🧠Neurology🧠 - Cerebral Vasculature

Question 1

What are the perfusion demands of the brain?

Answer 1

10-20% of cardiac output
20% of total body oxygen consumption
66% of liver glucos

Question 2

What do the perfusion demands leave the brain very vulnerable to?

Answer 2

Extremely vulnerable to any impairment of blood supply

Question 3

What major vessels supply blood to the brain?

Answer 3

Vertebral artery
Common carotid artery - splits into internal and external

Question 4

Name these 3 vessels

Answer 4

Question 5

Names these 3 vessels

Answer 5

Question 6

Name these 2 vessels

Answer 6

Question 7

Outline the venous drainage of the brain

Answer 7

Cerebral veins -> venous sinuses in the dura mater -> internal jugular veins -> brachiocephalic vein -> superior vena cava

Question 8

Name these 3 structures

Answer 8

Question 9

Name these 3 structures

Answer 9

Question 10

Name these 3 structures

Answer 10

Question 11

Name these 2 structures

Answer 11

Question 12

What layer sits immediately deep to the skull?

Answer 12

Dura mater

Question 13

What are the two layers of the dura mater?

Answer 13

Periosteal and meningeal

Question 14

Which layer of the dura mater forms structures?

Answer 14

Only the meningeal dura mater folds inwards to form structures, such as the falx cerebri and tentorium cerebelli
Periosteal dura mater stays tightly adhered to the skull

Question 15

Where do venous sinuses form?

Answer 15

Form in gaps between the two layers of the dura mater

Question 16

What are the different types of cranial haemorrhage?

Answer 16

Extradural (aka epidural) - skull has no naturally-occurring epidural space, spine does
Subdural
Subarachnoid
Intracerebral

Question 17

Outline an extradural haemorrhage

Answer 17

Haemorrhage occurs outside the dura
Arterial blood, high pressure (pressure cant escape down the foramen magnum) that can kill quickly
Usually trauma
Immediate clinical effects

Question 18

Outline a subdural haemorrhage

Answer 18

Haemorrhage occurs within/below dura
Venous blood, lower pressure initially, but can build over time
Usually trauma
Clinical effects can be delayed, but if left can be just as fatal as epidural

Question 19

Outline a subarachnoid haemorrhage

Answer 19

Haemorrhage occurs usually in the base of the brain - circle of Willis
Ruptured aneurysm
Almost always fatal

Question 20

Outline an intracerebral haemorrhage

Answer 20

Haemorrhage occurs with cerebral hemispheres
Spontaneous, usually due to hypertensive conditions
Poor prognosis

Question 21

What is a stroke?

Answer 21

Cerebrovascular accident (CVA)
“rapidly developing focal disturbance of brain function of presumed vascular origin and of >24 hours duration”
Thrombo-embolic (85%) or haemorrhage (15%)

Question 22

What is a thrombo-embolic stroke?

Answer 22

A blood clot (thrombus) breaks free and travels through the blood stream as an embolus
Reaches the cerebrum, restricting blood flow and causing an ischaemic event

Question 23

What is a transient ischaemic attack?

Answer 23

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

Question 24

Why should a TIA never go ignored?

Answer 24

Is a sign that someone is at significantly higher risk of developing a cerebral ischaemia, such as a stroke

Question 25

What is an infarction?

Answer 25

Degenerative changes which occur in tissue (such as cell damage and/or death) following the occlusion of an artery and therefore restriction of blood supply

Question 26

What is a cerebral ischaemia?

Answer 26

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

Question 27

What is an embolism?

Answer 27

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

Question 28

What statistics about strokes outline its importance as a public health issue?

Answer 28

3rd commonest cause of death 100,000 deaths in UK per annum 50% of survivors are permanently disabled 70% show an obvious neurological deficit

Question 29

What is the pneumonic for action when a stroke arises?

Answer 29

F.A.S.T **F**ace - face fallen on one side, unable to smile **A**rms - can they raise both arms and keep them there **S**peech - is their speech slurring? **T**ime - faster response means a better prognosis

Question 30

What are the risk factors for stroke?

Answer 30

Age Hypertension Cardiac disease Smoking Diabetes mellitus

Question 31

Label the cerebral artery perfusion fields

Answer 31

Question 32

Label the cerebral artery perfusion fields

Answer 32

Question 33

What are the symptoms of an anterior cerebral artery occlusion?

Answer 33

Paralysis of contralateral structures (leg>arm, face) Disturbance of intellect, executive function and judgement (abulia) Loss of appropriate social behaviour

Question 34

What are the symptoms of middle cerebral artery occlusion?

Answer 34

"Classic stroke" Contralateral hemiplegia (arm>leg) Contralateral hemisensory deficits Hemianopia Aphasia (if lesion is on L side)

Question 35

What are the symptoms of posterior cerebral artery occlusion?

Answer 35

Visual defects: -Homonymous hemianopia -Visual agnosia