Dirnagl - Cerebrovascular Disorders, Stroke

Question 1

What are the symptoms of stroke (FAST acronym)

Answer 1

Face drooping
Arm weakness
Speech difficulty
Time to call 911

Question 2

What are some specific stroke symptoms?

Answer 2

• motor deficit
• dysarthiria
• dysphagia
• aphasia
• sensory deficit
• ataxia
• visual disturbance
• headache
• not so common: impaired consciousness

Question 3

Are strokes painful?

Answer 3

Normally no, no nociceptors in the brain

-if there is hemorrhage, then yes. the meninges have nociceptors

Question 4

Which artery is most commonly affected in stroke?

A. anterior cerebral artery
B. middle cerebral artery
C. posterior cerebral arteries
D. posterior circulation

Answer 4

B. middle cerebral artery

Question 5

What are the important considerations after a patient has a Transient ischemic attack (TIA)?

Answer 5

• although do not leave a persistent deficit, TIA does increase risk for a major stroke
• TIA patients must be treated to prevent a stroke
• Annual risk of stroke during first 5 years - 5%
• treating a TIA with TPA may cause harm

Question 6

What are the main cerebral vascular diseases?

Answer 6

• Ischemic stroke
• Aneurysm
• Subarachnoid hemorrhage
• Primary intracerebral hemorrhage

Question 7

Which of the following is the most common cerebral vascular disease?

A. Ischemic stroke
B. Aneurysm
C. Subarachnoid hemorrhage
D. Primary intracerebral hemorrhage

Answer 7

A. Ischemic stroke (85% of cerebral vascular diseases)

Question 8

What are the different types of Ischemic stroke?

Answer 8

• atherothrombotic (50%)
• cardioembolic (30%)
• microangiopathic (20%)

Question 9

What is the only clinical proved pharmacological therapy in ischemic stroke?

Answer 9

i.v. thrombolysis

Question 10

What treatments of acute ischemic stroke have proven efficacy?

Answer 10

• stroke unit
• i.v. thrombolysis within 4.5 hr of symptoms
• endovascular treatment within 6 hours
• TPA

Question 11

What is the mortality rate of stroke?

A. 5%
B. 20%
C. 25%
D. 50%
E. 80%

Answer 11

C. 25%

Question 12

The risk of stroke is greater for men than for women.

A. true
B. false

Answer 12

A. true

25% of men and 20% of women can expect to suffer from a stroke if they live to be 85 years.

Question 13

Stroke is considered a ‘disease of the elderly’.

A. true
B. false

Answer 13

A. true

the most important risk factor for stroke is age

Question 14

What are some methods of secondary prevention of stroke?

Answer 14

• 300mg Aspirin
• Anticoagulants (cardiac embolism)
• treat hypertension
• quit smoking

Question 15

What is the Penumbra?

Answer 15

A functional lesion (cells are alive but have lost their function) that surrounds a structural lesion (cells have died).

• an area at risk for becoming a structural lesion - Neuroprotection potential?
• a region of silence in electrical activity, but with preserved metabolism
• decreased blood flow, but increased O2 extraction

Question 16

Why is a CT scan used immediately after stroke?

Answer 16

• CT cannot be used to see a lesion at this time
• is used because with CT you can detect hemorrhage
• if hemorrhage is present –> do NOT use TPA

Question 17

What is Diffusion Weighted Imaging (DWI)?

Answer 17

• A type of MRI
• uses the diffusion of water/protons (measures protons)
• in normal tissue: this diffusion happens normally
• if tissue is compromised, this movement is hindered
• DWI can detect abnormalities at 5hr post stroke already

Question 18

What is Perfusion Weighted Imaging (PWI)?

Answer 18

• inject a contrast agent - seen by MRI machine
• signal time course of the contrast agent
• colour coded (blue = relatively low flow)
• perfusion deficit occurs when blood flow is blocked and the contrast agent stays in tissue
• huge perfusion deficit in middle cerebral artery territory

Question 19

Stroke only affects neurons.

A. true
B. false

Answer 19

B. false

Now it is understood that microglia, oligodendrocytes, astrocytes, vessels, endothelium, basement membrane and ECM, immune cells, pericytes, and EC space may also be affected in addition to neurons.

Question 20

From a temporal perspective, inflammation and apoptosis occurs before energy failure/excitotoxicity of cells.

A. true
B. false

Answer 20

B. false

Energy failure/excitotoxicity of cells occurs at a time scale of min-hrs, whereas inflammation and apoptosis occur at a time scale of hrs-days.

Question 21

Is overactivation of the cell involved in stroke?

Answer 21

Yes. Overactivation causes excitotoxicity and energy loss.

-this was found as bloking the Glutamate receptor AMPA reduces infarct size

Question 22

What is Microglia’s role in stroke?

Answer 22

Can be either protective/damaging depending on context.

• in animal models, anti-inflammatory therapy protects the brain
• but also, microglia protect against injury, and their selective elimination dysregulates neuronal network activity after stroke.

Question 23

How can evolution affect a disease that is not under evolutionary pressure?

Answer 23

Via hypoxia, hypoxic environments

-we have mechanisms that can deal w these extreme conditions that also protect against stroke