Stroke Flashcards
define a stroke
focal neurological deficit that causes a vascular deficit and lasts longer than 24 hours
what parts of the brain does the anterior cerebral artery supply
superior and medial aspects of the cerebrum
what parts of the brain does the middle cerebral artery supply
majority of the lateral aspect of the cerebrum
what parts of the brain does the posterior cerebral artery supply
occipital lobe
if there is occlusion of the anterior cerebral artery, what clinical features occur
contralateral weakness and sensory loss to the leg
loss of bladder control
visual disturbance
if there is occlusion of the middle cerebral artery, what clinical features occur
contralateral weakness and sensory loss to the arm and face
homonymous hemianopia
visuospatial problems
if the middle cerebral artery is occluded on the dominant side, what additional features are seen
aphasia
apraxia
what is Wernickes aphasia
the ability to understand words and sentences is impaired but the ability to speak is not
therefore the speech is fluent but non-sensical
where is Wernicke’s area located
temporal lobe
what is Broca’s aphasia
the ability to produce speech is impaired but comprehension of language is not
therefore speech is laboured but makes sense
where is Broca’s area located
frontal lobe
if the posterior cerebral artery is occluded, what clinical features are seen
macular sparing homonymous hemianopia
what are the 2 types of stroke that can occur
ischaemic
haemorrhagic
outline the pathophysiology of ischaemic stroke
due to cerebral occlusion causing infarction
either thrombotic or embolic in origin causing occlusion of cerebral vessels and area of the brain is damaged
what is a thrombotic event causing a stroke
blockage of vessel at the site of occlusion
develops due to atherosclerosis of vessels
what is an embolic event causing a stroke
clots arise distally, break off from the site of origin and travel up to the brain via the internal carotids
usually due to previous MI, AF or endocarditis
what causes an haemorrhagic stroke to occur
develops as a result of intercerebral haemorrhage which reduces the blood supply to other parts of the brain
what is the main risk factor for developing haemorrhagic stroke
uncontrolled hypertension
which type of stroke is most common
ischaemic 80% of all strokes
outline the main modifiable risk factors for having a stroke
hypertension diabetes smoking increased clotting heart disease - AF, ischaemic, valvular
what areas of the brain are affected in a total anterior circulation stroke
blockage of both anterior and middle cerebral arteries
for a diagnosis of TACS what 3 features must be present
unilateral weakness of face, arm and leg
homonymous hemianopia
higher cerebral dysfunction - dysphasia and visuospatial problems
what areas of the brain are affected in a partial anterior circulation stroke
smaller than TACS, blockage of one of anterior or middle cerebral artery
for diagnosis of PACS what features must be present
2 of the following
unilateral weakness of face, arm and leg
homonymous hemianopia
higher cerebral dysfunction - dysphasia and visuospatial problems
what areas of the brain are affected in posterior circulation syndrome
damage to the areas supplied by posterior cerebral artery - vertebral and basilar arteries
for diagnosis of POCS, what features must be present
one of the following present
isolated homonymous hemianopia
cerebellar/brainstem syndrome - ataxia, nystagmus and diplopia
+/- confusion and mood changes
what causes a lacunar stroke to develop
due to multiple small vessel infarcts in basal ganglia and thalamus, it is a subcortical stroke therefore higher cerebral functions are preserved
what features are present in a lacunar stroke
one of the following
purely sensory stroke
ataxic hemiparesis
unilateral weakness +/- sensory symptoms in face, arms and legs
what causes a stroke from a carotid artery dissection to occur
spontaneously
whiplash trauma
how does a stroke from carotid artery dissection present
focal neuro deficits
pain in neck/face
Horner’s syndrome
lower cranial nerve symptoms
what is the first line investigation for someone presenting with symptoms of a stroke
CT brain if presenting acutely
MRI if presenting several days after the onset of symptoms
what is the immediate findings of an ischaemic stroke on CT
hyperdense segment representing intravascular thrombus/embolism - most commonly seen within the MCA
after the first few hours of a stroke what findings develop
loss of grey-white matter differentiation
what are the CT features of a chronic stroke
swelling reduces and gliosis begins to set in, very dense region around the area of infarction which causes a negative mass effect
what is the first line management of acute stroke
ABCDE
establish whether the stroke is ischaemic or haemorrhagic
monitor glucose and ensure adequate hydration
if an ischaemic stroke is detected within 4.5 hours of first presentation, how is it managed
thrombyolsis
what are the 2 agents that can be used for thrombolysis
IV altepase and tissue plasminogen activator
list some contraindications to thrombolysis
seizures recent surgery major infarct haemorrhagic stroke currently on anti-coags ischaemic stroke in last 3 months
if a patient presents after 4.5 hours of symptoms thrombolysis is ineffective true/false
true
how is a stroke managed after presenting after 4.5 hours
aspirin 300mg
following an ischaemic stroke, what secondary prevention measures must be in place
ABC - anti-platelets, blood pressure medication and cholesterol control
after a stroke, what medication is commenced irrespective of the extent of patient risk factor
statins and anti-platelets
whereas anti-hypertensives only commenced if clinical hypertension
