Cerebrovascular accidents

Question 1

Define cerebrovascular accident (CVA)

Answer 1

the sudden death of some brain cells due to lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain

Question 2

What is the colloquial term for a CVA?

Answer 2

Stroke

Question 3

What is a primary infarction zone?

Answer 3

an area of neurons that will suffer irreversible injury as a result of the lesion or infarct

Question 4

what is a secondary infarction zone?

Answer 4

The area of neutrons surrounding the primary zone that may recover from injury if blood flow is restored quickly.

Question 5

What area of the brain is most likely impacted if there are signs of visual disturbances?

Answer 5

The occipital lobe, as this is the area of the brain responsible for sight processing

Question 6

What symptoms may be seen if the primary infart zone is in the frontal or parietal lobes?

Answer 6

There would likely be some impact to fine motor skills or strength, as the border of these lobes is where the motor control is. Broca’s is also in the region, the infarct of which would likely cause difficulties with comprehension (understanding speech and forming sentences)

Question 7

What would a likely symptom be if the temporal lobe was the primary infarct zone?

Answer 7

This would likely affect formation of speech and may cause slurring as Wernicke’s area is here, which is responsible for the formation of speech

Question 8

What are the different types of cerebrovascular accident?

Answer 8

CVAs can typically be categorised into ischaemic, hemorrhagic, and TIA’s

Question 9

Name the major arteries that supply the following brain regions

• frontal lobe
• lateral hemispheres
• basal ganglia
• occipital lobe
• temporal lobes
• thalamus
• cerebellum
• brain stem

Answer 9

• frontal lobe = anterior cerebral arteries
• lateral hemispheres and basal ganglia = middle cerebral arteries
• occipital lobe, temporal lobes and thalamus = posterior cerebral arteries
• cerebellum and brain stem = basilar and vertebral arteries

Question 10

Review the major arteries of the brain and their relationship to different lobes and landmarks

Answer 10

Question 11

Define infarct

Answer 11

A small localized area of dead tissue resulting from failure of blood supply

Question 12

What is an ischaemic stoke?

Answer 12

Occurs when there is a sudden obstruction to a cerebral artery, as a result of an embolism or thrombus. The brain region supplied by the blocked vessel becomes ischaemic and infarct can occur if not resolved quickly

Question 13

What is an embolism?

Answer 13

a clot or air bubble that has mobilised from another palce in the body

Question 14

What is a thrombosis?

Answer 14

local coagulation or the formation of a clot in the circulatory system, typically it is associated with the formation of atherosclerotic plaque in the vessels

Question 15

What is Virchows triad?

Answer 15

Three risk factors that are important to the formation of a thrombus that greatly increase the liklihood of it’s occurance.

Question 16

What are some things that might cause blood stasis and therefore increase the liklihood of thrombus formaiton?

Answer 16

long-haul flights, recent surgery, atrial fibrillation or other arrythmias (where blood is not being properly circulated and therefore pools in the heart)

Question 17

What are some things that might cause hypercoaguability and therefore increase the liklihood of thrombus development?

Answer 17

some medication, recent surgery, obesity, pregnancy, supplamental estrogen use (e.g. contraceptives)

Question 18

What sort of thing can cause damage to the endothelium of the vein and therefore increase the liklihood of thrombus development?

Answer 18

hypertension, hyperglycaemia/diabetes, turbulent blood flow, hyperlipidaemia, increased oxidative stress

Question 19

What is a transient ischaemic attack (TIA)?

Answer 19

a transient form of cerebral ischaemia that produces neurological defecits but resolves completely within 24 hours

Question 20

TIA’s can be a warning sign that a person is at a high risk of stroke, what should be done to lower the chances of a CVA after a transient ischaemic attack?

Answer 20

Drug therapy should be commencent quickly, this would likely include the introduction of anticoagulant drugs

Question 21

What is a haemorrhagic stroke?

Answer 21

this occurs when a cerebral artery ruptures and there is a bleed into the brain tissue

Question 22

What chronic condition is strongly linked to the occurance of a haemorrhagic stroke?

Answer 22

hypertension, not only does this increase the liklihood of the development of structural weakness (such as aneurysm) but the degree of pressure of vessel walls is a contributing factor to their rupture

Question 23

Define aneurysm

Answer 23

a ballooning or widening in the wall of a blood vessel (generally an artery) as a result of weakness caused by vascular disease, such as atherosclerosis

Question 24

is a higher degree of morbidity associated with haemorrhagic or ischaemic stroke? Why?

Answer 24

Haemorrhagic, this is because the bleed can greatly displace brain tissue which can compress brain tissue locally or, when there is a profound shift laterally or inferiorly, other regions that are removed from the bleed can be compressed

Question 25

Where inthe brain circulation do most cerebral aneurysms form?

Answer 25

In the circle of willis (have to double check but likely due to high pressure and many ‘turns’ where blood hits against the vessel wall)

Question 26

What are the major risk factors for stroke?

Answer 26

hypertension, diabetes mellitus, hyperlipidaemia, smoking, age, family history, alcohol consumption, and heart disease

Question 27

What are the two main factors that dictate the type and severity of clinical manifestion of a CVA?

Answer 27

Location of leison and severity of bleed or blockage

Question 28

What is the most common location for an occlusion to occur in ischaemic stroke?

Answer 28

The middle cerebral arteries

Question 29

Give an example of the brain region damaged when the following functions are impacted

• language
• speech
• voluntary movement/ muscle weakness
• vision
• confusion/disorientation
• balance/ disequilibrium
• eye movements
• altered coordination and gait

Answer 29

Question 30

What does ROSIER stand for?

Answer 30

recognition of stoke in the emergency room

Question 31

What is the rosier used for?

Answer 31

It is the preferred stroke recognition/assessment tool of the SA wide stroke clincial network. It should be completed in any instance where there is an altered level of conciousness or a stroke may be suspected

Question 32

Explain the scoring system used in the ROSIER

Answer 32

Question 33

What is a code stroke?

Answer 33

Code stroke is what is used in SA Health hospitals and emergency services to allow patients to recieve treatment as soon as possible. It lets those who need to know that a stroke patient is coming and that they need to be prepared

Time is tissue

Question 34

What is the code stroke criteria?

Answer 34

• a stroke is clincally suspected, and
• ROSIER score is positive, and
• the patient has pre-morbid level of independant living, and
• arrival at CSU/STS will be within 4 hours of onset of symptoms, and
• travel time to the nearest CSU/STS is less than 60 minutes

*CSU = comprehensive stroke unit

*STS = Stoke thrombolysis service

Question 35

where are the comprehensive stroke units (CSU) in Adelaide?

Answer 35

Flinders medical centre

Royal Adelaide Hospital

Lyell McEwin Hospital