SCI Flashcards
What level does the SC end?
ends at L1-L2 interspace as the CONUS MEDULLARIS
How many segments does the SC have?
31 or 33 each with a pair of spinal nerves
Damage at the level of the cauda equina results in:
LMN lesion
descending collection of dorsal and ventral nerve rootlets
Examples of non-traumatic SCI:
vascular tumor infection autoimmune (transverse myelitis) spondlyosis / spinal stenosis developmental disorders (meningomyeloceole)
What type of traumatic injury has the highest incidence?
MVA (40-50%)
auto 38%, motorcycle 7%, other vehicle 1%
What is the leading cause of traumatic SCI in adults > 65?
jumps and falls
23% of traumatic SCI
Regionally, which part of the spine has the highest incidence of SCI?
cervical
(more mobility! upper c-spine injury more common in children bc head represents greater proportion of BW)
T, L, S each make up ~15%
Male vs. female incidence:
male 80-85%
female 15-20%
What age has increasing prevalence of SCI?
> 60 yoa
currently makes up about 12%
Age related incidence of SCI:
14-24: 50%
< 40: 80%
> 60: 12%
Tetraplegia results from ____ level injury and presents as:
aka quadriplegia
cervical
partial or complete paralysis of all 4 extremities and trunk
Paraplegia results from ____ and presents as:
below c-spine
partial or complete paralysis of all or part of trunk and both LE (UE intact)
The most common method of designating lesion level is to indicate:
the most distal functioning SC level
functional dermatome and myotome (at least mmt grade of 3)
Complete lesion is caused by:
Describe the presentation.
complete transection, severe contusion or extensive vascular impairment to SC
–> no motor or sensory fxn below the designated level
Incomplete lesion is caused by:
Describe the presentation.
most often from contusions
also from edema and partial transections
prognosis varies, but some recovery possible
–> some sensation or motor fxn (< 3 MMT) below the designated level of lesion
With oblique (asymmetric) injuries, there may be different fxnal levels on each side so…
score each side separately!
ASIA A
COMPLETE
no motor or sensory fxn below level of lesion including S4-5
ASIA B
INCOMPLETE
sensory but no motor fxn below level of lesion including sacral segments S4-5 (ANY sensory of motor fxn in anal region makes it an incomplete injury)
ASIA C
INCOMPLETE
Motor fxn preserved below level of lesion and more than half of the key muscles below the lesion level have a muscle grade < 3
ASIA D
INCOMPLETE
Motor fxn preserved below level of lesion and more than half of the key muscles below the lesion level have a muscle grade of 3 or better
ASIA E
NORMAL motor and sensory
What are the incidences based on injury severity?
Complete 45% / Incomplete 55% A 45% B 15% C 10% D 30%
What % of injuries are contusion?
40%
With ASIA A, what sign indicates potentially better prognosis?
anatomically incomplete lesions
Which region of the spine is more likely to produce complete injury?
thoracic
must be significant trauma to de-stabilize the otherwise stable t-spine compared to cervical and lumbar
What is the most common mechanism of injury?
flexion
Flexion injuries usually involve which levels?
C4 - C7
T12 - L2
due to increased mobility
Flexion injury results in:
wedge fx of ant. vertebral body
associated injuries: fx of posterior elements, anterior dislocation, disc disruption, facet jumping
Compression injury cause and result:
vertical force
endplate fx, burst fx
associated injuries: bone fragments in cord, disc rupture
Hyperextension injury cause and region most influenced:
strong posterior force or fall with chin in fixed position (elderly)
seen almost always in cervical region
Hyperextension injury results in:
fx of posterior elements
associated injuries: ALL rupture, disc rupture
Flexion-rotation injury cause and result:
posterior to anterior force with vertebral column rotated
fx of posterior pedicles, facets, lamina (very unstable)
associated injuries: posterior ligament rupture, sublux/dislocate facets (jumping)
Shearing injuries cause and result:
horizontal force
most frequent in thoracolumbar segment
associated injuries: dislocation
What is a jefferson fx?
