Stroke and subarachnoid haemorrhage

Question 1

What is the definition of a stoke?

Answer 1

Focal neurological symptoms lasting over 24 hours with a vascular cause

Question 2

What are the two main causes of stroke?

Answer 2

Cerebral infarcts or haemorrhages

Question 3

What are the two main ways that infarction causes damage?

Answer 3

Infarction is the most common form of stroke.
It causes Metabolic failure of neurones in the core of the stroke. It causes electrical failure in the neurones surrounding the core that recieve slightly more blood flow, this can be reversed if blood flow is restored in 4-6 hours

Question 4

How does a cardioembolism form?

Answer 4

When there is disrupted blood flow in the heart e.g. atrial fibrillation, this leads to formation of many small clots that can embolise to the brain

Question 5

What are lacunar infarcts?

Answer 5

They occur when there is occulsion of the small perforating arteries in the white matter and brainstem

Question 6

When will an infarct be visible on CT?

Answer 6

There will be loss of grey/white matter differentiation initially then after a period of days it will become very dark and demarcated

Question 7

What are the two main causes of intracerebral haemorrhage?

Answer 7

Chronic hypertension and amyloid angiopathy caused by deposition of amyloid proteins within blood vessels

Question 8

What sort of vessels rupture with chronic hypertension and with amyloid angiopathy?

Answer 8

With chronic hypertension deep perforating arteries normally rupture
With amyloid angiopathy there is usually multiple superficial haemorrhages

Question 9

What can be seen on CT following haemorrhage?

Answer 9

Initially it appears white due to the isodense liquid but then after some days will be indishtinguishable from an infarct. There may also be some mass effect from the blood

Question 10

What functions are the different brain lobes associated with?

Answer 10

• The frontal lobe is associated with consciousness, wakefulness, self-control, language production, and movement
• The parietal lobe is associated with sensation, language comprehension and production, spatial orientation, and calculation
• The occipital lobe is in control of vision
• The temporal lobe is in control of speech, memory, hearing, and smell
• The cerebellum controls balance and coordination, and the brainstem is associated with cranial nerve function and visceral reflexes

Question 11

What are the symptoms of lacunar syndromes?

Answer 11

Causes hemiplegia and sensory loss but no cortical signs

Question 12

What are the different presentations for anterior infarcts and posteriorinfarcts?

Answer 12

Anterior causes contralateral weakness and numbness in the limbs and face
In posterior infarcts there is dizziness, diplopia, nystagmus, cranial nerve palsies

Question 13

Why is it important to refer TIA patients?

Answer 13

10% will have a stroke in the next 90 days

Question 14

What is amaurosis fugax?

Answer 14

This is TIA of the retinal artery that causes monocular blindness for around 1-5 minutes

Question 15

What are the features of a TIA?

Answer 15

Sudden onset
Negatove symptoms
Focal synptoms
Neurological signs

Question 16

How does a subarachnoid haemorrhage present?

Answer 16

Sudden severe thunderclap headache that reaches maximum severity within 5 minutes of starting
Associated with:
Vomiting, depressed consciousness, neck stiffness, hypertension

Question 17

Where does a third nerve palsy indicate a subarachnoid haemorrhage to have occured?

Answer 17

Posterior communicating artery