[6] Carotid Artery Disease Flashcards Preview

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Flashcards in [6] Carotid Artery Disease Deck (94)
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1
Q

What is carotid artery disease?

A

The build-up of atherosclerotic plaque in one or more common and internal carotid arteries, resulting in stenosis or occlusion

2
Q

Is carotid artery disease always symptomatic?

A

No, the majority of cases are asymptomatic

3
Q

What % of ischaemic strokes are due to carotid artery disease?

A

15%

4
Q

How can carotid artery disease cause ischaemic strokes?

A

Plaque rupture and/or atheroembolism

5
Q

What is the pathophysiology of carotid artery disease?

A

Same as for atheroma elsewhere, starting with fatty streak, accumulating a lipid core, and formation of a fibrous cap

6
Q

What predisposes the atheromatous process specifically at the carotid artery?

A

The turbulent flow at the bifurcation of the carotid artery

7
Q

What is carotid artery disease usually classified based on?

A

Classified radiologically by the degree of stenosis

8
Q

What is considered to be mild carotid artery disease?

A

<50% reduction in diameter

9
Q

What is considered to be moderate carotid artery disease?

A

50-69% reduction in diameter

10
Q

What is considered to be severe carotid artery disease?

A

70-99% reduction in diameter

11
Q

What is considered to be total occlusion in carotid artery disease?

A

100% reduction in diameter

12
Q

What are the major risk factors for carotid artery disease?

A
>65 years
Smoking
Hypertension
Hypercholesterolaemia
Obesity
Diabetes mellitus
History of cardiovascular disease
Family history of cardiovascular disease
13
Q

How does carotid artery disease present?

A

It will often be asymptomatic, however may present as a focal neurological deficit

14
Q

How can carotid artery disease lead to focal neurological disease?

A

Can lead to transient ischaemic attack or stroke

15
Q

How long does a TIA last before resolution?

A

24 hours

16
Q

What is amaurosis fugax?

A

Transient visual loss that may be associated with TIA

17
Q

How long does a stroke last?

A

24 hours or more without full resolution

18
Q

How are strokes classified?

A

Oxford Stroke (Bamford) Classification

19
Q

What is the Oxford Stroke Classification based on?

A

The stroke symptoms in relation to the arterial regions involved

20
Q

What may be found on examination in carotid artery disease?

A

A carotid bruit may be auscultated in the neck

21
Q

What proportion of carotid bruits auscultated in the neck are associated with carotid stenosis?

A

About half

22
Q

Why is carotid stenosis likely to be asymptomatic if unilateral (apart from clinical features of stroke)?

A

Due to collateral supply from the contralateral internal carotid artery and vertebral arteries, via the Circle of Willis

23
Q

What are the different classifications of stroke according to the Oxford Stroke Classification?

A

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

24
Q

What % of strokes are total anterior circulation strokes?

A

20%

25
Q

What are total anterior circulation strokes?

A

Large cortical stroke in middle or anterior cerebral artery areas

26
Q

What are the signs and symptoms of a total anterior circulation stroke?

A

Must have all of;
Motor weakness or sensory deficit of >2/3 of face, arm, and leg
Homonymous hemianopia
High cortical dysfunction

27
Q

How can high cortical dysfunction manifest?

A

Dysphagia
Dyspraxia
Neglect

28
Q

What % of strokes are partial anterior circulation strokes?

A

35%

29
Q

What are partial anterior circulation strokes?

A

Cortical strokes in middle or anterior cerebral artery areas

30
Q

What are the signs and symptoms of partial anterior circulation strokes?

A

Will present with either;
2/3 of TACS criteria
Limited motor or sensory deficit (1 of leg, arm, or face)
High cortical dysfunction alone

31
Q

What % of strokes are lacunar strokes?

A

20%

32
Q

What are lacunar strokes?

A

Occlusion of deep penetrating arteries

33
Q

How will lacunar strokes present?

A

With any of;
Pure motor in 2 or 3 of face, arm, and leg
Pure sensory in 2 or 3 of face, arm, and leg
Pure sensorimotor in 2 or 3 of face, arm, and leg
Ataxic hemiparesis

34
Q

What % of strokes are posterior circulation strokes?