C1 fx of anterior and posterior arches
most often from hyperextension
What are two special types of C2 fxs?
odontoid (Types I-III)
Hangman’gs (Type I-III)
Describe hangman’s fx:
B fx of pedicles of axis (C2)
due to rapid acceleration/deceleration injury (chin on dash)
Type I usually non-surgical, type II/III usually require surgery
Brown Sequard Syndrome:
unilateral lesion (often incomplete) of SC resulting usually from stab wound
loss of motor and proprioception on the same side of the lesion beginning at the level of the lesion
loss of pain and temp on contra. side beginning a few dermatomes below level of lesion (S-t fibers may ascend a few levels before crossing)
Anterior cord syndrome:
often caused by disc herniation with severe flexion injury and by damage to anterior spinal aa. resulting in ant. cord damage
characterized by loss of motor fxn and loss of pain and temp, but preservation of proprioception, kinesthesia and vibratory sense
posterior cord syndrome
very rare; can result from post. spinal a. damage
presents with loss of proprioception, kinesthesia, and vibratory sense
central cord syndrome causes:
associated with hyperextension injuries of cervical cord (often minor)
related to congenital or degenerative narrowing of spinal canal
seen most often in elderly
“syrinx” = cavity in central cord
Conus Medullaris syndrome presentation:
combo of UMN and LMN lesion
UMN in sacrally innervated muscles and urologic dysfxn
LMN to nerve roots passing by that level (lumbar)
amt of deficit depends on low the conus goes in that particular person
conus medullaris syndrome cause:
possible with trauma at L1, L2 levels or thoraco-lumbar jxn
most common mech is seat belt injury
vertebra can retropulse, shear or burst or compression fx
central cord syndrome presentation:
may only involve pain and temp crossing fibers creating a “cape like” pattern of sensory loss (S-T)
If motor tracts involved, usually the lasting deficit is int he UE tracts (LE fibers tend to be more peripheral in white matter)
Good prognosis especial with decompression surgery
Sacral sparing cause and result:
incomplete lesion where most peripherally located sacral fibers are spared.
presents with perianal sensation, rectal sphincter contraction, contraction of toe flexors
Cauda equina injuries cause:
burst fx below L1 (conus medularis) - more than one nerve root usually involved. Differentially diagnose from lamina or pedicle fx, or jumped facet, or herniated disc, which would involve just one nerve root.
Cauda equina injury presentation:
usually not all nerve roots involved
peripheral nerve injury so can regenerate but still is not likely to be complete
Room escape injury cause and result:
refers to recovery of fxn of the damaged n. root
there may be nerve root damage at or near the level of the injury
What are 4 key complications with SCI:
- autonomic dysreflexia
- pain
- post-traumatic syringomyelia
- bowel and bladder dysfxn
Autonomic dysreflexia occurs in ___ % of those with SC injury above __.
48-85% above T6 (due to unregulated splanchnic reflexes)
What triggers autonomic dysreflexia and what do you do about it?
most commonly triggered by bowel or bladder stim
causes drastic inc. in systemic BP, bradycardia, headache, sweating inc. spasticity
this is a medical emergency! relieve blockage of catheter, change pt. position (have them stand to dec. BP)
What 2 categories of pain can present post SCI?
nociceptive pain: musculoskeletal (bone, joint, posture, overuse) and visceral (renal calculi, bowel, dysreflexia headache)
neuropathic pain: sharp, shooting, burning, electric, hyperesthesia
Neuropathic pain below the level of injury
resistant to tx
major complication after injury
often presents as allodynia
occurs in 26% of all SCI pts (but up to 58% in older adults)
Neuropathic pain at level of injury
in dermatome
n. root compression
cauda equina, syringomyelia
Neuropathic pain above the level of injury
compressive neuropathies related to posture, overuse, entrapment
CRPS
Post-traumatic syringomyelia occurs in __ % of those with SCI with onset of 1 month - ___ years after injury.
3-4%
1 month - 45 years
Post-traumatic syringomyelia pathophys:
cavitation of central canal (by syrinx)
associated with liquefaction of intraparenchyemal hematoma
cavity expands due to disrupted CSF flow out of cyst
also associated with tethered cord (cord adheres to dura)
What are signs and sxs of Post-traumatic syringomyelia?
chronic pain weakness loss of fxn dec. respiratory fxn inc. or dec. spasticity
Post-traumatic syringomyelia tx:
shunt to relieve CSF pressure
laminectomy to decompress cord
release of tethering
UMN lesion bowl and bladder dysfxn presentation and training program outcomes:
spastic bowel and bladder
training program can result in effective bowel and bladder management using reflexes for emptying
LMN lesion bowl and bladder dysfxn presentation and training program outcomes:
flaccid bowel and bladder (more incontinence)
training program less effective due to flaccid sphincter
What standardized tool can predict ambulatory capacity post injury?
motor and sensory ASIA score
Chances of walking are very poor if:
still rated as ASIA A at 1 month
Acutely, sparing of sensation to pin prick in a motor segment with MMT grade 0 indicates:
85% chance of motor recovery to at least grade 3
Walking at 6 months is correlated with:
presence of light touch and pin prick acutely post-injury (lateral white matter spared)
