Spinal Cord Injuries

Question 1

Spinal Cord lesions

• importance of spinal cord
• stats

Answer 1

> Spine = vital for conveying + integrating sensory and motor info
Lesion may affect/impair motor/sensory/autonomic functions
Depends on extent + level of lesion

Stats

• ~50,000 cases in UK (1000 new per year)
• 50% are under 30
• 80% are men

Question 2

Types of injury

Answer 2

> Traumatic lesions (e.g car accident/sports)

• 84%
• majority of these lesions are caused by spinal fracture displacing

> Non-traumatic lesions (e.g degenerative disc disease, spinal canal stenosis, tumour)
- 16%

Question 3

Vulnerable areas of spinal cord

Answer 3

> Cervical spine = C5-7 (55% of all lesions)
Mid thoracic = T4-7
Thoracolumbar = T12

> Autonomic disturbance

• sympathetic system is associated with thoracic + lumbar regions
• parasympathetic is associated with cervical and sacral regions

Question 4

Pathophysiology of spinal cord injuries

Answer 4

> To aid management of injury; spine requires

• normal oxygenation + perfusion
• acid/base balance
• ie. homeostasis needs to be maintained to aid healing

> Vasogenic oedema (excess fluid in extracellular spaces of spinal parenchyma due to damage of blood vessels) and altered blood flow will lead to clinical deterioration as it disrupts the homeostasis

Question 5

Mechanisms

Answer 5

> Destruction = direct trauma
Compression = bone fragment/hematoma/disc material
Ischaemia = damage/impingement of spinal arteries

Question 6

Tetraplegia

Answer 6

> impairment of cervical segments

> affects all four limbs

Question 7

Paraplegia

Answer 7

> impairment of thoracic/lumbar/sacral segments

> affects legs/pelvis/trunk - depending on level

Question 8

Complete spinal cord lesions

Answer 8

> complete loss of function below level of injury (total transection of cord)

Results in:
> Impairment of motor function
- damage to descending pathways = CNS/UMN
- damage to anterior motor neurone = PNS/LMN
> Spinal shock
- loss of tone + reflexes below level
- complete destruction of nerve cells at level = flaccidity
(with time the anterior horn cells below the level of the injury recover but have no higher centres controlling them = spasticity + spasms)
> Impairment of deep + superficial sensation
> Autonomic dysfunction
- impairment of vasomotor control - smooth muscle in vessels
- postural hypertension - (blood pressure changes with positional changes as less venous return so gravity has bigger impact)
- autonomic dysreflexia (headache + bp rises - keep sitting and find cause - pain?)
- problems with bladder/bowel/sexual function

Question 9

Incomplete lesions

Answer 9

> sparing of some neural activity below level of lesion
> 55-65% of cases
> Types:
- Central cord syndrome 
- Anterior cord syndrome 
- Brown-sequard syndrome
- Cauda equina syndrome

Question 10

Central cord syndrome

Answer 10

> ‘whiplash patients’
motor dysfunction in upper limbs - peripheral weakness
bladder dysfunction
corticospinal and spinothalamic tracts

Question 11

Anterior cord syndrome

Answer 11

> motor paralysis below lesion
loss of pain + temperature
retained proprioception + vibration (diagnostic tool as peripheral damage would mean these are lost)
cause = disc herniation

Question 12

Brown-Sequard syndrome

Answer 12

> motor deficit and numbness to touch/vibration on same side as lesion
loss of pain and temp on opposite side of lesion
common cause = stab/gunshot wound to cervical or thoracic spine

Question 13

Cauda Equina syndrome

Answer 13

> Compression of spinal nerve roots
> gradual unilateral onset 
> severe radicular pain (radiates to legs)
> saddle area sensation is affected
> asymmetrical/areflexic motor 
*Causes = lumbar stenosis/trauma/cancer

• vs conus medullaris syndrome
• sudden, bilateral onset
• less severe radicular pain but greater back pain
• perianal sensation is compromised
• symmetrical + hyperreflexic motor changes
• same causes

Question 14

ASIA impairment scale

Answer 14

> determines level of injury (+outcome measure for progress)
to determine level - most distal uninvolved segment of cord + skeletal level of lesion (not always the same due to how nerves travel down through intervertebral foramina)
- A: Complete - no motor/sensory function is preserved in S4-5 (done via rectal exam for tone + sensation by docs)
- B: Incomplete - sensory function only below level including levels S4-5
- no motor function below level
- C: Incomplete - some motor function is preserved below level (more than 1/2 < grade 3 oxford scale)
- D: Incomplete - some motor function is preserved below level (more than 1/2 > grade 3 on oxford)
- E: Normal

Question 15

ASIA myotomes + dermatomes

Answer 15

> C5 - shoulder abduction + lateral rotation
         - elbow flexors
> C6 - wrist extensors + flexors
         - pronators + supinators
> C7 - shoulder adduction + medial rotation
         - elbow extensors
> C8 - finger flexors + extensors
> T1 - finger abductors

> L2 - hip flexors
> L3 - knee extensors
> L4 - ankle dorsiflexors
> L5 - Long toe extensors
> S1 - ankle plantar flexors
> S4-5 - anal sphincter

Question 16

Rehabilitation - early stages

Answer 16

> maintaining tissue length 
> strength 
> balance
> mobility + transfers
> wheelchair management
> pressure care + awareness

Question 17

Rehabilitation - late stages

Answer 17

> Dressing
> Transfers
> pressure awareness
> Bladder/bowel care 
> standing
> car driving/transport
> sport
> employment
> relationships/parenting 
*aid return to 'normal'