stroke

Question 1

stroke

Answer 1

sudden loss of blood circulation to an area of the brain, resulting in a corresponding loss of neurological function

Question 2

ischaemic stroke

Answer 2

85%

ischaemia: decreased arterial blood flow or venous outflow from a tissue.
- caused by a platelet thrombosis that develops over a disrupted atherosclerotic plaque, or embolism of clot from another source e.g. heart

Question 3

gross and microscopic findings in stroke

Answer 3

• develops at periphery of the cortex
• reperfusion often does not occur so area of infarct remains pale, called a pale infarct
• swelling of brain occurs, loss of demarcation between grey and white matter, break down of myelin.
• gliosis is the reaction to injury; astrocytes proliferate at the margins of the infarct, macrophages remove liquid debris
• cystic area (spaces) develops after 10 days to 3 weeks due to liquifactive necrosis

Question 4

risk factors of thromboembolic strokes

Answer 4

most strokes associated with atherosclerosis therefore have same risk factors as other atherosclerotic conditions e.g. angina/MI.
hypercoaguable states are also a risk factor, and any other part of Virchow’s Triad (stasis, vessel wall injury and hypercoag)
- risk factors for embolic strokes relate to heart primarily e.g. atrial/ventricular thrombus (increased by AF), vegetations and atrial myxomas

Question 5

lacunar infarcts

Answer 5

• cystic areas of microinfarction less than 1cm in diameter.
• caused by hyaline arteriolosclerosis
• secondary to either hypertension or Diabetes Mellitus

Question 6

symptoms of stroke

Answer 6

• movement and sensation: contralateral hemiparesis/hemiplegia and sensory loss in limbs and trunk and face.
• speech: does speech sound slurred?
• vision: visual field defects
• personality: frontal lobe affected

Question 7

diagnosis of stroke

Answer 7

patient with acute onset of a neurological syndrome with persisting symptoms and signs needs urgent diagnostic assessment to differentiate between acute stroke and other causes needing their own specific treatments.
CT scan without contrast is the best for diagnosis, will distinguish haemorrhage from non haemorrhagic stroke.
MRI also used in equivocal cases, and is useful for identification of posterior fossa infarcts, but only after CT

Question 8

stroke treatment acutely

Answer 8

• depends on type of stroke and elapsed time to arrival at hospital.
• thrombolytic therapy in thromboembolic strokes- utilisation depends on time between initial symptoms and presentation to hospital.
• intra-arterial clot extraction can also be done in patients who thrombolysis is contraindicated in.
• thrombolytics are contraindicated in haemorrhagic strokes
• in some circumstances intracerebral haemorrhages can be surgically evacuated

Question 9

TIAs- Transient Ischaemic Attack- ‘mini stroke’

Answer 9

• transient episode of neurologic dysfunction caused by focal brain/spinal cord or retinal ischaemia without infarction, symptoms lass less than 24h.
  most atherosclerotic strokes are preceded by TIAs.
  Rx: antiplatelet therapy as soon as intracranial haemorrhage is ruled out: aspirin, clopidogrel. possible endarterectomy. treat risk factors and offer lifestyle advice. intention is to prevent future strokes

Question 10

stroke treatment chronically

Answer 10

1) antiplatelet treatment (aspirin, clopidogrel)
2) warfarin (or Xa inhibitor) for embolic type strokes caused by AF
3) treat risk factors for stroke