Spine

Question 1

Name the #

Answer 1

Chance #: horizontal splitting of the spinal canal, w/anterior wedge compression # + horizontal # through the posterior elements or distraction of the facet joints & spinous processes.

• No retropulsion is often seen.
• Flexion/distraction #s.
• Involved all 3 columns–very unstable.
  
  • All 3 ligaments torn: ant/post spinal ligaments, longitudinal spinal & ligamentum flavum.
• High assocn w/intra-abdo injuries: 65% pancreas & duodenum.
• Most commonly in upper lumbar & thoracolumbar junction.
• Associated w/lap-band seatbelt & no shoulder strap, i.e., back seat passenger.

Question 2

Dx? 34yo male w/neck pain after a weight-lifting accident.

Answer 2

Clay shoveler’s #: avulsion of a lower cervical/upper thoracic spinous process w/ “ghost sign”.

• “ghost sign” = double spinous process on the AP.
• Usually C7.
• From forceful hyperflexion, like shoveling.
• Can also occur w/direct trauma to the area.

Question 3

1. Name the injury.
2. What is its hallmark?

Answer 3

1. Hangman #.
2. Bilateral C2 pars interarticularis #s.

• Seen most commonly when the chin hits the dashboard in an MVA.
• Can occur through pedicles, but less commonly.
• There is often an associated # at the anterior/inferior corner of C2.
• Cord damage is uncommon as the pars defect widens the canal.
• 3 types, classified by the Effendi classification.
• Next steps:
  
  • Look for odontoid & C1 #s.
  • Get CTA to look at vertebral arteries.

Question 4

Which type of C1 # (Jefferson) is considered the most unstable?

Answer 4

• Burst # w/disruption of transverse ligament.
  
  • Sum of lateral displacement of the lateral masses of C1 over C2 (>7mm) is a sign of transverse ligament injury (rule of Spence).
  • 30% will have a C2 #.
  • Cord damage is rare b/c all of the axial loading force is directed into the bones.

Question 5

What is the difference b/w the alar & transverse ligaments?

Answer 5

Alar:

• Attaches the dens to the skull.

Transverse:

• Part of the cruciate ligament.
• Attaches the body of the dens to C1.
• If C1 is disrupted (Jefferson #), then if the lateral masses are slipped >7mm then the xverse ligament is likely ruptured.

Question 6

Which MR sequence can be used to detect acute cord hemorrhage?

Answer 6

T2* (susceptibility weighted images)

Question 7

What is the most common cause of vertebra plana in kids?

Answer 7

• eosinophilic granuloma

Question 8

1. What is suggestive of screw loosening in pts w/fusion hardware?
2. What is an indication of possibly motion across fused spinal levels?

Answer 8

1. >2mm lucency around the screw.
2. Centrally interrupted trabeculation:

Question 9

Dx?

Answer 9

Emphysematous OM: intraosseous gas.

• Rare but severe.
• Can be caused by the same bug as Lemierre’s (Fusoacterium necrophorum & Clostridium).
• Most often affects the vertebra, sacrum & long bones.

Question 10

What is the most common cause of this?

Answer 10

Dx: arachnoiditis: empty thecal sac sign.

• Most commonly spinal surgery: occurs in 10-15% of cases.
• Inflammation of the SA space.
• Can alternatively see central nerve root clumping: some or all of the nerves.

Question 11

Dx? 39yo male recently recovered from an URTI, presents w/bilateral lower extremity weakness & difficulty breathing.

Answer 11

Guillain-Barre syndrome: smooth, diffuse nerve root thickening & enhancement.

• Aka acute inflammatory demyelinating polyradiculoneuropathy.
• Underlying pathology is autoimmune demyelination.
• Ascending weakness (flaccid paralysis) shortly after a viral illness is highly suggestive.

Question 12

1. Most common bug to cause spinal epidural infection?
2. How is it spread?

Answer 12

1. Strep pneumonia.
2. Hematogenously: hence, IVDUs often get these.

Question 13

1. Most common bug to precipitate Guillain-Barre syndrome?
2. What 2 other pts are susceptible?
3. What is the most commonly affected cranial nerve?
4. Which spinal roots enhance more?
5. What is the syndrome called if symptoms last >8wks?
   
   1. What does this look like–classic sign?

Answer 13

1. Campylobacter.
2. SLE & lymphoma.
3. CN7, facial.
4. Anterior >> posterior, which is very strongly suggestive of GBS.
5. CIDP: chronic inflammatory demyelinating polyneuropathy.
   
