Download Contralateral side

1. Know the vasculature for the spinal cord, and what would be affected with a
dorsal/posterior spinal artery issue vs. a ventral/anterior spinal artery issue
1. Occlusion of the posterior spinal artery will cause what deficits?
a. Notice here that the posterior/dorsal artery supplies the gracile and
cuneate fasiculus which are a part of the DCML pathway. Occlusion
of this artery will cause deficits in fine touch and conscious
proprioception to the upper and lower extremities.
2. Occlusion of the anterior spinal artery will cause what deficits?
a. If the anterior spinal artery is effected the corticospinal tract will be
affected causing motor deficits on the ipsilateral side (the lesion will
be below the decussation causing the ipsilateral).
b. The spinothalamic tract will also be affected causing loss of pain and
temperature
I emailed Dr. Sarko to ask about the ipsilateral and contralateral sides on these to be sure.
When she responds I will add what she said to here.
2. Be able to discriminate cross-sections at the cervical, thoracic, and lumbar levels based
on characteristics and appearance
• You can identify cervical, thoracic, and lumbar levels from each other.
– The greatest amount of grey matter (cells) is largest in the spinal segments of
the cervical and lumbosacral enlargements
– The thoracic and upper lumbar levels have relatively small amounts of grey
matter since they innervate the thoracic and abdominal regions.
– The absolute number of nerve fibers in the white matter increases at each
successively higher spinal segment.
– The lateral horn is present from T1-L2.
– Fasciculi cuneatus and gracilis are BOTH present above T7.
– When comparing the cervical and lumbosacral enlargements, the dorsal horn
at cervical levels is narrower than that in lumbars; the ventral horn is broad in
both.
–
3. Lumbar punctures
• Needles can be inserted below L2 into the subarachnoid space without damaging
the spinal cord the long roots of the cauda equina will slide away from the needle tip
Usually go further, ~L4, to be sure you’re not hitting the spinal cord.
Lumbar puncture can be used to:
a) Collect CSF (cerebrospinal fluid) from the subarachnoid space
b) Introduce spinal anesthesia/epidural anesthesia
4. Herniated discs
• What is the most common type of herniated disk?
• Most commonly, the nucleus pulposus will herniate just lateral to the posterior
longitudinal spinal ligament
5. Herniated disks most often occur at what levels?
• Most often at L4/5, L5/S1 disc
• C5/6 and C6/7 common cervical levels
• Thoracic levels are rare
6. Brown Sequard syndrome
• Lesions that cause Brown-Sequard syndrome affect ½ of the spinal cord leaving
the other side intact. Due to the nature of the decussations in each pathway you
end up with an interesting pattern of symptoms.
1. hypotonia (LMN lesion, ventral horn motor neuron) Level of the
dermatome
2. A) spasticity, hypertonia (UMN lesion, damage to corticospinal tract) B)
conscious proprioception (position sense) and fine touch due to damage
to PCML/DCML pathway Ipsilateral side
3. loss of pain and temperature sensation (damage to spinothalamic
pathway) Contralateral side
7. Lesion of the dorsal root will cause what symptoms?
• Ipsilateral sensory disturbances: both fine touch/conscious proprioception from
PCML/DCML pathway sensory receptors and also pain/temperature loss in the
corresponding dermatome depending on the spinal cord level of the lesion.
• Motor function intact
8. Lesion of the dorsal horn will cause what symptoms?
• Ipsilateral loss of pain and temperature sensation in the affected spinal cord
segment(s)
• Motor function, conscious proprioception and fine touch intact.
9. Lesion of the gracile fasciculus will cause what symptoms?
• Ipsilateral loss of fine touch and conscious proprioception specific to the lower
extremity.
• Motor function and Pain/temperature intact.