ICL 2.4: Spinal Cord Injuries Flashcards
what are the biggest causes of spinal cord injuries?
- MVA
2. falls
what are the most common types spinal cord injuries?
- incomplete quadriplegia (C5)
2. incomplete paraplegia (T12)
which arteries supply the spinal cord?
- posterior spinal arteries (2)
they supply the posterior 1/3 of the cord
- anterior spinal artery
supplies the rest of the spinal cord = 2/3
what is the artery of adamkiewicz?
it’s a large, lumbar radicular artery that’s between T6 and L3
it’s a branch of the descending aorta
it connects with the anterior spinal artery so it’s a major source of blood for the anterior 2/3 of the cord!!!!!!
what is a compression fracture? which vertebra is most commonly effected?
C5 is the most common
it’s a wedge deformity; one side of the vertebra is squished
bony fragments may project into the spinal cord
nerve and cord damage is possible but not always if there isn’t protrusion
what is a unilateral facet joint dislocation? which vertebra is most commonly effected?
C5-C6 most common
usually caused by a flexion-rotation injury where one of the facets is more than 50% dislocated
if there is cord injury, most likely incomplete injury because the other facet joint will still be intact!
what’s the hallmark thing you’ll see on the x-ray of a unilateral facet dislocation?
bow tie sign
what is bilateral facet dislocation?
complete dislocation of vertebral body because both facets are dislocated
associated w/ very high risk of cord damage
due to extreme hyperflexion like whiplash (not as commonly caused by rotation)
what causes cervical hyperextension injuries? which vertebra is most commonly effected?
you’ll usually get a pinched off spinal cord from the hyperextension
C4-C5 most commonly effected
- acceleration-deceleration injuries like MVC
- falls in elderly with spondylosis**
spondylosis refers to degenerative changes in the spine such as bone spurs and degenerating intervertebral discs between the vertebrae
what is the mechanism of injury, stability, potential injury and most common level of a compression fracture?
caused by flexion/axial loading
stable if ligaments remain intact
could lead to crush fracture with fragmentation of vertebral body and projection of bony pieces into canal
most common at C5 level
what is the mechanism of injury, stability, potential injury and most common level of a unilateral facet dislocation?
caused by flexion rotation injury; the vertebral body has to be LESS than 50% displaced on x-ray
unstable if PLL is disrupted
if the spinal cord is effected it’ll be an incomplete SCI
C5-C6 is most likely to be effected
what is the mechanism of injury, stability, potential injury and most common level of a bilateral facet dislocation?
caused by extreme flexion
caused by flexion rotation injury; the vertebral body has to be MORE than 50% displaced on x-ray
could lead to anterior dislocation of cervical spine with spinal cord compression/compromise which could lead to a complete SCI
C5-C6 are most effected
what is the mechanism of injury, stability, potential injury and most common level of a cervical hyperextension injury?
leads to central cord syndrome
usually stable but anterior longitudinal ligament may be disrupted
hyperextension of the cervical spine could lead to the upper body because weaker than the lower body = incomplete
C4-C5 most likely to be effected
what is a Jefferson fracture?
burst fracture of C1 ring
usually stable with no neurological findings
caused by axial load that breaks both the anterior and posterior parts of the atlas
ex. pile driving someone or diving or something falling on your head
in an x-ray of the mouth, C1 won’t be lined up with C2
what is a Hangman’s fracture?
C2 burst fracture
usually bilateral from an abrupt deceleration injury aka like when you hang someone this is what breaks
most often stable with only transient neurological findings
looks like the pedicles of C2 are broken
what are the different types of odontoid fracture?
aka dens fracture of C2
type 1-3 with increasing severity
Type I: fracture through the tip of dens
Type II (most common): fracture through the base of odontoid at junction with the C2 vertebra
Type III: fracture extends from base of odontoid into the body of the C2 vertebra proper
what are the two main types of thoraco-lumbar fractures?
- chance fracture
2. vertebral compression fracture
what is a chance fracture?
most common thoraco-lumbar fracture
it’s a transverse fracture through the body and pedicles into posterior elements = literally goes straight through the vertebra from the front to the back in a sagittal view
usually caused by your seatbelt in a MVC but also seen in falls/crush injury w/ acute hyperflexion of thorax
what is a vertebral compression fracture?
an axial compression with or without flexion
causes a wedge deformity of the vertebral body (just like the compression fracture of a cervical vertebra!)
caused by trauma, osteoporosis, infection, or metastatic lesions
what are some of the non-traumatic causes of SCI?
- tumors
- transverse myelitis
- epidural abscess
- multiple sclerosis
- infection
which types of injuries are more likely to cause a complete loss of motor and sensory function?