A

20%

35
Q

What are posterior circulation strokes?

A

Occlusion of vertebrobasilar or PCA circulation, affecting brainstem, cerebellum or occipital lobe

36
Q

How do posterior circulation strokes present?

A

Variety of presentations can occur, but typically;
Ipsilateral CN palsy with contralateral motor or sensory defects
Bilateral motor or sensory defects
Isolated homonymous hemianopia
Cerebellar dysfunction

37
Q

What is the most common form of carotid artery disease?

A

Atherosclerosis

38
Q

What other pathologies can be involved in carotid artery disease?

A

Carotid dissection
Thrombotic occlusion of carotid artery
Fibromuscular dysplasia
Vasculitis

39
Q

What suggests carotid dissection as the pathology rather than atherosclerosis?

A

Patients are often younger (<50 years) and have an underlying connective tissue disease

40
Q

What might a carotid artery dissection be precipitated by?

A

Trauma or sudden neck movement

41
Q

How can a thrombotic occlusion of the carotid artery be differentiated from atheromatous plaques?

A

Only on imaging

42
Q

How will thrombotic occlusion of the carotid artery present clinically?

A

The same as atheroma

43
Q

What happens in fibromuscular dysplasia of the carotid arteries?

A

There is non-atheromatous stenotic angiopathy causing hypertrophy of the vessel wall

44
Q

Who does fibromuscular dysplasia predominantly affect?

A

Young (<50 years) females

45
Q

What vessels are most commonly affected in fibromuscular dysplasia?

A

Renal arteries

46
Q

How does carotid artery fibromuscular dysplasia present?

A

With focal neurological deficit

47
Q

What vasculitidies can cause carotid stenosis?

A

Various great vessel vasculitidies, such as Giant Cell Arteritis or Takayasu’s Arteritis

48
Q

How can carotid stenosis caused by vasculitides be differentiated from atherosclerotic causes?

A

Patients will typically have systemic symptoms, and other vessels may be affected

49
Q

What non-cerebrovascular conditions can manifest neurologically?

A
Hypoglycaemia
Todd's paresis
Subdural haematoma
SoL 
Venous sinus thrombosis
Post-ictal state
Multiple sclerosis
50
Q

What is Todd’s Paresis?

A

Unilateral motor paralysis following a seizure

51
Q

What investigations should be done in suspected stroke?

A

Urgent CT head
Bloods
ECG

52
Q

What is the purpose of a CT head scan in suspected stroke?

A

Check for infarction potentially amenable to thrombolytic treatment

53
Q

What bloods should be done in suspected stroke?

A
FBC
U&amp;Es
Clotting
Lipid profile
Glucose
54
Q

Why is an ECG done in suspected stroke?

A

Check for any potential source of clot

55
Q

Which patients may warrant screening for carotid artery disease?

A

Those who have had TIA or stroke, to look for disease precipitating the presentation
Asymptomatic patients with risk factors
Symptomatic patients who may warrant prophylactic surgical intervention

56
Q

How the carotid arteries be screened for disease precipitating stroke/TIA?

A

Duplex ultrasound scans

57
Q

What is the use of Duplex ultrasound scans in carotid artery disease?

A

They give a good estimate of the degree of stenosis, and exclude any other possible differentials

58
Q

Why are Duplex ultrasound scans good for screening asymptomatic patients for carotid artery disease?

A

It is cheap, non-invasive, and readily available

59
Q

How should lesions found within the carotid artery be further investigated?

A

CT angiography

60
Q

What is the use of CT angiography in carotid artery disease?

A

It gives a more accurate percentage stenosis, and characterises the diseased portion of the vessels for potential surgery if the USS scan shows a greater than 50% stenosis

61
Q

What initial management should all patients admitted with suspected stroke receive?

A

Start on high flow oxygen

Optimise blood glucose (4-11mmol/L)

62
Q

When should a swallowing screen assessment be made in suspected stroke?

A

On admission

63
Q

What does the initial management of stroke depend on?

A

The nature of the stroke

64
Q

How is an ischaemic stroke initially managed?

