Stroke & TIA Flashcards
How is a stroke clinically diagnosed?
- Sudden onset
- Focal neuro deficit
- Of presumed vascular origin
- Symptoms lasting 24hrs+ or death
- TIA= symptoms less than 24hrs
What are the 2 types of stroke
- Cerebral Haemorrhagic
- Cerebral Infarction/ischaemia
What is the pathophysiology of acute ischaemic stroke?
- Initial reduction in cerebral blood flow
- Cellular necrosis
- Alterations in cellular chemistry caused by ischaemia
Describe cerebral metabolism
- Glucose is the sole substrate for energy metabolism
- Glucose is metabolised by glycolytic sequence & tricarboxylic acid cycle
- Neurons require constant supply of ATP to maintain integrity-cannot be stored
What are causes of ischaemic stroke?
- Thrombosis= large (extra-cranial) & small (intra-cranial) arteries
- Embolism= from heart (cariogenic-AF) & proximal arteries (artery to artery)
Which artery occlusion has the highest mortality/disability rate?
Proximal anterior circulation in ischaemic stroke
How do stents work?
1) Place stent across occlusion-leave for 10mins
2) Reperfuse brain
3) Most cot will lyse neutrally/impove efficacy
4) Withdraw stent with small clot core
What are the causes of a TIA?
- Carotid artery disease/large artery disease
- Cerebral small vessel disease
- Cardiac embolism
What can a TIA mimic?
- Seizures
- Syncope
- Hypoglycaemia
- Migraine
- Acute confusional states
What are signs of an anterior circulatory TIA?
- Amarausis fugax
- Dysphasia
- Apraxia
- Inattention
What are signs of a posterior circulatory TIA?
- Ataxia
- Diploplia
- Vertigo
- Bilateral symptoms
What are signs of either an anterior or posterior circulatory TIA?
- Visual field defects (hemianopia)
- Hemiparesis
- Dysarthria
- Hemisensory loss
How can risk be assessed for stroke/TIA?
- ABCD2 score
- A= Age (above 60=1)
- B=BP (above 140/90=1)
- C=Clinical features (unilateral weakness=2, speech=1)
- D=Diabetes (yes=1)
- D=Duration of symptoms (60+mins=2, -10mins=0)
What is in a polypill?
- Statin
- Aspirin
- Folic acid
- Antihypertensives
What type of surgery is used for secondary vascular prevention?
Carotid endarterectomy