Lecture 27: Stroke

Question 1

Stroke characteristics

Answer 1

Common neurological disorder
Lasts >24 hours
Sudden onset
Vascular cause
Focal neurological deficit

Question 2

Stroke subtypes & what are they

Answer 2

Ischemic - arterial occlusion causing brain infarction

Intracerebral hemorrhage - bleeding into brain from ruptured artery

Subarachnoid hemorrhage - bleeding into subarachnoid space from berry aneurysm rupture

Question 3

Ischaemic stroke

Answer 3

Cardiac embolism
Arterial disease -> large artery (atheroma) / small artery (atheroma / lipohyalinosis)

Question 4

How can an atheroma in the carotid arteries lead to an ischaemic stroke

Answer 4

Atheroma formation -> rough surface & turbulent arterial blood flow -> clot / plaque formation in cerebral blood flow -> stroke

Question 5

Infarct growth over time

Answer 5

Infarct core becomes larger and ischaemic penumbra becomes smaller as more areas are deprived of blood

Question 6

Ischaemic penumbra

Answer 6

Brain tissue with

• reduced function & cerebral blood flow
• not fated to infarct
• potentially saved if blood flow restores spontaneously or therapeutically

Question 7

Infarcts due to embolism features

Answer 7

• thrombus
• form in heart
• break into circulation
• get stuck in cerebral artery
• Block blood flow to brain or retina
• disrupted brain function
• brain damage unless blockage cleared

Question 8

What are lacunar strokes

Answer 8

Small deep infarcts due to blocking of small penetrating arteries that supply deeper structures

Question 9

Symptoms that indicate a left middle cerebral artery territory stroke

Answer 9

Right sided weakness and sensory loss
Dysphasia -> dominant hemisphere (language location) affected

Question 10

Symptoms that indicate a right middle cerebral artery territory stroke

Answer 10

Left sided
- neglect
-sensory loss
- weakness

Anosagnosia -> patient not aware of their disability

Uncommon but signal for coming infarction

Question 11

Symptoms that indicate a left posterior cerebral artery territory stroke

Answer 11

Left homonymous hemianopia (half of visual field lost)

Question 12

Symptoms that indicate a right anterior cerebral artery territory stroke

Answer 12

Left sided leg weakness

Question 13

Symptoms that indicate a right cerebella’s stroke

Answer 13

Right sides limb incoordination

Question 14

Main cerebral vascular arterial territories

Answer 14

Middle cerebral artery

Anterior cerebral artery (supply frontal part of brain)

Posterior cerebral artery

Anterior choroidal artery (comes from first one)

Question 15

Transient ischaemic attacks (“mini strokes”) symptoms

Answer 15

Temporary occlusion of blood supply to brain -> Acute focal brain function loss

Duration: < 24 hrs (2-15 minutes)

Question 16

Intracerebral hemorrhage causes

Answer 16

Complex small vessel disease

Cerebral amyloid angiopathy (+ hypertension = increase stroke chance)

Arteriovenous capsular malformations [vascular malformation]

Saccular aneurysms (BVs outpoaching -> easy rupture/ BVs weakening -> can die) [vascular malformation]

Question 17

Why is Intracerebral hemorrhage catastrophic and someone can die easily due to it?

Answer 17

Bleed into skull -> nowhere to go when swell -> increase pressure -> squashed brain stem

Question 18

Three mechanisms of recovery after stroke

Answer 18

1. Neuronal plasticity + cerebral cortex reorganisation around lesion
2. Recruitment -> 2° motor areas in ipsilateral cerebral hemisphere [eg. people with speech problems]
3. Activation -> homologous areas of unaffected contra lateral hemisphere