Stroke Flashcards

1
Q

Describe the common pathology of small vessel disease?

A

Small Artery Lipohyalinosis

Hypertension causes thickening of small artery walls leading to luminal narrowing

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2
Q

What are borderzone anatomoses? [1]

A

Anastomoses between peripheral branches of cerebral arteries

Too small to compensate for blocked major arteries

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3
Q

What neglect syndromes result from right hemisphere damage? [4]

A
  • Visual Agnosia (Cant process left side vision)
  • Sensory Agnosia
  • Anosagnosia (Denial/unawareness of hemiplegia or stroke as a whole)
  • Prosopagnosia (Failure to recognise faces
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4
Q

Which cerebral artery supplies the basal ganglia? [2]

A

Middle cerebral -> Lenticulostriate arteries

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5
Q

What does the basilar artery supply? [3]

A

Brainstem, Cerebellum, thalamus

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6
Q

Where does the post cerebral circulation supply? [5]

A

Brainstem. Cerebellum and thalamus

+ Occipital and medial temporal lobes

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7
Q

What symptoms occur if the brainstem is ischemic? (Such as in post circulation infarcts) [6]

A
  • Coma
  • Ataxia, Vertigo, N&V
  • Cranial nerve palsies
  • Hemiparesis or hemisensory loss
  • Crossed sensori/motor deficits (Means ipsilateral cranial nerve signs and contralateral motor/sensory signs)
  • Visual field deficits
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8
Q

How do you classify strokes? [4]

A

Total Anterior Circulation Stroke (TACS)
Partial Anterior Circulation Stroke (PACS)
Lacunar Stroke (LACS)
Posterior Circulation Stroke (POCS)

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9
Q
Order the classes of stroke by prognosis? [4]
(Death or dependance at 6m)
Difference between (terminology) TACI and TACS?
A

Death or dependance at 6 months:

  • TACS 96%
  • PACS 45%
  • LACS 39%
  • POCS 38%

They are refferred to as **S instead of **I, meaning stroke syndrome instead of infarct prior to imaging as we cant yet be sure it is a stroke and not some other condition causing a stroke like syndrome.

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10
Q

Aims of treatment in stroke [3]

A

Restores supply
ABCDE
Prevents ischemia & extension
Protect brain tissue

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11
Q

Stroke treatments [4]

A

1) Arrange urgent NCCT scan if onset <4.5h
2) Thrombolysis with IV alteplase (tissue plasminogen activator, tPA) ASAP but NOT if >4.5 hours have elapsed.
2a) Can add Surgical Clot retrieval to increase chance. (thrombectomy)
3) Aspirin within 48 hours reduce risk of further strokes

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12
Q

Criteria for TPA use [4]

A

it is administered within 4.5 hours of onset of stroke symptoms (unless as part of a clinical trial)
haemorrhage has been definitively excluded (i.e. Imaging has been performed)

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13
Q

Contraindicaitons for thrombolysis
Relative [5]
Absolute [11]

A
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14
Q

What sort of treatments can reduce stroke risk after a TIA? [4]

A

Antiplatelets
Antihypertensives
Statins
Endarterectomy if atheroma

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15
Q

Whats involved in stroke secondary prevention? [4]

A
  • Anti-HTN
  • Anti-platelets: 75mg clopidogrel or aspirin + dypiridamole (if contraindicated/not tolerated) lifelong
  • Atorvastatin 80mg
  • Endarterectomy (mainly carotid)
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16
Q

Differentiating between different classes of stroke: LACS [4]
Where are the infarcts? [4]

A

At least one of:

  1. unilateral weakness (and/or sensory deficit) of face and arm, arm and leg or all three.
  2. pure sensory stroke.
  3. ataxic hemiparesis

Lacunar strokes are small in infarct in basal ganglia, internal capsule or thalamus and pons

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17
Q

Differentiating between different classes of stroke:
PACS [4]
Source: Oxford stroke classification/Bamford classification

A

Partial anterior circulation stroke
At least 2 of:
1. Unilateral hemiparesis and/or hemisensory loss of face, arm or leg
2. Homonymous hemianopia
3. Higher cognitive dysfunction (dysphasia)

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18
Q

Differentiating between different classes of stroke: TACS [4]
Source: Oxford stroke classification/Bamford classification

A

All 3 of:

  1. Unilateral hemiparesis and/or hemisensory loss of face, arm or leg
  2. Homonymous hemianopia
  3. Higher cognitive dysfunction (dysphasia)
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19
Q

Differentiating between different classes of stroke: POCS [4]
Source: Oxford stroke classification/Bamford classification

A

presents with 1 of the following:
1. cerebellar or brainstem syndromes
2. loss of consciousness
3. isolated homonymous hemianopia

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20
Q

Stroke by anatomy:

