SCI - Mechanisms of Injury and Acute Management

Question 1

What are the 3 mechanisms of Injury for SCI

Answer 1

Compression

Shearing

Distraction

Question 2

How could a compression injury happen

Answer 2

Can occur with a diving or football tackling injury

• Axial blow to the skull
• Often coupled with a flexion injury

Question 3

What does a compression injury do to the bones

Answer 3

Leads to a concave (burst) fx of the bony end plate

-Bony fragments enter the cord and rupture intervertebral disc

Question 4

How do compression fractures cause SC injuries

Answer 4

The bony fragments break off and travel into the spinal cord

Question 5

What are shearing forces

Answer 5

They move side to side.

Occur when a horizontal force is applied to the spine relative to an adjacent segment, and flexion/extension is blocked

Question 6

What part of the spine are more prone to damage from shearing force

Answer 6

Most common in the thoracic spine

Question 7

What type of damage is the result of a shearing force

Answer 7

Results in ligamentous damage and often results in abnormal axonal transmission

Question 8

Is distraction a common injury

Answer 8

not really, this is the least common type of SCI, it occurs with whiplash and that is a hyperextension injury.

hyperextension injuries are not common because of the spinous processes

Question 9

What does distraction do to the axons

Answer 9

Can result in longitudinal axonal shearing

Question 10

Is it important to reduce secondary cord damage

SCI

Answer 10

YES! Damage to the cord is rarely the result of the initial trauma, and is more commonly due to secondary effects of the injury

Question 11

Name 5 types of secondary effects from a SCI

Answer 11

Ischemia – damaged spinal arteries & vasospasms

Inflammation

Physical disruption of axons - stretching of the axon

Hemorrhage or edema

Ion derangement – altered membrane permeability leads to abnormal concentrations of K+ & Na+ (and you would want to prevent the neuron cascade)

Question 12

When there is traumatic injury to the SC this causes what type of responses in the body and what is this called

Answer 12

Spinal shock - happens when you have a traumatic injury to the spinal cord, the body responds by sending inflammation to that area.

That inflammation causes depression of a lot of he reflexes in that area and the loss of our sensory motor function below it (it kind of creates a wall so it can protect the area)

Now that this area is protected there will be ionic disruption, axon disruption, and flaccid paralysis (loss of all sensorimotor functions) below the level of injury

You also have vasodilation which leads to hypotension and bradycardia. This results in a decrease in CO.

You also have venous pooling because the muscle pump is not effective

Question 13

What is spinal shock - definition

Answer 13

A state of transient physiological reflex depression of cord function below the level of injury with associated loss of all sensorimotor functions.

Question 14

What are some signs and symptoms of spinal shock

Answer 14

Flaccid paralysis
Areflexia
Vasodilatations 🡪 
Hypotension
Bradycardia
↓ in cardiac output
Venous pooling

Question 15

How long does spinal shock last and what might this tell you about a patient’s prognosis

Answer 15

Can last for hours or for weeks - but the sooner it resolves the better the prognosis

typically resolves in 24 hours

Question 16

What does spinal shock do to the cardiovascular system

Answer 16

It causes vasodilation which leads to hypotension and bradycardia. This results in a decrease in CO.

You also have venous pooling because the muscle pump is not effective

Question 17

How would you test for Spinal Shock

Answer 17

An early sign of resolution is the presence of the bulbocavernosus reflex

(+) reflex indicates the end of spinal shock, and may precede the presence of DTRs or spasticity for several weeks

If the reflex is (+) without later sensory or motor return, a complete lesion is indicated

Question 18

What is the bulbocavernosus reflex

Answer 18

During digital rectal exam, pressure is applied to the glans penis or the glans clitoris by pulling on the catheter tube
Contraction around the examining digit = (+) reflex

(+) reflex indicates the end of spinal shock, and may precede the presence of DTRs or spasticity for several weeks

If the reflex is (+) without later sensory or motor return, a complete lesion is indicated

-a positive reflex is a good sign

Question 19

What are the first 3 steps of Acute Management of SCI

Answer 19

1. Pharmacologic management
2. Surgical realignment and stabilization
3. Prevention of secondary complications

Question 20

Pharmacologic management of SCI, What are the two main and there are 3 others

Answer 20

2 Main:

• Methylprednisolone
• GM1 Ganglioside

Others

• Interleukin-10
• Glutamate (AMPA) Receptor Blockers
• 4-Aminopyridine

Question 21

What is the standard of care for SCI

Answer 21

Methylprednisolone

Question 22

Methylprednisolone is, does and when should it be administered

Answer 22

“Standard of care”

Anti-inflammatory steroid – prevents swelling & damage at injury site

↓ the secondary effects

Administered in high doses & must be given within 8 hours of the onset of injury

Question 23

What does GM1 Ganglioside do

Answer 23

Evidence suggests that it may augment nerve growth & induce regeneration & sprouting

LEs appeared to be more affected by the drug than the UEs

Recovery appeared to be primarily due to restoration of muscle function in initially paralyzed muscles as opposed to muscles gaining greater strength

Question 24

What does Interleukin-10 do

Answer 24

potent anti-inflammatory; unclear about correct amount/combo needed?

Question 25

What does Glutamate (AMPA) Receptor Blockers do

Answer 25

neurotransmitter; decreases cell from firing in excess.

Because of active role that glutamate plays in secondary effects

Question 26

What does 4-Aminopyridine do

Answer 26

improves function in surviving spinal cord nerve cells long after the injury.

(supports the existing cells in the spinal cord)

Question 27

Surgical management of SCI

Answer 27

Surgical stabilization

Decompression

Question 28

What is surgical stabilization in regards to SCI

Answer 28

Injured spinal column is stabilized to prevent further damage to the cord and/or nerve roots

Question 29

How does decompression help SCI

Answer 29

Decompression has been shown to ↑ neurologic recovery

Research has shown that recovery ↓’s with ↑’ing time of compression & with ↑ compressive forces

Question 30

When people to have surgery for a SCI (2 Types)

Answer 30

• Traction: Gardner-Wells Tongs

- Internal Fixation

Question 31

Traction: Gardner-Wells Tongs is used for

Answer 31

Used acutely to provide traction

Inserted into the skull, with weights attached to provide traction

↓ dislocation and maintain alignment

Question 32

Surgical Management of SCI:

Internal Fixation is used for

Answer 32

(stabilizes the region)

Fusion of unstable joint(s) with hardware and/or bone autografts

Harrington rods are the most common for thoracic/lumbar injuries

Recent advances in transpedicular screws improve fixation
Pedicle is the strongest site posteriorly for fixation

Question 33

What are some types of non-surgical managements for a SCI (name 2)

Answer 33

• Halo Traction

- Orthoses (worn for 6-12 weeks)

Question 34

What are some advantages to halo traction

Answer 34

Advantages

• Early mobility
• Avoidance or delay of surgery

Question 35

What are some disadvantages to halo traction

Answer 35

Disadvantage

• Skin breakdown
• Dysphagia
• TMJ problems
• Limited UE movement