L&M Chapter 3

Question 0

What does blood do in brain?

Answer 0

Remove toxic waste products in neural tissue

Oxygen and glucose supply

Question 1

What is a stroke?

Answer 1

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

Question 2

What are the two types of stroke?

Answer 2

Hemorrhagic (bleeding from vessel) - 20%

Occlusive (blockage of vessel) - 80%

Question 3

What are two types of haemorrhagic stroke?

Answer 3

Subarachnoid (50%)

Intracerebral (50%)

Question 4

Describe intracerebral stroke

Answer 4

Blood escapes into surrounding tissue, destroys it

Localised

Question 5

What percentage of haemorrhagic strokes are subarachnoid?

Answer 5

Approx 50%

Question 6

What percentage of strokes are occlusive?

Answer 6

Approx 80% all strokes

Much lower mortality rate than haemorrhagic

Question 7

What are two main types of occlusive stroke?

Answer 7

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.

Question 8

What impacts on size of infarction (in occlusive stroke)

Answer 8

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

Question 9

Describe memory function after ischaemic strokes?

Answer 9

• 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)

Question 10

What is effect of stroke size on outcome?

Answer 10

Localised - less effect

Generalised - much greater cognitive disfunction

Question 11

What is recovery period after stroke

Answer 11

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

Question 12

What is vascular dementia?

Answer 12

Second most common dementia, after AD

Caused by multiple strokes, lesions over time

Question 13

What are some symptoms of frontal lobe stroke?

Answer 13

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

Question 14

Describe impairment of memory in stroke

Answer 14

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

Question 15

What are three types of head injury?

Answer 15

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

Question 16

What causes damage in CHI?

Answer 16

• movement of soft cerebral tissue against hard bony skull

- Stretching of brain from its stem

Question 17

Describe diffuse axonal injury in CHI

Answer 17

• 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

Question 18

What are coup injuries in CHI?

Answer 18

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

Question 19

What are contre-coup injuries in CHI?

Answer 19

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.

Question 20

Where are most common surface contusions (CHI)?

Answer 20

Frontal and temporal lobes, adjacent to sphenoidal ridge

Question 21

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

Answer 21

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

Question 22

What are secondary complications in CHI?

Answer 22

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

Question 23

Describe post traumatic amnesia in CHI

Answer 23

• 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)

Question 24

Describe behaviour and cognition after mod - severe CHI

Answer 24

- 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)

Question 25

Memory deficits in mod-severe CHI

Answer 25

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)

Question 26

What are mechanisms of recovery from CHI?

Answer 26

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

Question 27

Recovery aides for CHI?

Answer 27

Rest Not working Behavioral compensation and functional alternatives

Question 28

Where do subarachnoid strokes occur?

Answer 28

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

Question 29

What damage does subarachnoid stroke cause?

Answer 29

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

Question 30

What happens in an occlusive stroke?

Answer 30

Blood supply loss (ischaemia) to surrounding tissue | If goes for long enough, causes death of neuronal tissue (infarction)

Question 31

What damage can be caused by occlusive strokes?

Answer 31

Stretches brain, can create midline shift | Nature of brain damage depends on area where neural damage has happened

Question 32

What arteries supply the medial temporal lobes?

Answer 32

anterior choroidal arteries

Question 33

What arteries supply the thalamus?

Answer 33

posterior cerebral arteries

Question 34

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

Answer 34

anterior cerebral arteries

Question 35

What arteries supply the lateral frontal lobes?

Answer 35

middle cerebral arteries

Question 36

What do the posterior cerebral arteries supply?

Answer 36

the thalamus

Question 37

what do the middle cerebral arteries supply?

Answer 37

the lateral frontal lobes

Question 38

what do the anterior cerebral arteries supply?

Answer 38

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

Question 39

What do the anterior choroidal arteries supply?

Answer 39

the medial temporal lobes

Question 40

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

Answer 40

Occlusive stroke

Question 41

What is death of neuronal tissue called?

Answer 41

Infarction

Question 42

What is ischaemia?

Answer 42

Blood supply loss to neuronal tissue

Question 43

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

Answer 43

Frontal lobe stroke

Question 44

What are the symptoms of frontal lobe damage in CHI?

Answer 44

Achrogenesis (can't put time to event) - frontal lobe | Confabulation (frontal lobe)

Question 45

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

Answer 45

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)

Question 46

Occlusive strokes from which arteries cause most severe memory loss?

Answer 46

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

Question 47

What is cerebral thrombosis?

Answer 47

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

Question 48

What is cerebral embolism?

Answer 48

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

Question 49

What is neural plasticity?

Answer 49

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)

Question 50

What is neural reorganisation?

Answer 50

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)

Question 51

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

Answer 51

Impairment in encoding and retrieval of novel information