Blood Supply 1: Spinal Cord and Brainstem Flashcards
What is the anterior spinal artery derived from? Where is it?
Vertebral arteries. Formed from the right and left spinal arteries on the medulla, it lies in the anterior median fissure
What arteries supply the anterior spinal artery?
Anterior radicular arteries, derived from segmental vessels like vertebral arteries or intercostal arteries
What is the primary blood supply of almost the entire cervical spinal cord?
Branches of the vertebral artery -> including anterior and posterior spinal arteries + radicular branches
What region of the spinal cord is quite vulnerable to infarct (ischemic necrosis) during aneurysm dissection of the aorta?
Upper thoracic cord, as loss of radicular arteries during surgery would stop blood supply.
How must the aorta be moved during left-sided fracture repair of the vertebral bodies in the thoracic region?
Thoracic aorta must be moved to the right side, which is done by ligating several posterior intercostal arteries
How does the spinal cord maintain its blood supply after several posterior intercostal arteries have been ligated?
Anastomoses between anterior and posterior intercostal arteries, with blood supply from the internal thoracic artery (a branch of the subclavian)
What is the significance of the artery of Adamkiewicz and what type of artery is it?
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
What are the posterior spinal arteries derived from? What supplies them down the cord?
Vertebral arteries -> they are paired
Supplied by posterior radicular arteries
Why do posterior spinal arteries form an “apparent” discontinuous plexus?
Because the arteries have a tortuous path in and out of the spinal cord
What region of the spinal cord is supplied by the posterior spinal arteries?
Posterior 1/3 of the cord
What is the arterial vasocorona?
The anastomotic connections between atnerior and posterior spinal arteries which supply the peripheral portions of the lateral funiculi (white matter)
What branches supply the anterior 2/3 of the spinal card?
Anterior spinal artery, via its sulcal branches
Where does the posterior inferior cerebellar artery (PICA) arise from and what does it supply?
Arises from vertebral artery on each side
Supplies medulla, cerebellum, and inferior cerebellar peduncle
What do the vertebral arteries unite to form?
Basilar artery
What arteries does the basilar artery give rise to?
- Anterior inferior cerebellar arteries (AICA)
- Labyrinthine arteries (to inner ear) -> often from AICA
- Pontine arteries
- Superior cerebellar arteries
- Posterior cerebral arteries
What arteries supply the medulla?
Anterior and posterior spinal arteries, posterior inferior cerebellar (PICA), and branches from vertebral + basilar arteries
What arteries supply the pons and midbrain?
Superior cerebellar artery, AICA, branches from basilar artery
What arteries supply the cerebellum?
PICA, AICA, and SCA
What artery supplies the middle cerebellar peduncle?
AICA
What artery supplies the superior cerebellar peduncle?
Superior cerebellar artery
What causes inferior alternating hemiplegia?
destruction of anterior spinal artery very close to its origin off vertebral artery
What does inferior alternating hemiplegia cause?
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
What is Wallenberg’s syndrome also known as and what causes it?
Lateral Medullary Syndrome - caused by destruction of PICA, which damages all structures around dorsolateral mid-medulla levels, including inferior cerebellar peduncle
What are the symptoms of lateral medullary syndrome?
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
What causes lower lateral pontine syndrome? Where does this artery go?
Destruction or occlusion of AICA, this artery wraps around CN 7 / 8 at the cerebellopontine angle, also supplies middle cerebellar peduncle
What are the symptoms of lower lateral pontine syndrome?
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)
What causes rostral lateral pontine syndrome? What does that artery generally supply?
Destruction or occlusion of superior cerebellar artery, supplies the tegmenum of the mid and upper pons and lower midbrain
What are the symptoms of rostral lateral pontine syndrome?
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