Basilar artery infarct

A

Locked-in syndrome

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21
Q

Stroke by anatomy:

ACA [2]

A

Contralateral hemiparesis + sensory loss

Lower extremity > upper

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22
Q

Stroke by anatomy:

MCA [4]

A

Contralateral hemiparesis + sensory loss
Upper extremity > lower
Contralateral homonymous hemianopia
Aphasia

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23
Q

Stroke by anatomy:

PCA [3]

A

Contralateral homonymous hemianopia with macular sparing [2]

Visual agnosia

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24
Q

Define stroke [3]

A

A neurological deficit [1] of sudden onset [1] lasting >24 hours of vascular origin [1]

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25
Q

When is the main risk period for further strokes/TIAs following one?

A

The first two weeks.

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26
Q

Hemorrhagic stroke mx [5]

A

Rapid BP control if within 6h of symptom onset
Neurosurgical opinion
STOP anticoagulants and reverse, stop antiplatelets
Specialist stroke unit
Early mobilization

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27
Q

TIA initial mx [3]

Ix [6]

A
ABCDE
Immediate anti-platelet therapy Aspirin 300mg
Refer for assessment in hospital
Ix:
- Bloods
- CXR
- ECG
- ECHO
- Carotid doppler
- Brain imaging
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28
Q

TIA subsequent management [4]

A

o Further anti-platelet: CLOPIDOGREL
o Anti-coagulant: if in AF
o Modifiable cardiac RFs: BP control, statin, DM, stop smoking
o Carotid endarectomy: >70% stenosis

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29
Q

When would you offer thrombectomy?

Eligibility considerations

A

Offer thrombectomy as soon as possible and within 6 hours of symptom onset, together with intravenous thrombolysis (if within 4.5 hours), to people who have:
* acute ischaemic stroke and
* confirmed occlusion of the proximal anterior circulation [1]
* that has been demonstrated by computed tomographic angiography (CTA) or magnetic resonance angiography (MRA)
* NICE recommend a pre-stroke functional status of less than 3 on the modified Rankin scale and a score of more than 5 on the National Institutes of Health Stroke Scale (NIHSS)

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30
Q

Patterns of stroke: Lateral medullary syndrome (posterior inferior cerebellar artery) [3]

A
  • aka Wallenberg’s syndrome
  • ipsilateral:
    > ataxia
    > nystagmus
    > dysphagia
    > facial numbness
    > cranial nerve palsy e.g. Horner’s
  • contralateral: limb sensory loss
31
Q

Weber’s syndrome [2]

A

ipsilateral III palsy

contralateral weakness

32
Q

Patient presenting within 6-24 hour window including wake-up strokes - which circumstances would you consider thrombectomy?

A

Offer thrombectomy as soon as possible to people who were last known to be well between 6 hours and 24 hours previously (including wake-up strokes):
* confirmed occlusion of the proximal anterior circulation demonstrated by CTA or MRA and
* if there is the potential to salvage brain tissue, as shown by imaging such as CT perfusion or diffusion-weighted MRI sequences showing limited infarct core volume

33
Q

When would you consider thrombectomy together thrombolysis?

A

Consider thrombectomy together with intravenous thrombolysis (if within 4.5 hours) as soon as possible for people last known to be well up to 24 hours previously (including wake-up strokes):
* who have acute ischaemic stroke and confirmed occlusion of the proximal posterior circulation (that is, basilar or posterior cerebral artery) demonstrated by CTA or MRA and
* if there is the potential to salvage brain tissue, as shown by imaging such as CT perfusion or diffusion-weighted MRI sequences showing limited infarct core volume

34
Q

Cerebrovascular disease comes in two forms [2]

A
  • Localised interruption of blood or oxygen supply (Stroke)

- Generalised interruption of blood or oxygen supply

35
Q

What could cause a stroke? Outline 3 main mechanisms: vessel wall [4], blood constituents [2], blood flow [2]

A

Vessel Wall:

  • Aneurysm
  • Atheroma
  • Vasculitis
  • Strangulation

Blood Constituents

  • Thrombosis
  • Bleeding due to anticoags or reduced platelet/clotting factors

Blood flow:

  • Hypotension
  • Hypertension -> Bursting
36
Q

So what are the 3 main causes of localised interrupted blood supply to the brain (Stroke)?

A

Ischaemic:

  • Embolic eg Afib
  • Thrombotic (atherosclerosis)
  • Lacunar strokes

Haemorrhagic:

  • Intracerebral haemorrhage - HTN, vascular malformations
  • SAH (bleeding into subarachnoid space)

Watershed strokes

37
Q

Whats the difference between a TIA [3] & Stroke [3]?

