Week 6 - B - Regional Adult Trauma (1) - Spinal injuries (cervical, thoracolumbar), spinal cord injuries and myotomes

Question 1

When do cervical spine fractures tend to occur?

Answer 1

They tend to occur in high energy injuries eg road traffic accidents or falling from a height and may be associated with head injury

Question 2

Potentially dangerous unstable fractures may be missed in the unconscious or confused patient What may this result in regarding cervical spine fractures?

Answer 2

This may result in spinal cord injury

Question 3

One should have a low threshold for C‐spine immobilization with a hard collar and sand bags or blocks on a spinal board in any high energy injury or head injury (ABCD – Airway with C‐spine control).

What are the criteria that must be satisfied to clinically clear the c-spine?

Answer 3

In order to clinically clear a c-spine following trauma, ALL of the following criteria must be satisfied:

• * No history of loss of consciousness
• * GCS 15 with no alcohol intoxication
• * No significant distracting injury ((such as head injury, chest trauma or other fractures including more distal spinal fractures))
• * No neurological symptoms in the upper or lower limb
• * No midline tenderness on palpation of the c-spine
• * N pain on gentle active neck movement

Question 4

If there is any doubt over any of the criteria to clinically clear the c-spine, what happens to the hard collar that has been inserted for C-spine immobilization? What investigations are carried out once in hospital?

Answer 4

If there is any doubt over any of these criteria, the c-spine cannot be clinically cleared and the collar must stay in situ.

Further imaging in the form of X‐Rays (AP & lateral views +/‐ odontoid peg open mouth view) or CT scan of the c‐spine is required so that a c-spine injury can be radologically cleared.

Question 5

High c-spine fractures or dislocations may be fatal especially if above which level?

Answer 5

High c‐spine fractures or dislocations may be fatal especially if above C3 (above phrenic nerve - C3,4,5 - which supplies the diaphragm).

Question 6

How may stable and unstable c-spine injuries be treated?

Answer 6

More stable c‐spine injuries can be treated in a firm cervical collar.

Unstable injuries may require immobilization in a “halo vest” which is a type of external fixator with 4 pins into the skull.

• (broken neck Vinny Paz in Bleed for this (miles teller actor))

Question 7

The majority of thoracolumbar spine fractures occur due to motor vehicle accidents or falls from a height. What type of thoracolumbar fractures occur in the elderly due to oestoporosis?

Answer 7

Wedge fractures

Question 8

What is the management of a wedge fracture? What drug can increase the risk?

Answer 8

Symptomatic management

Steroids can causes osteoporosis increasing the risk of wedge fractures

Question 9

Whilst osteoporotic low energy fractures tend to be compression / wedge fractures which are relatively stable, younger patients with higher energy injuries tend to have what type of thoracolumbar fractures?

Answer 9

Younger patients tend to have Burst fractures - a type of compression fracture related to high-energy axial loading spinal trauma that results in disruption of the posterior vertebral body cortex or

Chance-flexion distraction fracture - excessive flexion of the spine

Question 10

What is an example of a cause of a CHance fracture? What sign may be seen one examination?

Answer 10

The cause is classically a head-on motor vehicle collision

Symptoms may include abdominal bruising (seat belt sign)

Question 11

What are the indications for surgery in thoracolumbar spinal fractures?

Answer 11

Indications for surgery include:

Presence of neurological deficit especially if progressive or very unstable injury

Unstable injury pattern with substantial loss of vertebral height,

displacement or involvement of the posterior ligamentous structures.

Question 12

The spinal cord or nerve roots can be damaged from contusion, compression, stretch or laceration.

What is spinal shock and what are the features?

Answer 12

Spinal shock is a physiologic response to injury with complete loss of sensation and motor function and loss of reflexes below the level of the injury.

* Anaesthesia, areflex flaccid paralysis of all segements and muscles innervated below the level of the injury

Question 13

How long does it usually take for spinal shock to resolve?

Answer 13

Can take up to 24 hours for spinal shock to resolve

Question 14

The bulbocavernous reflex is absent in spinal shock and its return signals the end of spinal shock. What is the bulbocavernous reflex?

Answer 14

This is when there is the reflex contraction of the anal sphincter with either a squeeze of the glans pens, tapping the mons pubis or pull of the urethral catheter

Question 15

Neurogenic shock occurs secondary to temporary shutdown of sympathetic outflow from the cord What is the range of this sympathetic outflow?

Answer 15

T1 to L2

Question 16

Neuorgenic shock is usually due to injury in the cervical or upper thoracic cord What does this lead to? Spinal shock can take up to 24 hours to resolve, how long does neurogenic shock take?

Answer 16

Leads to hypotension and bradycardia which usually resolves within 24-48hours

Question 17

In a male, what may occur due to unopposed parasympathetic stimulation in neurgoenic shock?

Answer 17

Priapsim may occur - patient is erect for hours

Question 18

Neurogenic shock must be differentiated from other forms of shock (hypovolaemic shock is much more common in trauma cases and should respond to fluid replacement therapy). How is neurgoenic shock treated?

