Stroke Flashcards
What is the definition of stroke?
- Neurological deficit of sudden onset lasting for more than 24 hours
- Vascular origin
What does TIA stand for?
- Transient ischaemic attack
What is a TIA?
- A stroke resulting in a neurological deficit of less than 24 hours
What are the 4 subtypes of stroke?
- TACS
- PACS
- LACS
- POCS
What does TACS stand for?
- Total anterior circulation stroke
What percentage of strokes are TACS?
- 20%
What is the mortality of TACS?
- The worst of the 4
What does PACS stand for?
- Partial anterior circulation stroke
What percentage of strokes are PACS?
- 35%
What does LACS stand for?
- Lacunar stroke
What percentage of strokes are LACS?
- 20%
What does POCS stand for?
- Posterior circulation stroke
What percentage of strokes are POCS?
- 25%
What is special about POCS?
- Highest recurrence rate
What do the symptoms of stroke depend on?
- The area of the brain affected
What are the 5 things that can be lost due to a stroke?
- Power
- Sensation
- Speech
- Vision
- Coordination
How can power be lost?
- Loss of motor control
- Clumsiness
- Weak limb
How can sensation be lost?
- Loss of feeling in areas of the body
What 2 ways can throat function be affected?
- Dysarthria (slurred speech)
- Dysphagia
What ways can visual function be affected?
- Visuospatial problems
- One eye affected
- Hemianopia
- Gaze palsy
What is hemianopia?
- Blindness over half the field of vision
What is gaze palsy?
- Inability to move the eyes in the same direction of motion
What 4 conditions can coordination be affected due to?
- Ataxia
- Vertigo
- Incoordination
- Nystagmus
What is ataxia?
- Loss of voluntary function
What is nystagmus?
Constant uncontrolled eye movements
What modifiable risk factors are there for stroke?
- Hypertension
- AF (loss of adequate blood flow to the brain)
What are the non modifiable risk factors for strokes?
- Age
- Race
- Family history
What is the cause of stroke?
- Damage to part of the brain due to blockage of a blood vessel by thrombus or embolism OR
- Haemorrhage from a ruptured blood vessel
What percentage of strokes are caused by infarction?
- 85%
What are the 5 ways that infarction can occur in vessels in the brain?
- Large artery atherosclerosis
- Cardioembolic stroke
- Small artery occlusion
- Undetermind/cryptogenic
- Rare causes
What percentage of infarcting strokes are caused by large artery atherosclerosis?
- 35%
What large artery is usually the one to cause an infarction due to it having atheromatous plaques and what do these plaques do to the artery?
- Carotid artery
- Cause carotid stenosis which will be heard as a bruit on examination
What is a cardioembolic stroke a result of?
- AF
What percentage of infarcting strokes are cardioembolic strokes?
- 25%
What type of stroke is a result from small artery occlusion?
Lacunar
What percentage of infarcting strokes are from small artery occlusion?
- 25%
What percentage of infarcting strokes are from undetermined/cryptogenic causes?
- 10 - 15%
What rare causes may result in a stroke?
- Aortic dissection
- Venous sinus thrombosis
What percentage of strokes are from haemorrhage?
- 15%
What is the main cause of haemorrhagic stroke?
- Primary intracerebral haemorrhage
What is a primary intracerebral haemorrhage?
- A bleed in the brain tissue
What pathologies can cause a primary intracerebral haemorrhage?
- Brain trauma
- Aneurysm
- Tumours
What type of haemorrhages account for the other 30% of haemorrhagic stroke?
- Subarachnoid
- Arteriovenous malformations
What initial tests should be carried out on presentation of a suspected stroke?
- Blood tests
- ECG
- CT scan
- MRI
- Carotid doppler
- Echocardiogram
What blood tests should be carried out?
- FBC (platelets and RBC’s)
- Lipid count
- ESR
What is the benefit of a CT scan?
- Quick
- Shows the area of the infarct
What are the benefits of an MRI?
- Better for ischaemic stroke diagnosis
What are the detriments of MRI?
- Takes longer
- Claustrophobic
Why is an echocardiogram used in stroke diagnosis?
- Look for clots in the heart
What unit should the patient be referred to after diagnosis?
- Stroke unit
What things should be done in the stroke unit?
- Mobility
- Concentrate on simple things for the patient such as swallowing and positioning
What treatment should be performed in the stroke unit?
- Anti coagulation
What initial treatment should be done to reduce effects of a stroke?
- THROMBOLYSIS
- Clot retrieval using minimally invasive surgery
What is the aim of thrombolysis?
- Restore perfusion before cell death occurs
What drugs are used in thrombolysis?
- Alteplase
- Reteplase
- Tenecteplase
What type of drug are all alteplase, reteplase and tenecteplase?
- Tissue plasminogen activators
What do tissue plasminogen activators do?
Convert plasminogen to plasmin to break down clot
At what time do risks of thrombolysis outweigh the benefits?
- Around 4.5 hours after event
How is minimally invasive clot retrieval surgery performed?
- Catherter with a retrieval device on the end
What is the typical history of presenting complaint of a stroke?
- Headache
- Vomiting
- Neck stiffness
- Photophobia
- Loss of consciousness
- Fit
- Incontinence
What does photophobia suggest?
- The stroke is haemorrhagic
What does post thrombolysis haemorrhage risk depend on?
- Infarct size
- Vessel occlusion
- Diabetes
- BP
- Age
