Ischaemic Stroke Flashcards
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What is an Ischaemic Stroke?
- Most common type of stroke where oxygen cant get to the brain due to a clot that blocks blood flow
- They’re characterised by rapidly developing signs of focal or global disturbance of cerebral function lasting more than 24 hours or leading to death
- These clots tend to happen in areas of plaque (atherosclerosis)
- Arteries narrow naturally as you age but aren’t a cause outright
Causes of Ischaemic Stroke
- Acute ischaemic strokes are usually caused be thrombotic or embolic occlusion of a cerebral artery
- Can also be haemorrhagic in nature
Pathophysiology of Ischaemic Stroke
- Caused by atherosclerosis which narrows the narrow.
- The plaque breaks off which causes an inflammatory response causing platelets to collect at the site
- This creates a block at the already narrowed artery, stopping blood flow to the brain
- Makes up 90% of all strokes
Pathophysiology of Haemorrhagic Stroke
- Blood vessels or an artery in the brain breaks open, causing a leakage of blood into the brain, stopping the delivery of oxygen and nutrients
- Also called a cerebral haemorrhage
- The build up of blood can also increase the cerebral pressure, causing swelling to the brain, further damaging the brain cells and tissues
Sub-Arachnoid Pathophysiology
- Haemorrhage from a cerebral blood vessel, aneurysm or vascular malformation into the subarachnoid space
- The presentation differs. Typically; sudden onset of severe headache/vomiting and with non-focal neurological signs that may include loss of consciousness and neck stiffness
Signs and Symptoms
- FAST symptoms
- One-sided paralysis/numbness
- Sudden loss/blurred vision (visual disturbances)
- Nausea/vomiting
- Confusion
- Loss of coordination/ balance/change in gait
- Difficulty swallowing (dysphagia)
- Difficulty expressing yourself (dysphasia
- Sudden severe headache
- Dizziness/Fainting/LOC
- Acute onset of neck pain or stiffness
TIA; Definition, Treatment and Non-Conveyance
- Definition - an acute loss of focal cerebral or ocular function with symptoms lasting less than 24 hours
- TIAs mean the pt is at a very high risk of a stoke and need urgent follow ups and investigations
- Even if almost all symptoms have gone, must treat as ongoing stroke
- Follow local guidelines of referral, aspirin administration if not conveyed to hospital
Possible Primary Survey; Ischaemic Stroke
- Obvious one sided paralysis
- Altered GCS
- LOC
- Possible A/B problem
History for Stroke
- What was she doing at the time? was it a sudden onset?
- New headache?
- Any recent falls or head injuries?
- Explore other assc symptoms; nausea, photophobia, visual disturbances, dizziness, confusion, loss of coordination, fainting/LOC
BE FAST Assessment
B - balance, loss of coordination
E - eyes, nystagmus, field of vision loss
F - ask pt to smile, looking for asymmetry
A - pronator drift, test for equal strength
S - ‘you can’t teach an old dog new tricks’
T - note time of onset, 20 mins on scene
What Counts as ‘Speech’ in Speech Assessment
- Naming items
- Jumbled words
- Lack of speech
- Reading
- Writing
PMH/SH/FH/DHx
- Previous TIA’s
- Allergies
- Recent surgeries or head injuries/brain trauma
- Any cardiovascular meds eg anticoags/antiplatelets
- Any FH of strokes
- Alcohol/smoking?
Risk Factors for Ischaemic Stroke
- Smoking
- High cholesterol
- High BP
- Lack of exercise
- Poor diet
- FH
ACHICE in Stroke
Important to put time of onset in ACHICE
Potential Drugs in Ischaemic Stroke
IV Fluids - if less than 90
Glucose 10%
Glucagon if not resolved
Aspirin - only given with suspected diagnosis or in the presence of ECG changes