Answer 18

Give IV fluids

* Also give atropine for slowed heart rate

* Vasopressors eg adrenaline for vasoconstriction

* Give dopamine or other inotropic drugs to increase heart contraction

Question 19

Spinal cord comrpession can be * Acute or chronic * Complete or incomplete

What is the commonest cause of spinal cord compression? How does complete cord compression or transection present?

Answer 19

Commonest cause of spinal cord compression is malignant compression of the spinal cord

Complete cord compression presents as spinal shock initially with flacccid areflex paralysis

* Bilateral paralysis below the level of compression

* Bilateral loss of sensation below the level of compression

Question 20

What signifies the ending of the spinal shock - ie what other symptoms may start? What reflex can be checked for?

Answer 20

End of spinal shock are when the features of an upper motor neurone lesions kick in

* ie stops being flaccid areflex paralysis and hyperreflexia and spasticity bein

Can check for bulbocavernosus reflex - when this returns, spinal shock has ended

Question 21

Spinal cord injuries can be classified as complete or incomplete: Complete spinal cord injury results in no sensory or voluntary motor function below the level of the injury (reflexes should return).

What is the prognosis of a complete spinal cord injury?

Answer 21

Very poor prognosis

Question 22

Incomplete cord injuries include * Central cord syndrome * Anterior cord syndrome * Posterior cord syndrome * Brown-sequard syndrome

Central cord syndrome is the most common incomplete cord injury pattern

What is central cord syndrome and what does it result in?

Answer 22

Central cord syndrome is when there is damage to the centre area of the spinal cord resulting in loss of movement and loss of certain sensation in mainly the arms (but not the legs)

Question 23

What is the main cause of central cord syndrome? Why is it that the lower limbs are less/not affected in central cord syndrome?

Answer 23

The main cause of central cord syndrome is usually due to hyperextension of the neck in an individual with osteoarthritis (cervical spondylosis in the neck) - can occur in younger patients

The lower limb fibres are arranged on the outside of the spinal cord compared to the upper limb fibres which are arranged nearer the centrre of the cord

Question 24

What defects does a patient with central cord syndrome present with?

Answer 24

Patients upper limbs and axial skeleton tend to be far greater affected than the less/non affacted lower limbs

Patients usually presents with loss of pain and temp, as well as weakness in the upper limbs and chest bilaterally

Almost cape-like spinothalamic and corticopsinal loss

Question 25

What does the anterior spinal artery supply in comparison to the posterior spinal artery?

Answer 25

The anterior spinal artery supplies the anterior 2/3rd of the spinal cord.

Its is formed by branches of the vertebral arteries joining

The posterior spinal artery is what supplies the dorsal columns, dorsal horns (posterior 1/3rd).

They are branches of each vertebral artery

Question 26

What is anterior cord syndrome and how does the patient present?

Answer 26

Anterior cord syndrome is where there is interruption to the anterior spinal artery

Patient presents with loss of motor function (corticospinal tract) and loss of pain, temperature and crude touch (spinothalamic tracts)

DCML is left unaffected

Question 27

Posterior cord syndrome is a rare type of incomplete spinal cord injury What is posterior cord syndrome? How does it present?

Answer 27

Posterior cord syndrome is caused by a lesion of the posterior portion of the spinal cord.

Can be caused by an interruption to the posteriro spinal artery

Patients will have a loss of fine touch, proprioception and vibration below the level of injury (DCML tract) (Spinothalamic and corticospinal tracts unaffected)

Question 28

What is the rare condition where there is a cord hemisection known as? What often causes this condition?

Answer 28

Rare condition where there is a cord hemisection is known as Brown Sequard syndrome

Usually the result of a penetrating injury from eg a stab wound

Question 29

What are the presenting features of Brown-Sequard syndrome?

Answer 29

Below the level of the hemisection

• Ipsilateral paralysis (corticospinal tract)
• Ipsilateral loss of fine touch, vibration and proprioception (DCML)
• Contralteral loss of crude touch, pressure, pain and temp (spinothalamic tract)

Question 30

What is a dermatome?

Answer 30

Dermatome is the area of skin supplied by a single spinal nerve

Question 31

What is the dermatome that supplies the thumb?

Answer 31

This is C6

Question 32

What is the dermatome supplying the abudction of the arm?

Answer 32

C5

Question 33

Which dermatome causes flexion of the digitis?

Answer 33

C8

Question 34

Which dermatome supplies the adduction and abduction of the digits?

Answer 34

This would be the T1 dermatome

Question 35

Which myotome causes extension of the knee?

Answer 35

This is L3 and 4 (femoral nerve comes from L2-4)

Question 36

Which muscle forms the quadrcieps tendon that causes extension of the knee?

Answer 36

Vastus medias, lateralus and intermedius

Vastus intermedius is covered by the rectus femoris

Question 37

Which myotome causes dorsiflexion of the toes and which causes plantarflexion?

Answer 37

Dorsiflexion - L5

Plantarflexion - S1,2

Question 38

What is the test to test the plantarflexion of the foot?

Answer 38

Ankle jerk reflex - hit the calcaneal tendon and it causes plantarflexion of the foot

Question 39

What is the test known as where squeezing the calf muscles causes plantarflexion of the foot?

Answer 39

Simmond’s test