Lecture 15 - Stroke Flashcards
Describe the epidemiology of stroke.
110,000 per year in UK at a cost of 7 billion.
Variable.
1 in 6 patients die in hospital.
1/2 of survivors need help for activities of daily living.
What is an ischaemic stroke?
85% of strokes are ischaemic.
Due to a blockage that interrupts cerebral blood flow, depleting the brain of oxygen and glucose leading to disrupted ATP synthesis and energy deficiency as well as impaired ion homeostasis and acid-base imbalance.
This leads to neuroinflammation, oedema and neuronal cell death inducing severe neurological deficits.
Blockage can be due to embolisms or thrombus.
What is a hemorrhagic stroke?
15% of strokes are hemorrhagic.
Due to bleeding in the brain by a rupture of a blood vessel or an aneurysm.
High morbidity and mortality.
Severe medical emergency with symptoms that are progressive as bleeding continues.
What can hemorrhagic stroke be subdivided into?
Intracerebral haemorrhage (ICH) - bleeding into the brain parenchyma.
Subarachnoid haemorrhage (SAH) - bleeding into the subarachnoid space.
What are the risk factors of stroke?
Age
Hypertension
Diabetes
Obesity
Smoking
Head trauma (hemorrhagic)
Overtreatment with anticoagulants
Blood clots originating from the heart and travelling to the brain (cardiac embolism)
What scans are used to idenitfy strokes?
CT and MRI
Can determine if the stroke ischaemic or hemorrhagic.
CT sensitive to detecting intracranial bleeds as iron in the blood readily absorbs the X-Rays and shows up as bright white.
Ischaemic stroke the infarct appears as dark on CT as the lesion contains more water.
Describe emergency treatment for strokes.
Important to get treatment quickly to confirm stroke is the problem.
FAST - face, arms, speech, time.
CT and MRI scans to confirm if it is a stroke and what kind.
Why is it important to seek medical treatment as soon as symptoms start for strokes?
Reduces brain damage and other complications.
Once neurons die that is it, they cannot recover so very important to prevent this to in turn prevent neurological deficits.
What are some stroke mimics?
Seizures
Syncope
Hypoglycaemia
Sepsis
Severe migraine
Space occupying lesions such as brain tumours.
What are the main treatments for ischaemic stroke?
Thrombolytic therapy - giving tPA by IV to break up the clot that blocks blood flow to the brain, best given within 4 hours of onset.
Aspirin and other medications to break up clots.
Catheter embolectomy - done if drugs do not adequately break up the clot and if the stroke is acute to one area. Catheter inserted to access the clot and remove it manually.
Angioplasty and stents - catheter threaded up to the carotid arteries, balloon inflated to open up the vessel and a stent inserted to support it.
Carotid endarterectomy - removal of plaque blocking carotid arteries, reducing the risk of stroke.
What are the main treatments for hemorrhagic stroke?
IV blood pressure lowering drugs given to prevent expansion of the haematoma.
If patient takes blood thinners treatment given to counteract these effects to prevent haematoma expansion.
If area of bleeding is large emergency surgery to remove the blood and relieve pressure on the brain.
What advancements have been made in the diagnostics of stroke?
Screening tool for stroke using artificial neural network - screening tool used to recognise acute cerebral ischaemia and differentiate it from stroke mimics in an emergency setting.
Blood biomarkers for different stroke types - GFAP (glial fibrillary acidic protein) high in hemorrhagic strokes. Ischaemic strokes show high D-dimer and low GFAP.
What is rapid assay diagnostic for acute stroke recognition?
RADAR
Supports the identification of LVO stroke and haemorrhage.
LVOne finger prick test consists of 2 lateral flow assays read in 12 mins and is sensitive for D dimer and GFAP.
