Stroke

Question 1

What is a stoke?

Answer 1

focal brain damage due to a problem in the local blood supply that causes loss of function.

Question 2

What is the difference between a stroke and TIA?

Answer 2

stroke >24hr symptoms
TIA<24hrs symptoms (usually <1hr)
15% of strokes are preceded by a TIA/minor stroke

Question 3

What are the two mechanisms of strokes?

Answer 3

Ischaemic stroke (infarct)- blockage or decrease in blood flow (85%)
Haemorrhagic stroke- bursting or fragility of vessels-->bleeding (15%)

Question 4

How does a stroke present?

Answer 4

focal loss of function- sensation loss, speech problems r movement deficit
sudden onset

Question 5

Briefly explain the blood supply of the brain

Answer 5

There are two circulations: the anterior circulation and the posterior circulation
Internal carotid then gives rise to the anterior cerebral artery and the middle cerebral artery (THE ANTERIOR CIRCULATION)- This supplies the front part of the brain.
THE POSTERIOR CIRCULATION arises from the vertebral arteries (which are branches of the subclavian arteries) and join up to give rise to the basilar artery.

Question 6

What part of the brain does the anterior cerebral artery supply? (and what % of strokes occur in this artery?)

Answer 6

medial anterior hemispheres

5-10% of strokes

Question 7

What part of the brain does the middle cerebral artery supply? (and what % of strokes occur in this artery?)

Answer 7

deep and lateral hemispheres

65-75% of strokes

Question 8

What part of the brain does the posterior cerebral artery supply? (and what % of strokes occur in this artery?)

Answer 8

occipital and medial temporal lobe

20-30% of strokes

Question 9

What part of the brain does the vertebro-basilar artery supply?

Answer 9

brainstem and cerebellum

Question 10

What areas/functions of the brain can be affected by a stroke?

Answer 10

Motor and sensory cortices 
deep motor and sensory pathways
higher functions
language areas
visual pathways

Question 11

What does brocas area control?

Answer 11

language production

Question 12

What does wernickes area control?

Answer 12

comprehension of speech

Question 13

What features would you expect in a stroke affecting the anterior circulation?

Answer 13

• blockage of the middle cerebral artery and the anterior cerebral artery
  –>hemimotor and/or hemisensory loss (affects 1 side)
  –>hemianopia
  –>higher cortical function loss (aphasia and neglect)
  If you have all three of the above you have a total anterior circulation syndrome (TACS) but if you have 2/3 you have a partial anterior circulation syndrome (PACS)

Question 14

What features are involved in lacunar syndromes?

Answer 14

blockage of small artery in hemisphere or brainstem

• ->face-arm-leg pure motor (internal capsule/pons)
• ->face-arm-leg pure sensory (thalamus)
• ->face-arm-leg sensorimotor (internal capsule/thalamus)

Question 15

What features would you expect in a stroke affecting the posterior circulation?

Answer 15

hemianopia
motor/sensory loss
eye movement disorders- CN nuclei affected
CN palsies
vertigo, loss of balance, and coordination (cerebellar problems)

Question 16

What kind of stroke are you thinking if a patient presented with: early morning headache, vomiting and loss of consciousness?

Answer 16

hemorrhagic stroke

CT scan required to determine this- bright white on CT scan represents blood.

Question 17

What other differentials can you have in suspected stroke?

Answer 17

seizure
syncope
sepsis
structural brain lesions
CNS infection
metabolic disturbances
migraine
vestibular disorders
CNS inflammation e.g. MS
PNS problem

Question 18

What are some risk factors of strokes?

Answer 18

Age, sex (m>f), hypercholesterolaemia, poor diet, CVD, obesity, HTN, smoking, social deprivation, alcohol, diabetes

Question 19

what is the most common cause of an ischaemic stroke?

Answer 19

large artery atheroma–>thrombotic event (don’t forget about cardiac emboli e.g. in AF

Question 20

What is atherosclerosis?

Answer 20

plaque build up in the walls of arteries leading to thickened walls, decreased lumen size and fragility.

Question 21

what is an arterial dissection?

Answer 21

tear in the artery wall leading to blood collecting within the walls narrowing the lumen and expanding it. Expansion of the lumen can compress surrounding structures e.g. the sympathetic chain–>Horner’s syndrome.

Question 22

Tests to order if suspected stroke

Answer 22

Bloods- FBC, ESR, U&E, Glucose, cholesterol
ECG
CXR
CT head- look for bleeds and tumours

Question 23

what should be done immediately if suspected stroke?

Answer 23

VTE (Venous thromboembolism) prophylaxis- anticoagulants, stockings etc
admit to stroke unit

Question 24

Treatment of strokes

Answer 24

thrombolysis- clot busters e.g. alteplase
aspirin
hydration
clot retrieval
decompressive craniotomy for large strokes

Question 25

What is a penumbra?

Answer 25

area around an ischaemic core that has decreased blood supply but can be saved if artery unblocked

Question 26

Types of haemorrhage strokes

Answer 26

- intracerebral- most common - subarachnoid- largely caused by aneurysms - intraventricular- starts in the parenchyma and moves to the ventricles - subdural

Question 27

Outline the presentation of an intracerebral stroke

Answer 27

``` headache vomiting increase BP focal deficit decreased consciousness - CT required for diagnosis ```

Question 28

How can you decrease BP acutely?

Answer 28

IV CCB- Nicardepine | Beta blockers- lobetolol

Question 29

How can you reduce BP long term?

Answer 29

ACEi | CCBs (oral)

Question 30

What drugs should you avoid giving in suspected or diagnosed stroke?

Answer 30

nitrates due to cerebral vasodilation and increased ICP

Question 31

What is a cavernoma?

Answer 31

an abnormal cluster of vessels in the brain that if looked at on a CT head it looks like popcorn.

Question 32

In the context of neuroradiology what does intra-axial mean?

Answer 32

inside the brain/in the brain parenchyma (inside cerebellum, brainstem etc)

Question 33

In the context of neuroradiology what does extra-axial mean?

Answer 33

outside pressing on brain e.g. meningioma

Question 34

In the context of neuroradiology what does supratentorial mean?

Answer 34

above posterior/tentorial fossa (cerebral hemispheres)

Question 35

In the context of neuroradiology what does infratentorial mean?

Answer 35

below the posterior/tentorial fossa (cerebellum and brainstem)

Question 36

What are the three meningeal layers?

Answer 36

dura mater- superficial arachnoid mater pia mater- deep cortical surface v.thin

Question 37

What is an extradural haematoma?

Answer 37

involves arterial blood, typically follows trauma. 80% are associated with skull fracture usually due to laceration of middle meningeal artery

Question 38

What is a subdural haematoma?

Answer 38

involves venous blood common in the elderly due to bleeding from bridging veins may have delayed onset

Question 39

what is a subarachnoid haemorrhage?

Answer 39

usually die to aneurysms, venous thrombosis, trauma (berry aneurysms, mycotic aneurysms, arterial dissection) sudden onset headache (like being hit over the head with a cricket bat) check CSF via lumbar puncture- any blood? CT angi required