Cerebral Infarction Flashcards
what % of stroke patients will die within a year?
1/3rd
what type of stroke is more common?
- ischaemic
- haemorrhagic
- ischaemic (85%)
what is the definition of a stroke?
the sudden onset of focal or global neurological symptoms caused by disruption of blood supply (ischemia or hemorrhage) and lasting more than 24 hours.
what are the main causes of ischaemic strokes?
atherosclerosis
cardioembolism
small artery occlusion
cryptogenic
what is the most common cause of a haemorrhagic stroke?
primary intracerebral haemorrhage
what percentage of strokes are haemorrhagic ?
15%
is the incidence of the different types of strokes the same over the world?
no
- in asia there is a slightly higher number of haemorrhagic strokes
what are the advantages of CT scans?
cheap
fast
can show bone very well
what are the pros and cons of MRI scans?
pros
- show more detail
- can show soft tissue very well
- very good for ischaemic strokes
- uses no radiation
cons
- takes longer
why is it good to do scans when the diagnosis is unclear?
good to get a diagnosis and to plan the treatment of the patient
how many deaths are there in the UK per year due to stroke?
67,000
state the cascade of ischaemia
- failure of cerebral blood flow
- interruption of blood supply
- can result in hypoxia
- prolonged hypoxia and result in anoxia
- anoxia results in infarction and necrosis
- further damage from oedema
what is ischaemic penumbra ?
the area of damage around the ischaemic core
what are the non modifiable risk factors of stroke?
- age
- male
- family history
- previous stroke
- genetics
what are the modifiable risk factors of stroke?
hypertension smoking cholesterol diet alcohol high BMI diabetes cardiac problems
what does high lipid levels increase the risk of?
Atheroma
what artery supplies the face, mouth and hand of the homunculus ?
middle cerebral artery
what artery supplies the arm, trunk and legs of the homunculus ?
anterior cerebral artery
what artery supplies the brocas area?
middle cerebral artery
what are the symptoms of a MCA occlusion ?
contra-lateral
- paralysis of face,arm,leg
- sensory loss
- homonymous hemianopia
- aphasia if dominant side is affected (left)
what main areas of the brain are affected with a MCA occlusion ?
brocas area
wernickes area
auditory area
sensory and motor areas
with a MCA occlusion which direct do the eyes gaze?
gaze towards the damaged side of the brain
and away from the paralysis
what is visual agnosia ?
when you can see one side of the lecture hall and not the other
what is sensory agnosia ?
when you can only feel one finger when the doctor was touching both sides of your body
what is anosagnosia?
neglect one side of their body
- refuse to believe one of their arms was there
what is prosopagnosia ?
failure to recognise faces
what is a good test to get the patient to do to test for neglect syndrome ?
ask them to draw a clock face and they will draw all the numbers on one side
what occurs during lacunar strokes ?
the small artery branches off the middle cerebral artery have a much smaller diameter compared to the MCA
therefore the high blood pressure can cause the small more fragile artery to rupture
what area of the brain tends to be affected by lacunar strokes ?
basal ganglia
what are the symptoms of lacunar strokes ?
pure motor and sensory symptoms
- no cortical signs e.g. visual or speech problems
what are the symptoms of brain stem dysfunction due to a PCA occlusion ?
coma vertigo nausea cranial nerve palsy ataxia hemiparesis hemisensory loss visual field defects
what three things should be done in the acute management of an ischaemic stroke?
- restore blood supply
- prevent extension of damage
- protect vulnerable brain tissue
what members of staff are involved with stroke patients ?
stroke nurses physiotherapists speech and language therapists occupational therapists dietitian psychologist orthoptist
what are the four classifications of strokes ?
TACS
PACS
LACS
POCS
what classification of stroke has the highest death rate?
TACS
- total anterior cerebral stroke
what are the 4 criteria for TPA?
symptoms onset <4.5 hrs
symptoms present >60mins
disabling neurological deficit
consent obtained
what does TPA stand for?
- treatment for strokes
tissue plasminogen activator
what are some contraindications for TPA?
haemorrhage possibility on CT scan recent surgery recent episodes of bleeding coagulation problems warfarin, aspirin high BP >185/110 glucose <2.8
what is the trial called which showed that thrombectomy reduces death and disability form stroke?
ESCAPE
is it important to plan secondary prevention for TIA patients ?
yes
- TIA patients have a high risk of stroke
what are some secondary prevention managements which can be used in stroke patients ?
anti platelets
anti hypertensives
statins
warfarin for AF
state some causes of TIAs
- atherosclerotic narrowing
- cardioembolism
- hypercoaguable state
- arterial dissection
- venous sinus thrombosis
what investigations should be done for stroke patients ?
routine bloods - FBC, Glucose, Lipids, ESR CT/ MRI - infarct, haemorrhage ECG - AF, LVH Echocardiogram - valves, ASD Carotid doppler US - stenosis Cerebral angiogram - vasculitis Hyper-coagulable blood screen
what are some differential diagnoses for strokes ?
hypoglycaemia Bell's palsy vestibular disease migraine demented patients with UTIs Intracranial masses
what are the objectives of stroke care?
- reduce mortality
- reduce disability
- improve care of patients and care givers
- improve patient and care givers knowledge
- maximise QOL
