Stroke Active Learning - J.Prun Flashcards
Describe stroke types & causes
Relate symptoms to anatomy
Describe initial stroke evaluation & management
Relate mechanisms of stroke to strategies for stoke prevention
Describe the mechanism of action, role, and contraindications of the use of TPA in stroke
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Definition of stroke?
Sudden onset of focal CNS deficit due to vascular cause!
What do TIA and TSI stand for?
Transient Symptoms of Infarction
Transient Ischemic Attack
What are the differences between TSI and TIA?
The key distinction of TIA is that it does not have permanent tissue damage.
TSI basically has resolved symptoms as well, but you still see evidence of the infarct on imaging
Why is it important to be able to identify the difference between TIAs and TSIs?
TSI is associated with increased risk for stroke in following weeks. TIA not so much
Difference between hemoorhagic and ischemic stroke?
Blood leaks into brain tissue vs blood clot stops blood supply
Stroke can be further divided into large and small vessel disease. Describe the broad main points of both kinds:
Large vessel:
-Can affect anterior and posterior circulation
ANT
-Common carotid - middle/anterior cerebral arteries
POST
-Vertebral - basilar -posterior cerebral artery
Small Vessel
- Involves penetrating arteries of the brain
- Lacunar
- Hypertension induces endothelial damage and bleeding
- Endothelial damage can also form clots - occlude
How will an intracerebral hemorrhage at the putamen present?
Contralateral hemiparesis, gaze paresis, aphasia
How will an intracerebral hemorrhage at the thalamus present?
Contralateral hemianesthesia
What are the similarities between Intracerebral and subarachnoid hemorrhages?
They are both bleeding into brain tissue
You can identify both on a Non-contrast CT
How do you manage intracranial hemorrhage?
Stop anticoagulants
Surgically remove clots
General cause of subarachnoid hemorrhage?
Trauma and shearing forces which tears vessels in the subarachnoid space, normally filled with CSF
Most common non-trauamatic cause of subarachnoid hemorrhage?
Rupture of intracranial anyeurisms
Subarachnoid hemorrhage management?
Nimodopine - a Ca channel blocker is thought to improve outcomes somewhat
For anyeurisms - clamps or coils used
Some differences between Intracerebral and subarahnoid hemorrhages?
Intracerebral
- Blood shows up in different areas wherever its bleeding
- focal neural deficits
- pain free
- no drugs to treat
Subarachnoid
- Anyeurisms
- Treat with Nimodipine
- Diffuse in CSF and subarachnoid
- THUNDERCLAP headache
What deficits will be produced by an anterior cerebral artery stroke?
- more likely to affect the legs
- associated with frontal lobe problems (personality)
- blindness in one eye
(one of the 1st branches off the ICA is the ophthalmic artery. Occlusion of the ophthalmic artery can cause amaurosis fugax or blindness in one eye. )
What deficits will be produced by a middle cerebral artery stroke?
- Face & arms are affected more than legs
- Patients often experience a homonymous hemianopsia
- Dominant hemisphere usually causes aphasia (language probs)
- Nondominant hemisphere causes contralateral hemineglect
What deficits will be produced by a vertebral artery stroke?
Affect: inferior cerebellum and lateral medulla
Cerebellar strokes cause symptoms of vertigo, blurred vision, vomiting, nystagmus, ataxia, & postural instability.
Lateral medulla = Wallenberg syndrome
-crossed symptoms, like:
numbness on the right side of the face and left side of the body due to damage to the cranial nerves on the ipsilateral side and damage to the sensory fibers above where they cross from the contralateral side
What deficits will be produced by a basilar artery stroke?
The basilar artery supplies rostral brainstem & occipital lobes
-Causes cranial nerve palsies, which may result in gaze problems, hemianopsia, & miosis.
- Bigger occlusions can cause more severe deficits and damage the reticular activating system leading to altered levels of consciousness
- mortality rates as high as 90%
What deficits will be produced by a posterior cerebral artery stroke?
The posterior cerebral artery (PCA) supplies the occipital lobes.
- present with a homonymous hemianopsia of the contralateral vision field.
- PCA infarcts of the nondominant hemisphere may result in neglect of the affected vision field.
- stroke may have less obvious signs for clinicians
What deficits will be produced by a lenticulostriate artery stroke?
The lenticulostriate arteries branch off the middle cerebral artery to deep structures of the brain
-stroke hallmark is a lack of cortical signs
Infarction of the posterior limb of internal capsule will result in pure motor stroke
-patients experience hemiparesis of the legs, arms & face on one side due to disruption of the descending corticospinal and corticobulbar tracts
Infarction of the lateral thalamus results in a pure sensory stroke
-patients experience numbness of the legs, arms & face on the contralateral side of the body.
What is the timeline for using fibrinoltic therapy on a stroke patient?
Must have had stroke less than 4.5 hours previous
Why on earth would you do a rectal exam on a stroke patient?
If you are thinking about giving a TPA (Tissue Plasminogen Activator) then you need to make sure that they don’t have any sort of occult GI bleeds that could be complicated with therapy…
If a patient has stroke symptoms related to anterior circulation, what is a good specialized test to check that out?
carotid doppler ultrasound
-can detect underlying carotid artery stenosis
