strokes Flashcards
clinical features of MCA stroke
most commonly affected vessel
contralateral weakness and sensory loss more marked in the upper limbs and lower half of the face than in lower limbs
gaze deviates towards side of infarction
clinical features of anterior cerebral artery stroke
ACA
contralateral weakness and sensory loss in the lower limbs more marked than in upper limbs
clinical features of posterior cerebral artery stroke
contralateral homonymous hemianopia with macular sparing due to occipital lobe involvement
contralateral sensory loss due to lateral thalamic involvement: light touch, pinprick, and positional sense may be reduced
memory deficits
vertigo, naesea
posterior inferior cerebellar artery
lateral medulary syndrome
anterior inferior cerebellar artery
lateral pontine syndrome
lenticulostriate arteries
lacunar syndrome
basilar artery
consciousness is preserved if the reticular activating system is not effected
vertebrobasilar insifficiency:
vertigo, drop attacks, tinnitus, hiccups, dysarthria, dysphagia
diplopia, gait ataxia, paresthesias
pontine syndromes
cerebellar syndromes
cortical signs
neglect, aphasia, visual feild loss
frontal lobe controls
movement and executive function
parietal lobe controls
sensory info
cerebellum controls
muscle coordination
brainstem controls
heart rate, BP, breathing, GI function, consciousness
the right cerebrum controls
muscles on the left
vertebral arteries and basillar arteries supply
cerebellum and brainstem
cerebral arteries supply
lateral portions of frontal, parietal and temporal lobes
anterior cerebral arteries supply
medial portions of the frotal and parietal lobes
connect via the anterior communicating arteries
basilar arteries divide to become
right and left posterior cerebral artery
occipital lobe and some of the termporal lobe and thalamus
lacunar strroke
involves deep branches of the middle cerebral artery that feed the basal ganglia
develops cysts
typically caused by hyaline atherosclerosis caused by diabetes or hypertension causing thick walls and reducing the size of the lumen
ischaemic core
brain tissue likely to die from ischaemia
ischaemic penumbraa
preserved by collateral circulation
has a chance to survive if circulation is restored
swelling on brain
swollen brain tissue can push onto unaffected side of the brain
cerbellar tonsil hernation - may push onto the brainstem and affect breathing and consciousness
anterior or middle cerebral artery stroke
numbness and weakess
posterior cerebral artery stroke affects
vision
TPA
thrombolitic enzyme
tissue plasminogen activator
activates body’s clot dissolving mechanisms
has a time limit for usage
subarachnoid haemorrhage
haemorrhage occurs between pia mater and subarachnoid mater of the meninges
causes of subarachnoid haemorrhage
ruptured berry aneurysm
arterriovenous malformation
trauma
clinical features of subarachnoid heamorrhage
rapid onset severe headache
meningeal signs: nuchal rigidity, headache, photophobia
sudden onset of focal neurologicaal deficits
clinical features of intracerebral haemorrhage
headache, confusion, nausea
sudden onset focal neurological deficits
diagnosis of subarachnoid haemorrhage
non contrast head CT to rule out haemorrhage)
MRI
CTA/MRA
lumbar puncture (if imaging is negative but clinical suspicion of subarachnoid remains high - may show xanthochromia)
xanthochromia
presence of bilirubin in the CSF secondary to the breakdown of RBCs, resulting in yellow discolouration
findings of ischaemic stroke on non-contrast CT
hyperdense MCA sign
effacement of sulci
loss of conrtico-medullary differentiation
oedema
findings of intracerebral haemorrhage
hyperdense lesion within the cerebral parenchyma
findings of subarachnoid haemorrhage on non-contrast CT
extensive area of hyperdense signals around the. circle of willis (most common location)
treatment of ischaemic stroke
tPA (if within <4.5 hours of onset of symptoms)
intra-arterial thrombolysis
thrombectomy
aspirin or clopidogrel for secondary prevention i
tPA
tissue plsminogen activator
A serine protease found on endothelial cells of the blood vessels. Catalyzes the conversion of plasminogen to plasmin, which is the main enzyme responsible for clot breakdown. Recombinant tissue plasminogen activators (e.g., alteplase, reteplase, tenecteplase) are used as thrombolytics in patients with acute coronary syndrome, pulmonary embolism, or ischemic stroke.
thrombolysis
The pharmacologic breakdown of blood clots formed in vessels. Indications include STEMI, stroke, massive pulmonary embolism, severe deep vein thrombosis, and acute limb ischemia. Agents used include streptokinase and alteplase.
treatment of intracerebral haemorrhage
reversal of coagulopathy
blood pressure management
surgical intervention if there are signs of herniation or increased ICP
treatment of subarachnoid haemorrhage
reversal of coagulopathy
blood pressure management
prevention of vasospasm
surgical clipping
endovasular coiling
visual feild defects in MCA stroke
contralateral homonymous hemianopia or superior/inferior quadrantopia
without macular sparing
macular sparing
A phenomenon in which macular vision is preserved despite adjacent visual field defects (e.g., in homonymous hemianopia due to a posterior cerebral artery stroke).
manifestations of MCA infarction
cerebellar syndromes
A characteristic set of symptoms associated with dysfunction of the cerebellum. Typical symptoms include ataxia, imbalance, uncoordinated movements (dysmetria), dysarthria, and oculomotor disorders (e.g., nystagmus).
manifestations of basilar artery stroke
consciousness is preserved is the reticular activating system is not affected
vertebrobasilar insufficiency: vertigo, drop attackes, tinnitus, hiccups, dysarthria, dysphagia, diplopia, gait ataxia, paresthesis
amaurosis fugax
sudden, painless loss of vision that lasts for seconds to minutes and is followed by spontaneous recovery (mostly unilateral)
lacunar stroke
A subcortical stroke that is primarily associated with hypertension and diabetes mellitus. Lipohyalinotic thickening of vessel walls results in the occlusion of small, penetrating arteries that supply the subcortical regions of the brain (internal capsule, pons, thalamus, putamen, and caudate). Typically presents as specific lacunar syndromes that are characterized by the absence of cortical signs (e.g., aphasia, hemianopsia, agnosia, apraxia).
lacunar infarcts will have an absense of _
cortical signs
eg. aphasia, neglect, visual feild loss, apraxia, agnosia
dysarthria
A condition of impaired articulation resulting from motor dysfunction of the tongue, lips, or vocal cords. Typical pathologic speech patterns include slurring, mumbling, staccato pronunciation, and changes in speed and pitch.
