S6) Cervical and Thoracic Spine Flashcards
Compare and contrast the cervical and thoracic spine in terms of vertebrae number and mobility
- Cervical spine: 7 vertebrae, mobile
- Thoracic spine: 12 vertebrae, immobile
Identify 4 characteristics of the cervical vertebrae
- Bifid spinous process (except C7)
- Transverse foramina
- Large triangular vertebral foramen
- Small & broad body
State 2 functions of the foramen transversium in the cervical vertebrae
- Conduit for vertebral artery (except C7)
- C7 foramen transmits the accessory vertebral vein
Describe the structure of the C1 vertebra (atlas)
- No vertebral body (body is fused with axis to form dens)
- Widest cervical vertebra
- Thick vertebral arches
State the superior and inferior articulations of the C1 vertebrae
- Superior: occiput of skull superiorly (atlanto-occipital joint)
- Inferior: C2 vertebra (atlanto-axial joint)
Describe the structure of the C2 vertebra (axis)
- Odontoid process (/dens)
- Rugged lateral mass
- Large spinous process
What is the purpose of the dens and transverse ligament of the axis?
Dens and transverse ligament prevent horizontal displacement of atlas as well as the independent movement of C1 on to C2
Describe the structure of the C7 vertebra (vertebra prominens)
- Longest spinous process
- Non-bifid spinous process
- Large transverse process is large
- Small foramen transversarium (accessory vertebral veins)
What is the ligamentum nuchae?
The ligament nuchae is a thickening of the supraspinous ligament
What is the ligamentum nuchae attached to?
- External occipital protruberance
- Spinous processes of all cervical vertebrae
State three functions of the ligamentum nuchae
- 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
Describe the movements of the cervical spine
Identify 3 characteristics of the thoracic vertebrae
- Demi-facets on vertebral body (whole facets T9-10)
- Costal facets on transverse processes (except T11-12)
- Small circular vertebral foramen
Describe the articulations of the thoracic spine
- Demi facets articulate with respective & inferior head of the rib
- Costal facets articulate with respective tubercle of rib
Describe the different functions of the anterior and posterior spinal cord
- Anterior cord – pain, temperature, light touch, pressure (sensory & motor)
- Posterior cord – vibration and proprioception
What is anterior cord syndrome?
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
Describe the effects of anterior cord syndrome
- Sensory problems (temperature, pain, light touch, etc)
- Motor problems depending on the neural level (part of spine affected)
What is central cord syndrome?
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
Describe the effects of central cord syndrome
- More central tracts move the arms and more lateral tracts move the legs
- Loss of motion and sensation in the arms (inverted paraplegia)
What is posterior cord syndrome?
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
Describe the effects of posterior cord syndrome
- Loss of proprioception
- Loss of co-ordination
What is a neural level?
A neural level is the last functioning (sensory & motor) level of a neuron
How do nerve roots exit the different regions of the spinal cord?
- 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
X-rays are good at observing the bony prominences of the cervical spine.
Identify the bony landmarks observed below:
MRI’s are better at observing soft tissue of the cervical spine than the bony prominences.
Identify the soft tissue structures observed below:
What is cervical spondylosis?
Cervical spondylosis is a degenerative osteoarthritis of intervertebral joints in cervical spine
Describe the symptoms of cervical spondylosis
- 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
What are Hangman’s fractures and how do they occur?
- 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)
What are Peg fractures and how do they occur?
- 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’
What are Jefferson’s fractures and how do they occur?
- 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
What is whiplash injury?
A whiplash injury is a neck injury caused by sudden hyperextension and hyperflexion of the neck (high mobility, low stability)
What anatomy changes are associated with a cervical prolapsed intervertebral disc?
- Tear of the annulus fibrosis
- Migration of nucleus pulposus into the spinal canal
Which nerve is affected in a left sided C5/6 prolapsed intervertebral disc?
What will the patient complain of?
C6 nerve:
- Pain – biceps into thumb and index finger
- Sensory deficit – paraesthesia in thumb and index finger
- Motor weakness – biceps and wrist extension
Which nerve is affected in a left sided C7/T1 prolapsed intervertebral disc?
What will the patient complain of?
C8 nerve:
- Pain — medial two fingers
- Sensory deficit — paraesthesia in medial two fingers
- Motor weakness — finger flexion, finger extension
What anatomical changes are associated with a cervical myelopathy?
- Osteoarthritis of the cervical spine
- Osteophytes
- Thickening ligamentum flavum
What will a patient complain of with a cervical myelopathy at C3/4?
- Pain — neck pain
- Sensory deficit — paraesthesia from shoulder down to feet
- Motor weakness — shoulder abduction
What will a patient complain of with a cervical myelopathy at C5/6?
- Pain – neck pain
- Sensory deficit – paraesthesia from shoulder down and feet
- Motor weakness – elbow flexion, wrist and finger movements
What is the clinical presentation of cervical myelopathy?
- Clumsiness
- Loss of fine motor movements
- Abnormal gait
- Loss of balance
What might a patient complain of in thoracic cord compression (T10 – tumour)?
- Pain – thoracic pain
- Sensory deficit – paraesthesia from umbilicus down, loss of sphincter control
- Motor weakness – weakness of all muscles in the legs
What might a patient complain of in thoracic cord compression (T5 - tumour)?
- 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
