Stroke (Cerebrovascular Disease) Flashcards

1
Q

What might be a general issue with imaging to determine stroke?

A

It takes time, and may have difficult distinguishing new lesions from old ones.

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2
Q

What does the FAST acronym mean for strokes?

A

Face - does one side droop?
Arms - does one arm drift downward
Speech - is it slurred or strange
Time - if you see any of these signs, time is of the essence

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3
Q

What are the four levels of clinical evidence?

A
  1. Randomized controlled trial - double blind + placebo
  2. Non-randomized controlled trial
  3. Observational studies with control
  4. Observational studies without control
  5. Case studies
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4
Q

What level of blood flow defines an infarcation of the brain?

A

<10 mL / 100 g / min

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5
Q

What is the majority of strokes and what causes them?

A

70-80% of strokes are ischemic strokes, up to 25% are due to clots / plaques from other areas

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6
Q

What is a TIA?

A

Transient ischemic attack - ministroke, symptoms disappear in less than 24 hours and most last less than 30 minutes. Increases your risk of future strokes

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7
Q

What is a hemorrhagic transformation?

A

When an ischemic stroke becomes a hemorrhagic stroke due to pressure buildup.

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8
Q

What causes hemorrhagic stroke and who is it common in?

A

Accounts for 20-30% of strokes, more common in children. Greatest predisposing factor is hypertension.

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9
Q

What is a thunderclap headache?

A

Sudden, severe headache “worst headache of your life” caused by hemorrhagic bleeding into the subarachnoid space

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10
Q

What type of aneurysm typically occurs at the anterior communicating artery?

A

saccular / berry

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11
Q

What is a fusiform aneurysm?

A

aneurysm characterized by bulges on all sides

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12
Q

What is a false aneurysm vs dissecting aneurysm? What can these cause?

A

False - bulge in blood vessel but no true rupture of intima

Dissecting - tunica intima is torn, leading to blood in the vessel wall

Both can cause an ischemic stroke

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13
Q

What type of stroke do AV malformations cause? What structure is associated with them?

A

Hemorrhagic stroke, due to buildup of pressure

An AVM nidus is associated with them

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14
Q

Where is central venous thrombosis most common, and what is the most common genetic cause?

A

Common in superior sagittal sinus. Common in genetic mutations to clotting factors

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15
Q

What percentage of patients have a patent foramen ovale and why is this a stroke risk factor?

A

25% of patients, it is a risk factor because systemic venous clots will be able to get into the arterial system through the foramen ovale

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16
Q

What are other common causes of emboli from the heart?

A

Causes 15-20% of strokes

Atrial fibrillation, endocarditis, or MI

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17
Q

When is the penumbra?

A

Part of the brain which can potentially be rescued, surrounding the infarcted area. Delayed necrosis + apoptosis of cells

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18
Q

What are the risk factors for stroke?

A
Hypertension
Heart disease, atrial fibrillation and especially rheumatic (from strep throat)
Diabetes
Smoking
Dyslipidemia
Previous stroke
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19
Q

What is non-contrast CT good for?

A

Hemorrhagic but not early ischemic stroke

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20
Q

What is perfusion CT good for?

A

Ischemic stroke and revealing penumbra

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21
Q

What is CT angiography good for?

A

Uses contrast, reveals flow in blood vessels

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22
Q

How do white matter, gray matter, and CSF appear on T1-weighted imaging?

A

White matter: light
Gray matter: Dark
CSF: Black

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23
Q

How do white matter, gray matter, and CSF appear on T2-weighted imaging?

A

White matter: dark
Gray matter: light
CSF: white

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24
Q

What is perfusion-weighted imaging good for? What sequence is it based off?

A

T2 - perfusion of tissue

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25
Q

What is diffusion-weighted imaging good for? What sequence is it based off?

A

T2 - Early detection of ischemic stroke

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26
Q

What is susceptibility-weighted imaging good for? What sequence is it based off?

A

T2 - venous blood and iron

27
Q

What is MR angiography imaging good for? What sequence is it based off?

A

T2 - Visualization of blood vessel flow

28
Q

What is FLAIR imaging good for? What sequence is it based off?

A

T2 - Fluid-attenuated inversion recovery - detects demyelination

29
Q

What is diffusion tensor imaging good for? What sequence is it based off?

A

T2 - used to delineate tracts within the brain

30
Q

What is mismatch imaging used for?

A

Mismatch = Perfusion - diffusion weighted, aka areas with lack of perfusion - areas with ischemic stroke damage = area of penumbra

31
Q

What is ultrasound good for?

A

Monitoring blood flow, also the sound waves increase the enzymatic reaction of thrombolytics

32
Q

What is TPA used for and what is its major disadvantage?

A

Tissue plasminogen activator - used to break up ischemic strokes caused by clots.

Major disadvantage: Must be given within 3 hours of stroke symptoms, and can be really dangerous if stroke was misdiagnosed and is actually hemorrhagic!!

33
Q

What is inter-arterial thrombolysis?

