3.18 Spinal Cord

Question 1

Describe Arterial Blood supply to Spinal Cord

Answer 1

1. One Anterior Spinal Artery
2. Two Posterior Spinal Arteries
3. Supplement branches
4. Functional blood supply

Question 2

1. One Anterior spinal artery

Answer 2

1. Midline vessel
2. Foramen Magnum
   Union Anterior spinal branches of Vertebral artery
   (rostral surface of medulla between pyramids)
3. Descends in midline fissure
   producing several branches to supply anterior 2/3 spinal cord

Question 3

2. 2 Posterior spinal arteries

Answer 3

1. Arise from PICA
   and Vertebral arteries
2. Descend to lie medial to roots of posterior cervical N
3. Supply posterior 1/3 Spinal cord
   fasciculus gracilis /cuneatus:
   vibration /light touch/proprioception
4. Significant variation exists in branching
5. Often excellent collateral anastomoses

Question 4

3. Supplemental Branches

Answer 4

1. 25-40 Additional Vessels
   Join adjacent arteries
   as Spinal cord descends
   in vertebral column

2. Cervical upper thoracic
VEtebral
thyrocostal
subclavian
costocervical arteries

3. T4-T9 Intercostals
   anterior and posterior branches

Question 5

3. Supplement branches

Answer 5

4. Below T9
   Main feeder vessel :
   Radicularis magna (artery Adamkiewicz)

a] 80% - Vessel enters cord via intervertebral foramina on left
derived from abdo aorta (t10-11)

b] 15%
arises @ T5 level
Lower cord
great proportion blood from iliac vessels
High incidence cauda equina
if vessels interrupted

5. Lumbar supply
   iliac/ lumbar/ lateral sacral artery

Question 6

4. Functional blood supply

Answer 6

Divided into 3 broad zones
good horizontal cross cover

Poor vertical overlap
renders cord vulnerable to watershed ischaemic insults

Question 7

Interruption of Anterior Spinal Artery

When + how

Answer 7

1. Main implications for vessel
   Focused around ruptured AAA
2. Hypotension
   worsened in presence atherosclerosis
   + luminal narrowing

can render large section thoracolumbar cord ischaemic + potentially infarcted

3. Endpoint seen during elective and emergency open AAA repair
   vessel lost during graft interposition
4. Risk of embolic occlusion

Question 8

Interruption of Anterior Spinal Artery

sequaelae

Answer 8

1. Loss motor function
   below lesion
   corticospinal + vestibulospinal
2. Loss of temperature and pain perception
   below lesion
   spinothalamic
3. Preserved dorsal columns mean vibration proprioception and light touch remain unaltered