S6) Cervical and Thoracic Spine

Question 1

Compare and contrast the cervical and thoracic spine in terms of vertebrae number and mobility

Answer 1

• Cervical spine: 7 vertebrae, mobile
• Thoracic spine: 12 vertebrae, immobile

Question 2

Identify 4 characteristics of the cervical vertebrae

Answer 2

• Bifid spinous process (except C7)
• Transverse foramina
• Large triangular vertebral foramen
• Small & broad body

Question 3

State 2 functions of the foramen transversium in the cervical vertebrae

Answer 3

• Conduit for vertebral artery (except C7)
• C7 foramen transmits the accessory vertebral vein

Question 4

Describe the structure of the C1 vertebra (atlas)

Answer 4

• No vertebral body (body is fused with axis to form dens)
• Widest cervical vertebra
• Thick vertebral arches

Question 5

State the superior and inferior articulations of the C1 vertebrae

Answer 5

• Superior: occiput of skull superiorly (atlanto-occipital joint)
• Inferior: C2 vertebra (atlanto-axial joint)

Question 6

Describe the structure of the C2 vertebra (axis)

Answer 6

• Odontoid process (/dens)
• Rugged lateral mass
• Large spinous process

Question 7

What is the purpose of the dens and transverse ligament of the axis?

Answer 7

Dens and transverse ligament prevent horizontal displacement of atlas as well as the independent movement of C1 on to C2

Question 8

Describe the structure of the C7 vertebra (vertebra prominens)

Answer 8

• Longest spinous process
• Non-bifid spinous process
• Large transverse process is large
• Small foramen transversarium (accessory vertebral veins)

Question 9

What is the ligamentum nuchae?

Answer 9

The ligament nuchae is a thickening of the supraspinous ligament

Question 10

What is the ligamentum nuchae attached to?

Answer 10

• External occipital protruberance
• Spinous processes of all cervical vertebrae

Question 11

State three functions of the ligamentum nuchae

Answer 11

• Maintains secondary curvature of cervical spine
• Helps the cervical spine support the head
• Major site of attachment of neck and trunk muscles e.g. trapezius, rhomboids

Question 12

Describe the movements of the cervical spine

Answer 12

Question 13

Identify 3 characteristics of the thoracic vertebrae

Answer 13

• Demi-facets on vertebral body (whole facets T9-10)
• Costal facets on transverse processes (except T11-12)
• Small circular vertebral foramen

Question 14

Describe the articulations of the thoracic spine

Answer 14

• Demi facets articulate with respective & inferior head of the rib
• Costal facets articulate with respective tubercle of rib

Question 15

Describe the different functions of the anterior and posterior spinal cord

Answer 15

• Anterior cord – pain, temperature, light touch, pressure (sensory & motor)
• Posterior cord – vibration and proprioception

Question 16

What is anterior cord syndrome?

Answer 16

Anterior cord syndrome is a condition where the anterior spinal cord artery is interrupted due to ischaemia/infarction of the anterior two-thirds of the spinal cord

Question 17

Describe the effects of anterior cord syndrome

Answer 17

• Sensory problems (temperature, pain, light touch, etc)
• Motor problems depending on the neural level (part of spine affected)

Question 18

What is central cord syndrome?

Answer 18

Central cord syndrome is a common cervical spinal cord injury resulting from neck trauma, leading to major injury to the central grey matter of the spinal cord

Question 19

Describe the effects of central cord syndrome

Answer 19

• More central tracts move the arms and more lateral tracts move the legs
• Loss of motion and sensation in the arms (inverted paraplegia)

Question 20

What is posterior cord syndrome?

Answer 20

Posterior cord syndrome is a rare condition caused by lesion of the posterior portion of the spinal cord or by an interruption to the posterior spinal artery

Question 21

Describe the effects of posterior cord syndrome

Answer 21

• Loss of proprioception
• Loss of co-ordination

Question 22

What is a neural level?

Answer 22

A neural level is the last functioning (sensory & motor) level of a neuron

Question 23

How do nerve roots exit the different regions of the spinal cord?

