Brain Blood Supply and Stroke

Question 1

Describe the course of the vertebral artery

Answer 1

• comes off the first part of the subclavian a.
• ascends in the neck through the foramina in the transverse processes on each side
• enters foramen magnum, pierces meninges to go to the subarachnoid space
• joins together to form the basilar a.
• ascends anterior pons
• terminates as the posterior cerebral a.

Question 2

Describe the course of the internal carotid artery

Answer 2

• the common carotid artery bifurcates at C4
• ascends and passes into the skull through the carotid canal in the temporal bone
• passes the cavernous sinus
• perforates dura mater at the anterior clinoid process
• divides into anterior and middle cerebral arteries
• gives off the posterior communicating artery

Question 3

What are the 7 segments of the internal carotid artery?

Answer 3

C1: cervical segment
C2: petrous segment
C3: lacerum segment
C4: cavernous segment
C5: clinoid segment
C6: ophthalmic segment 
C7: communicating segment

Question 4

What is TIA?

Answer 4

• transient ischaemic attack
• transient neurological dysfunction caused by focal brain/spinal cord/retinal ischaemia without evidence of an acute infarction

Question 5

What characterises a total anterior circulation syndrome (TACS)?

Answer 5

(ACA and MCA affected)

• hemiparesis/hemisensory loss
• dysphasia/visuospatial disorder
• homonymous hemianopia

Question 6

What characterises a partial anterior circulation syndrome (PACS?)

Answer 6

(ACA or MCA affected)
2 needed:
* hemiparesis/hemisensory loss
* homonymous hemianopia
* dysphasia/visuospatial disorder

Question 7

What characterises a posterior circulation syndrome (POCS)?

Answer 7

(cerebellum/brainstem damage)
1 needed:
* CN palsy and contralateral motor/sensory deficit
* bilateral motor/sensory deficit
* conjugate eye movement disorder
* cerebellar dysfunction (ataxia/vertigo/nystagmus)
* isolated homonymous hemianopia

Question 8

What characterises lacunar syndrome?

Answer 8

1 needed:

• pure sensory
• pure motor
• sensorimotor (damage in thalamus)
• ataxic hemiparesis

Question 9

Describe the effect of a PCA stroke

Answer 9

Dominant:

• alexia without agraphia
• visual agnosia (difficulty recognising objects)

Non-Dominant:
* prospagnosia (difficulty recognising faces)

Bilateral:

• cortical blindess and denial (Anton Syndrome)
• confabulation

Question 10

Describe the effect of a basilar artery occlusion

Answer 10

• coma/hypersomnolence
• quadriplegia
• diplopia
• ‘locked-in’ syndrome

Question 11

What arteries supply the cerebellum?

Answer 11

• superior cerebellar artery
• pontine arteries
• anterior inferior cerebellar artery
  (all branches of basilar artery)

Question 12

What are the stroke mimics?

Answer 12

• seizures
• sepsis
• syncope
• SOL (tumour/SDH)
• somatisation (psychogenic)

Question 13

Describe how you would identify acute/subacute/chronic stroke on imaging

Answer 13

Acute (0-7 days)

• ADC-MRI: hypointense
• DWI: marked hyperintense

Subacute (1-3 weeks):

• ADC-MRI: hyperintense (wk 3)
• DWI: hyperintense

Chronic (>3 weeks):

• ADC-MRI: hyperintense
• DWI: hypointense

Question 14

What is the treatment for an ischaemic stroke?

Answer 14

• non-enhanced CT to rule out intracranial haemorrhage
• O2 therapy and blood sugar control (4-11mmol/l)
• bloods, coagulation screen, FBC, Us and Es

ONCE CLINICALLY CONFIRMED:
either:
* thrombolysis with altepase (within 4hr)
* aspirin (within 24hrs - always)
* thrombectomy

Question 15

Describe the secondary prevention after a stroke

Answer 15

• anti-thrombotics (clopidogrel or aspirin and dipyridamole)
• BP control <130/80 with CCBs, thiazide diuretics, ACEis etc.
• lipid control if >4mmol/l with statin

Question 16

Describe the common presentation of a subarachnoid haemorrhage

Answer 16

• feels like patient has been hit on the back of the head
• ‘worst headache of life’
• sudden LOC