Blood Supply 1: Spinal Cord and Brainstem

Question 1

What is the anterior spinal artery derived from? Where is it?

Answer 1

Vertebral arteries. Formed from the right and left spinal arteries on the medulla, it lies in the anterior median fissure

Question 2

What arteries supply the anterior spinal artery?

Answer 2

Anterior radicular arteries, derived from segmental vessels like vertebral arteries or intercostal arteries

Question 3

What is the primary blood supply of almost the entire cervical spinal cord?

Answer 3

Branches of the vertebral artery -> including anterior and posterior spinal arteries + radicular branches

Question 4

What region of the spinal cord is quite vulnerable to infarct (ischemic necrosis) during aneurysm dissection of the aorta?

Answer 4

Upper thoracic cord, as loss of radicular arteries during surgery would stop blood supply.

Question 5

How must the aorta be moved during left-sided fracture repair of the vertebral bodies in the thoracic region?

Answer 5

Thoracic aorta must be moved to the right side, which is done by ligating several posterior intercostal arteries

Question 6

How does the spinal cord maintain its blood supply after several posterior intercostal arteries have been ligated?

Answer 6

Anastomoses between anterior and posterior intercostal arteries, with blood supply from the internal thoracic artery (a branch of the subclavian)

Question 7

What is the significance of the artery of Adamkiewicz and what type of artery is it?

Answer 7

It is an anterior radicular artery around the L2 level, supplies the lumbosacral enlargement of the spinal cord. Important to remember in abdominal surgery / trauma

Question 8

What are the posterior spinal arteries derived from? What supplies them down the cord?

Answer 8

Vertebral arteries -> they are paired

Supplied by posterior radicular arteries

Question 9

Why do posterior spinal arteries form an “apparent” discontinuous plexus?

Answer 9

Because the arteries have a tortuous path in and out of the spinal cord

Question 10

What region of the spinal cord is supplied by the posterior spinal arteries?

Answer 10

Posterior 1/3 of the cord

Question 11

What is the arterial vasocorona?

Answer 11

The anastomotic connections between atnerior and posterior spinal arteries which supply the peripheral portions of the lateral funiculi (white matter)

Question 12

What branches supply the anterior 2/3 of the spinal card?

Answer 12

Anterior spinal artery, via its sulcal branches

Question 13

Where does the posterior inferior cerebellar artery (PICA) arise from and what does it supply?

Answer 13

Arises from vertebral artery on each side

Supplies medulla, cerebellum, and inferior cerebellar peduncle

Question 14

What do the vertebral arteries unite to form?

Answer 14

Basilar artery

Question 15

What arteries does the basilar artery give rise to?

Answer 15

1. Anterior inferior cerebellar arteries (AICA)
2. Labyrinthine arteries (to inner ear) -> often from AICA
3. Pontine arteries
4. Superior cerebellar arteries
5. Posterior cerebral arteries

Question 16

What arteries supply the medulla?

Answer 16

Anterior and posterior spinal arteries, posterior inferior cerebellar (PICA), and branches from vertebral + basilar arteries

Question 17

What arteries supply the pons and midbrain?

Answer 17

Superior cerebellar artery, AICA, branches from basilar artery

Question 18

What arteries supply the cerebellum?

Answer 18

PICA, AICA, and SCA

Question 19

What artery supplies the middle cerebellar peduncle?

Answer 19

AICA

Question 20

What artery supplies the superior cerebellar peduncle?

Answer 20

Superior cerebellar artery

Question 21

What causes inferior alternating hemiplegia?

Answer 21

destruction of anterior spinal artery very close to its origin off vertebral artery

Question 22

What does inferior alternating hemiplegia cause?

Answer 22

Destruction of pyramidal tract -> contralateral spastic paralysis

Destruction of medial lemniscus -> contralateral fine touch loss

Destruction of hypoglossal nerve as it exits preolivary sulcus -> ipsilateral deviation of tongue

Question 23

What is Wallenberg’s syndrome also known as and what causes it?

Answer 23

Lateral Medullary Syndrome - caused by destruction of PICA, which damages all structures around dorsolateral mid-medulla levels, including inferior cerebellar peduncle

Question 24

What are the symptoms of lateral medullary syndrome?

Answer 24

ALS damage -> contralateral
Nucleus ambiguus damage -> hard to swallow, hoarse voice, uvula deviation to contralateral side
Spinal nucleus / tract of V -> ipsilateral pain / temp on face
Inferior cerebllar penduncle -> posterior spinocerebellar tract / CCT loss = ataxia from lack of unconscious proprioception
Horner’s syndrome -> loss of descending reticulospinal fibers which activate sympathetics, ipsilateral ptosis, miosis, anhydrosis

Question 25

What causes lower lateral pontine syndrome? Where does this artery go?

Answer 25

Destruction or occlusion of AICA, this artery wraps around CN 7 / 8 at the cerebellopontine angle, also supplies middle cerebellar peduncle

Question 26

What are the symptoms of lower lateral pontine syndrome?

Answer 26

facial paralysis, dry eye (facial nerve is PANS to lacrimal gland), decreased salivation (loss of sublingual / submandibular), loss of taste on anterior 2/3, deafness (CN8), nystagmus to opposite side (no input from ipsilateral side, fast reset the other way)

Question 27

What causes rostral lateral pontine syndrome? What does that artery generally supply?

Answer 27

Destruction or occlusion of superior cerebellar artery, supplies the tegmenum of the mid and upper pons and lower midbrain

Question 28

What are the symptoms of rostral lateral pontine syndrome?

Answer 28

Bilateral ataxia and intention tremor -> loss of blood supply to decussation and entire superior cerebellar peduncle

Contralateral sensory loss to body and face -> affects sensory body including ML, VTTT, DTTT, ALS