Cerebral Vasculature

Question 1

How much weight does the brain make up?

Answer 1

2%

Question 2

How much of the cardiac output does the brain use?

Answer 2

10-20%

Question 3

How much of the oxygen does the brain use?

Answer 3

20%

Question 4

How much of the liver glucose does the brain use?

Answer 4

66%

Question 5

What is the process of venous drainage in the brain?

Answer 5

cerebral veins -> venous sinuses in the dura mater -> internal jugular vein (look at sinuses, circle of willis)

Question 6

How would you get an extradural haemorrhage?

Answer 6

trauma, immediate clinical effects (arterial, high pressure)

Question 7

How would you get a subdural haemorrhage?

Answer 7

• trauma, can be delayed clinical effects (venous, lower pressure)
• Space between dura and arachnoid

Question 8

How would you get a subarachnoid haemorrhage?

Answer 8

ruptured aneurysms

Question 9

How would you get an intracerebral haemorrhage?

Answer 9

spontaneous hypertensive - inside brain

Question 10

What is a stroke?

Answer 10

• Cerebrovascular accident (CVA)

- “rapidly developing focal disturbance of brain function of presumed vascular origin and of >24 hours duration”

Question 11

What are the two types of stroke?

Answer 11

thromboembolic + haemorrhage

Question 12

How common is a thrombo-embolic stroke?

Answer 12

85%

Question 13

How common is a haemorrhage stroke?

Answer 13

15%

Question 14

What is a transient ischaemic attack (TIA)?

Answer 14

rapidly developing focal disturbance of brain function of presumed vascular origin that resolves completely within 24 hours

Question 15

What is an infarction?

Answer 15

Degenerative changes which occur in tissue following occlusion of an artery

Question 16

What is cerebral ischaemia?

Answer 16

Lack of sufficient blood supply to nervous tissue resulting in permanent damage if blood flow is not restored quickly

Question 17

What is thrombosis?

Answer 17

formation of a blood clot (thrombosis)

Question 18

What is an embolism?

Answer 18

plugging of small vessel by material carried from larger vessel e.g. thrombi from the heart or atherosclerotic debris from the internal carotid

Question 19

What are the risk factors for a stroke?

Answer 19

1. Age
2. Hypertension
3. Cardiac disease
4. Smoking
5. Diabetes mellitus

Question 20

What are the symptoms in an anterior cerebral artery stroke?

Answer 20

1. Paralysis of contralateral structures (leg more than arm or face)
2. Disturbance of intellect, executive function and judgement (abulia)
   3, Loss of appropriate social behaviour

Question 21

What are the symptoms in a middle cerebral artery stroke?

Answer 21

1. “Classic stroke”
2. Contralateral hemiplegia: arm > leg
   - (MCA also supply deep motor structures so may get complete hemiplegia on one side of body as deep structures taken out as well)
3. Contralateral hemisensory deficits
4. Hemianopia
5. Aphasia (L sided lesion)

Question 22

What are the symptoms in a posterior cerebral artery stroke?

Answer 22

1. visual deficits
2. homonymous hemianopia
3. visual agnosia

Question 23

How does blood get to the head?

Answer 23

• Common carotid artery
• Internal carotid
• Vertebral artery

Question 24

When is an extradural haemorrhage going to happen?

Answer 24

fracture pterion, middle meningeal rarely rupture (no pace between dura and skull) but because arterial high pressure constrict dura away from skull so raised intercranial pressure