Neuro spine Flashcards
spinal cord blood supply
- anterior spinal artery-arise BL from termination of vertebral arteries –> join at foramen magnum.
- Ant 2/3
- 2 paired pst spinal arteries-from vertebral arteries or PICA; discount and reinforced by multiple segmental or radiculopial branches
- artery of adamkiewicz (great anterior radiculomedullary artery)
- 75% from left side aorta btw T8-T11, supplies lower 2/3
conus medullaris-where does it terminate? When should you think tethered cord?
- Terminates at L1
- inferior endplate L2/L3
differences in epidural fat cervical vs lumbar
cervical-predom venous plexus
-lumbar-fant ant and pst to cord
epidural lipomatosis
HTr of epidural fat in people on CS
Torg-Pavlov ratio
used to assess spinal stenosis
-cervical canal diameter : VB width <0.85
which part of spine is stenosis most symptomatic
cervical
congenital spinal stenosis
usually from short pedicles
degenerative spinal dx-types
1) spondylosis deformans-Normal aging. OPh at rim/margin
2) intervertebral osteochondrosis- centered in disc space: nucleus pulposus & VB EPs
osteophytes vs syndesmophytes
- osteophytes-horz/oblique w/ “claw-like” appearance. formed at vertebral margin. DJD/spondylosis
- syndesmophyte-vertical, symmetric & thinner. Ossification of annulus fibrosis. Seen in ankylosing spondylitis
“high intensity zone” of annulus
- Annular fissure/tear seen on MR.
- fissures are found in all degenerative discs but not all fisursures are visualized as HIZs.
which img is more sensitive than MRI in diagnosis of annular fissure?
discography, still not 100%
schmorl node/intervertebral herniation-what, how common, where, appearance acute vs chronic
- herniation of disc material through defect in VB EP into actual marrow
- v common (75%)
- lower thoracic/upp spine
- acute: T2+ (edema), T1- (sim to OM)
- chronic-sclerotic rim
Scheurermann’s (juvenile kyphosis)-what is it, classic scenario, how many have ass scoliosis?
Multiple levels of wedged VBs with associated schmorl’s nodes –> kyphosis (40˚ in thoracic or 30˚ in TL.)
- thoracic spine of teenager
- 25% ass scoliosis
limbus vertebra
- herniated disc material btw non-fused apophysis of adj vertebral body
- fracture mimic!
Disc nomenclature-herniation, bulge
Herniation < 25%
Bulge >25%
subtypes disk herniation
- protrusion-base wider
- extrusion-neck narrower than herniation
- sequestrum-broken off
localizing herniation in craniocaudal plane
-disc, suprapedicle, pedicle, infrapedicle
did sal’s pain increase?
localizing herniation in axial plane-which is MC and most syx
central, subarticular (MC), foramina (most syx via rel to dorsal root gang), extraforaminal
-no, he called someone for exedrine
how many pairs of spinal nerves
31
MC loc herniation
90% at L4-L5, L5-S1
conjoined nerve root
- most common developmental anomaly of nerve root
- two n roots arise from single dural sleeve
- app: asymm anterolateral corner of dural sac on axial T1 MRI. N root abscent at one level and duplicated at level below/above
Absolute CI to LP/myelogram
- (+) ICP or obstructed CSF flow
- bleeding diathesis (hypo coagulable)
- I allergy
Relative CI to LP
- vary per institution
1) overlying inf, hematoma, scarring
2) recent myelogram (<1wk)
3) hx of seizures
indication for fluoro guided LP
1) advanced degenerative spondylosis
2) post surgical change
3) obesity
4) MRI contraindicated