A

Both are ischaemia to a localised section of brain tissue

TIA:

  • Reversible Ischaemia
  • Tissue still viable

Stroke:

  • Irreversible ischaemia
  • Localised brain death (i.e. infarct)
38
Q

What happens to the brain tissue during a regional cerebral infarct? [5]

A

The region is classically wedge shaped reflecting the in->out arterial supply. [1]

The tissue becomes soft, yellowy discoloured and begins to disintegrate [1] typically in a cystic appearance [1]

There may be visible congested vessels [1] and swelling around the area [1]

39
Q

How does infarcted brain tissue appear histologically? [2]

A

Visibly lost neurons [1]

Foamy macrophages - Part of the repair process prior to gliosis (Scar tissue formation) [1]

40
Q

Why are cerebral arteries so likely to have aneurysms? [3]

A

They are very thin walled due to their lack of muscle. [1]
This is so that there’s no way cerebral blood can be diminished [1]

This when coupled with hypertension leads to aneurysms which can burst [1]

41
Q

How does a ruptured aneurysm cause localised interruption of blood flow? [2]

A

The haemorrhage means blood doesnt get through and compresses the brain [1]

Can also get distal ischaemia due to arterial spasm [1]

42
Q

Where do cerebral aneurysms most often form? [2]

A
  • Microaneurysms in the Basal Ganglia

- Berry Aneurysms in the Circle of Willis

43
Q

What are the main causes of a generalised interrupted blood supply or hypoxia? [3]

A
  • Low O2 in the blood (Hypoxic Hypoxia) e.g. CO poisoning or resp arrest
  • Inadequate supply of blood e.g. Cardiac arrest, swollen brain or hypotension
  • Rarely an inability to use the O2 such as cyanide posioning
44
Q

What are the main types of Generalised interrupted blood supply? [3]

A
  • Hypotension
  • Cardiac Arrest
  • Complex Case (Combines various types of ischaemia form multiple causes)
45
Q

What pattern of infarction could be caused during an Operation in which there is a prolonged period of hypotension? [3]

A

Generalised interrupted blood flow [1]

  • -> poor perfusion to the borders between arterial territories in the brain [1]
  • -> So you get a pattern of ischaemia and infarction [1] at the interfaces between these area (watershed infarcts) [1]
46
Q

If someone goes into cardiac arrest and is resuscitated after several minutes, describe their pattern of ischaemia?

A

They go several minutes with no supply of blood so Generalised interruption

Causes infarction all over the brain

They get Laminar (lined) cortical necrosis [1] i.e. large areas of grey matter thin and necrose [1]

47
Q

Lets say a woman comes in with a known Coronary artery disease, bouts of pneumonia and suffers a cardiac arrest, describe her pattern of ischaemia? [3]

A

This is known as a Complex Case [1], she has multiple different sources of ischaemia causing different patterns in her brain:

  • Watershed infarcts from her time poorly ventilated due to pneumonia [1]
  • Regional infarcts related to localised loss of blood flow from atheromatous disease [1]
  • Laminar Cortical infarcts due to complete cessation of blood flow during cardiac arrest [1]
48
Q

Prognosis strokes - what % ability to lead independent lifestyle? Mortality within 1y?

A

50% of survivors become dependant on others for daily activities
& roughly 1/3rd die within a yr

49
Q

What is the ischaemic penumbra? [3]

A

Region around the edge of the ischaemic core [1] because blood & O2 supply is reduced locally after an ischaemic event [1]
The tissue may remain viable for several hours due to collateral circulation. [1]

50
Q

Radiological imaging stroke [4]

A

Non-contrast CT scan

  • First option
  • MRI with DWI
  • Carotid ultrasound scanning
  • CT angiography
51
Q
Compare CT and MRI
CT pros [2]
CT cons [2]
MRI pros [2]
MRI cons [2]
A

CT pro: infarcts show up clearer + darker; can exclude hemorrhagic stroke
CT cons: <6h not as sensitive, poor visualization for POCs
MRI pros: better for POCs, increased sensitivity to acute ischemia and smaller infarcts
MRI cons: $$$, longer scanning time

52
Q

Diabetes and stroke risk [1]

Smoking and stroke risk [2]

A

Diabetes causes an increases risk up to 3fold.

Smoking doubles risk of stroke and triples risk of SAH

53
Q

Alcohol and stroke risk [2]

A

Small amounts actually decrease risk but heavy drinking more than doubles it

54
Q

Alcohol and stroke risk [2]

A

Small amounts actually decrease risk but heavy drinking more than doubles it

55
Q

What 3 other investigations must you carry out to identify underlying cause of stroke?

A
  • Routine bloods
  • ECG (LVH or AF)
  • Echocardiogram (Valves, ASD/VSD)
56
Q
Case study:
O/E can move eyes up and down
Breathing spontaneously 
No other movements
She has CV risk factors
A

Diagnosis: locked in syndrome secondary to pontine infarction

57
Q

Locked in syndrome
What are causes [2]
Why are vertical eye movements preserved?

