Chapter 4 - Cerebrovascular Disease

Question 1

It is a clinical term applied to any abrupt nontraumatic brain insult— literally “a blow from an unseen hand.”

Answer 1

Stroke

Question 2

This is a permanent injury which occurs when tissue perfusion is decreased long enough to cause necrosis, typically due to occlusion of the feeding artery.

Answer 2

Infarction

Question 3

These are classically defined as transient neurologic symptoms or
signs lasting less than 24 hours, which may serve as a “warning sign” of an
infarction occurring in the next few weeks or months.

Answer 3

Transient ischemic attacks (TIAs)

Question 4

Etiologies of ischemic stroke (2)

Answer 4

1. Thrombi(2/3)
2. Emboli (1/3)

Vasculitis, vasospasm, coagulopathies, global hypoperfusion and venous thrombosis - 5% or fewer of acute strokes

Question 5

Percentage of total cardiac output the brain consumes in order to maintain its minute-to-delivery of glucose and oxygen.

Answer 5

20%

Question 6

Differential diagnosis of ischemic stroke in pediatric age group (7)

Answer 6

1. Congenital heart disease
2. Blood dyscrasias
3. Meningitis
4. Arterial dissection
5. Trauma
6. ECMO (extracorporeal membrane oxygenation)
7. Venous thrombosis

Question 7

Differential diagnosis of ischemic stroke in young adult age group (7)

Answer 7

1. Cardiac emboli
2. Atherosclerosis
3. Drug abuse
4. Arterial dissection
5. Coagulopathy
6. Vasculitis.
7. Venous thrombosis

Question 8

Differential diagnosis of ischemic stroke in elderly age group (6)

Answer 8

1. Atherosclerosis
2. Cardiac emboli
3. Coagulopathy
4. Amyloid
5. Vasculitis
6. Venous thrombosis

Question 9

Why are gray matter more susceptible to ischemia?

Answer 9

Gray matter normally receives three to four times more blood flow than white matter, and is therefore more likely to suffer under conditions of oligemia.

Question 10

Why are watershed zone prone to infarction?

Answer 10

Cells served by penetrating end-arteries or those residing in the watershed zone between major territories have no alternate route for perfusion

Question 11

What is the “insular ribbon sign”?

Answer 11

Blurring of the gray-white layers of the insula due to early edema.

Question 12

Hyperintense signal on diffusion-weighted images (DWIs) (“light-bulb sign”) precedes T2 hyperintensity, typically develops at what time?

Answer 12

Develops 6 to 12 hours post ictus.

Question 13

What disease is responsible for the majority of ischemic events in the ICA territory?

Answer 13

Atherosclerotic disease

Question 14

Other causes of significant internal carotid artery narrowing?
(Other than atheroscleroticdisease)

Answer 14

1. Arterial dissection
2. Trauma
3. Fibromuscular dysplasia
4. Tumor encasement
5. Prior neck radiotherapy
6. Connective tissue disease

Question 15

Hemodynamic effects to be seen in ICA when there is stenosis of what degree?

Answer 15

1. > 80% reduction in area
   Or
2. > 60% decrease in diameter

Question 16

Gold standard for preprocedure carotid artery evaluation

Answer 16

Selective common carotid angiography

• But is being replaced by noninavsive studies in many centers.

Question 17

The anterior cerebral artery is divided into three subgroups.

Which are?

Answer 17

1. Medial lenticulostriates serve the rostral portions of the basal ganglia
2. Pericallosal branches supply the corpus callosum
3. Hemispheric branches serve the medial aspects of the frontal and parietal
   lobes

Question 18

The medial lenticulostrates supplies what area?

Answer 18

1. Anterior-inferior aspect of the internal capsule
2. Putamen
3. Globus pallidus
4. Caudate head
5. Portions of the hypothalamus
6. Optic chiasm

Question 19

What supples the head/anterior internal capsule region?

Answer 19

Recurrent artery of Heubner

Question 20

Symptoms of medial lenticulostriate territory infarction.

Answer 20

1. Problems in speech production (motor aphasia)
2. Facial weakness
3. Disturbance in mood and judgment

Question 21

Unilateral damage in the ACA hemispheric branches will cause what?

Answer 21

Preferential leg weakness on the opposite side of the body.

Question 22

Bilateral AVA infarction lead to what?

Answer 22

Incontinence and an awake but apathetic state known as akinetic mutism.

Question 23

Triggering evens of watershed infarction (4)

Answer 23

Episodes of transient global hypoperfusion -

1. Cardiac arrest
2. Massive bleeding
3. Anaphylaxis
4. Surgery under general anesthesia

Question 24

Characteristic clinical findings of watershed infarct

Answer 24

1. Weakness isolated to the upper arms (man in a barrel syndrome)
2. Cortical blindness
3. Memory loss

Question 25

Small subcortical infarcts - 2 to 5 mm cavities left in the brain as a result of occlusion of a penetrating artery causing infarction and ensuing encephalomalacia

Answer 25

Lacunes

Question 26

Characteristic locations of lacunar infarcts

Answer 26

1. Lenticular nucleus (37%)
2. Pons (16%)
3. Thalamus (14%)
4. Caudate (10%)
5. Internal capsule/corona radiata (10%)