Spinal Cord Injury Classifications

Question 1

Two categories of Spinal Cord injury

Answer 1

traumatic (result of external physical impact) and non-traumatic (result of disease, infection or tumour)

Question 2

Etiology

Answer 2

Traumatic SCI typically occurs in the younger age group, 20-30 years of age, with male to female ratio of 4:1
Causes:
- 50% motor vehicle/motorcycle crashes
- 30% to 40% falls and work-related injuries
- cervical spine is most common region of injury

Question 3

layers of spinal cord protection

Answer 3

Spinal cord is wrapped in tough layers of dura
Rarely torn or transected by direct trauma

Question 4

Initial Injury: Spinal cord injury due to cord compression by

Answer 4

• bone displacement
• interruption of blood supply to cord
• tumour

Question 5

Initial injury causes (2)

Answer 5

Cord compression
Penetrating trauma (gunshot or stab)

Question 6

Primary Injury

Answer 6

Initial mechanical disruption of axons as a result of stretch or laceration

Question 7

Secondary injury

Answer 7

ongoing, progressive damage that occurs after initial injury - caused by swelling from the immune system
within 24 hours after injury there is the development of edema, above and below the level of injury as a result of ischemic damage and may cause permanent cord damage - anything we can do to minimize secondary injury is crucial

Question 8

Apoptosis

Answer 8

death of cells that occurs as a normal and controlled part of an organisms growth and development
occurs after initial injury and may continue for weeks or months after initial injury

Question 9

Initial Injury: Autodestruction

Answer 9

Complete cord damage in severe trauma related to autodestruction of cord
- petechial hemorrhages are in central grey matter of cord shortly after injury

Question 10

Addition results of secondary injury (3)

Answer 10

• Resulting hypoxia reduces oxygen tension below level that meets metabolic needs of spinal cord
• Lactate metabolites
• Increased vasoactive substances (norepinephrine, serotonin, dopamine) - at high enough levels these lead to vasospasms which leads to necrosis

Question 11

Pathophysiology of secondary injury

Answer 11

• By < 24 hours, permanent damage may occur because of edema
• Edema secondary to inflammatory response is harmful because of lack of space for tissue expansion
• Results in spinal cord compression and extension of edema below and above injury which increases ischemic damage

Question 12

Extent of neurological damage caused by spinal cord injury results from: (2)

Answer 12

Primary injury damage
Secondary damage

Question 13

Primary injury damage

Answer 13

actual physical disruption of axons

Question 14

Secondary damage due to (4)

Answer 14

Ischemia
Hypoxia
Microhemorrhage
Edema

Question 15

Spinal Shock
What is it?
Characterized by (3)

Answer 15

TEMPORARY neurological syndrome
1. Decreased reflexes (means maybe they can return)
2. Loss of sensation
3. Flaccid paralysis below the level of injury
Experienced by about 50% of people with acute spinal cord injury

Question 16

How long does spinal shock last?

Answer 16

This can last from days to months and may mask post-injury neurologic functioning. May mask what the patient is capable fo returning to. Acute shock state. People can often return to a much higher level of functioning than they initially seem to be capable of

Question 17

Neurogenic shock
what is it?
Characterized by: 3

Answer 17

Caused by SCI at T5 or above
Loss of vasomotor tone caused by injury
Characterized by
1. hypotension, and non-compensating heart rate (bradycardia)
2. hypothermia
3. Loss of sympathetic innervation
Important clinical cues

Question 18

Neurogenic shock: Hemodynamic Syndrome

Answer 18

Hemodynamic syndrome of massive vasocilation without compensation and results from the loss of sympathetic nervous system vasoconstriction tone caused by spinal cord injury

Question 19

Loss of sympathetic nervous system innervation causes: (3)

Answer 19

1. peripheral vasodilation
2. venous pooling
3. decreased cardiac output

Question 20

Classification of SCI: classified by Mechanism of Injury (MOI) (3)

Answer 20

• skeletal level of injury
• neurological level of injury
• completeness or degree of injury

Question 21

Major mechanisms of injury are (5)

Answer 21

• flexion
• hyperextension
• flexion-rotation (most unstable because ligamental structures that stabilize the spinal cord are torn- implicated in severe neurological deficits)
• extension-rotation
• compression

Question 22

Level of Injury: Skeletal Level

Answer 22

Injury is at the vertebral level, where there is most damage to vertebral bones and ligaments

Question 23

Level of Injury: Neurological Level

Answer 23

Lowest segment of spinal cord with normal sensory and motor function on both sides of the body

Question 24

Level of injury may be: 3

Answer 24

cervical
thoracic
lumbar
Not sacral because the spinal cord ends by L1 and L2

Question 25

what causes quadriplegia?

Answer 25

paralysis of all four extremities occurs (tetraplegia or quadriplegia) if the cervical cord is involved.

Question 26

what causes paraplegia?

Answer 26

Paraplegia results if thoracic or lumbar cord is damaged

Question 27

Phrenic nerve paralysis

Answer 27

C3-C5 – phrenic nerve damage. Diaphragm innervation is damaged. Dysfunction in capacity to breath

Question 28

Degree of Injury: Complete Cord Involvement

Answer 28

results in total loss of sensory and motor function below level of lesion (injury)

Question 29

Degree of Injury: Incomplete (partial) cord involvement

Answer 29

results in mixed loss of voluntary motor activity and sensation and leaves some tracts intact
Capacity to regain potentially much more function than complete

Question 30

ASIA Impairment Scale

Answer 30

American Spinal Injury Association (ASIA) impairment scale
Commonly used for classifying severity of impairment resulting from spinal cord injury
Combines assessment of motor and sensory function
Determines neurological level and completeness of injury
Useful for:
- recording changes in neurological status
- identifying appropriate functional goals for rehabilitation