Answer 23

• Initially, nerve roots in cervical spine exit above their vertebral body until the C7/T1 junction
• After this junction, nerve roots exit below their vertebral body but above their respective intervertebral disc

Question 24

X-rays are good at observing the bony prominences of the cervical spine.

Identify the bony landmarks observed below:

Answer 24

Question 25

MRI's are better at observing soft tissue of the cervical spine than the bony prominences. Identify the soft tissue structures observed below:

Answer 25

Question 26

What is cervical spondylosis?

Answer 26

**Cervical spondylosis** is a degenerative osteoarthritis of intervertebral joints in cervical spine

Question 27

Describe the symptoms of cervical spondylosis

Answer 27

- Pressure on nerve roots leads to **radiculopathy:** I. Dermatomal sensory (paraesthesia, pain) II. Myotomal motor weakness - Pressure on the cord leads to **myelopathy:** I. Global weakness II.Gait dysfunction & loss of balance

Question 28

What are Hangman's fractures and how do they occur?

Answer 28

- **Hangman's fractures** are unstable fractures which occur due to hyperextension of head on neck - Axis fractures through the pars interarticularis leading to the forward displacement of C1 & C2 on C3 (spondylisthesis)

Question 29

What are Peg fractures and how do they occur?

Answer 29

- **Peg fractures** (odontoid fracture) occur due to a fracture through the odontoid process often due to a blow to back of head *e.g. falling against a wall when balance is compromised* - ‘Open mouth’ X-ray = ‘peg view’

Question 30

What are Jefferson's fractures and how do they occur?

Answer 30

- **Jefferson's fractures** are fractures of the anterior and posterior arches of the atlas often due to increased axial load *e.g. diving into shallow water* - Typically causes pain but no neurological signs but may damage arteries at base of skull with secondary neurological sequelae *e.g. ataxia, Horner’s syndrome*

Question 31

What is whiplash injury?

Answer 31

A **whiplash injury** is a neck injury caused by sudden hyperextension and hyperflexion of the neck (high mobility, low stability)

Question 32

What anatomy changes are associated with a cervical prolapsed intervertebral disc?

Answer 32

- Tear of the **annulus fibrosis** - Migration of **nucleus pulposus** into the spinal canal

Question 33

Which nerve is affected in a left sided C5/6 prolapsed intervertebral disc? What will the patient complain of?

Answer 33

C6 nerve: - **Pain** – biceps into thumb and index finger - **Sensory deficit** – paraesthesia in thumb and index finger - **Motor weakness** – biceps and wrist extension

Question 34

Which nerve is affected in a left sided C7/T1 prolapsed intervertebral disc? What will the patient complain of?

Answer 34

C8 nerve: - **Pain** — medial two fingers - **Sensory deficit** — paraesthesia in medial two fingers - **Motor weakness** — finger flexion, finger extension

Question 35

What anatomical changes are associated with a cervical myelopathy?

Answer 35

- Osteoarthritis of the cervical spine - Osteophytes - Thickening ligamentum flavum

Question 36

What will a patient complain of with a cervical myelopathy at C3/4?

Answer 36

- **Pain** — neck pain - **Sensory deficit** — paraesthesia from shoulder down to feet - **Motor weakness** — shoulder abduction

Question 37

What will a patient complain of with a cervical myelopathy at C5/6?

Answer 37

- **Pain** – neck pain - **Sensory deficit** – paraesthesia from shoulder down and feet - **Motor weakness** – elbow flexion, wrist and finger movements

Question 38

What is the clinical presentation of cervical myelopathy?

Answer 38

- Clumsiness - Loss of fine motor movements - Abnormal gait - Loss of balance

Question 39

What might a patient complain of in thoracic cord compression (T10 – tumour)?

Answer 39

- **Pain** – thoracic pain - **Sensory deficit** – paraesthesia from umbilicus down, loss of sphincter control - **Motor weakness** – weakness of all muscles in the legs

Question 40

What might a patient complain of in thoracic cord compression (T5 - tumour)?

Answer 40

- **Pain:** high thoracic pain - **Sensory deficit:** paraesthesia below the nipples and loss of sphincter control - **Motor weakness:** weakness of all muscles in the legs and intercostals