Circle of Willis lesions

Question 1

What artery is this?

Answer 1

Anterior cerebral artery (ACA)

Question 2

How would a lesion in this artery present?

Answer 2

Contralateral hemiparesis and sensory loss
-Lower extremity > upper extremity

This is ACA (anterior cerebral artery)

Question 3

what is this artery?

Answer 3

Middle cerebral artery (MCA)

Question 4

How would a lesion in this artery present?

Answer 4

This is the MCA (middle cerebral artery)

Contralateral hemiparesis and sensory loss
-upper extremity> lower extremity
-Homonymous hemianopia (as MCA supplies Broadmanns area 8 containing frontal eye fields ect)
-Aphasia (think of position of Broca’s/ Wernicke’s)

Question 5

what artery is this?

Answer 5

anterior communicating artery

Question 6

what artery is this?

Answer 6

internal carotid

Question 7

what artery is this?

Answer 7

retinal/ opthalmic artery

Question 8

what does a lesion in this artery lead to?

Answer 8

this is retinal/ opthalmic artery

leads to Amaurosis fugax (temporary blindness/ transient vision loss)

Question 9

what is this artery?

Answer 9

Posterior communicating artery

Question 10

what is this artery?

Answer 10

Posterior cerebral artery

Question 11

What does a lesion in this artery cause?

Answer 11

-Contralateral homynomous hemianopia with macular sparing
-Visual agnosia (for example knows what a bike handle is + bike seat but cant recognise them on a bike)

This is the PCA (posterior cerebral artery)

Question 12

what are these arteries called?

Answer 12

Pontine arteries

Question 13

what is this artery called?

Answer 13

Basilar artery

Question 14

What would a lesion in this artery cause?

Answer 14

‘Locked in’ syndrome
-this is when the patient is aware but cant move anything apart from eyes

This is the Basilar artery

Question 15

What is this artery?

Answer 15

superior cerebellar artery

Question 16

what is this artery?

Answer 16

Anterior inferior cerebellar artery

Question 17

How does a lesion in this artery present?

Answer 17

This is a lesion in the anterior inferior cerebellar artery

Causes Lateral Pontine Syndrome:
Ipsilateral Facial paralysis/ deafness
Contralateral limb/ torso sensory loss

Question 18

What is this artery?

Answer 18

Posterior inferior cerebellar artery

Question 19

What does a lesion in this artery lead to?

Answer 19

This is the posterior inferior cerebellar artery

Leads to Lateral Medullary syndrome/ Wellenberg syndrome:
Horner syndrome (decreased pupil size, drooping eyelid, decreased sweating on one side of body)
Contralateral limb/torso pain and temperature loss
Ataxia, nystagmyus
Ipsilateral facial pain and temperature loss

Distinguishing factor between PICA and AICA: PICACHEW- PICA cant chew= dysphagia

Question 20

Painful third nerve palsy- where is the lesion likely to be?

Third nerve palsy:
Eye is deviated ‘down and out’
Ptosis
Pupil may be dilated

Answer 20

Posterior Communicating artery aneurysm