8. Cerebrovascular Disease

Question 1

what are the 4 types of stroke

Answer 1

subarachnoid haemorrhage
primary intracerebral haemorrhage
ischaemic stroke
transient ischaemic attack

Question 2

which is the most common type of stroke

Answer 2

ischaemic stroke (80% of cases)

Question 3

what normally causes a subarachnoid haemorrhage

Answer 3

occurs when an aneurysm on the surface of the brain bursts and leaks

Question 4

where does the bleeding occur in the subarachnoid haemorrhage

Answer 4

bleeding occurs in the space that surrounds the brain

Question 5

where does the bleeding evolve from in a primary intracerebral haemorrhage

Answer 5

evolves from within the tissue of a brain

Question 6

what normally causes primary intracerebral haemorrhage

Answer 6

hypertension or amyloid angiopathy

Question 7

what happens in ischaemic stroke

Answer 7

a blockage prevents the flow of blood and oxygen to the brain

Question 8

describe transient iscahemic attacks

Answer 8

also known as a mini stroke - symptoms only last for a short amount of time as the blockage preventing blood flow is only temporary

Question 9

what structure ensures constant blood flow to the brain

Answer 9

the circle of Willis

Question 10

what does NIHSS stand for

Answer 10

the national institute of health stroke scale

Question 11

what does the NIHSS assess

Answer 11

the level of disability and neurological impairments on. scale from 0-42 0 with 42 the equivalent of death

Question 12

on a CT scan, what is the white structure encasing the brain called

Answer 12

the cranial vault

Question 13

how can a brain bleed be identified on a CT

Answer 13

the presence of a faint white line

Question 14

what does infarction mean

Answer 14

the term for tissue injury that happens following reduced blood flow

Question 15

what does ischaemia mean

Answer 15

reduced blood flow

Question 16

how many strokes every year in the EU

Answer 16

1 million per year

Question 17

give me a striking statistic on strokes

Answer 17

stroke is the second most common cause of death worldwide

Question 18

name the 4 long-term complications associated with strong

Answer 18

increased long term mortality
physical, cognitive and behavioural impairments
chronic disability
recurrent stroke
increased risk of further vascular events

Question 19

what is the biggest cause of stroke (what %)

Answer 19

atherothromboembolism = 50% of strokes

Question 20

describe the Oxford vascular study as evidence for age as a risk factor

Answer 20

difficult to assess incidence of strokes. however, a longitudinal study directed by Oxford University found 75% of cerebrovascular diseases occurred in those aged 65+

Question 21

what is a limitation of the Oxford vascular study

Answer 21

limited as numbers do not include possible, recurrent or suspected cerebrovascular events

Question 22

name 3 races with an increased risk for stroke

Answer 22

black populations
maori and pacific islands
south asian populations living in the UK

Question 23

why do black populations have an increased risk of stroke

Answer 23

due to comorbidities: increased risk of diabetes mellitus and hypertension

Question 24

who do NZ people have a higher risk of stroke than

Answer 24

higher risk than europeans

Question 25

why do south asian populations in the UK have a high risk factor for stroke

Answer 25

high prevalence of vascular disease due to genetic susceptibility, dietary and lifestyle factors

Question 26

stroke as a result of atherosclerosis is high in rural china, what does incidence grow by each year?

Answer 26

stroke incidence rises annually at a rate of 8.7%

Question 27

what factors make pregnant and postpartum females more prone to stroke

Answer 27

gestational hypertension caesarean delivery pre-eclampsia - can all lead to aneurysm rupture as blood volume and cardiac output increase

Question 28

women with gestational diabetes are how much more likely to have a stroke

Answer 28

6-9 fold

Question 29

what does pre-eclampsia cause

Answer 29

endothelial dysfunction and impaired cerebral autoregulation

Question 30

why is it interesting that the risk of perpiartuqm stroke is associated with caesarean delivery

Answer 30

perhaps this is because women at risk of stroke are encouraged to have a C-section. this would explain why incidence is higher in this group.

Question 31

how many times more likely to suffer a stroke are people who take cocaine

Answer 31

6 x more likely

Question 32

how does cocaine cause stroke

Answer 32

increases BP = could burst an aneurysm cocaine promotes thrombotic strokes by causing hypercoagulable states

Question 33

what evidence is there for a role of infections in preceding stroke

Answer 33

seasonal variation in stroke incidence and the fact that 10-35% of patients have an infection in the week preceding stroke

Question 34

what chronic infections are associated with increased stroke risk

Answer 34

chlamydia pneumoniae helicobacter pylori

Question 35

name some modifiable risk factors for stroke

Answer 35

hypertension psychosocial stress smoking

Question 36

how do these risk factors increase propensity to stroke

Answer 36

- promote the formation of atherosclerotic plaques - these plaques in the brain compromise endothelial ability to regulate microvascular flow

Question 37

why is it important that the brain is able to regulate microvascular flow

Answer 37

ensures that the brains energy supply matches demand - this can be mismatched when atherosclerotic plaques compromise this process

Question 38

some of these risk factors can increase production of reactive oxygen species (ROS), what does this mean?

Answer 38

free radical superoxide inactivates nitric oxide resulting in a loss of vasoregulatory and loss of anti-aggregant effects

Question 39

what are the two main zones of an ischaemic stroke

Answer 39

the core zone the penumbra

Question 40

what occurs in the core zone

Answer 40

rapid neuronal death and the death of supporting cellular elements e.g. glial cells

Question 41

how do neurons and glial cells die in the core zone

Answer 41

the loss of oxygen and glucose results in an energy deficit. this facilitates ionic imbalance and mitochondrial failure. activation of a series of enzymes results in the fast breakdown of cell structures and the loss of cellular integrity

Question 42

what happens to the neurons in the penumbra

Answer 42

they remain viable for several hours. they will die if reperfusion is not established

Question 43

what supplies neurons in the penumbra with their blood supply

Answer 43

collateral arteries

Question 44

how can neurons in the penumbra be damaged even if blood flow is restored

Answer 44

they can face excitotoxicity = excess glutamate = calcium influx and production of free radicals.

Question 45

what breaks down after ischaemic stroke and contributes to the oedema and bleeding into the infarcted area

Answer 45

the blood brain barrier

Question 46

what molecule is involved in BBB breakdown

Answer 46

matrix metalloproteinases

Question 47

what percentage of stroke patients go on to develop dementia in the months following stroke

Answer 47

~ 25%

Question 48

what facilitates dementia formation post stroke

Answer 48

white matter lesions which interrupt neural pathways involved in cogntion

Question 49

what is the term given for these small white matter lesions

Answer 49

leukoaraiosis

Question 50

what happens when these white matter lesions form

Answer 50

they facilitate demyelination, axonal loss and microglial activation = neuronal loss involved in cognition

Question 51

what is the development of dementia dependent on

Answer 51

the location and volume of the stroke and the presence of other cerebral pathologies