Cerebrovascular Disease

Question 1

Global cerebral ischemia (diffuse hypoxic ischemic encephalopathy) occurs when there is a _____.

Answer 1

generalized reduction of cerebral perfusion

(due to blood lost due to trauma, surgery or shock)

Question 2

Morphologic findings of global cerebral ischemia (3)

Answer 2

1. Watershed (Border Zone) infarcts and laminar necrosis
2. Necrosis of purkinje cells in the cerebellum OR of pyramidal neurons in the Sommer sector of the hippocampus

Question 3

3 ways that a cell (neuron) can exhibit selective vulnerability for necrosis?

Answer 3

1. They have a higher metabolic demand
2. They release excessive amount of AA NT which can be toxic to post-synaptic neuron
3. excitotoxicity

Question 4

Global cerebral ischemia can lead to

Answer 4

Widespread neuronal death→ clinical brain death

Question 5

Watershed (Border Zone) infarct occurs in the _____ (location)

Answer 5

Far end of the distribution of the anterior and middle cerebral arteries (it is poorly perfused where they meet)

(this leaves it likely to undergo infarction if it demands too much metabolically)

Question 6

Define laminar necrosis

Answer 6

Necrosis that occurs in a lamina and spreads along the cerebral cortex

(these are affected first when there is a decrease in blood flow to the brain)

Question 7

What is it?

Location of brain?

Answer 7

1. Watershed or Border Zone infarct in a patient with global cerebral ischemia
2. Parasagittal region of the hemisphere

(most common area for watershed infarct)

Question 8

Answer 8

• Histological side of the cerebral cortex
• Arrows point to an area of laminar necrosis

Question 9

Where is this most likely located?

Answer 9

This is likely a deeper area of the brain

Question 10

Focal cerebral ischemia is an occlusion of the

Answer 10

Local blood supply (infarction)

Question 11

Causes of focal cerebral ischemia

Answer 11

1. Atherosclerosis
2. Vasculitis
3. Emboli
4. Thrombus (especially patients with a hypercoagulable state)

Question 12

What is the difference between nonhemorrhagic or hemorrhagic infarcts?

Answer 12

1. Nonhemorrhagic (anemic) infarcts occur when due to an atherosclertic block→ occludes artery
2. Hemorrhagic (red) infarct occurs when an embolus suddenly excludes the artery and lyses→ collateral vessels pre-perfuse→hemmorhage

(it is important to make the distinction between the two for medication)

Question 13

Why is it important to make a distinction between a non hemorrhagic and a hemorrhagic infarct?

Answer 13

Thrombolytic medications = contraindicated in hemorrhagic infarcts

(we can make this distinction with an MRI)

Question 14

Early on an infarcted area of focal cerebral ischemia is described as ____.

Answer 14

Soft and edematous

(encephalomalacia; malacia=softening)

Question 15

Later on and infarct is phagocytized and a _____ is left.

Answer 15

cystic cavity is surrounded by gliosis

(there are no fibroblasts in the area to fill it in)

Question 16

Answer 16

Hemorrhagic infarct in the temporal lobe

Question 17

Answer 17

Non hemorrhagic infarct in the temporal lobe (oval)

Question 18

Answer 18

Acute cerebral infarction

(note the red-neuron changes: pykanosis of nuclei and eosinophilic)

Question 19

Answer 19

1. Infarct at about 10 days exhibiting necrotic debris with infiltration by macrophages and surrounding reactive gliosis.
2. Reactive gliosis can be seen in the lower right corner
3. Brain tissue is liquefying

Question 20

Answer 20

Small old infarct consisting of small cystic space accompanied by some surrounding gliosis

(8 weeks-years old)

Question 21

Hypertensive cerebrovascular disease leading to dementia: pathophysiology

Answer 21

Increase blood pressure → athero and arteriosclerosis→ vascular multi infarct dementia

Question 22

Binswanger disease

Answer 22

When infarcts mainly involve subcortical white matter

Question 23

Symptoms of vascular (multi-infarct) dementia:

Answer 23

1. Dementia
2. Gait disturbance
3. Pseudobulbar signs

Question 24

Hypertensive cerebrovascular disease leading to lacunar infarcts: pathophysiology

Answer 24

Increase blood pressure → arteriolosclerosis deep penetrating vessels (small muscular arteries and arterioles in the cerebral hemispheres and brainstem)→ end up being empty cystic spaces

(internal capsule, basil ganglia and ponds or common sites)

Question 25

Answer 25

Lacunar infarct in the caudate and putamen

Question 26

Where are these typically found?