A

Damage to ventral pons
Pontine infarct
Basilar artery obstruction
Can be precipitated by neck trauma causing vertebral artery dissection

Horizontal eye movements coordinated in Pons but Midbrain and vertical eye movements preserved

58
Q

In what patients would a carotid endarterectomy definitely be indicated?

A
  • recommend if patient has suffered stroke or TIA in the carotid territory and are not severely disabled
  • should only be considered if carotid stenosis > 70% according ECST** criteria or > 50% according to NASCET*** criteria
59
Q

What are the complications of Carotid Endarterectomy [4]

A

Infection

  • Bleeds
  • Nerve Damage
  • Perioperative Stroke (due to rupturing plaque or the vessel clamping causing hypoperfusion of the brain)
60
Q

Agnosia definition

Types of agnosia [4]

A

inability to interpret sensations and hence to recognize things

  • Visual agnosia
  • Sensory agnosia
  • Anosagnosia
  • Prosopagnosia
61
Q

Describe prevalence of hemorrhagic vs ischemic strokes

A

Haemorrhagic (Around 15%)

Ischaemic (Around 85%)

62
Q

Fluid management in stroke patients

A
  • manage fluids in this immediate post-event period as hypovolaemia can worsen the ischaemic penumbra, as well as increase risk of other complications such as infection, deep vein thrombosis, constipation and delirium
  • over-hydration can also complicate matters by leading to cerebral oedema, cardiac failure and hyponatraemia, therefore it is important to regularly review fluid status in these patients
  • encourage oral hydration when able
63
Q

The NICE guidelines recommend maintaining a blood sugar level between ———– in people with acute stroke

A

The NICE guidelines recommend maintaining a blood sugar level between 4 and 11 mmol/L in people with acute stroke
* hyperglycaemia leads to worse outcomes, leaky BBB

64
Q

Use of anti-hypertensive medications should only be used for blood pressure control in patients post ischaemic stroke if there is a hypertensive emergency with one or more of the following serious concomitant medical issues (according to the NICE guidelines): [5]

A
Hypertensive encephalopathy
Hypertensive nephropathy
Hypertensive cardiac failure/myocardial infarction
Aortic dissection
Pre-eclampsia/eclampsia
65
Q

Consequences of lowering BP too much post-ischemic stroke

A

This is because lowering blood pressure too much can potentially compromise collateral blood flow to the affected region, and possibly hasten the time to complete and irreversible tissue infarction

66
Q

What are the recommendations on how fast you should lower BP?
Which anti-HTN drugs would you be able to use? [3]

A

If if treatment is indicated, UptoDate recommend cautious lowering of blood pressure by approximately 15% in the first 24-hours after stroke onset

Rx: intravenous labetalol, nicardipine and clevidipine

67
Q

Management of BP for patients who are candidates for thrombolytic therapy for acute stroke is different

A
  • blood pressure should be reduced to 185/110mmHg or lower as elevated BP can affect thrombolytic eligibility and delay treatment
68
Q

Feeding assessment and management of any concerns regarding swallow [2]

A

All patients presenting with acute stroke must be SCREENED for safe swallowing function prior to further oral intake, as dysphagia is common after stroke
Specialist input for any concerns regarding swallow within 24h of admission and no more than 72h after admission, remain NBM until assessed

69
Q

Recommendations for patients deemed unsafe for oral intake [2]

A

Patients should receive nasogastric tube feeding, ideally within 24 hours of admission, unless they have had thrombolytic therapy
2nd line:
- Nasal bridle tube or gastrostomy

70
Q

FAST screening tool (for general public)

ROSIER score is used by medical professionals [8]

A
  1. Exclude hypoglycaemia first, then assess the following:
  2. LOC or syncope -1
  3. Seizure activity -1
  4. New acute onset of: (all +1 pt)
    - Asymmetric facial weakness
    • asymmetric arm weakness
    • asymmetric leg weakness
    • speech disturbance
    • visual field defect
71
Q

ROSIER score clinical significance?

A

A stroke is likely if > 0.

72
Q

Atrial fibrillation post stroke [3]

A
  • following a stroke or TIA, WARFARIN or a direct thrombin or factor Xa inhibitor (APIXABAN 5MG BD)
  • Antiplatelets should only be given if needed for the treatment of other comorbidities
  • Start 14d after stroke
  • If imaging shows a very large cerebral infarction then the initiation of anticoagulation should be delayed
73
Q

Case scenario

What to do with aspirin in patient who is thrombolysed with or without AF

A

Aspirin 300mg to be started within 24 hours after haemorrhagic transformation excluded.
2 weeks aspirin then clopidogrel

74
Q
A