SCI Flashcards
(128 cards)
common traumatic causes to SCI and what percent are traumatic
70%
high risk activities, MVA, GSW, stabbings, falls, acts of violence, recreational/sports, medical negligence
what percent of SCI are caused by non-traumatic injury and what are examples
30%
usually results from disease/pathology
AVM, thrombus/embolus/hemorrhage, subluxation (RA or Down’s syndrome), infections (syphyillis, transverse myelitis), neoplasms, syringomyelia, spinal stenosis
why are incidences of SCI decreasing in regards to MVA
seat belt laws, air bags
violence incidence rates of SCI have been increasing, when are they found to be the highest (around what time)
in summer
on saturdays and sundays
what is the MOI for traumatic SCI
excessive motion/force in any of the planes of spinal motion
- results in fx or dislocation
- intensity and direction of force determine extent of injury
- combinations of force create the most damage
what does C5 SCI commonly result in
quadriplegia/tetraplegia (all 4 extremities involved)
what does T12 SCI commonly result in
paraplegia
what are other common locations for SCI
C7 and L2
what is the MOI of a hangman’s fx and what vertebrae does it involve
fx seen with excessive flexion injury
C2 fracture
describe effects of shearing forces on SC
- occurs with horizontal force to the spine
- disrupts ligamentous stability
- associated with fx dislocations in thoracolumbar region
describe the effects of distraction forces on SC
- traction force
- least common MOI
- occurs with significant momentum of head that creates tensile force on the spine
what type of injury is distraction common in
cervical whiplash injury
occurs due to impingement by fx bone, soft tissue or both; causes primary damage to SCI
contusion
types of primary damage to SC
- contusion
- microscopic hemorrhage/tissue laceration/tissue necrosis
- demyelination
microscopic hemorrhage, tissue laceration, tissue necrosis begin within ___ in _____ matter after initial injury and then spread to ___ matter
hours
gray
axonal white
process of demyelination begins in peripheral spinal N roots and spreads over _____ segments
1-3
once swelling and traumatic response subsides, necrotic SC tissue is replaced by
scar tissue
cysts
cavities
does primary or secondary damage cause more damage
secondary
examples of secondary damage to SC
ischemia
inflammation
ion deranagement
apoptosis
scarring
describe how ischemia effects the SC
- mechanical trauma to anterior spinal arteries/arterioles and vasospasm disrupts blood flow to gray matter area and tracts
how quickly does blood flow diminish to gray matter first
only 2-3 hours
CNS is very intolerant to ischemia, irreversible damage to neurons can occurs in _____ following trauma
15-30 seconds
how does inflammation affect SC damage
- cells damaged in initial trauma release proinflammatory substances that attracts neutrophiles to area
- results in expansion of area of tissue damage 24-48 hours
- other immune system cells remain in area for up to 8 weeks post-injury to complete process of phagocytosis and oxydation
how does ion derangement effect the SC
- abnormal levels K+ and Na+ accumulate in intra and extracellular spaces that results in loss of neuronal excitability
- accumulation of Ca+ ions disrupt cellular function, results in demyelination and destruction of cell membrane and leads to cell death (apoptosis)
- initial apoptosis occurs at level of injury for 4-24 hours but prolonged for up to 3 weeks in segments rostral and caudal to site of injury