Answer 26

1. Internal capsule 2. Basal ganglia 3. White matter 4. Thalamus 5. Pons (typically seen in patients with hypertension)

Question 27

Lacunar infarcts of the ______ will lead to significant motor deficits

Answer 27

internal capsule (typically seen in patients w/HTN)

Question 28

Intraparenchymal hemorrhage is also known as \_\_\_\_\_.

Answer 28

Intracerebral hemorrhage

Question 29

Intraparenchymal hemorrhage

Answer 29

Spontaneous & non-traumatic hemorrhage

Question 30

MCC of intraparenchymal hemorrhage

Answer 30

Hypertension

Question 31

MCC of intracerebral hemorrhage in patients with hypertension?

Answer 31

Charcot Bouchard microaneurysms (involves small muscular arteries and arterioles. They also have ganglionic hemorrhages)

Question 32

Second most common cause of intraparenchymal hemorrhage?

Answer 32

Cerebral amyloid angiopathy (Aβ40 deposited in vessel walls & **Lobar hemorrhages**)

Question 33

What are other causes of spontaneous intraparenchymal Hemorrhage?

Answer 33

1. Hemorrhagic diathesis (deficient in coagulation factor or platelet dysfunction) 2. Vasculitis 3. Tumors (most commonly occurs in the lobes of the cerebral hemispheres)

Question 34

Early on an intraprarenchymal hemorrhage is \_\_\_\_\_\_.

Answer 34

Extravasated blood compresses brain parenchyma

Question 35

Later on, an intraparenchymal hemorrhage leaves a \_\_\_\_\_.

Answer 35

Cavity surrounded by rim of hemiosiderin-laden macrophages & gliosis (there are no fibroblasts in the brain to fill in this hole)

Question 36

Answer 36

Spontaneous intracerebral hemorrhage

Question 37

ganglionic hemorrhages are typically located in the

Answer 37

Basal ganglia or thalamus (common in patients w/HTN)

Question 38

Answer 38

Cerebral amyloid angiopathy (these usually give rise to **lobar hemorrhages)**

Question 39

\_\_\_\_\_\_ usually gives rise to lobar hemorrhages, whereas \_\_\_\_\_\_\_most commonly gives rise to ganglionic hemorrhages.

Answer 39

* Cerebral amyloid angiopathy * hypertension

Question 40

Answer 40

* Histologic section of small arteriole of cerebral cortex * Cerebral amyloid angiopathy * Amyloid (Aß₄₀) is the yellow part in the arteriole (stained with Congo red)

Question 41

Subarachnoid hemorrhage most common cause

Answer 41

Saccular (berry) aneurysm (occur in 2% of ppl)

Question 42

Saccular aneurysms occur in or near

Answer 42

The Circle of Willis

Question 43

Cause of saccular aneurysm

Answer 43

Congenital attenuation or absence of the media of arteries (typically where they come to join together)

Question 44

Once a saccular (Berry) aneurysm becomes bigger than 10 mm in diameter, there is a _____ risk of rupture per year. Mortality rate?

Answer 44

* 50% * 35% (higher if they bleed again)

Question 45

What are the typical locations of Saccular (Berry) aneurysms

Answer 45

* 30% internal carotid complex * 30% anterior communicating artery * 30% trifurcation (one of the middle cerebral arteries) (20 to 30% of cases have multiple aneurysm sites)

Question 46

MCC of Intraparenchymal and/or subarachnoid hemorrhage

Answer 46

Arteriovenous malformation (AVM)

Question 47

Define arteriovenous malformation (AVM)

Answer 47

Composed of a tangled network of dilated blood vessels

Question 48

Arteriovenous malformations are caused by

Answer 48

Focal congenital absence of capillary bed in the brain→ arteries will then directly communicate with arteries→ veins can't handle the pressure→ rupture

Question 49

Patients with arteriovenous malformation typically present with _____ (2).

Answer 49

* Seizures * Hemorrhage (intraparenchymal or subarachnoid)

Question 50

Answer 50

Arteriovenous malformation ("bag of worms")

Question 51

Arteriovenous malformation ratio male to female

Answer 51

2/1

Question 52

What is the most common cause of a lobar hemorrhage in an elderly patient?

Answer 52

Cerebral amyloid angiopathy