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
Technical overview LP: where to enter, what to target, direction of bevel
- L2/L3 or L3/L4 (Below conus)
- target inter laminar space (just off midline)
- bevel directed opposite direction you’re trying to steer
- always aspirate before injecting
how to know if you’ve done a successful myelogram?
- contrast pooling at needle tip
- subdural injection in fat around thecal sac if pooling posterior lateral
how to reduce post dural puncture headache
small needle (25G, 22G if dx LP)
- diamond shaped needle tip (non-cutting, atraumatic)
- replace stylet before withdrawing
- bevel parallel with fibers to push (not cut)
post dural puncture headache (PDPH)-what, better/worse, time frame, mx
- intracranial hypotension secondary to defect in thecae sac s/p P
- BL, better laying down, worse sitting up or with straining
- 24-48hrs (larger leaks earlier)
- mx- conservative –> blood patch 72 hrs.
- super severe –> ct head (r/o SDH)
blood patch
inject 3-20cc of pts own blood into epidural space near original puncture site
Failed Back Surgery Syndrome
recurrent or residual LBP after disk surgery.
40%
complications of spine surgery
1) recurrent residual disk- no enhancement
2) epidural fibrosis-posterior, enhance homogeneously on delayed img
3) arachnoiditis- >6wk=abN
“clumped n roots”, “empty thecae sac”
arachnoiditis
post spinal surgery scar vs residual disc
both look like a bunch of mushy crap
- scar homogenous enhances delayed
- residual disc-no enh
Odontoid fracture types-which is most common? At risk of non-union? Best prognosis? Which are unstable?
1) upper part 2/2 avulsion alar ligament. Rare
2) most common. fx at base. High non-union rate. unstable.
3) dens–> body of C2. best prognosis for healing. Unstable
how many people with Jefferson fx have ass C2 fx
30%
Jefferson fracture- MOA, app, neuro dam?
- axial loading injury
- ant and pst arches blown out laterally –> widening lateral masses-increased distance btw masses and dens
- minimal cord dam
os terminale
apophysis at orthotropic aspect of dens
os odontoideum
os terminale + hypoplastic dens. Ass with Morquio’s syndrome.
dystopic os terminale/odontoideum
fused to clivus
hangman fx-moa, app, neuro damage, associated injuries
- chin hits dashboard
- BL pars defect at C2 (or pedicle, less likely –> ass ant subluxation C2 (>2mm)
- cord damage uncommon (pars defect widens canal)
- ass: avulsion ALL –> fx anterior inferior corner of C2
flexion teardrop-moa, appearance, neuro dam
- hyperflexion. impaction injury. “ran into a wall”
- ant inferior body fracture –> pst sublux –> anterior cord syndrome (85% neuro defects)
extension teardrop
- hyperextension, distraction injury, “hit from behind”
- avulsion ALL –> ant/inf body fracture
- more stable (stable in flexion, unstable in extension)
clay shoveler’s fracture-moa, app, associated sign
- avulsion lower cervical/upper thoracic SP (C7 MC)
- forceful hyperflexion
- “ghost sign”-caudal displacement of broken SP –> double sinus process at level above on AP radiograph
Chance fracture-moa, where, associations
Flexion/distraction fx
- lap band seat belt, high ass organ trauma
- 3 column
- upper lumbar, TL levels
“ghost sign”
Caudal displacement of broken SP –> double sinus process at level above on AP radiograph
Facet dislocation spectrum
sublux –> perched –> locked
UL vs BL facet dislocation
UL-hyperflex + rotation. Stable
BL-severe hyperflex –> disruption PLL –> VB ant disloc 1/2 the AP diam. Highly US
inverted hamburger sign
subluxed facet dislocation
Atlantoaxial instability-distance cut off, associations, special about kids, usual fakeout?
- ant arch C1 & dens > 5mm (for children, 2.5 mm for adults)
- DS, juvenile RA
- kids can have rotation w/o fracture. NEVER in adult (unless DS, RA).
- head tilt in scanner
transverse cruciform ligament
straps dens to ant arch of C1
pars interarticularis defect (spondylolysis or adult isthmus spondylolisthesis)-MOA, location, cause of pain, “pseudo-disc”
- repetitive micro trauma related to hyperetension
- 90% L5/S1
- pain via radiclopathy of L5 at L5/S1
- “pseudo-disc”-ass deformed annular fbrs
ways to assess unstable spinal fracture
1) acute segmental kyphosis >11˚
2) acute anterolisthesis > 3-4 mm
3) gross motion on flexion/extenion imaging
4) power ratio, Harris lines
5) spinal column theory
power ratio
basion/pst spinolaminar line distance: ant arch of atlas/opisthion line distance.