   1. Onion bulb nerve roots: thickened.
   2. Can also see the same thing in Charcot Marie-Tooth disease.

• Can occur after URTI or GI infections.
• Typically, young adults or kids.
• Ascending paralysis & can affect respiratory muscles.
  *

Question 14

1. What best describes the function of the dorsal columns?
2. DDx for this case?

Answer 14

1. Sensory: fine touch, vibration, proprioception.
2. Inverted V sign: Vit B12 deficiency, HIV, HSV, ADEM.

Question 15

1. Dx:?
2. What serum abnormality may be seen here?
3. Early in the disease, what happens to the SI joint?

Answer 15

1. Ank spond: fused syndesmophytes, bilateral SI joint fusion & chronic L3 #.
2. CRP.
   
   • Ank spond is a seronegative spondyloarthropathy, so RF is absent.
3. Subchondral bone resorption along the iliac side of the SI joint.

Question 16

Dx?

Answer 16

Vit B12 deficiency: “inverted V-sign”, bilateral, symmetrically increased T2 signal of the dorsal columns w/o enhancement.

• Aka subacute combined degeneration.
• Typically begins in the upper thoracic region & then either ascends or descends.
• DDx: HIV, ADEM.

Question 17

What is the most common malignancy of the spine?

Answer 17

Mets.

Question 18

Name the 1st & 2nd most common intramedullary intradural spinal tumours.

Answer 18

1. Schwannoma
2. Meningioma:
   
   • The most commonly in the T-spine, followed by C-spine, and rarely in the LS-spine.
   • If multiple, think NF-2.
   • Calcs are common, like the above.

• Other possibilities: neurofibroma, drop mets.

Question 19

Dx?

Answer 19

Myxopapillary ependymoma: large, extramedullary, intradural mass at the filum terminal; homogenous enhancement w/low T2 at the margins b/c of hemorrhage; w/scalloping of the vertebral bodies.

• They commonly have tumoral cysts & are long-segment (~4 vertebral bodies).
• They are the most common tumours of the cauda equina region, can also present at the conus.
• Present in younger (35yo) males.
• They can be large & sausage-shaped.

Question 20

Name the most common intramedullary spinal mass in adults.

Answer 20

Ependymoma.

Question 21

Name the most common spinal intramedullary tumour in peds?

Answer 21

Astrocytoma

• Favours the upper T-spine.
• Fusiform cord dilation over multiple segments.
• Eccentric.
• T1 dark, T2 bright & enhance.
• May have associated cysts/syrinxes.

Question 22

Dx of this lesion & specifically if there are cutaneous lesions.

Answer 22

Neurofibroma (nerve sheath tumour): envelops the adjacent nerve root.

NF-1 (NF-2 lacks cutaneous manifestations).

Question 23

What Ix sign suggests a specific diagnosis?

Answer 23

• Flow void = paraganglioma.

Question 24

Dx?

1. Classic presentation?

Answer 24

Osteoid osteoma: central nidus (<1.5cm) w/surrounding dense sclerosis; T2 hypoenhancing nidus surrounded by T2 hyperintense edema & enhancing reactive zone.

1. Night pain relieved w/aspirin or painful scoliosis.

• 75% in the posterior elements.
• If >1.5cm then called osteoblastoma.
• Some pts have scoliosis 2dry to muscle spasm.
• Usually pts <30yo.
• RFA can treat them.

Question 25

In adults, what are the most common non-CNS solid tumours to present w/leptomeningeal mets?

Answer 25

* Lung & breast ca, but lymphoma can too.

Question 26

Dx?

Answer 26

**Hemangioblastomas (vHL)**: cyst + nodule; wide cord + considerable cord edema. * These can sometimes demonstrate flow voids. * Thoracic level is most common, 2nd most = cervical. * Panc cysts are common. * 25-40% of hemangioblastomas occur in pts w/vHL. * AD disease. * In vHL, 75% occur in the cerebellum, 25% in spine.

Question 27

Dx? 30yo female. 1. Which vessel wall layer is typically affected?

Answer 27

**Takayasu arteritis**: thick soft tissue circumferentially around the L ICA & string-like narrowing of the R ICA. 1. All 3 layers of vessel wall, typically beginning w/adventitia then working inwards. * Involves the Ao & its major branches. * Pulmonary artery involvement may also be seen. * Most common in younger females. * Can present w/TIAs & HTN, also fever, wt loss & fatigue.

Question 28

TvT: astrocytoma vs. ependymoma

Answer 28

Question 29

Dx?

Answer 29

**Aggressive spinal hemangioma**: normal-appearing vertebral hemangioma but w/soft tissue component narrowing the spinal canal.

Question 30

Dx? Male w/genetic disorder.

