Stroke Flashcards
What is stroke?
Sudden onset of focal neurologic deficit resulting from the interruption of blood flow to an area in the brain (similar to ischemia in heart attacks)
What are some consequences of stroke?
Deficits depend on area of brain affected:
Hemiplegia (monolateral paralysis)
Hemiparesthesia (monolateral numbness)
Blindness in one eye
Speech disturbance
More general symptoms (dizziness, weakness, headaches, confusion)
What is FAST in terms of stoke?
It descibes four common symptoms of a stroke
F(ace is it drooping?)
A(rms can you raise both?)
S(peech is it slurred or jumbled?)
T(ime to call 911 right away)
What is the most devastating thing about stroke?
The disability that can develop due to brain damage.
Is stroke risk the highest in younger patients?
No, it tends to increase greatly following retirement age (over 65), but begins to climb at 50
Why should we agressive in reducing stroke risk?
We can prevent unnecessary severe disability following a preventable stroke
What is a transient ischemic attack (TIA)?
They are a focal neurological deficit as a result of ischemia lasting less than 24 hours and without evidence of infarction on imaging studies (no equivalent for troponin)
What is the risk of a full-blown stroke in patients that have had a transient ischemic attack (TIA)?
7.5-17.4% risk of stroke within 3 months, and 50% of these strokes occur within 48 hours
Due to such a high risk, these patients should be considered for secondary prevention
What are the main types of stroke?
Ischemic (87% of cases)
Hemorrhagic (13%)
Describe hemorrhagic strokes?
They have…
Higher death rate
HIgher morbidity
Risk factors: aneurysm, hypertension, and DAPT
What are the four types of ischemic stroke?
The main two types are:
Atherosclerotic (20%)
Cardioembolic (20%)
The other two are the following:
Cryptogenic (30%) unknown cause
Lacunar (25%) small vessel stroke
Other causes (5%)
What causes the damage in hemorrhagic stroke?
Ischemia from hemorrhaging can starve brain tissue form oxygen.
The BBB protects neurons from blood, so in hemorrhagic stroke the neurons are exposed to blood. This causes inflammatory response
What can cause cardioembolic stroke
?
Thrombi (clots) can break off and travel through the aorta —> carotid arteries —> small cerebral vessels
The thrombi fragments get stuck in the small cerebral vessels, the obstruction causes ischemia
What conditions pose a greater risk for thrombus generation within or on the heart?
Atrial fibrillation (intra-atrial thrombus)
Mechanical heart valves (valvular thrombus)
How is cardioembolic stroke preventing?
Prevention is often focuses on the use of anticoagulant medications (warfarin, DOACs)
How is a cardioembolic stroke diagnosed?
If a patient has a stroke, it is determined to be cardioembolic by the following results:
ECG findings of atrial fibrillation (increased risk for atrial clots)
Left atrial thrombus
Absence of significant atherosclerosis on imaging/ultrasound
What should patients do if a patient experiences signs of stroke?
Send them to the emergency, it is important to get an objective diagnosis required for accuracy
Advanced imaging is used to determine:
Ischemia vs. Hemorrhage
Alternate diagnosis (tumour)
What is done in the hospital when a patient presents a stroke?
Everyone eligible for a fibrinolytic is given one, it is the only repurfusion strategy. Needs to be given within 3h of onset of symptoms to be effective
Can be given between 3-4.5h in patients under 80, DOAC use, severe stroke, history of stroke and diabetes
What are fibrinolytics?
They are plasminogen activators (conversion of plasminogen into plasminogen). Plasminogen breaks down fibrin clots