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September lectures yr 3 (2018) > Stroke: clinical diagnosis and classification > Flashcards

Stroke: clinical diagnosis and classification Flashcards

1
Q

Define stroke:

A

neurological deficit:

  • sudden onset
  • focal
  • presumed to be of non-traumatic vascular origin
  • lasts for >24 hours
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2
Q

What are the 2 main types of strokes?

A

Cerebral infarct - 81%

Intracerebral haemorrhage

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3
Q

What are the characteristics of a cerebral infarct?

A

Occluded blood vessel

  • Mean (norm) cerebral blood flow= 50ml/100g/min - electrical failure occurs at 20-10ml/100g/min
  • metabolic failure at <10ml/100g/min
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4
Q

Define penumbra

A

area surrounding an ischaemic event

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5
Q

What are some example mechanisms of cerebral infarcts?

A 
large artery disease
cardioembolic stroke
small artery disease (lacunar) 
cryptogenic strokes - cerebral ischaemia of unknown or obscure origin 
others: endocarditis, vasculitis
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6
Q

What is the commonest cause of young stroke?

A

carotid dissection

  • minor trauma to the neck can cause it
  • Classic triad (2 out of 3)
    1) unilateral pain (face, neck, head)
    2) horner’s syndrome
    3) anterior circulation stroke or TIA
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7
Q

What is a cardioembolism?

A

blood clot forms in the heart and embolises to the brain- can be caused by atrial fibrillation

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8
Q

What are lacunar infarcts?

A

occlusion of small perforator arteries
involves deep white matter and brainstem
RF: hypertension, diabetes and hyperlipidaemia

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9
Q

What do infarcts look like on CT?

A

Dark - low attenuation

  • loss of grey and white matter differentiation
  • sulcal effacement - mass effect on brain parenchyma can push gyri together therefore displacing the csf between sulci

Can be difficult to see the infarct early on but by doing multiple scans it can be useful in timing when the stroke occurred

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10
Q

What are the 2 mechanisms of non traumatic ICH?

A

Primary- 78-88%

  • chronic hypertension
  • amyloid angiopathy

Secondary ICH

  • vascular abnormalities - ateriovenous malformation, aneurysm
  • tumour
  • impaired coagulation
  • vasculitis
  • drug induced - e.g. warfarin
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11
Q

What does an ICH appear like on a CT scan ?

A

Appears bright - high attenuation - obvious straight away
Becomes isodense after a few days due to Hb breakdown
Often surrounded by low attenuation due to oedema/ischaemic necrosis

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12
Q

When do extradural haemorrhages usually occur?

A

after head trauma

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13
Q

What are the roles of the frontal lobe?

A

Consciousness, wakefulness, self-control, language production (Broca’s area), eye movement, body movement (motor cortex)

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14
Q

What are the roles of the parietal lobe?

A

Sensation, spatial orientation, calculation

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15
Q

What are the roles of the temporal lobe?

A

speech (language comprehension- Wernicke’s area), smell, hearing, memory

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16
Q

What are the roles of the occipital lobe?

A

vision

17
Q

What are the roles of the brainstem?

A

eye movements, pupil reflexes, swallowing, balance, breathing, consciousness

18
Q

What are the roles of the cerebellum?

A

balance, coordination

19
Q

What are the arteries in the neck that supply the brain?

A

x2 internal carotid arteries
x2 vertebral arteries (also supply the spinal cord)
Due to the circle of willis, if you lose one/two of these arteries the brain will still be perfused

20
Q

What are the 3 stroke syndromes?

A

TACS - total anterior circulation stroke / PACS (partial anterior circulation stroke)

POCS - posterior circulation stroke

LACS - lacunar stroke

21
Q

What blood vessels are affected in thrombotic occlusion of TACS and what are the common mechanisms?

A

85% thrombotic occlusion of ACA, MCA or ICA
Mechanisms:
- large vessel disease e.g. atherosclerosis /dissection
- cardioembolic

22
Q

What blood vessels are affected in a cortical ICH of TACS origin and what are the common mechanisms?

A

15% cortical ICH ACA or MCA territory
Mechanisms:
- secondary ICH - vascular malformation, tumour
- primary ICH- amyloid angiopathy

23
Q

What are the clinical features of an anterior circulation stroke?

