Session 9 - Strokes incomplete

Question 1

What is a stroke?

Answer 1

The damaging or killing of brain cells starved of oxygen as a result of the blood supply to part of the brain being cut off.

Question 2

What is a transient ischaemic attack (TIA)?

Answer 2

A stroke that recovers within 24hrs from the onset of symptoms.

Question 3

What is stroke syndrome?

Answer 3

Constellation of signs and symptoms produced due to occlusion or damage of an artery supplying part of the brain.

Question 4

What are the two main types of stroke?

Answer 4

Ischaemic (85%)

Haemorrhagic (10%)

Question 5

What are the other possible causes of stroke?

Answer 5

Dissection

Venous sinus thrombosis

Question 6

In ischaemic stroke where could the clot have come from?

Answer 6

Carotid arteries
Vertebral/Basilar arteries
Heart - AF, valvular disease, prosthetic valves, septic emboli (endocarditis), intra-cardiac thrombus
Aorta

Question 7

What are some other rarer causes of thrombus formation that can then lead on to stroke?

Answer 7

Vasculitis
Sickle cell anaemia
Cocaine (coke stroke)

Question 8

Which two arteries form the anterior circulation? Which arteries are they branches of?

Answer 8

Anterior cerebral arteries
Middle cerebral arteries
(Both branches off the internal carotids)

Question 9

What arteries form the posterior circulation? What arteries are they branches of?

Answer 9

Posterior cerebral arteries
Cerebellar arteries
Arteries supplying the brainstem
(All branches of the vertebral arteries)

Question 10

Which areas of the brain are supplied by the anterior circulation?

Answer 10

Medial ascpects of the frontal and parietal lobes

Anterior part of corpus callosum

Question 11

How will a patient with an anterior cerebral artery stroke present?

Answer 11

Motor:

• contralateral
• lower limb affected more than upper limb (medial part of precentral gyrus affected)
• initially flaccid paralysis followed later by spasticity (upper motor neurone signs)

Sensory:

• contralateral
• loss of all sensory modalities in lower limb

Damage to paracentral lobules:
- loss of voluntary control of micturition

Damage to corpus callosum:

• split brain syndrome
• alien hand syndrome

Question 12

What areas of the brain are supplied by the middle cerebral arteries?

Answer 12

Majority of the hemisphere.
Basal ganglia
Internal capsule
Macular cortex