3.21.14 39 Vasculopathology

Question 1

What’s the difference between hypoxia and ischemia?

Answer 1

Ischemia = loss of circulation
Hypoxia = decreased oxygen
—
Ischemia always leads to hypoxia, but not all hypoxia = ischemia

Question 2

What’s an infarct?

Answer 2

Death of tissue

Question 3

What are the causes of ischemic infarct?

Answer 3

Atherosclerosis

Thrombosis

Question 4

What is the cause of hemorrhagic infarct?

Answer 4

Incomplete occlusion followed by recirculation:

Vessels become weak, reperfusion leads to hemorrhage

Question 5

What is the difference between hemorrhagic infarct and primary hemorrhage?

Answer 5

Primary hemorrhage is not preceded by infarct; brain tissue is displaced (hematoma)

Question 6

What is the progression of an infarct (tissue changes)?

Answer 6

Within 24 hrs: acute neuronal injury
>24hrs: infarction
1st week: neutrophils
2-3 weeks: macrophages replace neutrophils
Gradual gliosis
6-8 wks: cavity formation

Question 7

Myocardial infarcts, ruptured aortic aneurysms, and GI bleeds can lead to what type of CNS problem?

Answer 7

Generalized/global ischemia and hypoxia

Question 8

What is the characteristic appearance of ischemic neurons?

Answer 8

Red neurons

Question 9

What two areas are most sensitive to ischemia?

Answer 9

Sommer’s sector (CA1) of hippocampus

Purkinje cells

Question 10

What is laminar necrosis? What characterizes this microscopically?

Answer 10

Watershed infarcts - typically targets cortical layers 3,5,6 (pyramidal cells)
Band-like pattern of necrosis –> areas near the surface are protected by the meninges

Question 11

What defines brain death relative to persistent vegetative state?

Answer 11

Flat EEG

Absence of perfusion, reflexes, respiration

Question 12

What is respirator brain?

Answer 12

Autolysis of brain tissue when pt is kept alive on mechanical ventilation - soft, liquefied brain tissue

Question 13

Why shouldn’t tPA (fibrinolytic treatment) be given after 3 hrs?

Answer 13

Danger of hemorrhagic infarction: reperfusion can rupture damaged blood vessels

Question 14

Atherosclerosis and thrombosis typically lead to…

Answer 14

Ischemic infarction

Question 15

Embolism, vasospasm, extrinsic compression, and reperfusion typically lead to…

Answer 15

Hemorrhagic infarction

Question 16

Trauma usually leads to what types of hemorrhage?

Answer 16

Epidural and subdural

Question 17

Vascular pathology usually leads to what types of hemorrhage?

Answer 17

Intracranial and subarachnoid

Question 18

Hypertension can cause what types of brain bleeds?

Answer 18

Intracerebral and cerebral hemorrhage

Question 19

Berry aneurysms lead to what types of brain bleeds?

Answer 19

Subarachnoid

Question 20

What types of vascular malformations can lead to hemorrhage?

Answer 20

Arteriovenous malformations

Cavernous hemangiomas

Question 21

What are arteriovenous malformations?

Answer 21

Thick arteries and veins without capillary channels

Question 22

What is a cavernous hemangioma?

Answer 22

Dilated, intercommunicating veins without brain tissue in between

Question 23

What are dissecting aneurysms?

Answer 23

Atherosclerotic damage leads to cracks in the intima –> blood seeps through, widening the cracks

Question 24

What is vasogenic edema?

Answer 24

Most common cerebral edema
Fluid in extracellular space (white matter only)
Disruption of BBB in infarct, hemorrhage, tumor, trauma

Question 25

What is cytotoxic edema?

Answer 25

Fluid in intracellular space (white and gray matter)

Cellular membrane injury due to hypoxia or metabolic events

Question 26

What herniation occurs when brain tissue crosses under the cerebral falx?

Answer 26

Cingulate/subfalcine

Question 27

What herniation occurs when tissue from the temporal lobe gets compressed within the tentorial notch?

Answer 27

Uncal/transtentorial

Question 28

What herniation occurs when the cerebellum gets compressed in the foramen magnum?

Answer 28

Tonsillar

Question 29

What herniation occurs when brain tissue leaks out the skull?

Answer 29

Transcalvarial/fungating

Question 30

Secondary hemorrhage in the brain stem occurs due to compression following what herniation? What is this hemorrhage called?

Answer 30

Transtentorial/uncal

Duret hemorrhage