Brain Circulation and Strokes

Question 1

What is a stroke?

Answer 1

Acute neurological impairment due to ischemia or hemorrhage.

Question 2

What is the most common stroke?

Answer 2

Ischemic strokes.

Question 3

What is an ischemic stroke?

Answer 3

Acute neurological deficits caused by impaired blood flow to the nervous system.

Question 4

What scans are used to image strokes? Why?

Answer 4

MRI and CT scans, because they can detect brain density changes as well as presence of blood.

Question 5

Who is more susceptible to stroke at a younger age? (M or F)

Answer 5

Male

Question 6

Who is more susceptible to stroke at an older age? (M or F)

Answer 6

Female.

Question 7

Through what arteries does blood flow to the brain? Which are present in the posterior plane? Which are present in the anterior plane?

Answer 7

2 Carotid arteries in the anterior plane. 2 Vertebral arteries in the posterior plane.

Question 8

What causes impaired blood flow to the brain? (4)

Answer 8

1. Vessel problems.
2. Heart problems.
3. Blood problems.
4. Mitochondial disease.

Question 9

What CBF level is considered normal?

Answer 9

60-50 ml/100g/min.

Question 10

What is the threshold CBF past which synaptic transmission is halted?

Answer 10

20ml/100g/min.

Question 11

During a stroke, what is the region of the brain that faces reversible damage that can recover with suboptimal function if CBF is restored?

Answer 11

The penumbra.

Question 12

During a stroke, what is the region of the brain that obtains irreversible damage even when CBF is restored?

Answer 12

Infarct core.

Question 13

At what CBF level does the infarct core develop?

Answer 13

12ml/100g/min.

Question 14

What occurs to the brain when it is ischemic? How does this occur?

Answer 14

Cellular injury and death:
Apoptosis
Excitotoxicity from glutamate
Inflammation
Oxidative stress
Mitochondrial dysfunction

Question 15

What is the function of the BBB? What cells is it composed of?

Answer 15

FXN: Limit entry of blood products into the brain.
Composed: astrocytes, endothelial cells, pericytes, neurons.

Question 16

What drug is used to break down an ischemic stroke blood clot? How does it do this?

Answer 16

tPA: converts plasminogen into plasmin to break down fibrin (clots).

Question 17

What is TIA? How is it diagnosed?

Answer 17

Transient ischemic attack,

-Patient completely recovers within 24 hours, no infarct core present in CT or MRI.

Question 18

What artery supplies most of the brain? Which region of the sensory/motor cortex does it nourish?

Answer 18

Middle cerebral artery; the arm.

Question 19

What artery nourishes the occipital lobe?

Answer 19

Posterior cerebral artery.

Question 20

What are the unique symptoms of an MCA ischemic stroke?

Answer 20

Numbness in the arms.

Question 21

What are the unique symptoms of a PCA ischemic stroke?

Answer 21

Vision problems/blindness.

Question 22

What are the unique symptoms of an ACA ischemic stroke?

Answer 22

Numbness in legs.

Question 23

What is a lacunar stroke?

Answer 23

A stroke resulting from obstruction in lacunar vessels that stem from MCA. Causes defciits in the basal ganglia.

Question 24

What is the treatment for an acute stroke?

Answer 24

1. ABC: airway breathing and circulation.
2. IV tPA or endovascular therapy to remove clot.
3. Neuroprotective factors put in place.

Question 25

How are ischemic strokes prevented?

Answer 25

Treatment of vascular risk factors, administrations of antiplatelets/anticoagulants. Takeaway: treat underlying cause.

Question 26

What criteria in patients best suit endovascular therapy?

Answer 26

1. Small infarct core. | 2. Large artery occlusions (not quickly broken down by tPA)

Question 27

What is the most common/important cause of stroke?

Answer 27

Hypertension.

Question 28

What is carotid atherosclerosis? How is it treated?

Answer 28

Plaque buildup in the carotid artery causing thrombosis; treated by carotid endarterectomy or stent.

Question 29

What is a carotid/vertebral dissection? How to treat?

Answer 29

Occlusion of the CA or VA caused by blood clot formation due to tear in arterial wall, treated by anticoagulants/antiplatelets.

Question 30

What is small vessel lacunar stroke caused by?

Answer 30

Hypertension and diabetes or microvascular disease.

Question 31

How is small vessel lacunar stroke treated?

Answer 31

Antiplatelet.

Question 32

What is a cardioembolic stroke? What is the most common cause/risk factor?

Answer 32

A clot that migrates from the heart to the brain. The highest risk factor is atrial fibrillation.

Question 33

How is a cardioembolic stroke treated?

Answer 33

Anticoagulants

Question 34

What is atrial fibrillation?

Answer 34

Irregular contraction of atria that encourages the formation of clot in atrium.

Question 35

How do anticoagulants differ from antiplatelets?

Answer 35

Anticoagulants block coagulation cascade to prevent clotting, antiplatelets prevent platelets from adhesing to eachother

Question 36

What is a hemorrhagic stroke?

Answer 36

Neurological deficit caused by bleeding occuring inside or around the brain tissue.

Question 37

What are the subtypes of hemorrhagic strokes?

Answer 37

Epidural, subdural, subarachnoidal, intercerebral.

Question 38

How do intercerebral hemorrhages present?

Answer 38

Similar to ischemic strokes | -headache, altered level of consciousness.

Question 39

What is the main cause of IntC.H Stroke?

Answer 39

Hypertension.

Question 40

How do subarachnoid hemorrhagic strokes present?

Answer 40

Sudden headache, neck stiffness, altered level of consciousness, cranial nerve 3 palsy (no pupil dilation).

Question 41

What is the major cause of subarachnoid strokes?

Answer 41

Aneurysm ruptures.

Question 42

How are aneurysms treated?

Answer 42

Clipping or coiling to prevent bursting.