WEEK 6 - Spinal Injury

Question 1

What is the pathophysiological cascade associated with spinal cord injury?

Answer 1

1. Haemorrhage within pia mater & grey matter.
2. Oedema in the white matter which impairs circulation
3. Reduced vascular perfusion & development of ischaemic areas
4. Accumulation of endogenous opioids
5. Release of toxic excitatory aa (glutamate) & ROS
6. Massive swelling response leads to swelling of the cord - contributes to its dysfunction
7. Within first few days of injury progressive axonal changes, development of necrotic zones, proliferation of microglia, changes in astrocytes
8. Cord is replaced by collagenous tissue in 3-4 weeks

Question 2

What are the clinical manifestations associated with spinal cord injury?

Answer 2

Paraplegia (T1) & quadriplegia, depending on level of injury
Spinal shock with cessation of all motor, sensory reflex (bladder/bowel/sexual) & autonomic functions linked to complete transection of the spinal cord.
Neurogenic shock - cervical or upper thoracic injuries
Less severe acute spinal cord injury
Loss of voluntary movement, loss of sensations in body parts below the injury level; loss of autonomic reflexes below the level of injury.
Return of spinal neuron excitability can occur depending on degree of damage

Question 3

What are the common causes/triggers for lower back pain?

Answer 3

Unknown aetiology
Risk factors: heavy lifting, obesity
Affects men & women equally

Secondary causes:
Disc prolapse, degenerative disc disease, osteoporosis
Sprain, fracture, inflammation

Question 4

What are the common types of injuries that can result in spinal cord trauma?

Answer 4

Vertebral injuries such as simple fractures, compressed/burst fractures, dislocations
Vertebral injuries occur mostly in the cervical and lumbar regions.

Question 5

What are the common types of accidents that can result in spinal cord trauma?

Answer 5

Traumatic - MVA, falls, sporting activities, surgical complications
Non-traumatic - tumours, degenerative diseases, ageing, infection

Question 6

What is the goal of managing an acute spinal cord injury?

Answer 6

Reduce neurological deficit & prevent additional damage eg. hypoxia, shock
Immobilise, stabilise, support

Question 7

Were do intramedullary tumours occur and what do they do?

Answer 7

Arise: Neural tissue
Produce dysfunction by invasion & compression
Cord enlarges as a result of growing tumour, causing distortion of adjacent white matter tracts.
Ependymomas = derived from ependymal cells lining ventricles & spinal cord
Astrocytomas = most common intramedullary spinal cord tumours in children & adults, develop from astrocytes, 90% are low grade tumors.

Question 8

Where do extramedullary tumours occur?

Answer 8

Outside spinal cord

Question 9

Where do extramedullary extradural tumours arise and what do they do?

Answer 9

Arise: The vertebral structure
Cause compression of the spinal cord & nerve roots, destroy white matter tracts
Early symptoms = weakness
Pain at site is common & appears before signs of spinal cord dysfunction

Question 10

Where do extramedullary intradural tumours arise and what do they do?

Answer 10

Arise: From the meninges or nerve roots.
Meningioma - most common in thoracic area, onset middle/late years, usually benign (encapsulated)
Schwannoma - most common intradural primary tumours which arise from the nerve roots

Question 11

What is degenerative disc disease?

Answer 11

Caused by biochemical alterations of the disc
Fibrocartilage replaces nucleus pulposus; nucleus pulposus shrinks, break in the annulus fibrosus, disc prolapse/herniation.
Common in adults >30 yo