Spinal cord injury

Question 1

Define autonomic dysreflexia.

Answer 1

Clinical syndrome which occurs when patients have had a spinal cord injury at T6 or above.

Question 2

What is the pathophysiology of autonomic dysreflexia?

Answer 2

Afferent signals (usually caused by faecal impaction or urinary retention but many triggers exist) cause a sympathetic spinal reflex via thoracolumbar outflow.
The usual parasympathetic response is stopped by the cord lesion
This causes unbalanced physiological response above the level of the cord lesion causing:

• severe HTN - which may cause haemorrhagis stroke
• flushing
• sweating

Question 3

What is the management of autonomic dysreflexia?

Answer 3

Removal/control of the stimulus
Treatment of any life-threatening HTN +/- bradycardia

Question 4

What are the signs of spinal cord injury on examination?

Answer 4

UMN signs below the level of the lesion
LMN signs at the level of the lesion

Question 5

What are the most common causes of traumatic spinal cord injury?

Answer 5

Motor vehicle accidents - most common
Falls
Violence e.g. gunshot wounds
Sports accidents
Other

Question 6

What is the classification of TSCI?

Answer 6

Complete - damage across the whole width of spinal cord
Incomplete - injury across part of the spinal cord so only partially affecting sensation or movement below the level of injury

AOSpine Injury Classification System is used worldwide

Question 7

What is the pathophysiology of spinal cord injury?

Answer 7

1. Initial acute impact -> concussion of spinal cord
2. Compression on spinal cord from increased pressures from rigid structures like vertebrae that are displaced by the injury
3. Increased tissue pressure means blocked venous return which promotes oedema and ischaemia if arterial supply is also compromised
4. Ischaemia of the spinal cord causes nerve damage called gliosis

Question 8

What are the clinical features of spinal cord injury?

Answer 8

Depend on level and completeness of the injury:

• Around 10% will cause tetraplegia or paraplegia
• Pain may not be present in every case
• Loss of motor function
• Loss of sensory function
• Bowel incontinence
• Urinary incontinence

Question 9

What are the grades of impairment from spinal cord injury?

Answer 9

Question 10

What investigations should be done for spinal cord injury?

Answer 10

A to E assessment
Cervical spine immobilisation
CT - if suggested by the Canadian C-spine rules for cervical spine injury
MRI - done in children if suggested by the Canadian C spine rules for cervical injury
XR - plain film is first line in suspected thoracic or lumbosacral injury

Question 11

What is the management of spinal cord injury?

Answer 11

1. 3 point C-spine immobilisation
2. Restrict movement of the spine e.g. backboard strapping
3. Pain management
4. Regular neurological observations
5. Referral to neurosurgery - although not all will require surgery; depends on displacement, stability and associated neurological deficit

Conservative - bed rest, cervical collars, motion restriction, traction then early mobilisation and rehabilitation
Surgical - absolute indications for surgery are if evidence of progressive neurological deficit or dislocation-type injury. Early intervention (< 24hrs) is associated with better outcomes

Question 12

What is central cord syndrome?

Answer 12

Most common incomplete SCI usually in elderly with spinal stenosis from a traumatic fall (i.e. relatively minor injury)

Central cord syndrome causes disproportionatel greater motor impairment in upper vs lower extremities, bladder dysfunction and sensory loss which varies below level of injury.

Question 13

What is anterior cord syndrome?

Answer 13

Lesions affecting the anterior two thirds of the spinal cord sparing the dorsal columns, usually from injury to the anterior spinal artery. Most likely from disc or bone fragments rather than primary arterial cause.

Anterior cord syndrome = complete loss of movement, and pain and temperature loss, BUT preserved light touch.

Posterior cord syndrome = the opposite effect: loss of light touch sensation, BUT it preserves movement, and pain and temperature sensation.

Question 14

What is Brown Sequard syndrome?

Answer 14

Caused by penetrating trauma causing hemisection of the cord.

Contralateral loss of pain and temperature
Ipsilateral loss of light touch and vibration

Question 15

What is Brown Sequard syndrome?

Answer 15

Caused by penetrating trauma causing hemisection of the cord.

Contralateral loss of pain and temperature
Ipsilateral loss of light touch and vibration