Stroke Flashcards
what is the definition of a stroke?
syndrome of rapid onset cerebral deficit lasting >24 hours
85% of strokes are haemorrhagic - true or false?
false
85% are ischaemic, 15% are haemorrhagic
what condition is associated with 5 fold increase in stroke and what score is used to determine specific patient risk?
AF
CHA2DSVASc score
what score is used to determine bleeding risk in anticoagulation?
HAS-BLED
however, patient would need to fall 300 times for risk of bleeding to outweigh benefit of anticoagulation
what type of stroke is low cholesterol associated with?
haemorrhagic
what are the 2 main causes of ischaemic stroke?
atherosclerosis
cardioembolic
what are the two main causes of cardioembolic ischaemic stroke?
atheroma in internal carotid or aortic arch
embolic from heart due to AF
what are the two kinds of haemorrhagic stroke?
intracerebral
subarachnoid
where are intracerebral bleeds most commonly found?
basal ganglia
what causes primary intracerebral bleeds?
hypertension (deep on MRI)
amyloid angiopathy (lobar on MRI)
what causes secondary intracerebral bleeds?
arteriovenous malformation
aneurysm
tumour
what is most common cause of subarachnoid haemorrhage and where does this occur?
rupture of berry aneurysm
most commonly occurs in internal carotid or vertebro-basilar circulation
what increases the risk of berry aneurysms?
smoking
hypertension
kidney disease
what are the symptoms of berry aneurysm rupture?
severe headache
vomiting
LOC
what does the frontal lobe control?
motor function
higher cognition - thought processing, reasoning, intelligence
what does the parietal lobe control?
sensory function
sensory association
vision - fibres for lower quadrant visual field
what does the temporal lobe control?
language
hearing
vision - fibres for upper quadrant visual field
memory and emotion
association
what does the occipital lobe control?
vision
what does the cerebellum control?
balance
movement
co-ordination
what is the difference between brocas area and wernickes area?
brocas - speech production
wernickes - understanding speech and using correct words
what lobes do the anterior cerebral arteries supply?
frontal and parietal
what lobes do middle cerebral arteries supply?
frontal
parietal
temporal
what lobe does the posterior cerebral arteries supply?
occipital
what does the right side of the brain control?
left side of body creativity music spatial orientation artistic awareness
what does the left side of the brain control?
right side of body spoken language reasoning number skills written language
what is total anterior circulation syndrome?
large stroke affecting a large vessel of the anterior circulation and subsequently many smaller downstream vessels supplying various brain regions
Hence, all functions of anterior circulation (anterior and middle cerebral arteries) disrupted
TACS is the most severe type of stroke - true or false?
true - only 5% of patients alive and independent at 1 year
what are the features of TACS?
hemiplegia involving at least 2 of face, arm and leg +/- hemisensory loss
- middle CA = face and arm
- anterior CA = leg
hemianopia (usually contralateral)
higher cortical dysfunction
how many features are required for diagnosis of TACS?
all
what is partial anterior circulation syndrome?
smaller stroke affecting a smaller vessel of the anterior circulation when compared with TACS
hence, less downstream arteries are affected and not all functions of the anterior circulation (anterior and middle cerebral arteries) are disrupted
what % of patients are alive and independent at 1 year following PACS?
55%
what are the features of PACS?
2 or 3 of TACS features
or isolated cortical dysfunction such as dysphagia
or pure motor / sensory signs less severe than in lacunar syndromes (eg monoparesis)
what is a lacunar infarct?
mildest of strokes affecting the smallest vessels
the deep perforating arteries supply specific areas and infarction results in specific, yet minimal symptoms associated with the posterior or anterior circulations
what % of LACS patients are alive and independent at 1 year?
60%
what are the features of LACS?
pure motor deficit
pure sensory deficit
sensory and motor deficit
ataxic hemiparesis
how many features are required for diagnosis of LACS?
1 feature
*any 2 of face, arm and leg
what specific features cannot be present in order to diagnose LACS?
higher cortical dysfunction
posterior circulation syndrome symptoms
*these are not supplied by deep perforating arteries
what is posterior circulation syndrome?
large stroke affecting the vertebrobasilar vessels and their branches which supply the occipital lobe, brain stem and cerebellum
the vertebrobasilar vessels also contribute greatly to the circle of willis
the symptoms indicate the affected vessel
what % of patients are alive and independent 1 year after POCS?
60%
what are the features of POCS?
cranial nerve palsies
bilateral motor and/or sensory deficits
conjugate eye movement disorders
isolated homonymous hemianopia
cortical blindness
cerebellar deficits without ipsilateral motor / sensory signs
how is a stroke diagnosed?
CT - quickly
if this is normal = MRI
what does an intracranial bleed look like on CT?
acutely (within 3 days) = blood shows up as white
after this, it is broken down and becomes black
what does ischaemia look like on CT?
darker
loss of sulci definition
loss of grey / white matter definition
*dense MCA is really common
what is the acute treatment of ischaemic stroke?
thrombolysis (alteplase - start in 4.5 hours)
antiplatelet (aspirin 300mg - start within 24 hours and continue daily for 2 weeks)
acute treatment for haemorrhagic stroke is less clear cut but what kind of things are often done?
decompressive surgery
surgical intervention - surgical clipping, endovascular techniques
lower BP
what is the long term management of atherosclerotic / carotid ischaemic stroke (white and platelet rich)?
antiplatelet (clopidogrel 75mg - after 2 weeks, aspirin is replaced by this for life)
statin (atorvastatin - start within 48 hours and continue lifelong)
what is the long term management of cardioembolic ischaemic stroke (red and protein rich)?
anticoagulant (warfarin - review after 2 weeks)
statin (atorvastatin - start within 48 hours of stroke symptoms and continue lifelong)
what is long term management of haemorrhagic stroke?
monitor BP closely
what is carotid endarterectomy and when could this be used?
surgical procedure to remove a build up of fatty deposits (plaque) which cause narrowing of carotid artery
used to reduce recurrence of stroke
how is dysphagia managed after a stroke?
initial swallow screen
if abnormal - assessment by speech and language
may need NG tube placement or textured diet and thickened fluids depending on swallow
what must those with acute stroke be screened for risk of on admission and at least weekly thereafter?
malnutrition
