Stroke Flashcards
What is the definition of a TIA?
A clinical syndrome characterized by an acute loss of focal brain or monocular function with symptoms lasting less than 24 hrs and which is thought to be due to inadequate cerebral or ocular blood supply, without ischemic changes in Diffusion Weighted Imaging (DWI)***actually something lasting less than 15 minutes (def less than 1 hr). **w/o evidence of acute infarction
What is a stroke?
death of brain tissue b/c of lack of blood flow
What is the definition (technical) of stroke?
Clinical syndrome characterized by an acute loss of focal brain or monocular function with symptoms lasting greater than 24 hrs and which is thought to be due to inadequate cerebral or ocular blood supply.
What are the 2 main types of stroke?
Ischemic (thrombosis-narrowed bv & embolism-traveling clot)Hemorrhagic (intracerebral & subarachnoid aneurysm)
What % of strokes are ischemic? Hemorrhagic?
Ischemic (80%)Hemorrhagic (20%)
Which % of ischemic strokes are thrombosis? Embolism?
Thrombosis: 50%Embolism: 30%
What is a risk for an intracerebral stroke?
HTN
Where does stroke fall in terms of causes of death?
4th leading cause of deathleading cause of disability
What types of strokes do small vessels that are thrombosed v. large vessels that are thrombosed?
small vessels–smaller damage amount, called lacunar strokeslarger vessels–massive stroke more likely
What are the non-modifiable risk factors for strokes?
Age Sex-M>F Race (e.g., African-Americans) Family history of stroke Prior stroke/TIA
What are the modifiable risk factors for strokes?
SmokingHypertension Alcohol abuseDiabetes ObesityHyperlipidemia Physical inactivityAtrial fibrillationHomocystemiaCarotid stenosis
What is the most common cause of subarachnoid hemorrhage? Spontaneous cause?
All subarachnoid hemorrhage: traumaSpontaneous causes: aneurysm
T/F Up to approximately 10% of people who suffer transient attacks (TIAs) will develop a stroke within 5 years.
False. 30% of people. Huge deal.
What is the risk of stroke post-TIA at 1 mo? 1 year? 5 years?
1 mo: 4-8%1 year: 12-13%5 years: 24-29%
T/F Death rates from strokes are increasing since the 1900s.
False. the death rates are decreasing–we treat them better. But it will start to increase soon just b/c of the sheer number of people.
T/F In the elderly population, strokes are as common in males as females.
True.
If you supplement a patient w/ homocystemia with Vit B…are they at less risk for a stroke or MI?
No. sadly.
What is the stroke belt?
coordinates with the bible belt. Southern states.
What produces the death of the neurons in a stroke?
death of the sodium potassium pumptissue starts to die within minutesdamage is irreversible, can’t reverse this damage but can treat.
T/F Time=Brain.
TRUE! Reason for stroke units.
T/F The duration, severity, and location of focal cerebral ischemia determine the extent of brain function and thus the severity of stroke
True.
Lack of ______ and _____ deplete the cellular energy stores required to maintain electrical potentials and ion gradients.The membrane that surrounds each affected neuron becomes “leaky,” and the cell loses________ & _______ , the tissue’s medium for energy exchange
glucose & oxygenpotassium and adenosine triphosphate (ATP)
There are several drugs on the market that treat things related to stroke that are a part of the coagulation cascade. Which parts of the coagulation cascade are targeted?
Factor 10-3 drugs targetThrombin Inhibitor–used for atrial fibrillation.
On contact with collagen, ______ become activated & aggregate at the site of injury. This surface is catalytic for several coagulation reactions that generate thrombin.
platelets
How does atherosclerosis begin?
begins in response to chronic minimal injury to endothelium of blood vessel**involves many players: monocytes, lipoproteins, platelets, lymphocytes, smooth muscle cells
T/F with more plaque formation–the more likely to have a stroke.
True.
What does each of these levels of atherosclerosis consist of? Types I, II, III
Type I: minimal endothelial injuryType II: intimal injuryType III: thrombus formation
If you have a migraine with an aura…you could have what?
endothelial cell dysfunctioncould put you at greater risk to have a stroke
Plaque builds up in the _____ layer of the blood vessel & then ____ infiltrate.
intimal layer of bvinflammatory cells infiltrate
Along with macrophages, _______ cells make up a lot of the bulk of atherogenesis.
Smooth muscle cells. they grow in atherosclerosis.
T/F Some plaques ulcerate, leaving the deeper layers of the blood vessel open to blood cells.
True.
What makes plaques vulnerable to rupture?
stress on plaque cap during systolereduction of collagen content with infiltration of foam cells
What are the 3 ways that oxidized LDL-cholesterol contributes to atherogenesis?
- Cytotoxic properties that promote endothelial injury.2. chemoattractant for monocytes3. inhibits departure of macrophages from plaques
Describe how an MI could lead to a stroke in time.
MI weakens ventricle of heart. blood falls in there & you get a clot.a piece of clot breaks off & travels into general circulationsome emboli go to brain & produce a stroke
Where do cardiogenic emboli usu lodge?
80% of the time–middle cerebral artery10% of the time–posterior cerebral artery10% of the time–vertebral artery
How do large vessels sometimes lead to strokes?
thrombosis w/i the large vessel. Plaque formation. Narrowing of lumen.
How does small vessel occlusion usu happen?
via damage by HTNleads to thickening of b.v. mediadeposition of fibrinoid materialsmall vessels often give lacunar strokesCalled lipohyalinosis
Where do lenticulostriate arteries go?
to the basal ganglia
What’s something scary to keep in mind when I get my hair cut after school gets out?
um…be careful when you put your head back in the tub b/c if you bang your neck too hard you could get arterial dissection & stroke out.
