Strokes

Question 1

What is the definition of stroke?

Answer 1

inadequate blood flow to the brain resulting in cell death

Question 2

What is a TIA?

Answer 2

brief episode of neurological dysfunction that is:

• caused by focal brain or retinal ischemia
• has complete resolution of sx
• typically lass < 1 hr
• w/out evidence of infarction

Question 3

What is the risk factor for stroke 2 days after TIA?

Answer 3

10%

Question 4

What are the clinical symptoms of stroke?

Answer 4

• Sudden
  
  • confusion, trouble speaking or understanding
  • numbness or weakness of the face, arm, or leg especially on one side of the body
  • trouble seeing out of one or both eyes
  • trouble walking, dizziness, loss of balance or coordination
  • severe headache with no known cause or no prior history of headache
  • neglect

Question 5

What would you be looking for in a CT that indicates stroke?

Answer 5

hypodensity

Question 6

When looking at a stroke on MRI, what two sets should you look at together?

Answer 6

ADC & DWI

Question 7

Why do we see brightness with stroke on a DWI MRI?

Answer 7

loss of perfusion → increased edema →influx of fluid/protons that light up

Question 8

Identify the type of aphasia indicative of leach level of the flow chart

Answer 8

Question 9

What areas of language do we want to test when assessing stroke?

Answer 9

naming, fluency, comprehensive, repetition, prosed/singing, reading, writing

Question 10

What are the 2 types of stroke? Which is more common?

Answer 10

• Hemorrhagic: blood leaking out into the brain
• Ischemic: loss of blood flow (85%)
  
  • thrombolic - clot develops in that specific area (usually d/t plaque build up)
  • embolic- clot forms somewhere else & shoots up to the brain (MC cardioembolic stroke)

Question 11

Identify the characteristics of ischemic strokes relative to the following variable:

Acute / Hyperacute?

Headache?

Consciousness?

Herniation?

Territory?

Answer 11

• Acute / Hyperacute? either
• Headache? none-moderate
• Consciousness? relatively preserved
• Herniation? rare or occurs later
• Territory? clear vascular territory

Question 12

Identify the characteristics of hemorrhagic strokes relative to the following variable:

Acute / Hyperacute?

Headache?

Consciousness?

Herniation?

Territory?

Answer 12

• Acute / Hyperacute? hyperacute
• Headache? severe
• Consciousness? usually impaired if large
• Herniation? occurs early
• Territory? no obvious territory

Question 13

Identify the arterial territory of the brain indicated in the provided image

Answer 13

Question 14

What percent of all strokes are cardiothromboembolic?

Answer 14

20-30%

Question 15

What are the major risk factors/etiologies for cardiothromboembolic stroke?

Answer 15

atrial fibrillation (x5)

acute MI w/ left ventricular thrombus

mechanical valve (mitral > aortic)

infective endocarditis

DVT → patent foramen ovale

intrapulmonary shunt

Question 16

Ischemic stroke often occurs in what small-vessel diseases?

This most commonly affects which specific vessels?

Answer 16

HTN / diabetes

vessels in subcortical/basal ganglia/brainstem area

Question 17

Ischemic stroke often occurs in what large-vessel diseases?

This most commonly affects which specific vessels?

Answer 17

hyperlipidemia, hypovolemia

PCA, MCA, ACA, carotids

Question 18

What type of stroke is shown on the provided DWI image?

Answer 18

watershed stroke - string of pearls sign

between MCA & ACA territory, but all in one hemisphere

Question 19

This watershed stroke suggests what etiological cause?

Answer 19

ipsilateral carotid stenosis & hypovolemic state

loss of blood pressure → loss of perfusion → w/ stenosis lose have stroke in area between MCA & ACA territory

Question 20

What type of stroke is shown on the provided DWI image?

Answer 20

punctate

small, round infarcts cortically & in both hemispheres

Question 21

The punctate stroke shown in the provide image is suggestive of what etiological cause?

