Week 202 - Stroke

Question 0

Name the two main types of stroke and state which is more common by far

Answer 0

Ischaemic (85%)

Haemorrhagic (15%)

Question 1

What is the definition of a stroke?

Answer 1

A neurological deficit related to an atraumatic vascular event (within the brain)

Question 2

What does EDH stand for and what is it?

Answer 2

Extra-dural haematoma. It is not classed as a stroke as it forms outside of the outermost later of the meninges between the dura and the skull or spinal column

Question 3

What does SAH stand for and where does it occur?

Answer 3

Subarachnoid haemorrhage > extracerebral / intracranial ruptured aneurysm, occurs between the pia mater and arachnoid layers of the meninges.

Question 4

Briefly describe the structure of the cerebral arteries and Circle of Willis

Answer 4

From the internal carotid arteries branch the left and right middle cerebral arteries and the anterior cerebral arteries. Connecting the left and right anterior cerebral arteries is the anterior communicating artery. The posterior communicating arteries also branch off the ICA and link to the posterior cerebral arteries which arise from the single basilar artery formed by the joining of the two vertebral arteries

Question 5

What are the 3 main clinical features of stroke?

Answer 5

1) focal clinical deficits
2) negative clinical phenomena (i.e. loss of function)
3) sudden onset

Question 6

What are the principle risk factors for stroke?

Answer 6

Vascular ones largely:

• HTN - overweight - smoking - alcohol - diabetes
• little exercise - poor diet - age

Question 7

Which areas of the brain (broadly) do the MCAs supply?

Answer 7

The lateral cerebral cortex and the anterior temporal lobes

Question 8

Which areas of the brain do the ACAs supply?

Answer 8

The medial frontal lobe of the cerebral cortex and superior medial parietal lobes largely

Question 9

Which area of the brain do the PCAs supply?

Answer 9

The posterior aspect of the brain - the occipital lobe

Question 10

What clinical signs would exist with an anterior cerebral arterial stroke?

Answer 10

Contralateral UMN lower-limb motor weakness and sensory dysfunction. Behavioural abnormalities and aphasia may been seen if prefrontal cortex and supplemental motor areas are involved

Question 11

Where is Broca’s area (in the vast majority) and what is it involved with?

Answer 11

Left inferior frontal lobe (left frontal hemisphere); involved in the articulation of speech

Question 12

If Broca’s area is affected by stroke what is the resulting clinical feature?

Answer 12

Expressive Motor Dysphasia/Aphasia - difficulty with production of language and forming intelligible sentences though understand / comprehend others well. Stick to short sentences.

Question 13

Where is Wernicke’s area (in the vast majority) and what is it involved with?

Answer 13

Left superior posterior portion if the temporal lobe (left temporal hemisphere); involved in the comprehension of language.

Question 14

If Wernicke’s area is affected by stroke what is the resulting clinical feature?

Answer 14

Receptive (sensory) dysphasia / aphasia - difficulty with comprehension of others words and own words. Speech may be fluent but usually nonsensical

Question 15

If a patient presents with left homonymous hemianopia where is the damage (infarct) most likely to be?

Answer 15

Right posterior cerebral artery territory > right occipital lobe

Question 16

What is the most common type of/area for stroke?

Answer 16

Infarct; middle cerebral artery

Question 17

If a patient presents with right-sided facial weakness (particularly lower face), right arm and leg weakness with sudden onset of severe headache, BP of 190/110 mmHg and HR 52 what is the likely cause?

Answer 17

Left-sided haemorrhagic stroke

hints: right-sided limb weakness, sudden painful onset, Cushing reflex

Question 18

If a patient presents with signs of painful CNIII palsy what is a likely vascular cause?

Answer 18

An unruptured enlarging posterior communicating artery applying pressure to the oculomotor nerve

Question 19

How might you differentiate a SAH from a migraine?

Answer 19

Both can be described as a “thunderclap headache” but it is likely that SAH will present with meningism (neck stiffness) and maximal headache experienced in a short space of time

Question 20

Why do SAHs rarely present with focal signs?

Answer 20

They tend to spread quite widely, effecting several areas

Question 21

Why is the middle meningeal artery vulnerable to rupture upon a blow to the side of the head?

Answer 21

It lies beneath the pterion, a fragile portion of the skull over the temple

Question 22

What defines a TIA?

Answer 22

A neurovascular event with symptoms lasting <24hrs (in reality symptoms tend to be no longer than 20 mins)

Question 23

What is CVST and how does it tend to differ from arterial stroke?

Answer 23

“Cerebral Venous Sinus Thrombosis” - essentially DVT of the brain. Evolves slowly, raised ICP, secondary bleeding, no respect for arterial territories, often occur in a very different demographic e.g. young

Question 24

List some risk factors for CVST

Answer 24

hypercoagulability; pregnancy; combined pill; thrombotic disorders; dehydration; malignancy

Question 25

In what way would management of a CVST generally differ from that of an ischaemic arterial stroke?

Answer 25

Anti-coagulate rather than treat with thrombolysis (though may occasionally thrombolyse)

Question 26

With an infarction stroke what are the time restrictions imposed upon use of thrombolysis treatment?

Answer 26

Must be within 3hrs of onset (used in around 10% of all cases)

Question 27

What investigation must be performed with all patients suspected of stroke?

Answer 27

CT head, early on

Question 28

What is the most important thing to rule out with the use of CT in stroke?

Answer 28

Haemorrhage, as thrombolysis, anti-coagulation and ant-platelet contraindicated in haemorrhagic stroke

Question 29

What is particularly advantageous about the use of MRI in suspected stroke?

Answer 29

Shows subtle defects early on (though is not routinely used in stroke investigation

Question 30

Which areas of the brain are most susceptible to ischaemic injury?

Answer 30

Watershed zones, where arterial blood supplies meet

Question 31

Where to berry / saccular aneurysms most commonly form?

Answer 31

At arterial junctions / bifurcations e.g. where MCA branches off Internal carotid arteries or between the anterior communicating and anterior cerebral arteries etc