TEST QUESTION
- bilateral cervical facet dislocations
- thoracolumbar flexion-rotation injuries
- trans-canal gunshot wounds
which types of injuries are more likely to cause an incomplete loss of motor and sensory function?
TEST QUESTION
- cervical spondylosis - falls
- unilateral facet joint dislocations
- non-canal penetrating gunshot/stab injuries
what 3 things do you assess during a neurologic assessment?
- motor strength, weakness = myotome
- sensory disturbances = dermatome
- reflex changes
which motor functions are controlled by which cervical vertebra?
C5 = elbow flexors
C6 = wrist flexors
C7 = elbow extensors
C8 = finger flexors
T1 = finger abductors (little finger)
which motor functions are controlled by which lumbar vertebra?
L1 = hip flexors
L3 = knee extensors
L4 = ankle dorsiflexors
L5 = long toe extensors
S1 = ankle plantar flexors
what is a dermatome?
an area of skin innervated by one sensory nerve root
how do you score motor function?
0-5
0 = Total Paralysis
1 = Palpable or visible contraction
2 = Active movement, gravity eliminated
3 = Active movement, against gravity
4 = Active movement, against some resistance
5 = Active movement, against full resistance 5+ = Normal corrected for pain/disease
NT = Not testable
how can you tell the neurological level of injury?
after you do motor and sensory testing and then you see how far down everything is intact
so you find the most caudal segment of the spinal cord with both normal sensory and motor function on both sides of the body
you need more than a 3/5 motor and 2/2 for light touch to pass
Which of the follow will most likely lead to an incomplete spinal cord injury?
A. Bilateral cervical facet dislocation
B. Thoracolumbar flexion-rotation injuries
C. Cervical spondylosis - falls
D. Gunshot wound through the spinal canal
C. Cervical spondylosis - falls
what are the 4 types of spinal cord syndromes?
- central cord syndrome
- anterior cord syndrome
- brown-sequard syndrome
- posterior cord syndrome
**they are all incomplete SCI!!
what is central cord syndrome?
the most common form of cervical spinal cord injury
characterized by loss of motion and sensation in arms and hands but lower extremities are fine so you can walk to the door but can’t turn the knob
due to major hyperextension injury to the central corticospinal tract of the spinal cord (injury to the central part of the spinal cord)
central cord syndrome is more common in which population?
elderly
due to hyperextension injury
what is anterior cord syndrome?
caused by ischemia of the anterior spinal artery which effects the anterior 2/3 of the spinal cord so you have motor and pain loss with preservation of position, vibration and deep pressure sensation
often seen with artery of adamkowitz injury so it’s usually seen at the thoracic level and below
leads to loss of movement, pain and temperature
still able to feel position, vibration, and touch
what is Brown-Sequard syndrome?
one half of the spinal cord is effected
you lose motor function on the same side as the cord damage but you lose sensory function on the opposite side = not pain, temperature, sensation
what is posterior cord syndrome?
the poster 1/3 of the spinal cord is effected
this causes ataxia, poor balance but normal senses and strength; almost as if the person was drunk
what is the point where the spinal cord ends called?
conus medullaris
what would happen if you have a conus medullaris injury?
this would be a T12-L2 vertebral level injury of sacral cord &; LS nerve roots
you’d have normal motor function but sadly distribution sensory loss; the abnormalities would be symmetric
bowel, bladder, sexual dysfunction
hyperreflexic
what would happen if you have a cauda equina injury?
this would be if you had an injury below L1-L2 to sacrum vertebral level nerve roots
sensory loss in nerve root distribution with asymmetric symptoms
pain is more significant than conus medullaris injury but bowel, bladder, sexual function is normal
hyporeflexic
what are the most common complications of a spinal cord injury?
- pneumonia
- dcubitus ulcers
- DVT
- PE
- infection
the 3 most common secondary medical complications that lead to a higher risk of dying post SCI, when compared to the general population are pneumonia, septicemia and pulmonary emboli
which spinal cord syndrome has the highest prevalence?
central cord syndrome –> can happen in the elderly and MVA
more common than anterior cord syndrome, posterior cord syndrome and brown-sequard syndrome
what are some of the cardiovascular complications of SCI?
Hypotension
Autonomic
Dysreflexia
DVT
Pulmonary Embolus
Poikylothermia = can’t control body temperature
what are some of the pulmonary complications of SCI?
- pneumonia
- atelectasis
- ventilatory failure
- sleep apnea
“C3, 4, 5 keep the diaphragm alive!”
where is pressure ulcer formation most common?
- sacrum
- heel
- ischium
- scapula
- scapula
what are the types of fractures associated with the spine that may lead to spinal cord compromise?
- Jefferson
- Hangman
- odontoid
- chance
what is the test done to assess spinal cord function?
the ASIA exam is the current international standard utilized to identify neurologic level of spinal cord injury and to classify either complete or incomplete SCI
