Blood Supply, Hemorrhage, & Herniation

Question 1

What are the four parts of the ICA?

Answer 1

Cervical part, petrous part, cavernous part, cerebral part

Question 2

What are the three parts of the vertebral a?

Answer 2

Cervical part, atlantic part, intracranial part

Question 3

What is vertebrobasilar insufficiency?

Answer 3

decreased blood flow of vertebral a to the brain

Question 4

What can cause vertebrobasilar insufficiency?

Answer 4

Extreme hyperextension of the head, extreme head rotation, subclavian steal syndrome

Question 5

What forms the circle of willis?

Answer 5

ICA (x2), ACA (x2), anterior communicating a (x1), posterior communicating a (x2), PCA (x2)

Question 6

Which artery is not part of circle of willis?

Answer 6

MCA

Question 7

Which vessels can compress CN II?

Answer 7

ICA, ACA, and anterior communicating a

Question 8

Which vessels can compress CN III?

Answer 8

Sandwiched between PCA and superior cerebellar a

Question 9

Which vessels can compress CN V?

Answer 9

Superior cerebellar a (aberrant loops)

Question 10

Which vessels can compress CN VI?

Answer 10

Labyrinthine a and AICA

Question 11

Which vessels can compress CN VII?

Answer 11

AICA (aberrant loops)

Question 12

Where does the ACA supply in the brain?

Answer 12

Medial and superior surfaces of frontal/parietal lobes

Question 13

Where does the MCA supply in the brain?

Answer 13

Lateral surface of frontal/parietal and superior surface of temporal lobe

Question 14

Where does the PCA supply in the brain?

Answer 14

Occipital lobe and inferior temporal lobe

Question 15

What deficits can be seen in the border zone between ACA/MCA?

Answer 15

Motor, sensory, language, and behavioral deficits

Question 16

What deficits can be seen in the border zone between MCA/PCA?

Answer 16

Vision and language problems

Question 17

What are the segments of the ACA?

Answer 17

A1 - precommunicating
A2 - infracallosal
A3 - precallosal
A4 - supracallosal
A5 - postcallosal

Question 18

What are the segments of the MCA?

Answer 18

M1 - sphenoidal/horizontal
M2 - insular
M3 - opercular
M4 - cortical

Question 19

What are the segments of the PCA?

Answer 19

P1
P2
P3 - quadreminal segment
P4 - cortical segment

Question 20

Which arteries supply different parts of the medulla?

Answer 20

Anterior spinal a does the medial aspect
PICA does the lateral aspect
AICA does the cochlear nuclei (CN VIII)
Posterior spinal a does the dorsal aspect

Question 21

What arteries supply the pons?

Answer 21

Branches off the basilar a

Question 22

Which arteries supply different parts of the pons?

Answer 22

Paramedial branches supply medial aspect

Long circumferential branches supply lateral aspect

Question 23

What arteries supply the midbrain?

Answer 23

Mostly branches from posterior cerebral a

Question 24

Which arteries supply different parts of the midbrain?

Answer 24

Branches of P1 supplies anteromedial part of midbrain

Branches of P3 supplies lateral structures

Question 25

Which arteries supply different parts of the forebrain?

Answer 25

Branches of P2 supply LGN and MGN Lenticulostriate arteries supply internal capsule Anterior choroidal a supplies internal capsule

Question 26

Which arteries supply different parts of the spinal cord?

Answer 26

Posterior spinal arteries supply dorsal/posterior columns Sulcal branch of anterior spinal a supplies dorsal and ventral horn Anterior spinal a and posterior spinal a do the corticospinal tract

Question 27

What is usually the source of bleeding for intracerebral hemorrhages? (hemorrhagic strokes?)

Answer 27

MCA (usually causes midline shift due to all the bleeding)

Question 28

What compartment is above the tentorium cerebelli?

Answer 28

The supratentorial compartment, divided into R/L by falx cerebri

Question 29

What compartment is below the tentorium cerebelli?

Answer 29

The infratentorial compartment

Question 30

What is the tentorial notch?

Answer 30

Continuation of the supra and infratentorial compartments

Question 31

What is a subfalcine herniation?

Answer 31

Occurs in the supratentorial compartment when brain tissue is displaced under the falx cerebri.

Question 32

What can a subfalcine herniation compromise?

Answer 32

May compress ACA (frontal/parietal lobe), could compromise lower limbs

Question 33

What is a transtentorial herniation?

Answer 33

Brain displaced downward toward tentorial notch.

Question 34

What can a transtentorial herniation compromise?

Answer 34

Compromises upper brainstem and CN III. May compress basilar a and PCAs, associated with decorticate rigidity -> decerebrate rigidity

Question 35

What is an uncal herniation?

Answer 35

Uncus (and sometimes portions of parahippocampal gyrus) extrude over edge of tentorium cerebelli and through tentorial notch

Question 36

What can an uncal herniation compromise?

Answer 36

Can impinge on midbrain

Question 37

What is a tonsillar herniation?

Answer 37

Cerebellar tonsils through foramen magnum

Question 38

What can a tonsillar herniation compromise?

Answer 38

Compression of medulla and upper cervical spinal cord (cardiac and respiratory centers)