A

1) Contralateral UMN hemiparesis and/or hemisensory loss
2) Higher mental function problems - dominant left cortex (dysphasia), non dominant R cortex (apraxia, inattention)
3) Hemianopia - blindness over half of the visual field

TACS = 3/3
PACS = 2/3
24
Q

What usually causes lacunar syndrome?

A

95% infarction in pons and basal ganglia - mostly small vessel disease
Affect anterior or posterior circulation
5% deep (subcortical) haemorrhage- mostly PICH due to hypertension

25
Q

What are the clinical features of lacunar syndrome?

A

Contralateral UMN hemiplegia
Contralateral hemisensory loss
Contralateral upgoing plantar
NO cortical problems- hemianopia, dysphasia, apraxia, neglect

26
Q

What are the 2 types of posterior circulation syndromes?

A

85% vertebrobasilar territory occlusion
-Mechanism : large vessel disease, cardiodembolic

15% brainstem haemorrhage
-Mechanism: primary or secondary ICH but NOT amyloid angiopathy

27
Q

What are the clinical features of a posterior circulation stroke?

A

dizziness, vertigo, diplopia, dysphagia, ataxia, cranial nerve palsies, and uni/bilateral limb weakness
HALLMARK: cross neurological deficits- ipsilateral cranial nerve deficits with contralateral motor weakness and upgoing plantar

28
Q

What are some examples of posterior circulation syndrome?

A

brainstem stroke syndrome
PCA stroke
Cerebellar stroke
Basilar artery thrombosis

29
Q

What are the 3 types of midbrain strokes?

A

1) weber - ipsilateral 3rd contraplegia
2) claude - contra rubral trmor
3) benedikt - ipsilateral contraplehia and rubral tremor

30
Q

What are the 3 types of pons strokes?

A

1) marie-fox syndrome - ipsilateral ataxia, contralateral plagia and spinothalamic
2) raymond syndrome - ipsilateral 6th contraplegia
3) milard-gubler syndrome - ipsilateral 6, 7th and contraplegia

31
Q

What are the 2 types of medulla strokes?

A

1) dejerine = ipsilateral 12th, contraplegi and dorsal column
2) wallenberg - ipsilateral 5, 8, 9, 10, horner’s, ataxia, contralateral spinothalamic

32
Q

What types of stroke are often unrecognised by the pt?

A

PCA infarct or occipital haemorrhage

- contralateral homonymous visual field defect

33
Q

What are the clinical features of a cerebellar stroke (infarction or haemorrhage)?

A

nausea, vomiting, loss of balance, vertigo, headaches, ipsilateral ataxia, intention tremor, heel shin incoordination, nystagmus, dysarthia, risk of obstructive hydrocephalus (because cerebellum is close to the 4th ventricle) and coma

34
Q

What are the clinical features of a basilar artery thrombosis ?

A 
bi/unilateral cranial nerve palsies
severe quadraplegia
bilateral upgoing plantar 
coma
respiratory arrest 
locked-in syndrome-complete muscle paralysis except for upward gaze
35
Q

What is a TIA?

A

Temp stroke syndrome <24 hours that resolves spontaneously

mainly due to ischaemia

36
Q

What is a amaurosis fugax?

A

retinal artery TIA - norm caused by large vessel disease
transient monocular blindness 1-5mins - abrupt or peaking severity <5mins
moves from periphery towards centre- partial or complete
visual disturbance- dark, foggy, gray, white
painless
usually occurs in isolation

37
Q

What do TIAs almost NEVER cause?

A

global symptoms - syncope, blackout, general feelings of dizziness
migrainous symptoms - headache or visual disturbance
Burning or painful sensation in the limbs
recurrent falls
seizure like symptoms that develop over mins/horus
daily symptoms

38
Q

What are the neurological deficits in vascular vs mimic?

A

Stroke:

  • sudden onset
  • Negative symptoms - take away functions
  • definite focal symptoms or able to lateralise signs
  • presence of neurological signs
  • OCSP subclassification possible

Mimic:

  • gradual onset symptoms
  • positive symptoms
  • nonfocal/nonspecific symptoms or cognitive impairment
  • abnormal signs in non-neurological systems
  • prior history of unexplained transient neurologic attack

September lectures yr 3 (2018) (56 decks)

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