->1= unstable ligament
Harris lines rule of 12
both basion-dens and basion-posterior axial distance <12mm
occipitocervical instability-causes, ways to assess
- causes=trauma, DS, or congenital
- powers ration & Harris lines rule of 12
Denis 3 spinal column concept-when to use
- Thoracolumbar (lower cervical) spinal fractures
- anterior column: ALL–> ant 2/3 VB
- middle column: pst 1/3 VB –> PLL
- pst column: posterior ligaments & elements.
How does management change with an unstable fracture?
stabilized via internal fusion or external bracing/reduction
Canadian C-spine rule
- age >65yrs
- paresthesia
- dangerous mech: fall >3ft or 5 stairs, axial load to head, high speed MVA, pedestrian vs car, hulk smash
Nexus criteria
- focal neuro deficit
- ML tenderness
- altered LOC
- intoxication
- distraction injury
criteria for imaging spine in trauma
- Canadian C spine Rule
- Nexus Criteria
unstable spine fractures
- atlanto-occipital and Atlanta-axial dislocations
- odontoid 2, 3
- Jefferson
- Hangman
- flexion tear drop
- extension tear drop in extension *(Eek!)
- vertebral overriding >3mm (subluxation) or angulation > 11 degrees
- BL facet dislocation/sublux
- 2 con’t or 3 column thoracolumbar
stable spine fractures
- odontoid type 1
- extension tear drop (in flexion)
- clay shoveler’s
- UL facet dislocation
- TP fracture
- single column
types of spinal cord syndromes related to trauma. Which is really bad?
- anterior cord- worst
- brown sequard-
- central cord-
- posterior cord-
Central cord syndrome-who, deficit
- old lady w/ spondylosis or young person with bad extension injury
- UE > lower (coricospical tracts are lateral in LE)
anterior cord syndrome- mech and deficit
- mech: flexion injury
- immediate paralysis
brown sequard syndrome-mech and deficit
- mech: rotation or penetration
- IL motor and proprioception/tactile/vibration
- CL pain & T
posterior cord syndrome- mech and deficit
- uncommon
- hyperextension
- loss of proprioception/tactile/vibration
AVFs/AVMs types
1) dural AVF w/ single coiled vessel-MC
2) intramedullary nidus
3) juvenile
4) intradural perimedullary
type 1 spinal avm/avf
-dural AVF w/ single coiled vessel
which is the most common spinal AVF/AVM?
type 1 (dural AVF)
type 2 spinal avm/avf- what, risks, mc pres, ass
intramedullary nidus from anterior or pst spinal a.
- aneurysms –> bleed
- mc pres=sah
- ass=hht, KTS (or other vascular syndromes)
type 3 spinal avm/avf-who? prognosis?
Juvenile
- v rare, complex
- horrible prognosis
type 4 spinal avm/avf-what, subtypes, where
- Intradural perimedullary
- subtypes: single vs multiple arterial supply
- near conus
Foix Alajouanine syndrome- pathophys, what, classic hx, img
- vascular malformation (dural AVF) –> venous HTN –> congestive myelopathy
- 45 yr old male with LE weakness & sensory deficits
- img: T2+ cord (edema) + FVs (serpentine, punctate, serpiginous) (vs CSF pupation artifacts=blob like)
hydromyelia vs syringomyelia
- hydromyelia-lined by ependyma
- syringomyelia-not lined by ependyma
syrinx-what, causes, img
- central cord dilation
- 90% congenital (Chiari I, II, DW, KF, myelomeningoceles)
- 10% acquired (trauma, tumor, vascular insufficiency)
- central T2+ dilation surrounded by totally normal cord
myelopathy
- diseased spinal cord
- usually from disc/OP compression
“owl’s eye sign”
spinal cord infarct
spinal cord infarct-causes, app
- MC ant a –> central/anterior horn T2+ (GM most vulnerable to itch.) Long segment (>2 VBs), diffusion.
- idiopathic=mc
- aortic aneurysm stent graft
- emboliizaiton bronchial artery
5 categories Spinal demyelination (T2/Flair hyperintensity
1) demyelinaiton
2) tumor
3) vascular
4) inflamm
5) infectious
MS in the cord-appearance, MC loc, how often isolated, when you see atrophy.
- short segment, affecting part of cord
- cervical
- isolated lesion ~10%
- +/- atrophy if disease burden large
Transverse myelitis-what, causes, app, types
-focal inflammation/enlargement of cord (2/3 cross sectional area), long segm
-causes-infectious, post-vaccination, rabies, SLE, Sjogren’s, paraneoplastic, AVMs)
-“acute partial”= <2 segms. Higher risk for dev MS
“acute complete” - >2 segms
acute partial vs acute complete TM-which has higher risk MS?
acute partial
ADEM spinal demyelination-what, blood test
- dorsal WM (but can involve GM)
- anti-MOG IgG+ 50%
- brain lesions usually
Neuromyelitis optica of the spine-aka, what part of CNS is favored/who gets brain lesions, appearance, pathophys.
