Cerebral Infarction

Question 1

define stroke

Answer 1

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

Question 2

what are the three most common causes of ischaemic stroke?

Answer 2

> large artery thrombosis
cardioembolic
small artery occlusion

Question 3

what can cause haemorrhagic stroke?

Answer 3

> primary intracerebral haemorrhage

> secondary intracerebral haemorrhage: subarachnoid, arteriovenous malformation)

Question 4

describe the ridiculously simple pathophysiology of ischaemia

Answer 4

> failure of cerebral blood flow to part of the brain
results in varying degree of hypoxia
hypoxia stresses brain metabolism and if its prolonged = anoxia
anoxia leads to infarction

Question 5

what can further damage result form after infarction in a stroke?

Answer 5

> oedema (dependent on size and location)

> secondary haemorrhage

Question 6

what is ischaemic penumbra?

Answer 6

area surrounding ischaemic event which will have reduced blood flow. ischaemic core will die no matter what you d but the penumbra could be saved?

Question 7

name some non-modifiable risk factors for stroke?

Answer 7

> previous stroke
being old
being male
family history

Question 8

what is the most important modifiable risk factors for stroke?

Answer 8

hypertension

Question 9

why is hypertension a risk factor in stroke?

Answer 9

> chronic worsens atheroma (virchows) and affects small arteries
majority of hypertension is poorly managed

Question 10

what is small artery lipohyalinosis?

Answer 10

hypertrophy of the blood vessel wall and resultant lumen diameter loss in small arteries

Question 11

by how much does diabetes mellitus increase stroke risk?

Answer 11

3 fold

Question 12

what is the increased risk of cerebral infarction in smokers?

Answer 12

2 fold increase

Question 13

what is the affect of lipids on stroke risk?

Answer 13

increased serum lipids increase vessel wall atheroma as in creased plasma levels of low density lipoprotein results in excessive amounts of LDL within the arterial wall

Question 14

what are some modifiable risk factors?

Answer 14

> alcohol
> obesity
> inactivity
> impaired cardiac function
> oral contraceptives with high estrogen content
> hypercoagulable states

Question 15

where are border zone anastomoses?

Answer 15

between peripheral braches of anterior, middle and posterior cerebral arteries

Question 16

name some symptoms of anterior cerebral artery occlusion

Answer 16

Contra-lateral:
> paralysis of foot and leg
> sensory loss over foot and leg
> impairment of gait and stance

Question 17

what are symptoms of middle cerebral artery occlusion dominant side?

Answer 17

> contralateral:
- paralysis of face/arm/leg
- sensory loss face/arm/leg
- homonymous hemianopia
> gaze paralysis to the opposite side
> aphasia on dominant side
> dysphasia

Question 18

what can an ophthalmic artery blockage be?

Answer 18

a warning stroke.

often a curtain coming down over the vision

Question 19

describe the symptoms of a middle cerebral artery occlusion on non-dominant hemisphere

Answer 19

> contralateral hemiplegia
> homonymous hemianopia
> agnosia: neglect symptoms:
- visual agnosia
- sensory agnosia
-anosagnosia 
- prosopagnosia

Question 20

what is anosagnosia?

Answer 20

denial of hemiplegia

Question 21

what is prosopagnosia?

Answer 21

failure to recognise faces

Question 22

what sort of stroke affects the basal ganglia?

Answer 22

lacunar stroke

Question 23

name lacunar stroke syndromes

Answer 23

> pure motor stroke
pure sensory stroke
dysarthria- clumsy hand syndrome
ataxic hemiparesis

Question 24

what stroke is devoid of cortical signs

Answer 24

lacunar strokes

Question 25

what does the posterior circulation of the brain supply?

Answer 25

> brain stem > cerebellum > thalamus > occipital and medial temporal lobes

Question 26

what are some symptoms of brainstem dysfunction?

Answer 26

``` > coma > vertigo > nausea and vomiting > cranial nerve palsies > ataxia > hemiparesis > hemisensory loss > crossed sensori-motor deficits > visual field deficits ```

Question 27

what should ischaemic stroke therapies do?

Answer 27

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

Question 28

who works on a stroke unit?

Answer 28

``` > nurses > physiotherapists > speech and language therapists > OT's > dietician > psychologists > orthoptist ```

Question 29

name 4 classifications of stroke

Answer 29

> total anterior circulation stroke > partial anterior circulation stroke > lacunar stroke > posterior circulation stroke

Question 30

what stroke classification will have brainstem signs?

Answer 30

posterior circulation stroke

Question 31

what stroke must have hemianopia?

Answer 31

lacunar stroke

Question 32

what stroke type will most likely have death or dependence at 6 months?

Answer 32

total anterior stroke

Question 33

what is the criteria for TPA use?

Answer 33

> < 4.5 hour symptom onset > disabling neurological deficit > symptoms present >60 minutes > consent obtained

Question 34

what would exclude IV TPA use?

Answer 34

``` > anything increasing possibility of haemorrhage - blood on CT - recent surgery - recent bleeding episode - coagulation problems > BP >185 systolic or >110 diastolic > glucose <2.8 or >22mmol/L ```

Question 35

what is a warning sign of stroke?

Answer 35

TIA

Question 36

what is a treatment for symptomatic internal carotid artery stenosis?

Answer 36

carotid endarterectomy

Question 37

what are the investigations for stroke?

Answer 37

``` > routine blood tests > CT/MRI head scan > ECG > ECHO > carotid Doppler ultrasound (stenosis) > cerebral angiogram > hypercoagulable blood screen ```

Question 38

what is the secondary prevention for stroke?

Answer 38

``` > antihypertensives > antiplatelets > lipid lowering agents > warfarin for AF > carotid endarctectomy ```