Answer 21

cardioembolic etiology

Question 22

What territory is impacted in the provided DWI/

Answer 22

MCA superior division territory

Question 23

The provided DWI image is indicative of what etiological cause of stroke?

Answer 23

watershed or thrombotic stroke

Question 24

What type of stroke is shown in the provided DWI image?

Answer 24

lacunar infarct

Question 25

The provided image of lacunar infarct on DWI is suggestive of what etiological cause of stroke?

Answer 25

small vessel disease | (hypertension, diabetes)

Question 26

List the components fo the cerebral vasculature affected by atherosclerotic disease from high to low:

Answer 26

high to low * basilar artery * carotid * cavernous sinus * MCA & ACA divisions

Question 27

What is carotid dissection?

Answer 27

tearing of the inner wall of an artery blood enters the tunica media of the vessel & forms intramural hematoma

Question 28

What characteristics can increase a persons chance of having a carotid dissection?

Answer 28

* Ehler's Danlos Syndrom IV * marfan syndrome * autosomal dominant polycystic kidney disease * osteogenesis imperfecta type I

Question 29

What is the clinical presentation of a patient with carotid dissection? Treatment?

Answer 29

ipsilateral cervical pain (25%) headache (66%) ipsilateral Horner Syndrome (\<50%) TIA (50-95%) days/hours after dissection Treatment: anti-platelet therapy

Question 30

Describe the stroke pathophysiology

Answer 30

mismatch of blood pressure & blood volume → brain wants to maintain constant cerebral blood flow → cerebral vasodilation to maximize blood flow (allow for optimal blood oxygen extraction) → autoregulation is overwhelmed due to the insufficient cerebral perfusion pressure → blood flow decreases → tissue hypoperfusion

Question 31

What is it called when the surrounding tissue in a stroke tries to respond to the loss in blood flow?

Answer 31

penumbra | (goal area for tissue recovery)

Question 32

How long is brain tissue viable?

Answer 32

until cell death occurs can still be recovered even if it is not optimally metabolically function

Question 33

Every 30 minutes in delay in acute perfusion leads to what percent irreversible outcome?

Answer 33

10%

Question 34

What treatment for ischemic stroke increases the likelihood of patient independence at three months post event?

Answer 34

intravenous thrombolysis via recombinant tissue plasminogen activator (tpa) within 4.5 hrs

Question 35

patients with what kind of stroke are a candidate for _endovascular thrombectomy_? within what timeframe post stroke?

Answer 35

large vessel occlusion 24 hrs from onset

Question 36

What type of stroke is shown in the provided image?

Answer 36

MCA branch ischemic stroke

Question 37

Occlusion of what artery causes “locked in syndrome”? how?

Answer 37

**basilar artery involving the pons** disconnects pons & medulla from midbrain / supratentorium

Question 38

What type of movement is spared in “locked in syndrome”? Why?

Answer 38

**vertical eye movements** controlled by interstitial nucleus of MLF (located in midbrain just dorsal to red nucleus)

Question 39

What are the modifiable risk factors for stroke?

Answer 39

* hypertension * dyslipidemia * diabetes * metabolic syndromes * atrial fibrillation * carotid stenosis * cigarette smoking * alcohol use * obesity * physical inactivity * obstructive sleep apnea

Question 40

How long after quitting smoking is risk of stroke decreased? Cessation of smoking after how long brings risk of stroke to that of non-smoker?

Answer 40

after 2 yrs → risk decreased 5yrs

Question 41

What medications can be given to patients to mitigate risk of stroke?

Answer 41

* anti platelet * aspirin, plavix * anticoagulation * coumadin, NOACs * statin

Question 42

Women with what characteristic are predisposed to stroke?

Answer 42

* migraine with aura * supplmenetal estrogens * tobacco use

Question 43

What procedure can be performed to decrease risk of stroke? In what situations is this appropriate?

Answer 43

carotid endarterectomy. either * 70-99% stenosis * 50-69% stenosis + symptomatic