A

IV alteplase (r-tPA), if patients are admitted within 4.5 hours of symptom onset and meet the inclusion criteria

65
Q

What medication should be started as an inpatient in ischaemic stroke?

A

300mg aspirin OD

66
Q

How long should 300mg aspirin OD be given after ischaemic stroke?

A

14 days

67
Q

How is a haemorrhagic stroke initially managed?

A

Referral to neurosurgery for potential clot evacuation

Correction of any coagulopathy

68
Q

Is neurosurgery always advised for haemorrhagic stroke?

A

No, neurosurgery is often not advised for haemorrhagic stroke, unless superficial lobar bleed or ventricular bleed

69
Q

What should all patients with a known stroke or TIA be started on?

A

Cardiovascular risk factor management

70
Q

What is involved in cardiovascular risk factor management?

A

Long-term anti-platelet therapy
Statin therapy
Aggressive management of any hypertension and/or diabetes mellitus
Smoking cessation

71
Q

What anti-platelet therapy is typically used following a stroke or TIA?

A

Aspirin 300mg OD for 2 weeks, then clopidogrel 75mg OD

72
Q

What can be used if clopidogrel is not tolerated as anti-platelet therapy following stroke/TIA?

A

Trial combination therapy aspirin and dipyradimole

73
Q

What statin therapy is ideally used following stroke/TIA?

A

Atorvastatin 80mg OD

74
Q

When should patients with carotid artery disease be referred for surgical revascularisation?

A

Symptomatic carotid artery stenosis >50%

75
Q

How quickly should revascularisation be performed in a symptomatic patient?

A

As soon as possible, with current targets within 2 weeks for patients with stabilised neurology and fit for surgical intervention

76
Q

Are patients with asymptomatic carotid artery stenosis of >70% surgically treated?

A

Very rarely, unless they are young and have had symptomatic contralateral stenosis

77
Q

What is advised for any dysphagia or dysphasia following stroke?

A

Referral to Speech and Language Therapy (SALT) team

78
Q

What is advised for any ongoing mobility issues following stroke?

A

Physiotherapy and Occupational Therapy input

79
Q

What do many stroke patients require for their long term recovery?

A

Rehabilitation

80
Q

What is the mainstay of surgical treatment for ischaemic stroke prevention?

A

Carotid endarterectomy (CEA)

81
Q

What does CEA involve?

A

Removing the atheroma and associated damaged intima, thereby reducing the risk of future strokes or TIAs

82
Q

Why is CEA a superior option to carotid stenting?

A

Carotid stenting is associated with an early and sustained 55% increased hazard for long-term major adverse effects

83
Q

How is a CEA performed?

A

The artery is isolated and clamped, before an arteriotomy is created and often a temporary bypass shunt placed for the duration of the procedure. The plaque and diseased intima are carefully dissected from within the artery. The arteriotomy is closed with a patch graft.

84
Q

When is shunting especially important in a a carotid endartectomy?

A

For any contralateral occlusive disease to minimise any cerebral hypoperfusion

85
Q

Why does careful attention need to be paid when dissecting the plaque and diseased intima from within the artery in a carotid endartectomy?

A

As to not create any free edge that could result in dissection

86
Q

Why is the arteriotomy closed with a patch graft in carotid endartectomy?

A

To prevent iatrogenic stenosis, and reduce the risk of re-stenosis

87
Q

What are the main risks of CEA surgery?

A
Stroke 
Nerve damage 
Myocardial infarction
Local bleeding
Infection
88
Q

What nerves can be damaged in a carotid endartectomy?

A

Hypoglossal
Glossopharyngeal
Vagus nerve

89
Q

What is the mortality of a stroke at 7 days?

A

12%

90
Q

What is the mortality of stroke at 30 days?

A

19%

91
Q

When does the most significant improvement from rehabilitation occur?

A

Between 4-6 weeks

92
Q

What % of stroke survivors remain dependant at 1 year?

A

50%

93
Q

In which patients is the rate of dependancy 1 year post stroke significantly lower in?

A

Patients who are fit for carotid endarterectomy

94
Q

What are the complications of stroke?

A
Dysphagia
Seizures
Ongoing spasticity
Bladder or bowel incontinence
Depression and anxiety
Cognitive decline