Stroke: clinical diagnosis and classification

Question 1

Define stroke:

Answer 1

neurological deficit:

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

Question 2

What are the 2 main types of strokes?

Answer 2

Cerebral infarct - 81%

Intracerebral haemorrhage

Question 3

What are the characteristics of a cerebral infarct?

Answer 3

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

Question 4

Define penumbra

Answer 4

area surrounding an ischaemic event

Question 5

What are some example mechanisms of cerebral infarcts?

Answer 5

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

Question 6

What is the commonest cause of young stroke?

Answer 6

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

Question 7

What is a cardioembolism?

Answer 7

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

Question 8

What are lacunar infarcts?

Answer 8

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

Question 9

What do infarcts look like on CT?

Answer 9

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

Question 10

What are the 2 mechanisms of non traumatic ICH?

Answer 10

Primary- 78-88%

• chronic hypertension
• amyloid angiopathy

Secondary ICH

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

Question 11

What does an ICH appear like on a CT scan ?

Answer 11

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

Question 12

When do extradural haemorrhages usually occur?

Answer 12

after head trauma

Question 13

What are the roles of the frontal lobe?

Answer 13

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

Question 14

What are the roles of the parietal lobe?

Answer 14

Sensation, spatial orientation, calculation

Question 15

What are the roles of the temporal lobe?

Answer 15

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

Question 16

What are the roles of the occipital lobe?

Answer 16

vision

Question 17

What are the roles of the brainstem?

Answer 17

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

Question 18

What are the roles of the cerebellum?

Answer 18

balance, coordination

Question 19

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

Answer 19

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

Question 20

What are the 3 stroke syndromes?

Answer 20

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

POCS - posterior circulation stroke

LACS - lacunar stroke

Question 21

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

Answer 21

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

Question 22

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

Answer 22

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

Question 23

What are the clinical features of an anterior circulation stroke?

Answer 23

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

Question 24

What usually causes lacunar syndrome?

Answer 24

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

Question 25

What are the clinical features of lacunar syndrome?

Answer 25

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

Question 26

What are the 2 types of posterior circulation syndromes?

Answer 26

85% vertebrobasilar territory occlusion -Mechanism : large vessel disease, cardiodembolic 15% brainstem haemorrhage -Mechanism: primary or secondary ICH but NOT amyloid angiopathy

Question 27

What are the clinical features of a posterior circulation stroke?

Answer 27

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

Question 28

What are some examples of posterior circulation syndrome?

Answer 28

brainstem stroke syndrome PCA stroke Cerebellar stroke Basilar artery thrombosis

Question 29

What are the 3 types of midbrain strokes?

Answer 29

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

Question 30

What are the 3 types of pons strokes?

Answer 30

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

Question 31

What are the 2 types of medulla strokes?

Answer 31

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

Question 32

What types of stroke are often unrecognised by the pt?

Answer 32

PCA infarct or occipital haemorrhage | - contralateral homonymous visual field defect

Question 33

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

Answer 33

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

Question 34

What are the clinical features of a basilar artery thrombosis ?

Answer 34

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

Question 35

What is a TIA?

Answer 35

Temp stroke syndrome <24 hours that resolves spontaneously | mainly due to ischaemia

Question 36

What is a amaurosis fugax?

Answer 36

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

Question 37

What do TIAs almost NEVER cause?

Answer 37

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

Question 38

What are the neurological deficits in vascular vs mimic?

Answer 38

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