A

Used in large vessel occlusion, often heparin and pro-urokinase, used after TPA would no longer be effective

34
Q

What is balloon angioplasty and stenting?

A

Balloon opens narrowed vessel and stent is left in if needed

35
Q

What is embolectomy and clot aspiration?

A

Use a wire to break up the thombus / embolus, then aspirate the pieces. Can be done with things which surround the clot or break it up mechanically (MERCI, PENUMBRA, SOLITAIRE)

36
Q

How many neurons are lost each minute of ischemia?

A

1.9 million neurons per minute

37
Q

What is the treatment for subarachnoid hemorrhage?

A

Clipping of aneurysm or using coiling

38
Q

What is the treatment for cerebellar hemorrhage?

A

Occipital craniotomy

39
Q

What is the treatment for intraventricular hemorrhage?

A

Ventriculostomy (insertion of tube)

40
Q

What is the most common stroke region, and what is the most dangerous type of stroke in this region?

A

Anterior Brain Circulation Syndrome (70%)

Most dangerous = massive cerebral infarcation. Embolic stroke is the worst because there is no time for collaterals to form (vs atherosclerotic)

41
Q

What is the main cause of death in internal carotid embolic stroke? What will the patient do?

A

Edema and brain herniation

patient’s head and eyes will move towards the side of the lesion, and will have contralateral motor and sensory loss

42
Q

What is the feature of an anterior choroidal artery stroke?

A

Usually a lacunar syndrome with pure motor or sensorimotor hemiparesis, since it supplies the posterior limb of internal capsule, LGN, and hippocampus

43
Q

What is the most common artery to be affected in stroke? How is a large vs malignant infarct defined?

A

Middle cerebral artery

Large: 2-3 territories
Malignant - all territories

44
Q

What causes acute complete MCA infarct, and what part of the body is spared?

A

Infarct in M1. Only part that is spared is low leg (supplied by anterior cerebral artery)

45
Q

What two arteries branch from M1, and what is considered the “artery of stroke”? What does that cause?

A
  1. Medial Lenticulostriate Arteries
  2. Lateral Lenticulostriate Arteries (Artery of Stroke)
    - > Charcot’s artery, causes the classical symptoms of stroke because it supplies the post. internal capsule and basal ganglia, including hemiparesis, hemihypesthia (sensory loss) and dysarthria
46
Q

What causes complete superficial MCA infarct? How does this differ from acute complete MCA infarct?

A

Proximal M2 ischemia at MCA bifurcation. There are less cognitive deficits than M1.

47
Q

What does superior (anterior) M2 stroke cause?

A

Contra arm and face sensory deficits, but NOT visual deficits (no temporal involvement)

48
Q

What does inferior (posterior) M2 stroke cause?

A

Similar deficits but including visual deficits (hemianopsia or quantrantanopsia)

49
Q

What infarcts are included in M3?

A
  1. Leptomeningeal - highly variable

2. Medullary perforating - infarct of centrum ovale, or cortical white matter

50
Q

What are M4 infarcts?

A

Stroke of terminal branches supplying the cortex

51
Q

What is the main infarct of the anterior cerebral artery?

A

Medial striate artery / recurrent artery of Heubner - supplies head of caudate + ant. limb of internal capsule. Causes weakness of contralateral arm / leg and hemichorea

52
Q

What problems are more common in a posterior vs anterior circulation syndrome?

A

Posterior is more likely to cause visual / gaze problems

53
Q

What is the most common of the vertebral artery infarcts?

A

Lateral medullary / Wallenburg syndrome (PICA loss)

54
Q

What causes medial medullary syndrome / inferior alternating hemiplegia?

A

Anterior spinal artery infarction

55
Q

What causes locked-in syndrome?

A

Infarct of basilar artery

56
Q

What does posterior cerebral artery infarct cause?

A

Contralateral hemianopsia, possible macular stparing

57
Q

What causes rostral lateral pontine syndrome?

A

Superior cerebellar artery infarct

58
Q

What causes lower lateral pontine syndrome?

A

AICA infarct

59
Q

What is a Lacunar stroke syndrome?

A

Small vessel disease, usually subcortical, which is common in vertebrobasilar system. Makes up 20% of all strokes, with better recovery than other strokes but high risk of further problems

60
Q

What are the five types of lacunar strokes? Which two are most common?

A
  1. Pure motor
  2. Pure sensory - lesion of VP nucleus
  3. Sensorimotor - internal capsule - common
  4. Dysarthria - basilar pons lesion, with clumsy hands
  5. Ataxic hemiparesis - common
61
Q

What are the two types of watershed infarcts and what causes them generally?

A

Cause: Distal regions of two arterial systems, commonly hypotension

  1. Cortical - superficial and wedge-shaped
  2. Internal - central semiovale along lateral ventricle, single lesion
62
Q

What does bilateral internal watershed injury cause?

A

Proximal upper and lower limb weakness -> man-in-the-barrel

63
Q

What is a capsular warning syndrome?

A

Pure motor hemiparesis with repetitive TIAs, may be caused by small infarct of internal capsule such as lateral LSA. Precursor to a larger stroke