Aside from the things we have already talked about…what are some causes of stroke?
fibromuscular dysplasia: overgrowth of intima & mediaArteritis (Takayasu’s & Giant Cell)Arterial DissectionDecreased systemic perfusionFabry’s disease
In muscular dysplasia..you can get bleeding of _____ blood vessels.
extra cranial blood vessels
What are some important stroke warning signs?
Sudden weakness, paralysis, or numbness of the face, arm and the leg on one or both sides of the bodyLoss of speech, or difficulty speaking or understanding speechDimness or loss of vision, particularly in only one eyeUnexplained dizziness (especially when associated with other neurologic symptoms), unsteadiness, or sudden fallsSudden severe headache and/or loss of consciousness
What are the things on your differential diagnosis when you see a patient with stroke symptoms?
Ischemic StrokeHemorrhagic StrokeCraniocerebral/cervical traumaMeningitis/ EncephalitisIntracranial MassSeizure with persistent neurological signsMigraine with persistent neurological signsMetabolic problem
What are 2 types of intracranial mass on your differential diagnosis?
tumorsubdural hematoma
What are some metabolic considerations when you see a patient with stroke symptoms?
Hyperglycemia Hypoglycemia Post-cardiac arrest ischemia Drug/narcotic overdose
What do you associate with each of these stroke types? Atherothrombotic?Embolism?Primary small vessel disease?
Atherothrombotic: occlusion of larger arteriesEmbolism: cardiogenicPrimary small vessel disease: lipohyalonosis
Which brain tissue are you trying to save with stroke treatment?
the penumbra
When a person comes into the ER for stroke symptoms…which test do you usu order & why?
CT–good in times of emergency, won’t be able to see stroke right away…but can see if it is a hemorrhagic stroke. Then DON’T give anti-thrombolytic therapy to the pt!
T/F Even in left-handed people the left hemisphere is often dominant.
True.
What are some signs of a left hemisphere stroke?
Aphasia Right hemiparesis Right-sided sensory loss Right visual field defect Poor right conjugate gaze Dysarthria –slurred speechDifficulty reading, writing, or calculating
What are some signs of a right hemisphere stroke?
Neglect of left visual field Extinction of left-sided stimuli-move 2 hands & they only see 1.Left hemiparesis Left-sided sensory loss Left visual field defect Poor left conjugate gaze Dysarthria Spatial disorientation Drowsy, sleep a lot. **sometimes these pts don’t realize that anything is wrong.
What are some signs of a Posterior Circulation (Vertebrobasilar Territory) Stroke?
Ataxia, gait abnormalitiesDiplopia, oscillopsia, nystagmus, dysconjugate eye movementsNausea & vomiting (center is in area post-rema)Crossed hemiparesis, hemisensory deficitsHeadache more common
What are some possible neurodeficits secondary to a lesion that you could see in the frontal lobe?
akinesiaapraxiaataxiabehavioral changes
What are some possible neurodeficits secondary to a lesion that you could see in the parietal lobe?
sensory losshemianopiaapraxiaGerstmann’s syndrome
What are some possible neurodeficits secondary to a lesion that you could see in the temporal lobe?
Pure word deafnessBehavioral disturbancesSuperior quadrant visual loss
What are some possible neurodeficits secondary to a lesion that you could see in the occipital lobe?
vision loss
Tests for the Emergent Evaluation of the Patient with Acute Ischemic Stroke?
CT of the brain without contrast Electrocardiogram Chest x-ray Hematologic studies Serum electrolytes Blood glucose Renal and hepatic chemical analyses National Institutes of Health Scale (NIHSS) score
Under special circumstances extra tests that may be necessary?
Cervical spine x-rayArterial blood gasLumbar punctureElectroencephalogram (EEG)
What are some things to make sure you do with stroke patients?
maintain adequate tissue oxygenation & O2 inhalationmaintain optimal BP b/c autoreg is faulty during a strokemaintain good blood glucose-hyperglycemia poorer outcomes.management of fever–hyperthermia worsens ischemia
When should TPA be given?
hopefully w/i 1 hour.but can be given up to 4.5 hours after stroke symptoms began. **b/c of reperfusion injury
What are some good anti-platelet agents?
Aspirin Plavix AggrenoxStatinsAtorvastatin
What are some known factors that cause stroke progression?
HypotensionHyperglycemiaHyperthermiaInfectionCerebral hypoperfusion
With brain edema, you see deviation of what?
the falx cerebri
How do you (generally speaking) treat brain swelling?
fluid restrictionhyperventilation (lower PCO2) osmotic diureticsdrainage of CSF (ventriculostomy)surgery (lobectomy)peaks at 3-4 days following stroke
So a stroke patient had super high BP & they lowered it artificially to 130/80 mmHg. Then his stroke symptoms did not resolve after TPA. Why?
b/c his autoreg is out of whack b/c of stroke & lower his BP that drastically cause lack of perfusion to his brain tissue. Lost the penumbra. **in stroke patients cerebral pressure directly related to cerebral blood flow
Med student who skiied & fell & then had stroke symptoms later on…what happened?
they had dissection of left vertebral artery
T/F No patient should be given dextrose solution who has had a stroke.
True. Could cause hyperglycemia if a diabetes pt too & could worsen stroke.
Why do you need to take a CT of a patient 24 hours after the stroke?
to see if the TPA has caused a hemorrhage
When can you use VTE prophylaxis?
36 hours after a stroke
