Cerebral vasculature

Question 1

What artery supplies the brain?

Answer 1

-Vertebral artery
-Internal carotid artery
-Common carotid artery

Question 2

What is the benefit of the arrangement of the arteries of the brain?

Answer 2

-Arranged in a circle (“circle of willis”
-If one artery was blocked, supply on the other side of the structure can flow in & compensate

Question 3

Describe the mechanism for venous drainage of the brain?

Answer 3

1. Cerebral veins (drain into)
2. venous sinuses in the dura mater (that drains into)
3. The internal jugular vein

Question 4

What are the different types of haemorrhage you can have?

Answer 4

1. Extradural
   * trauma, immediate clinical effects (arterial,
   high pressure)
2. Subdural
   * trauma, can be delayed clinical effects
   (venous, lower pressure)
3. Subarachnoid
   * ruptured aneurysms
4. Intracerebral
   * spontaneous hypertensive

Question 5

What is a stroke?

Answer 5

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

Question 6

What are the 2 types of stroke you can get?

Answer 6

1. Thrombo-embolic (blockages)
2. Haemorrhage

Question 7

What is a Transient ischaemic attack (TIA):

Answer 7

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

Question 8

What is infarction?

Answer 8

Degenerative changes which occur in tissue following occlusion of an artery

Question 9

What is Cerebral ischaemia?

Answer 9

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

Question 10

What is hypoxea?

Answer 10

Lack of a component of blood (e.g. oxygen carried)

Question 11

What does thrombosis mean?

Answer 11

formation of a blood clot (thrombus)

Question 12

What is an embolism?

Answer 12

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

Question 13

Name 5 risk factors of stroke

Answer 13

Age
Hypertension
Cardiac disease
Smoking
Diabetes mellitus

Question 14

What arteries supply the cerebral cortex?

Answer 14

-anterior cerebral artery
-middle cerebral artery
-Posterior cerebra artery

Question 15

What would a block in the anterior cerebral artery lead to?

Answer 15

1. Paralysis of contralateral structures= weakness
   (leg > arm, face)- more likely to affect the lower limbs
2. Disturbance of intellect, executive function and judgement (abulia)
3. Loss of appropriate social behaviour + hypersexuality

Question 16

What would a block in the middle cerebral artery lead to?

Answer 16

“Classic stroke”
1. Contralateral hemiplegia (paralysis): arm > leg- can also cause complete hemiplegia
2. Contralateral hemisensory deficits (loss of touch sensation + muscle weakness)
3. Hemianopia (Loss of half their visual field)
4. Aphasia-difficulty with their language or speech (L sided lesion)- 2 types

Question 17

What are the 2 types of aphasia

Answer 17

1. Expressive aphasia:
   -patient can’t find the right words to answer questions
   -“word recall issue”
2. Receptive aphasia:
   -Patient has issue in Wernicke’s area
   -cannot understand the question

Question 18

What would a block in the posterior cerebral artery lead to?

Answer 18

Visual deficits
* homonymous hemianopia
* visual agnosia (cannot recognise/ interpret visual information)

Question 19

How can fatty deposits lead to stroke?

Answer 19

Yellow discolouration in the walls of vessels= build-up of atheroma, fatty deposits that cause
atherosclerosis or “hardening of the arteries”
- vessel can’t dilate or constrict
- Blood flow cannot be controlled

Question 20

What is occlusion?

Answer 20

Complete or partial blockage of a blood vessel

Question 21

What are the 5 dural venous sinuses?

Answer 21

1. Superior sagittal
2. Straight
3. Confluence
4. Transverse
5. Sigmoid

Question 22

How would you treat a subdural haematoma?

Answer 22

1. Refer to neurosurgeons
2. they would drill burr holes
3. Take out a small skull flap
4. Remove the blood
5. Then reassemble the skull flap

Question 23

How would you tell the difference between an extradural bleed and subdural on a CT scan?

Answer 23

Extradural: acute bleeding
(immediate clinical effects)
blood is freash
appears white on CT

Subdural: more chronic
(can have delayed clinical effects)
blood is older
appears darker on CT