Cerebral Infarction

Question 1

What is a stroke?

Answer 1

Rapid loss of brain function due to a disturbance in the blood supply to the brain

Question 2

What are the two types of stroke?

Answer 2

Ischemic - blockage caused by a thrombus and embolus

Haemorrhagic

Question 3

Difference between thrombus and embolus

Answer 3

thrombus is in a vein due to small moving blood

embolus can be anything in any vessel that blocks blood flow (thromboembolism is a thrombus that has travelled)

Question 4

Which arteries to the brain can be effected?

Answer 4

internal and external carotid

vertebral

Question 5

Why is atrial fibrillation associated with stroke?

Answer 5

Dilated atria means blood is slow moving and allows clots to form

Question 6

Define ischaemia

Answer 6

Reduced blood/oxygen supply to tissue

Question 7

Define necrosis

Answer 7

Death of cells

Question 8

What will happen to intracranial pressure during stroke and what is the danger of this?

Answer 8

Pressure will increase because of brain swelling which can damage nerve cells further

Question 9

What % of strokes are ischaemic?

Answer 9

80%

Question 10

In which patients are embolic strokes most common?

Answer 10

AF
Heart attack
After heart surgery

Question 11

Which type of stroke is more dangerous and why?

Answer 11

Haemorrhagic

Can only be prevented by controlling high blood pressure and only helped by surgery

Question 12

Risk factors for stroke

Answer 12

Age
Hypertension
Previous stroke/TIA
Diabetes
High cholesterol
Smoking
AF

Question 13

What is digoxin used for?

Answer 13

AF

Question 14

What is a TIA?

Answer 14

The result of temporary disruption of the circulation to part of the brain due to embolism or thrombosis to brain arteries.
recovery within 24 hours

Question 15

Symptoms

Answer 15

Weakness of arm or leg on one side of body
Slurred speech (dysarthria)
Drooping of corner of mouth
Dysphagia
Inability to find the right words to speak (expressive dysphasia)
Inability to understand others (expressive dysphasia)

Question 16

What is expressive dysphasia?

Answer 16

Unable to understand speech/ find the right words to speak

Question 17

Signs

Answer 17

FAST
Evidence of AF (irregular pulse)
Hypertension
Bruit (noise of turbulent blood flow hear over carotid artery in neck)

Question 18

Abnormal test results

Answer 18

Brain CT or MRI showing ischaemia, swelling, infaction

Ultrasound of carotid artery showing narrowing due to atherosclerosis

Echocardiagram showing blood clot

ECG showing evidence of AF (irregular, absent P waves)

Question 19

How does digoxin work?

Answer 19

Reduces conductivity of AV node to control heart rate, and increase force of contraction

Inhibits Na+/K+ ATPase which increases intracellular sodium which is exchanged for calcium = stronger contraction

Question 20

How could wafarin help prevent stroke?

Answer 20

Prevent left atrial thrombus

Question 21

What factors does warfarin stop and how?

Answer 21

10
9
7
2

interferes with vitamin k metabolism

Question 22

What type of drug is lisinopril?

Answer 22

ACE inhibitor

Question 23

How do ACE inhibitors work?

Answer 23

Block angiotensin converting enzyme (ACE) which turns angiotensin I into angiotensin II

angiotensin II acts on blood vessels to cause vasconstriction

so ACE inhibitors (e.g. lisinopril) lower blood pressure

Question 24

What are some types of antihypertensives?

Answer 24

angiotensin converting enzyme inhibitors (ACEi)
angiotensin II receptor blockers
Beta blockers
Calcium channel blockers
Thiazides

Question 25

How do beta blockers reduce blood pressure?

Answer 25

Block adrenaline to lower heart rate and lower bp

Question 26

How do calcium channel blockers reduce blood pressure?

Answer 26

revent calcium from entering cells of the heart and blood vessel walls to slow contractions, resulting in lower blood pressure

relax and widen blood vessels by affecting the muscle cells in the arterial walls

Question 27

How do Thiazides reduce bp?

Answer 27

increasing the amount of salt and water that is excreted through urine

Question 28

How can stroke be prevented?

Answer 28

Anticoagulants (warfarin) for AF
Antiplatelets (aspirin) for carotid atherosclerosis
Antihypertensives