Answer 30

**Dural ectasia/dysplasia in NF-1**: enlargement of the CSF spaces w/scalloping of adjacent bone.

Question 31

1. Dx; 45yo male? 2. What syndrome can result from this?

Answer 31

**Dural AV fistula**: innumerable T2 flow voids along the dorsal surface of the cord; the cord is usually swollen & w/high T2 signal. 1. Foix-Alajouanine syndrome: cengestive myelopathy 2dry to venous congestion/HTN. * Classic Hx is a 45yo male w/LE weakness + sensory deficits. * Will see high T2 signal in the cord. * Most common in T-spine. * Fistula b/w the dorsal radiculomedullary arteries & radiculomedullary vein with the dural nerve sleeve. * Gold standard for Dx is angiography.

Question 32

Dx? Dizziness & abnormal neck Doppler.

Answer 32

**Subclavian steal**: occuluded proximal L subclavian a. w/flow in the post-vertebral segment via the patent L vertebral a. * This results in retrograde flow in the ipsilateral vertebral artery on US. * Can also occur in the innominate a. * These pts often have upper extremity claudication as the retrograde flow may not be sufficient for adequate tissue perfusion.

Question 33

1. Which sequence was used to obtain this image? 2. What is it showing?

Answer 33

1. Phase-contrast sequence CSF flow. 2. Lack of flow-related signal in the dorsal SA CSF space at the cervicomedullary junction, compatible w/crowding 2dry to tonsillar ectopia (Chiari I).

Question 34

Dx, 2 different pts?

Answer 34

**Chiari 1**: tonsillar ectopia w/syrinx seen in upper cord of 2nd pt. * Inferior displacement of the tonsils below the foramen magnum \>=5mm. * May be idiopathic or 2dry to posterior fossa or craniovertebral junction abnormalities. * Caudally-displaced tonsils are typically pointed or peg-like. * The most common complications result from altered CSF flow dynamics & include syrinx or hydrocephalus. * Chiari 1.5: a new entity which is Chiari 1 + inferior brainstem descent (typically the inferior margin of the 4th ventricle (obex)). * Tx: suboccipital craniectomy & often resection of the posterior arch of C1 to restore normal CSF flow.

Question 35

Dx?

Answer 35

**Lipomyelocele**: fat located b/w the neural placode ventrally & spinal defect dorsally, but w/overlying intact skin; w/tethered cord & terminal syrinx; expansion of the lumbar spinal canal. * The neural placode lipoma interface lies w/in the spinal canal. * This is an intraspinal lipoma in contiguity w/the subcutaneous fat via the defect in the posterior elements. * If the neural placode projects through the defect into the subcutaneous tissues then this would be a lipomyelomeningocele. * The lipoma may be intra- or extradural. * There is typically mild expansion of the spinal canal & distension of the SA space at the level of the defect.

Question 36

Dx?

Answer 36

**Caudal regression syndrome (type 1)**: sacral agenesis beyond S1, early termination of the conus (at T11-12), which also appears blunted. * Type 1: high termination of the conus (above L1), which is blunted or wedge-shaped, typically assoc w/sacral anomalies above S1. * Often w/associated GU or GI malformations, commonly: renal agenesis, hydronephrosis, anal atresia & imperforate anus. * Also often have vertebral segmentation anomalies. * Associated w/diabetic embryopathy.

Question 37

Dx?

Answer 37

Caudal regression syndrome, type 2: low-lying, tethered cord w/less severe sacral agenesis, here, which is coccyx agenesis. * Low-lying, tethered cord w/less severe sacral agenesis, typically below S2

Question 38

Dx?

Answer 38

**Fatty filum terminale (aka fibrolipoma)**: high T1 signal w/in the filum at L4-S1, which is suppressed on STIR images; normal conus position. * Conus terminates at the normal position. * Refers to fat in an otherwise normal size filum (transverse diameter \<2mm). * Most commonly is incidental & no further Ix required.

Question 39

Dx?

Answer 39

**Terminal ventricle**: dilation of the distal central canal in the distal spinal cord. * Aka ventriculus terminalis or 5th ventricle. * C-E MRI is instrumental to show lack of enhancement, nodularity or septations in pts w/suspected conus neoplasms. * Incidental finding, often found in kids; no additional f/u required.

Question 40

Dx?

Answer 40

**Chiari I**: small posterior fossa w/inferior displacement of the vermis, cervicomedullary kinking, tectal breaking & flattening of 4th vent. * Small posterior fossa cannot accommodate the growing brainstem & cerebellum. * The cerebellum is displaced superiorly w/mass effect on the tectum, causing beaking, as well as inferiorly, flattening the 4th vent. * Nearly all pts have myelomeningocele.

Question 41

Dx?

Answer 41

Diastematomyelia. * 2 types: 1. 2 hemicords w/2 dural sheaths. 2. 2 hemicords w/a common dural sheath. * Commonly assoc w/vertebra segmentation anomalies & spinal dysraphism. * May have progressive scoliosis or cutaneous stigmata, e.g., hairy patch (\>50% of cases).