral compensation and functional alternatives

28
Q

Where do subarachnoid strokes occur?

A

Occurs in meninges, between pia mater (bottom layer) and arachnoid layer (middle)

29
Q

What damage does subarachnoid stroke cause?

A

Can cause hydrocephalus
Generalised ‘squashing’ of brain
Generalised brain damage, dampening of all systems incl intellect

30
Q

What happens in an occlusive stroke?

A

Blood supply loss (ischaemia) to surrounding tissue

If goes for long enough, causes death of neuronal tissue (infarction)

31
Q

What damage can be caused by occlusive strokes?

A

Stretches brain, can create midline shift

Nature of brain damage depends on area where neural damage has happened

32
Q

What arteries supply the medial temporal lobes?

A

anterior choroidal arteries

33
Q

What arteries supply the thalamus?

A

posterior cerebral arteries

34
Q

What arteries supply the medial frontal lobes, mamillary bodies, fornix, anterior cingulate cortex?

A

anterior cerebral arteries

35
Q

What arteries supply the lateral frontal lobes?

A

middle cerebral arteries

36
Q

What do the posterior cerebral arteries supply?

A

the thalamus

37
Q

what do the middle cerebral arteries supply?

A

the lateral frontal lobes

38
Q

what do the anterior cerebral arteries supply?

A

the medial frontal lobes, mamillary bodies, fornix, anterior cingulate cortex

39
Q

What do the anterior choroidal arteries supply?

A

the medial temporal lobes

40
Q

What kind of stroke causes death of neural tissue due to loss of blood supply to the neurons?

A

Occlusive stroke

41
Q

What is death of neuronal tissue called?

A

Infarction

42
Q

What is ischaemia?

A

Blood supply loss to neuronal tissue

43
Q

What kind of stroke would lead to Inappropriate comments, confabulation
Lack of anxiety or concern about state
Lack of planning or organisation
Impaired unassociated word pairings, same level as associated
Less loss of visual memory

A

Frontal lobe stroke

44
Q

What are the symptoms of frontal lobe damage in CHI?

A

Achrogenesis (can’t put time to event) - frontal lobe

Confabulation (frontal lobe)

45
Q

What kind of impairment does MTL damage lead to [CHI]?

A

Retrograde memory (weeks leading up to event) - temporal lobe damage, impacting consolidation of recently encoded memory
Anterograde impairment (can’t learn new info).
Can’t encode arbitrarily related info (MTL), or semantically meaninful info (lateral anterior system)
Bilateral (damage to verbal and non-verbal)
Delayed recall impairment (impaired retrieval), little benefit from recognition (could also indicate frontal lobe damage; due to lack of encoding, hard to tell)

46
Q

Occlusive strokes from which arteries cause most severe memory loss?

A

anterior choroidal arteries (MTLs) or posterior cerebral arteries (thalamus)

47
Q

What is cerebral thrombosis?

A

narrowing of vessel, caused by build up of plaque (aatherosclerosis)

48
Q

What is cerebral embolism?

A

plaque comes from elsewhere in body, gets stuck in narrower vessels in brain.

49
Q

What is neural plasticity?

A

Systems that already contributed to a function will take more of a role. Works better for highly networked systems, not insular (where one part of system has strict responsibility - eg learning and memory)

50
Q

What is neural reorganisation?

A

systems that already contributed to a function will take more of a role. Works better for highly networked systems not insular (where one part of system has strict responsibility - eg learning and memory)

51
Q

What type of memory loss is caused by damage to frontal lobes?

A

Impairment in encoding and retrieval of novel information