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Flashcards in cerebral infarction (clinical) Deck (29)
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1
Q

what is a stroke defined as?

A

sudden onset of focal or global neurological symptoms caused by ischaemia or haemorrhage and lasting more than 24 hours

2
Q

what percentage of strokes are ischaemic?

A

about 85%

3
Q

what differentiates a transient ischaemic attack from a stroke?

A

symptoms resolve within 24 hours

most TIAs resolve within 1-60mins

4
Q

what is the most common cause of ischaemic stroke?

A

large artery atherosclerosis

5
Q

what is the most common cause of haemorrhagic stroke?

A

primary intracerebral haemorrhage

6
Q

what does prolonged hypoxia lead to?

A

anoxia

7
Q

what does anoxia lead to?

A

infarction (complete cell death, which leads to necrosis)

8
Q

what can cause further damage in a stroke patient?

A

edema depending on the size and location of the stroke

secondary haemorrhage into the stroke

9
Q

what are some non modifiable risk factors for stroke?

A

previous stroke
being old
being male
having a horrible family history

10
Q

what is the effect of diabetes on the chances of having a stroke?

A

increases the incidence of stroke up to 3 fold in both sexes

11
Q

what is the effect of smoking on the chances of having a stroke?

A

2 fold increased risk of cerebral infarction

3 fold risk of sub arachnoid haemorrhage

12
Q

what is the effect of increased serum lipids?

A

increase stroke risk due to blood vessel wall atheroma

13
Q

what does increased plasma level of LDL result in?

A

excessive amounts of LDL within the arterial wall

14
Q

what is the effect of alcohol on stroke risk?

A

small amounts of alcohol decrease stroke risk

heavy drinking increases the chances of having a stroke 2.5 times

15
Q

what comprises the anterior arterial supply to the brain

A

2 anterior cerebral arteries

2 middle cerebral arteries

16
Q

what comprises the posterior arterial supply to the brain?

A

2 vertebral arteries
3 pairs of cerebellar arteries
2 posterior cerebral arteries

17
Q

where are borderzone anastomoses located?

A

between the peripheral branches of the anterior, middle and posterior cerebral arteries

18
Q

what are some symptoms of anterior cerebral artery occlusion?

A

contra lateral-
paralysis of the foot and leg
sensory loss over foot and leg
impairment of gait and stance

19
Q

what are some symptoms of middle cerebral artery occlusion?

A

contra lateral:
paralysis of face/arm/leg
sensory loss face/arm/leg
homonymous hemianopia
gaze paralysis to opposite side
aphasia if stroke is on the dominant side
unilateral neglect and agnosia for half of the external space if non dominant stroke

20
Q

what are some symptoms of right hemisphere damage?

A

left hemiplegia
homonymous hemaniopia
agnosias (neglect syndromes)

21
Q

what are 4 types of agnosias?

A

visual agnosia
sensory agnosia
anosagnosia (denial of hemiplegia)
prosopagnosia (failure to recognise faces)

22
Q

what structures are involved in a stroke affecting the posterior circulation of the brain?

A

brainstem
cerebellum
thalamus
occiptal and medial temporal lobes

23
Q

what should acute ischaemic stroke therapies aim to do?

A

restore blood supply
prevent extension of ischaemic damage
protect vulnerable brain tissue

24
Q

what is the criteria for tissue plasminogen activator use

A

less than 4.5 hours from symptom onset
disabling neurological deficit
symptoms present for more than 60 minutes
consent obtained

25
Q

what is the exclusion criteria for IV TPA?

A

anything that increases the possibility of haemorrhage
BP > 185 systolic or ?110 diastolic
glucose <2.8 or ?22mmol/L

26
Q

what can increase the possibility of haemorrhage?

A

blood on CT scan
recent surgery
recent episodes of bleeding
coagulation problems

27
Q

what is an effective treatment for symptomatic internal carotid artery stenosis?

A

carotid endarterectomy

28
Q

what investigations are appropriate for stroke?

A
routine blood tests
CT or MRI head
ECG
echo
carotid doppler
cerebral angiogram
hyper coagulable blood screen
29
Q

what are some common secondary prevention medications for stroke?

A
anti hypertensives
anti platelets
lipid lowering agents
warfarin for AF
carotid endarterectomy