Stroke Flashcards
Define stroke
Sudden death of brain cells due to blockage of blood flow or rupture of an artery to the brain parenchyma
List causes of stroke with %
Ischaemia 85%
Haemorrhage 12%
SAH 3%
Give 2 reasons why intracranial haemorrhage causes problems
Blood is irritating to brain tissue so it swells
The haematoma that forms raises intracranial pressure
List 6 causes of intracranial haemorrhage
HTN Ruptured aneurysm or AV malformation Haemorrhagic necrosis Venous outflow obstruction Trauma Altered haemostasis
Rank the following from lightest to darkest on a CT scan:
CSF, bone, water, Ca, oedema, air, metal, contrast
Metal –> bone –> Ca –> contrast –> blood –> oedema –> water –> CSF –> air
What is the word used to describe pattern of haemorrhagic stroke?
Dynamic - slowly expanding haematoma
Why is intracranial arterial occlusion a problem?
Results in brain area being deprived of O2 and glucose
Where does the anterior circulation come from?
Internal carotids
What arteries make up the anterior circulation?
Anterior and middle cerebral arteries
What does the anterior circulation supply?
Hemispheres except occipital lobes
What arteries make up the posterior supply?
Vertebral and basilar arteries
What does the posterior circulation supply?
Brainstem, cerebellum, occipital lobes
What happens in the ischaemic cascade?
Cell is stunned so basement membrane stops working
Water seeps into cell uncontrolled
Cells swell and pop
Leads to necrosis
Inflammation occurs due to debris clearing
End up with fluid filled cavity
What are the 3 main causes of ischaemic stroke
Large vessel atherosclerosis
Small vessel disease
Cardio-embolic
List 3 examples of large vessel atherosclerosis leading to stroke
Intracranial stenosis
Carotid stenosis
Aortic arch plaque
What are the risks of large vessel atherosclerosis leading to stroke?
Same as heart disease ones
HTN, DM, age, male, cholesterol, high BMI, FH
List 3 examples of cardio embolic causes of stroke
AF
Valve disease
Ventricular thrombi
How do you prevent large vessel atherosclerosis from leading to stroke?
Give antiplatelets eg aspirin
How do you prevent cardio embolic causes of stroke?
Oral anticoagulation
Which are more prevalent in stroke, + or - signs?
Negative
How do you investigate a potential stroke?
Hx - inc travel ABCDE Neuro and systemic exam Temp, BP, pulse CT /MRI FBC ECG and dopplers
Where is the stroke?
Aphasia, right hemiparesis, sensory loss and visual field defects. Difficulty reading and writing.
Left (dominant) hemisphere
Where is the stroke?
Neglect of left visual field, unable to notice left sided stimuli. Left hemiparesis, sensory loss and visual field defects. Spatial disorientation.
Right (non dominant) hemisphere
Where is the stroke?
Motor or sensory loss in all 4 limbs. Gait ataxia. Diplopia. Nystagmus. Bilateral visual field loss.
Brain stem / cerebellum / posterior hemispheres