- “Devics”-Optic n and cervical cord. Monophasic or relapsing
- longer segm, full transverse
- brain lesions (periVt) MC in asian people.
pathophys of periVt lesions in NMO?
NMO IgG –< aquaporin 4 channels, which are found in highest conc around Vts.
Subacute combined degeneration-pathophys, mc loc, sign
- vitB12 deficiency
- BL, symmetric, dorsal columns, no enh
- “inverted V sign” (V for vitamin)
- upper thoracic –> asc or desc
HIV vacuolar myelopathy-who, MC findings
- mcc sc dysfunction in untreated AIDS, ie: late finding
- atrophy=MC (thoracic mc, cervical –> rostral progression)
- T2 signal symmetric pst columns (like SACD)
appearance of posterior artery ischemia
UL (sim to MS)
arachnoiditis-what, causes, img
- inflamm of SAS
- infection, post-surgical (10-15%)
- empty thecal space sign-n roots adherent peripherally
- central nerve root clumping-form single central scarred band
Guillain barre syndrome-what, causes, appearance, MC CN involved?
- acute inflammatory demyelinating polyneuropathy (AIDP)
- ascending flaccid paralysis
- causes: campylobacter, surgery, lymphoma, SLE
- enh of nerve roots of caudate equina (ant > pst)
- FN=mc cn
chronic inflammatory demyelinating polyneuropathy (CIDP)-what, img
- chronic counterpart to GBS (GBS improved in 8 wks)
- gradual, protracted weakness
- “thickening enhancing “onion bulb” nerve roots. “dreadlocks, locs, data”
Spinal cord tumor locations
intramedullary, extra medullary intramural, extradural
intramedullary spinal tumors
- astrocytoma-mc in peds
- ependymoma-most common in adults
- hemangioblastoma-VHL
- mets-lung (70%)
spinal astrocytoma-who, where, img
- MC sc tumor in peds
- upper thoracic
- fusiform dilation of cord over multiple segments
- eccentric, T1-, T2+, hetero enh
- +/- rostral, caudal cysts (benign syrinx’s)
- expansile remodeling of the osseous spinal canal.
spinal ependymoma-who, where, img
- MC sc tumor in adults
- lower spinal cord/conus/FT (can be in cervical)
- myxopapillary form-conus/FT
- hemorrhage, dark T2 cap (hemosiderin), tumoral cysts 1/4, long segm (~4), central loc, homogenous enhancement.
spinal astrocytoma vs ependymom
- AC=pediatric. upper cord. eccentric. hetero enh
- Epend=adult, lower cord, central, homog enh, T2 dark cap
spinal hemangioma-who, where, classic look
- VHL 30%
- thoracic –> cervical
- wide cord + sign edema. +/- Adjacent serpiginous draining meningeal varicosities
intramedullary mets
v rare
-lung 70%
VHL associations
- pheochromotyoma
- CNS hemangioblastoma (Cerebellum 75%, spine 25%)
- endolymphatic sc tumor
- pancreat cysts, islet cell tumors
- Clear cell RCC
- papillary cyst adenoma of epididymis
- epididymal cysts
extra medullary intradural spinal cord tumors
schwannoma-MC
NF
Meningioma
Drop mets
SC schwannoma-where, ass if multiple, app
- mc extra medullary intramural spinal cord tumor
- solitary lesion from dorsal nerve root
- mult=NF2, carney complex
- dumbbell shape-skinny handle in intraforaminal component
- T1-, T2+, enh
- central necrosis or hem
SC neurofibroma-what, img, malignancy
- involve who nerve + sheath
- 2 types=solitary + plexiform
- target sign-T2 dark centrally + bright rim
- malignant degeneration 5-10%-think if rapid growth
Difficult or impossible to distinguish solitary NF from schwannoma by imaging
NF more often fusiform
Target sign more common with NF than schwannoma
Hemorrhage, cystic or fatty degeneration more common with schwannoma
-plexiform SC neurofibroma
- ML bulky n enlargement
- pathogenomoic for NF 1
SC meningioma–who, where, img
- F (70%)
- pstlat thoracic spine, anterior cervical spine
- T2+, T1 iso/+, homog enh+, Ca
Drop mets-which cancers. Classic sign?
- MB= MC 1˚
- 2˚- breast –> lung –> melanoma
- “zuckerguss”-coat cord, nerve roots
Extradural sc tumors
-vertebral hemangioma
-osteoid osteoma
-osteoblastoma
-ABC
-GCT
-chordoma
-leukemia
mets-prostate, breast, lung, lymphoma, myeloma
vertebra plana
pancake flat VB
- kids: eusinophilic granuloma, NB met
- adults: Mets/myeloma in adult.
what is special about vertebral chordomas
- more aggressive/malignant
- classic story: involvement 2+ adj VBs 2/ intervening disc
